Generator Operation Manual QN1 SEC G 04 TP 004

QUANG NINH THERMAL POWER JOINT STOCK COMPANY

2×300 MW

GENERATOR & AUXILIARIES OPERATION MANUAL SEC


2 × 300 MW – Anthracite Coal Fired Power Station

Generator & Auxiliaries

Operation Manual

Date: 2008-09-16 No.:QN1-SEC-G-04-TP-004 Rev. : A


2×300 MW


INDEX

1 SCOPE ....................................................................................................................................................... - 1 -

2 NORMATIVE REFERENCE.................................................................................................................. - 1 -

3 TECHNICAL SPECIFICATION AND PERFORMANCE OF GENERATOR-TRANSFORMER UNIT

AND AUXILIARIES .............................................................................................................................. - 1 -

3.1 GENERATOR ........................................................................................................................................ - 1 -

3.2 TRANSFORMERS .................................................................................................................................. - 9 -

3.3 AUXILIARIES ..................................................................................................................................... - 13 -

4 PROTECTION OF GENERATOR-TRANSFORMER UNIT ........................................................... - 22 -

4.1 GENERAL REQUIREMENTS AND REGULATIONS .................................................................................. - 22 -

4.2 PROTECTION CONFIGURATION OF GENERATOR-TRANSFORMER UNIT ............................................... - 24 -

5 OPERATION OF GENERATOR.......................................................................................................... - 28 -

5.1 INSPECTION AND PREPARATION BEFORE THE STARTUP ...................................................................... - 28 -

5.2 STARTUP AND SYNCHRONIZATION ..................................................................................................... - 29 -

5.3 OPERATION MAINTENANCE AND ADJUSTMENT OF GENERATOR AND AUXILIARIES ........................... - 35 -

5.4 GENERATOR DISCONNECTION ........................................................................................................... - 41 -

5.5 DISPOSAL OF GENERATOR FAULT AND ABNORMAL CONDITION......................................................... - 42 -

6 EXCITATION SYSTEM OF GENERATOR ....................................................................................... - 52 -

6.1 GENERAL DESCRIPTION OF EXCITATION SYSTEM .............................................................................. - 52 -

6.2 OPERATION OF UNITROL 5000 EXCITATION REGULATOR ................................................................ - 53 -

6.3 OPERATION INSTRUCTION OF EXCITATION REGULATOR CONTROL PANEL ......................................... - 55 -

6.4 EXCITATION SYSTEM FAULT AND ALARM INFORMATION ................................................................... - 57 -

7 TRANSFORMER OPERATION (220 KV 500 KV 400V) .................................................................. - 58 -

7.1 OPERATION MODE............................................................................................................................. - 58 -

7.2 OPERATION AND MAINTENANCE ....................................................................................................... - 63 -

7.3 ABNORMAL OPERATION AND TROUBLE DISPOSAL OF TRANSFORMER ............................................... - 68 -

8 AUXILIARIES ELECTRICITY SYSTEM.......................................................................................... - 72 -

8.1 OPERATION MODE OF 6KV SYSTEM .................................................................................................. - 72 -

8.2 OPERATION MODE OF 400V SYSTEM................................................................................................. - 72 -

8.3 ELECTRIC SWITCHING OPERATION .................................................................................................... - 75 -

8.4 ABNORMAL CONDITIONS AND DISPOSAL .......................................................................................... - 81 -

Date: 2008-09-16 No.:QN1-SEC-G-04-TP-004 Page - 1 - Rev. : A


2×300 MW


9 DC SYSTEM ........................................................................................................................................... - 85 -

9.1 DESCRIPTION .................................................................................................................................... - 85 -


9.3 ABNORMAL CONDITIONS AND DISPOSAL .......................................................................................... - 88 -

10 UPS POWER SUPPLY .......................................................................................................................... - 90 -

10.1 DESCRIPTION .................................................................................................................................... - 90 -

11 STATION MOTORS .............................................................................................................................. - 95 -


11.2 ABNORMAL CONDITIONS AND DISPOSAL ........................................................................................ - 100 -

12 POWER DISTRIBUTION DEVICE .................................................................................................. - 103 -

12.1 CIRCUIT BREAKER .......................................................................................................................... - 103 -

12.2 DISCONNECT SWITCH.......................................................................................................................- 111 -

12.3 BUSBAR AND CABLES ..................................................................................................................... - 114 -

12.4 CURRENT TRANSFORMER (CT) AND POTENTIAL TRANSFORMER (PT) ............................................ - 117 -

12.5 LIGHTNING ARRESTER .................................................................................................................... - 120 -

12.6 SPECIAL INSPECTION ....................................................................................................................... - 120 -

13 DIESEL GENERATOR AND EMERGENCY POWER SUPPLY ................................................... - 121 -

13.1 EQUIPMENT SPECIFICATION............................................................................................................. - 121 -

13.2 INTERLOCKING LOGIC DESCRIPTION OF D/G AND EMERGENCY POWER.......................................... - 122 -

13.3 NORMAL OPERATION, MAINTENANCE AND NOTICE ........................................................................ - 123 -

13.4 ABNORMAL CONDITIONS AND DISPOSAL ........................................................................................ - 124 -

14 110 KV SYSTEM OPERATION ......................................................................................................... - 128 -

14.1 110 KV SYSTEM OPERATION MODE .................................................................................................. - 128 -

14.2 110 KV SYSTEM OPERATION ............................................................................................................ - 131 -

14.3 ABNORMAL OPERATION AND TROUBLE DISPOSAL OF TRANSFORMER ............................................. - 134 -

14.4 110 KV SYSTEM SWITCHING OPERATION PROCEDURES .................................................................... - 139 -

15 RELAY PROTECTION AND AUTOMATIC DEVICE.................................................................... - 155 -

15.1 MANAGEMENT REGULATIONS ON OPERATION OF RELAY PROTECTION AND AUTOMATIC DEVICE ... - 155 -

15.2 INSPECTION OF RELAY PROTECTION DEVICE................................................................................... - 158 -

15.3 ACTION OF RELAY PROTECTION AND AUTOMATIC DEVICE ............................................................. - 159 -

15.4 PRINCIPLE SUMMARY AND OPERATION SPECIFICATION ................................................................... - 159 -

16 APPENDIX............................................................................................................................................ - 176 -



2×300 MW


16.1 CHARACTERISTICS CURVE OF GENERATOR ..................................................................................... - 176 -

16.2 LAYOUT OF GENERATOR TEMPERATURE ELEMENTS........................................................................ - 181 -



2×300 MW

GENERATOR & AUXILIARIES OPERATION MANUALSEC

1 Scope

This manual specifies the principles, methods and procedures for starting, stop, operating maintenance, control and regulation, downtime maintenance and accident treatment of Quang Ning Thermal Power Joint Stock Company 2×300MW generating unit. All levels of personnel of Quang Ning Thermal Power Joint Stock Company, engaged in generating operation, equipment repair and productive technology management must know very well all or relevant parts of this manual and strictly comply with this manual.

2 Normative Reference

The following standard contains provisions which, through reference in this text, constitute

provisions of this manual. At the time of publication，the standard indicated was valid. All

standards are subject to revision, and parties to agreements based on this manual are encouraged to investigate the possibility of applying the most recent edition of the standard indicated below and the latest edition of the standard referred to applies.

No. Standard Code Standard Name

01

DL408-91 Working Regulation of Power safety (Electrical Part of PowerPlant and Substation)

02

DL558-94 Code of Investigation for the Electric Power ProductionAccidents

03 Guo Dian Fa（2000）

No. 589 Twenty-five Key Requirements to Prevent Serious Accident andFailure in Electric Power Operation

04 Manufacturer’s Equipment Data and Design Data

3 Technical Specification and Performance of Generator-Transformer Unit

and Auxiliaries

3.1 Generator

3.1.1 Specification of Generator Proper

Items Parameters Items Parameters

Model

QFSN—300—2 No-load excitation current

987A

Rated capacity

353MVA No-load excitation voltage

113V

Rated active power

300 MW Full-load excitation current

2510A

Rated reactive power 186MVar Full-load excitation 302V



2×300 MW


voltage

Power factor

0.85(lag) Stator coil DC resistance

0.00212Ω/phase

Frequency

50Hz Stator coil ground capacitance

0.209μF/ phase

Number of poles

2 Rotor coil DC resistance

0.0923Ω

Efficiency

98.8％ Rotor coil self-inductance

0.857H

Mode of connection

Y--Y First-order critical speed

870rpm

Short circuit ratio

0.6 Second-order critical speed

2380rpm

Insulation class B Excitation mode Self shunt excitation

Total loss

3400kW

Manufacturer Shanghai Electrical Machinery Plant

Short circuit ratio 0.6 Stator iron loss 435kW

Rotor winding copper

loss（75）

721kW Stator winding copper

loss （75）：

816kW

Mechanical loss 707kW Stray loss 538kW

Total loss

3400kW

Direct axis synchronous reactance

186％

Note: cooling mode is water-hydrogen-hydrogen cooling, i.e. stator coil and connecting line and outgoing line bushing adopts inner water cooling; rotor winding and stator core and end all adopt hydrogen cooling.

3.1.2 Technical Specification of Generator Cooling System


Cooling mode Water-hydrogen-hydrogen Cold hydrogen maximum temperature

48

Inner cooling water flow

55m3/h Cold hydrogen minimum temperature

40

Inner cooling water 0.15～0.20MPa Cold hydrogen ＜40，＞50



2×300 MW


pressure temperature alarm value

Inner cooling water inlet temperature

45～50 Hydrogen cooler cooling water flow

440m3/h

Inner cooling water outlet maximum temperature

85 Hydrogen cooler water inlet maximum temperature

35

Inner cooling water outlet temperature rise

31 Stator winding temperature

≯90

Rated hydrogen pressure

0.31MPa Stator core temperature rise

≯74

Hydrogen purity Above 96％ Average temperature rise of rotor

≯64

Expected temperature of cold hydrogen

46

Note: two groups of coolers are available respectively at both ends of generator base and each group of cooler is divided into independent two subgroups on waterway.

3.1.3 Specification of Excitation System Equipment

3.1.3.1 System Introduction

300MW turbo-generator excitation system adopts A5S-O/U231-A3200 static excitation

system produced by Switzerland Badun ABB industrial AG.

The system mainly adopts excitation transformer connected in parallel to generator terminal, for excitation power source, after silicon controlled rectifying, supplies generator with magnetic field current. Automatic voltage regulator (AVR) changes the angle of flow of silicon controlled rectifying device to control magnetic field current of generator and make generator operation condition operate according to AVR control mode.

The system mainly consists of generator-terminal excitation transformer, silicon controlled rectifying device, automatic voltage regulator, field suppression and overvoltage protection device, excitation starting device and auxiliaries (necessary monitoring, protection and alarm devices), etc.

For excitation transformer and current transformer used for measurement and protection, there are two groups including six ones at primary side and there is one group including three ones at secondary side. Excitation starting device makes them form a complete self shunt excitation system.

3.1.3.2 Specification of Excitation Equipment



2×300 MW



Model

A5S-O/U231-D3200 Cabinet II maximum output

5100A DC/20sec

Rated voltage

350V DC Cabinet III maximum output

6800A DC/20sec

Ceiling voltage

755V DC

Mode of rectification Three-phase full-controlled bridge

Silicon controlled reverse withstand voltage

2900V

Quantity of rectifying cabinet

3

Rated value of cabinet II output

2800A DC

Cooling mode

Forced air cooling

Rated value of cabinet III output

3800A DC Forced excitation ceiling current

2 times of rated rotor current

Current equalization factor

＞0.85

3.1.3.3 Parameters of Field Suppression Switch


Switch model SACE Emax E3 Breaking current 40k A

Rated current 3200A Control voltage (DC) 220VDC

Non-linear resistance material

ZnO Number of main contact

3

Manufacturer

ABB Break time of field suppression switch

＜0.06 S

3.1.3.4 Main System Performance of Self Shunt Static Excitation System

Forced excitation ceiling value of excitation voltage and current: when generator-terminal voltage is rated in the case of rated operation condition, voltage: 2.5 times, current: 2 times;

Allowable duration of forced excitation: 20s;

Reaction speed: high starting response (<0.1s);

Excitation system meet long-time operation requirement of 1.1 times of generator rated excitation current.

The time of excitation system reaching forced excitation ceiling voltage is not more than 500ms.

The gain margin of open loop frequency characteristic of excitation control system is

Gm≥6dB and phase angle margin is Φm≥40°.



2×300 MW


In the case of no-load ±5％ step, generator voltage overshoot is not more than 30％ of step; regulating time is not greater than 5s; number of voltage swing is not more than 3 times.

When the automatic excitation regulator is used to raise generator voltage from zero

automatically, the overshoot of generator stator voltage is not more than 10％ of rated voltage;

oscillation number is not more than 3 times; regulating time should not be greater than 10s.

When the generator reject rated reactive power, generator stator voltage should not exceed

115％ of rated value.

In the case of generator no-load operation, when the frequency varies by ±1％ each, the

change of generator voltage should not be greater than ±0.25％ of rated voltage value.

When the excitation current is not more than 1.1 times of rated value, maximum instantaneous value of rectifying voltage applied to both ends of generator rotor winding should

not be greater than 30％ of predelivery power frequency test voltage amplitude peak of rotor

winding.

3.1.3.5 Parameters of Excitation Transformer


Model ZLSC9-3150/20 Manufacturer Hainan Jinpan

Capacity 3150kVA Type Dry type

Primary rated voltage 20kV Insulation class F class

Secondary rated current

2756 Connecting mode

YD 11

Secondary rated voltage

660V Cooling mode AN/AF natural air cooling

3.1.3.6 Excitation System Signal and Protection Setup

a) Coil overtemperature alarm

b) Overcurrent inverse time protection, acting on field suppression switch to stop

c) Overcurrent quick-break protection, acting on field suppression switch to stop

3.1.3.7 Silicon Controlled Rectifying Device

a) Rectifying structure is three-phase full-controlled bridge, with inversion capacity.

b) Rated output voltage and current values and short-time overcurrent value all should meet the requirements of 1.1-times rated capacity and forced excitation operation.

c) There are three rectifying cabinets. If one cabinet breaks down and exits alarm, the other two cabinets can meet the requirements of various operation conditions including 1.1-times rated excitation capacity and forced excitation.

d) During operation, when any in-phase rectifying component is damaged, silicon

controlled rectifying cabinet should meet generator operation under various operation



2×300 MW


conditions including forced excitation and it has no need of withdrawing fault component.

e) Silicon controlled component is not designed by means of connection in series to

eliminate the problem of voltage equalization between components. Current equalization factor should not be less than 0.85.

f) Surge absorption measure is taken at AC-DC side to suppress peak overvoltage and favorable measure for restraining reversing overvoltage should be taken.

g) Each silicon controlled component is provided with quick-break fuse protection to be convenient to eliminate short-circuit fault current. The fusing can be detected and an alarm signal is given.

h) The forced opening air cooling mode is adopted. Standby cooling fan must be equipped, when operating fan breaks down, standby fan can be put into operation automatically.

i) Alarm signal of excitation system:

Any one or two rectifying cabinets exit operating alarm; silicon controlled fuse is blown

Radiator or air is overheated; cooling fan fails;

Air flow is over-low.

Automaitc voltage regulator (AVR) of generator

Main Parameters of AVR


Regulating precision ≤±0.5％ Automatic regulating range

(70％～110％)UGN0

Regulating error ratio ±15％ Manual regulating range

20％IfO～110％IfN

Time constant ≤30ms

UGNO is no-load rated voltage of generator; If0 is no-load excitation current of generator and IfN is full-load rated excitation current of generator.

3.1.3.8 Automatic Voltage Regulator (AVR) of Generator

The double-channel digital system is adopted; regulating mode is PID for terminal voltage; magnetic field current is by means of PI.

a) Functions:

1) Realize automatic monitoring of generator terminal voltage and have relevant protection system.

2) Automatic tracking between both channels is by means of bumpless transfer. Each channel has complete function and has independent operating capacity.



2×300 MW


3) Each channel is equipped with AVR constant voltage automatic regulating and constant current manual regulating unit, with manual tracking automatic and bumpless transfer each other.

4) AVR can conveniently modify parameters and realize online display and fault self-check.

5) AVR auxiliary functions:

Rotor instantaneous overcurrent protection

Rotor overcurrent limitation

Rotor inverse time overcurrent limitation and protection

Generator voltage/frequency limitation and protection (V/Hz)

Low excitation limitation

Power system stabilizer (PSS)

PT disconnection protection

6) AVR signal:

AVR1 # channel fault

AVR2 # channel fault

Over magnetic flux alarm

Low excitation limitation operation Rotor

inverse time limitation operation

Overcurrent inverse time limitation alarm

PT disconnection

Automatic operation

Manual operation

AVR normal

Excitation starting failure

Upper set point limit arrival

Lower set point limit arrival

Constant reactive regulation put-in

PSS put-in

PSS exit

AVR operating power source vanishing



2×300 MW


7) AVR operating logic:

In normal state, double channels operate automatically; one channel is in service and the other channel is standby; standby channel tracks the operation of operating channel automatically.

When an automatic channel fails, fault channel exits in an undisturbed way and a signal is made.

When operating channel fails, constant excitation current of the channel operates manually and a signal is made.

8) AVR should be provided with serial communication port to be convenient for communication with upper computer. Communication protocol is MODBUS.

9) Main performance of AVR:

Regulating precision: ≤±0.5％

Regulating error ratio: ±15％

Time constant: ≤30ms

Voltage regulating range: automatic regulation: (70 ％～ 110 ％ )UGNO; manual

regulation: 20％Ifo～110％IfN

Note: UGNO is no-load rated voltage of generator; If0 is no-load excitation current of generator and IfN is full-load rated excitation current of generator.

10) Two circuits of AVR operating power sources are all DC 110V; one circuit is used for AVR control and the other circuit is used for tripping 2.

11) Technical requirements of field suppression device:

z Field suppression device should suppress the field reliably in the case of normal

operation or internal fault of generator.

z Field suppression logic: properly delay tripping field suppression switch by inversion.

z Adopt field suppression switch + silicon carbide non-linear resistance field suppression and overvoltage protection mode.

z Main loop insulation level of field suppression should not be lower than insulation level of generator rotor winding.

z Field suppression overvoltage peak under rated and forced excitation current

should not exceed 40％ of effective value of predelivery insulation withstand

voltage.

z Parameters of field suppression switch:

Switch model: SACE Emax E3

Rated current: 3200A



2×300 MW


Rated voltage: 1000V

Maximum overcurrent capacity: 6kA (continuous 20s), 50kA (3s)

Maximum breaking capacity: 50kA

Maximum field suppression voltage: 2000V

Number of main contact: 3

Break time of field suppression switch: ≤0.06 s

Silicon carbide non-linear resistance parameters:

Protection voltage value in the case of two-times forced excitation current field

suppression: ≯1900V±10％ (peak value)

Capacity: 1MJ

Field suppression time: about 4.4s (no load)

12) Technical requirements of excitation starting loop

z The capacity of excitation starting transformer is about 12 kVA.

z Excitation starting mode: take a circuit of AC 380V power source from I and II-phase auxiliary power MCC section, after rectifying, provide excitation starting power source; excitation starting loop is type of short-time operating system and it is allowed to power on to start excitation once at an internal of 5min. When the generator voltage rises to specified value, excitation starting loop will be disconnected automatically. On the graphic display of unit DCS, the position signal of excitation starting loop switch is available.

13) In case symmetrical or asymmetrical short circuit occurs at high voltage side of generator, excitation system should guarantee normal operation.

3.2 Transformers

3.2.1 Main Transformer

Name of Equipment

NO. 1 Main Transformer

NO. 2 Main Transformer

Manufacturer Shenyang Transformer Co., Ltd. Shenyang Transformer Co., Ltd.

Model SFPZ-360000/220 DFPZ-120000/500

Number of phases

Three-phase 50Hz

Single-phase 50Hz

Rated capacity 360000kVA 3×120000kVA

Rated voltage （242±10×1.0％）/20kV (550/1.732±10×1.0％）/20kV

Rated current 860/9623A 396/6000A



2×300 MW


Cooling mode ODAF ODAF

Wiring category YNd11 YNd11

No-load loss ≤80kW

Load loss ≤240kW

Impedance voltage

14.0 ％

14.5 ％

Voltage regulating mode

On load

On load

3.2.2 Auxiliary Transformer

Name of Equipment 1# and 2# High-voltage House Service

Transformers

Manufacturer Shenyang Transformer Co., Ltd.

Model SFZ-CY-50000/20

Number of phases Three-phase 50Hz

Rated capacity 50000/31500-31500kVA

Rated voltage （20±10×1.0％）/6.8-6.8kV

Rated current 1443.38/2674.5-2674.5A

Cooling mode ONAN

Wiring category Dyn1yn1

No-load loss 27.15kW

Load loss 160kW

No-load current 4.8A

Impedance voltage 19%

Voltage regulating mode On load

3.2.3 Standby Transformer

Name of Equipment standby transformer


Model SFZ-CY-50000/115TH




2×300 MW


Rated capacity 50000/31500-25000-31500kVA

Rated voltage （115±10×1.0％）/6.8—6.8kV

Rated current 251.02/2674.49A

Cooling mode ONAN

Wiring category YNyn0yn0d11

No-load loss 33.6kW

Load loss 160kW


Impedance voltage 19％


3.2.4 Technical Specification of 400V Station Transformer

Name of

Equipmen

Steam turbine

Transforme r

Boiler

Transformer

Electric Dust collecting

Transformer

Lighting

Transformer

Common

Transformer

Ash handling

Transform er

Model SCB9-1000 /6

SCB9-1250/ 6

SCBZ9-1600/ 6

SCB9-500/6 SCB9-2000/ 6

SCB9-100 0/6

Capacity kVA

1000

1250

1600

500

2500

1000

Voltage 6.6±2×2.5％/0.42kV

High-volt age side current A

87.5

109

140

43.7

175

87.5

Low-volta ge side current A

1375

1718

2199

687

2749

1375

Wiring category

Dyn11

Impedanc e voltage

％

6％

6％

8％

4.5％

10 ％

6％

Insulation class

H

H

H

H

H

H



2×300 MW


Maximum temperat ure rise

125K

125K

125K

125K

125K

125K

Number of phases

Three phases

Frequenc y

50Hz

Cooling mode

Self cooling/air cooling

Manufact urer

Shanghai ABB Transformer Co., Ltd.

Name of Equipme

nt

Ash Yard

Transformer

Chemical Water

Transformer

Coal Handling

Transformer

Water Supply

Transformer

Circulating Water

Transforme r

Administrati ve Zone

Transformer

Model

SCB9-200/6 SCB9-1250/ 6

SCB9-2000/ 6

SCBZ9-1000/ 6

SCB9-500/ 6

SCB9-800/6

Capacity kVA

315

1250

2500

1000

500

1250

Voltage 6.6±2×2.5％/0.42kV

High-volt age sidecurrent A

17.5

109

175

87.5

43.7

70

Low-volt age side current A

275

1718

2749

1375

687

1100

Wiring category

Dyn11

Impedan ce

voltage％

4％

6％

10％

6％

4.5％

6％

Insulatio n class

H

H

H

H

H

H

Maximu m temperat

125K

125K

125K

125K

125K

125K



2×300 MW


ure rise

Number of phases

Three phases

Frequenc y

50Hz

Cooling mode

Self cooling/air cooling

Manufact urer

Shanghai ABB Transformer Co., Ltd.

3.3 Auxiliaries

3.3.1 Technical Parameter of 1# Main Transformer on-load Tap Switch

Item Name Unit Technical Data Remark

Technical parameter of on-load tap switch

Equipment model and manufacturer

MR－Ⅲ350Y123C10193W

Germany

Rated level capacity kVA 10.193

Rated voltage kV 220

Voltage regulating series series ±10

Connection mode Y

Number of phases Three phases

Technical parameter of electric motor

Rated power kW 0.75

Rated voltage V 380

Rated current A 3.4/2.0

Frequency Hz 50

Gear number 1-10, 11A, 11B, 11C, 12-21

Number of revolutions of tapping conversion drive shaft of each phase

revoluti ons

33



2×300 MW


Number of revolutions of tapping conversion manual operation of each phase

revoluti ons

33

3.3.2 Technical Parameter of 2# Main Transformer on-load Tap Switch




MR－Ⅲ350Y123C10193W

Germany




Connection mode Y



Rated power kW 0.75

Rated voltage V 380


Frequency Hz 50

Gear number 1-10, 11A, 11B, 11C, 12-21


revoluti ons

33


revoluti ons

33

3.3.3 Technical Parameter of on-load Tap Switch of 1# and 2# High-voltage House Service

Transformers




MR－Ⅲ350Y123C10193W

Germany



2×300 MW



Rated voltage kV 20


Connection mode Y



Rated power kW 0.75

Rated voltage V 380


Frequency Hz 50

Gear number 1-10, 11A, 11B, 11C, 12-21


revoluti ons

33


revoluti ons

33

3.3.4 Technical Parameter of on-load Tap Switch of station transformer




MR－Ⅲ350Y123C10193W

Germany




Connection mode Y



Rated power kW 0.75

Rated voltage V 380




2×300 MW


Frequency Hz 50

Gear number 1-10, 11A, 11B, 11C, 12-21


revoluti ons

33


revoluti ons

33

3.3.5 Transformer Tap and Wiring Diagram

1# main transformer tap

High-voltage Side Low-voltage Side

Tapping Position

Voltage（V）

Current（A）

Voltage（V）

Current（A）

1 266200 780.8

2 263780 788

3 261360 795.2

4 258940 802.7

5 256520 810.3

6 254100 818

7 251680 825.8

8 249260 833.9

9 246840 842

10 244420 850.4

11a

11b

11c

242000

858.9

12 239580 867.5

13 237160 876.4

14 234740 885.4

15 232320 894.7

16 229900 904.1

17 227480 913.7

18 225060 923.5

19 222640 933.6

20 220220 943.8

21 217800 954.3

20000

10392.3



2×300 MW


2# main transformer tap


Tapping Position

Voltage（V）

Current（A）

Voltage（V）

Current（A）

1 605000/ 343.55

2 599500/ 346.70

3 594000/ 349.91

4 588500/ 353.18

5 583000/ 356.51

6 577500/ 359.91

7 572000/ 363.37

8 566500/ 366.90

9 561000/ 370.49

10 555500/ 374.16

11a

11b

11c

550000/

377.9

12 544500/ 381.72

13 539000/ 385.61

14 533500/ 389.59

15 528000/ 393.65

16 522500/ 397.79

17 517000/ 402.02

18 511500/ 406.35

19 506000/ 410.76

20 500500/ 415.28

21 495000/ 419.89

20000

6000

1# and 2# high-voltage transformer tap


Tapping Position

Voltage（V） Current（A） Voltage（V） Current（A）

1 22000 1312．16 2 21800 1324．2 3 21600 1336．46 4 21400 1348．95 5 21200 1361．68 6 21000 1374．64 7 20800 1387．86

6800 2674.5



2×300 MW


8 20600 1401．34 9 20400 1415．07 10 20200 1429．08 11a

11b

11c

20000

1443．38

12 19800 1457．96 13 19600 1472．83 14 19400 1488．02 15 19200 1503．52 16 19000 1519．34 17 18800 1535．51 18 18600 1552．02 19 18400 1568．89 20 18200 1586．13 21 18000 1603．75

01# starting-standby transformer tap


Tapping Position

Voltage（V） Current（A） Voltage（V） Current（A）

1 126500 228．2 2 125350 230．3 3 124200 232．43 4 123050 234．6 5 121900 236．81 6 120750 239．07 7 119600 241．37 8 118450 243．71 9 117300 246．1 10 116150 248．54 11a

11b

11c

115000

251．02

12 113850 253．56 13 112700 256．14 14 111550 258．79 15 110400 261．48 16 109250 264．23

6800 2674．49



2×300 MW


17 108100 267．04 18 106950 269．92 19 105800 272．85 20 104650 275．85 21 103500 278．91

3.3.6 Technical Specification of Generator Outlet Switch

No.

Specification and Model

Items

HECS-100L

1 Rated voltage（kV） 20

2 Rated current（A） 13000

3 Thermal steady current（kA） 100

4 Dynamic steady curren（t kA） 280

5 Mechanical life（number of

times）

20000

6 SF6 rated air pressure Mpa 0.62

7 SF6 alarm air pressure Mpa 0.56

8 SF6 block air pressure Mpa 0.54

9 Manufacturer ABB High Voltage Technique Co., Ltd.

3.3.7 Technical Parameter of 6kV Switch:

Model ZSG

Rated voltage 7.2kV Rated current 630～3150A

Mechanical life

30000 times

Times of full-capacity short circuit current break

≥50 times (50kA, 20 times)

Rated frequency

50Hz

Rated short-circuit break current (effective value)

25～50kA

Rated dynamic steady current (peak)

63～125kA

4s thermal steady current (effective value)

25～50kA

Rated power frequency

42kV Operating mode Manual and electric



2×300 MW


withstand voltage

Mechanism type

Spring energy storage type

Manufacturer

Shanghai General Guangdian Engineering Co., Ltd.

3.3.8 Technical Parameter of 400ＶSwitch::

Model ME-630~2505 DWX-15C200~630

Rated current 630～2900A 200～630

Rated breaking current 50～80kA 50kA

Rated voltage 400V 400V

Rated insulation voltage 660V 660V

Full-break time About 30ms

3.3.9 Technical Specification of Enclosed Busbar:

Name Main Busbar Auxiliary Branch

Model QLFM-20/12500 QLFM-20/12500

Rated voltage（kV） 20 20

Maximum voltage（kV） 24 24

Rated current（Ａ） 12500 1600

Insulation level（kV） 68 68

Ambient temperature（） ±40 ±40

Busbar operating temperature

maximum temperature（）

90

90

Casing operating temperature

maximum temperature（）

70

70

Spacing（mm） 1400 1050

Manufacturer Zhenjiang East China Electric Power Equipment Factory

3.3.10 Specification of DC System Equipment:

1# and 2# units: valve-controlled storage battery parameter

Name Main Machine Hall 220V Storage

Battery

Common 220V Storage Battery



2×300 MW


Model 1BTB01GR001 9BTB01GR001

Capacity 1500Ah 400Ah

Number of battery

104 pcs

104 pcs

Manufacturer Yuasa Battery (Guangdong) Co., Ltd.

3.3.11 UPS Technical Parameter:

Item Name Design Data Remark

Model BORRI E—2001

Capacity 80kVA

Power factor 0.8

UPS AC input

1. Voltage 380/220V AC±15％

2. Frequency 50Hz±6％

3. Wiring system Three-phase and three-wire system

4. Short circuit current

40kA

Effective value of three-phase symmetrical short circuit current under rated voltage

Bypass system input

1.Input voltage 400V AC±15％ The same as output value

2. Frequency 50Hz±6％

3. Current

31.5kA Effective value of single-phase short circuit current under rated voltage

UPS DC input

1. Voltage 220V 50Hz

2. Normal input voltage range

220V DC -20％～+47％ Voltage stabilization operating range

3. Maximum input voltage range

220V DC-25％～+47％

Limit operating range

UPS output

1. Gross efficiency ≥94％



2×300 MW



2. Voltage AC 220V

3. Voltage stabilization range

a) Static voltage stabilization

precision: 0 ～ 100 ％ , load sudden

load change: ±1％;

b) Dynamic voltage stabilization

precision: 100％, load sudden load

change: ±4％;

4. Time ＜25ms

5. Inverter

a) Output capacity: 80kVA b) Overload capacity is not less than:

125％ rated load, 10min


6. Static switch change-over time

＜3ms

7. Static switch and bypass system overload capacity is not less than

125％ rated load, 60min 150％ rated load, 30min


Short circuit characteristic

100ms inverter: 200％ rated load

Operating environment

Temperature: 0 ～ 40

(recommended value: 25)

Humidity: ＜95％ (＋25)

4 Protection of Generator-Transformer Unit

4.1 General Requirements and Regulations

4.1.1 Any voltage-borne electric equipment or operating line must be in protected operating state. In special case, if protection device must be stopped, a prior permission must be granted according to the following principles.

4.1.1.1 In any case as follows, it must be submitted to dispatching department for approval.

Main transformer and starting-standby transformer zero-sequence protection

Protection device of equipment and line operated directly under command of dispatcher is unsound.

4.1.1.2 In any case as follows, it must be submitted to company’s chief engineer for approval.

a) Main transformer differential or gas protection is stopped;


2×300 MW


b) Protection of other 6kV and above systems in the factory.

4.1.2 For other protection and automatic devices within company’s jurisdiction, with permission of shift chief-operator, relaying protection and automatic device of uninterrupted power equipment can be inspected, tested and adjusted.

4.1.3 It is not allowed to stop the protection and automatic device of standby equipment without permission, if necessary, the regulations stated in item 4.1.1 should be complied with.

4.1.4 In normal condition, the put-in and exit of relaying protection and automatic device and switching of protection mode should be made by special strap and switch and are not allowed to make at will by method of disconnecting secondary joint to add temporary line.

4.1.5 After relaying protection and automatic device are inspected and repaired, explicit written explanation and conclusion must be made (when necessary, attach drawing for explanation), if the settings are changed, the changer should make a written explanation and it can not be put into operation without conclusion.

4.1.6 Before operating by special operating mode, relaying protection setting personnel should be notified in advance to check whether existing protection settings meet the requirement of special operating mode, and after check, a clear explanation should be given to operator in time.

4.1.7 After the setting is modified and new protection is put into operation, the operator must check it according to protection scheme or temporary setting notification and setting printed out or explanation given by relaying protection personnel, after check, the protection disclosure sheet should be signed jointly. The dispatcher should check the settings according to printed settings and relaying protection explanation.

4.1.8 Normal operation of relaying protection is subject to the specified mode corresponding to primary mode in setting list and the dispatcher’s temporary notice.

4.1.9 Sequence of putting in protection device: put in DC power source first and then put in outlet strap. Before putting in hard strap, measure with high internal resistance multimeter and both lower and upper terminals of strap have no DC voltage; before putting in functional soft strap, inspect that relevant protection outlet signal indicator light is off.

4.1.10 During equipment repair by service interruption, the protection that has an impact on operating equipment should be stopped in advance; before equipment put into operation and standby use, the protection should be put into operation.

4.1.11 The generator longitudinal differential, transformer differential, busbar differential, distance, zero sequence, negative sequence and power directional protections in the case of new installation, overhaul or secondary loop changing should not be put into operation until the accuracy of measurement of secondary device is correct by means of primary current and voltage detection. In the case of generator starting, synchronizing and transformer charging, differential protection should be put in trip; after the equipment is on-load, relevant protection strap should be stopped according to the requirement of



2×300 MW


No. Equipment Name Quantity

Cabinet A

Generator-transformer protection cabinet, each cabinet includes: 2

1

G60 E00 HCH F8L H6T M8L P6C U6C W6C digital generator

management relay includes the following protection: (generator G60)

Generator differential

Generator 100% stator grounding

Generator negative-sequence current (specified/ inverse)

1

relaying protection personnel, so as to measure current and voltage phase and difference current.

4.1.12 The starting and stop of protection of hot operating starting relaying protection outlet

should be implemented according to the shift chief-operator’s order and in accordance with hot operating personnel and relaying protection personnel’s explanation.

4.1.13 Both put-in and stop of normal operation of relaying protection and automatic device are operated by operators. When protection put-in and stop need changing secondary line or changing the settings in microcomputer protection, it should be operated by protector. Any vibrating operation is prohibited on in-service protection panel and automatic device. In special case, safety measures or relevant stop protection must be available. Any radio communication equipment is strictly prohibited to be used in central control room and relaying protection room.

4.1.14 Each shift should inspect relaying protection and automatic device according to the following items during shift take-over and intermediate inspection.

4.1.14.1 Relaying protection and automatic device should be free of peculiar smell, overheating, abnormal noise, vibration and abnormal signal.

4.1.14.2 Inspect that all outdoor terminal boxes are well-sealed; PT secondary switch is in put-in position; CT is free of open circuit.

4.1.14.3 The switch and strap test component subordinated to device should be in correct position.

4.1.14.4 Relay contact is free of shaking and heating.

4.1.14.5 On state of indicator light subordinated to device and put-in and stop of protection comply with current operating mode.

4.1.14.6 Relay is free of actuating signal, plate falling and other abnormal phenomenon.

4.2 Protection Configuration of Generator-Transformer Unit

Generator-transformer protection is by GE type (imported from USA) generator-transformer protection

device produced and provided by Shanghai Relay Co., Ltd. Protection cabinet includes A, B, C and D

cabinets.



2×300 MW



Generator excitation loss (generator low-voltage and negative-sequence

voltage block)

Generator overexcitation (specified/ inverse)

Generator out of synchronism

Generator reverse power

Sequential-trip reverse power

Generator inter-turn (with negative-sequence power direction block)

Generator overvoltage

Impedance

Generator overload

Generator circuit breaker failure protection

PT disconnection detection and block

2 T35 E00 HCH F8N H6U digital transformer management relay includes the following protection: (excitation transformer T35)

Excitation transformer differential

1set

3 Generator rotor grounding protection device 1set

4 Other components of protection cabinet （1）Casing outlet relay

（1）Casing signal relay (panel back)

Terminal block (Phoenix)

Automatic air switch (Siemens), etc.

Cabinet B


1 G60 E00 HCH F8L H6T M8L P6C U6C W6C digital generator management relay includes the following protection: (generator G60)

Generator differential Generator 100% stator grounding

Generator negative-sequence current (specified/ inverse)

Generator excitation loss (generator low-voltage and

negative-sequence voltage block)

Generator overexcitation (specified/ inverse) Generator out of synchronism

1



2×300 MW



Generator reverse power Sequential-trip reverse power

Generator inter-turn (with negative-sequence power direction block)

Generator overvoltage

Impedance

Generator overload

Generator circuit breaker failure protection

PT disconnection detection and block

2

F35-E00-HCH-F8L-H6U

Excitation transformer overcurrent

1





4

Non-power output protection 1

Cabinet C


1 T60 E00 HCH F8N H6U M8L P6C digital transformer management relay includes the following protection: (main transformer G60)

Generator-transformer three-phase differential (three sides) Main transformer overexcitation

Main transformer high-voltage side zero sequence differential

Main transformer overcurrent

Circuit breaker starting failure

System low voltage (block excitation loss)

20kV specified time grounding

1

2 T60 E00 HCH F8N H6U M8L P6C digital transformer management relay includes the following protection: (high-voltage house service transformer- T60)

High-voltage house service transformer differential protection (three

1



2×300 MW



sides) High-voltage house service transformer low-voltage side zero

sequence differential (two)

High-voltage house service transformer high-voltage side overcurrent High-voltage house service transformer low-voltage side branch

overcurrent





4

Non-power output protection 1

Cabinet D


1 T60 E00 HCH F8N H6U M8L P6C digital transformer management relay includes the following protection: (main transformer T60)

Main transformer differential Main transformer high-voltage side zero sequence overcurrent

Main transformer overcurrent

Main transformer overexcitation

Circuit breaker starting failure

System low voltage (block excitation loss)

20kV specified time grounding

1

T35 E00 HCH F8N H6U M8L P6C U8L W6C digital transformer management relay includes the following protection: (high-voltage house service transformer T35)

High-voltage house service transformer differential High-voltage house service transformer overcurrent

High-voltage house service transformer zero sequence overcurrent

(two) High-voltage house service transformer low-voltage branch

overcurrent

Date: 2008-09-16

No.:QN1-SEC-G-04-TP-004

Page - 27 -

Rev. : A


2×300 MW







3 Protection supervisor 1set

5 Operation of Generator

5.1 Inspection and Preparation before the Startup

5.1.1 All works of generator loop are finished and all work sheets are ended; safety measures such as ground wire, sign board and railing, installed for repair safety, are all removed; fixed barrier and permanent sign board have been restored.

5.1.2 Inspect that static excitation device of generator is put into operation normally, without abnormal signal.

5.1.3 Inspect that all signals of generator system should be normal.

5.1.4 Inspect primary and secondary loop system and relevant equipment of generator; the loop should be complete and meet operating condition.

5.1.5 Put-in and exit of generator relaying protection and automatic device have been implemented according to relevant requirements, with normal operation.

5.1.6 Put generator sealing bus micro-supercharging device into operation and the operation is normal.

5.1.7 Inspect that generator has been filled with hydrogen completely; pressure, purity, humidity and temperature are normal; inner cooling water is free of leakage and water quality is acceptable.

5.1.8 Confirm the following parameters and pass the test:

5.1.8.1 For insulation resistance of generator stator coil (waterless after dried), insulation resistance to ground of approaching operating temperature: ≥500MΩ (2500V megohmmeter); for the electric equipment including that is connected to generator stator loop and can not be switched off by knife-switch, insulation resistance: ≥20MΩ (2500V megohmmeter), absorptance: ≥1.3. If the measuring result is obviously lower than the

measured value in the past two times and is 1/3 ～ 1/ 5 of the last time (considering the

change of temperature and humidity), the reason should be found out.

5.1.8.2 For insulation resistance of generator rotor coil, when rotor coil is in 20 cold state,

insulation resistance is greater than or equal to 10MΩ (500V megohmmeter).



2×300 MW


5.1.8.3 Insulation resistance of oil cover inside and outside generator excitation terminal bearing seal is greater than or equal to 1MΩ (500V megohmmeter).

5.1.8.4 Insulation resistance of generator brush yoke conducting ring is greater than or equal to

10MΩ (500V megohmmeter).

5.1.8.5 Insulation resistance of excitation transformer winding is greater than or equal to 6MΩ (2500V megohmmeter) and absorptance is greater than or equal to 1.3.

5.2 Startup and Synchronization

5.2.1 The startup or synchronization of generator is forbidden in any case as follows:

5.2.1.1 Main protection function of generating unit is lost or any trip protection is off normal;

5.2.1.2 DCS system is out of working order;

5.2.1.3 Generator excitation system fails to work normally;

5.2.1.4 Generator stator cooling water system is abnormal or water quality is unacceptable;

5.2.1.5 Hydrogen purity inside generator is below 90％; hydrogen pressure is less than 0.14Ｍ

Pa;

5.2.1.6 Synchronizing device of generator fails to work normally;

5.2.2 Auxiliary Power System Energization

5.2.2.1 6kV busbar energization by 500kV or 220kV system: make sure that all repair works of

main transformer, high-voltage house service transformer and 6kV A and B-section auxiliary power system are finished and all work sheets are ended; safety measures such as ground wire, sign board and railing, installed for repair safety, are all removed; fixed barrier and permanent sign board have been restored. Main transformer, high-voltage house service transformer and relevant electric equipment loops are complete and meet operating condition; all protection devices are put into operation normally.

6kV busbar energization:

a) Change 6kV A and B-section busbar and its power source incoming line loop to cold standby state from repair (measure busbar insulation that is acceptable).

b) Charge up 1# and 2# main transformers and high-voltage house service transformer by means of line normally.

c) Energize 6kV busbar respectively by means of 6kV A and B-section operating power source (put busbar PT into operation before energization).

5.2.2.2 6kV busbar energization by 110kV system: make sure that all repair works of starting-standby transformer and 6kV A and B-section auxiliary power system are finished and all work sheets are ended; safety measures such as ground wire, sign board and railing, installed for repair safety, are all removed; fixed barrier and permanent sign board have been restored. Starting-standby transformer and relevant electric equipment



2×300 MW


loops are complete and meet operating condition; all protection devices are put into operation normally.

6kV busbar energization:

a) Change 6kV A and B-section busbar and its power source incoming line loop into

cold standby state from repair (measure busbar insulation that is acceptable).

b) Close #01 starting-standby transformer 110kV switch and charge up #01 starting-standby transformer normally.

c) Energize 6kV busbar respectively by means of 6kV A and B-section standby source

switch (put busbar PT into operation before energization).

5.2.2.3 380V auxiliary power system: (Make sure that all repair works in 380V auxiliary power system are finished and all work sheets are ended; safety measures such as ground wire, sign board and railing, installed for repair safety, are all removed; fixed barrier and permanent sign board have been restored. Relevant electric equipment loops are complete and meet operating condition; all protection devices are put into operation normally.)

a) Respectively energize 380V steam turbine PC A section and boiler PC B section by means of steam turbine transformer.

b) Respectively energize 380V boiler PC A section and boiler PC B section by means of boiler transformer; energize safety PC A section and PC B section busbar respectively by means of 380V boiler PC A section and boiler PC B section.

c) Energize common PC section busbar by means of common transformer.

d) Energize lighting PC section busbar by means of lighting transformer.

e) Energize electric dust collecting PC section busbar by means of dust collecting transformer.

f) Energize administrative zone PC section busbar by means of administrative zone transformer.

g) Energize water supply PC section busbar by means of water supply transformer.

h) Energize ash handling PC section busbar by means of ash handling transformer.

i) Energize coal handling PC section busbar by means of coal handling transformer.

j) Energize circulating water PC section busbar by means of circulating water transformer.

k) Energize chemical water PC section busbar by means of chemical water transformer.

l) Energize ash yard PC section busbar by means of ash yard transformer.

5.2.2.4 Diesel-engine generator recovery hot reserve

5.2.2.5 Inspect normal condition of each MCC, power control box, distribution panel power



2×300 MW


source and load in panel, in main machine building and auxiliary machine building.

5.2.3 Test before Startup

5.2.3.1 Necessary tests after repair

a) Tripping and closing test and relaying protection drive test of generator outlet switch,

excitation switch and 6kV operating source switch

b) Excitation system test (including excitation system rectifying cabinet operating and standby fan change-over test)

c) Diesel-engine generator and safety section power source switching test

d) 6kV auxiliary power quick-acting switching-off test

e) UPS power source switching test

5.2.3.2 Selective test after repair

a) Generator pseudo-synchronization test

b) Generator no-load test

c) Generator short-circuit test

d) Other test determined according to repair items

5.2.4 Preparation operation before parallel (before steam turbine constant-speed)

5.2.4.1 Close the operating and signal power switches (I and II) of generator outlet on-off;

5.2.4.2 Close the DC power switch of generator protection cabinet and inspect in failure-free

operation;

5.2.4.3 Inspect the put-in correctness of each protection strap of generator protection cabinet A (main steam stop valve closing strap is put into operation after generating unit is in synchronization; mis-power on or suddenly applying voltage protection strap exits after generating unit is in synchronization);

5.2.4.4 Inspect the put-in correctness of each protection strap of generator protection cabinet B (main steam stop valve closing strap is put into operation after generating unit is in synchronization; mis-power on or suddenly applying voltage protection strap exits after generating unit is in synchronization);

5.2.4.5 Inspect the put-in correctness of each protection strap of generator protection cabinet B (main steam stop valve closing strap is put into operation after generating unit is in synchronization);

5.2.4.6 Inspect that AC excitation starting power switch on MCC panel has been put into operation normally;

5.2.4.7 Close the trip 2 control DC power switch inside excitation device;

5.2.4.8 Close the on-off control DC power switch inside excitation device;



2×300 MW


5.2.4.9 Close the 24V DC control power switch inside excitation device;

5.2.4.10 Close the power switch of silicon controlled rectifying power cabinet cooling fan and inspect in failure-free operation;

5.2.4.11 Close the power switch inside excitation device;

5.2.4.12 Close the AC power switch of rectifying DC 24V inside excitation device;

5.2.4.13 Inspect local excitation control panel and DCS graphic display are free of alarm and fault information;

5.2.4.14 Switch the local/remote control on local excitation control panel to “remote control” mode;

5.2.4.15 Switch the excitation channel on local excitation control panel to “automatic channel”

operating mode;

5.2.4.16 Inspect that F1～F6 power source fuses should be closed inside excitation system

power cabinet, free of fusing signal;

5.2.4.17 Select the “channel 1” operating mode on local excitation control panel;

5.2.4.18 Inspect that MK is in off position;

5.2.4.19 Inspect that generator outlet PT high-voltage fuse should be closed, with good contact;

5.2.4.20 Push generator outlet TV and outlet LA car to operating position;

5.2.4.21 Close the secondary air switch of generator outlet TV low voltage;

5.2.4.22 Inspect that generator outlet on-off proximity and remote control switch transfers to “remote control” position;

5.2.4.23 Inspect that generator outlet switch three-phase SF6 gas pressure gauge should be in

good condition;

5.2.4.24 Inspect that generator outlet switch spring energy storage indication should be normal;

5.2.4.25 Inspect that generator outlet switch is in off position;

5.2.4.26 Inspect that generator outlet knife-switch is in tripping position.

5.2.5 Generator Parallel

5.2.5.1 Provisions and precautions for generator voltage-raising parallel operation:

a) Before generator voltage-raising parallel operation is implemented, an order must be

given by shift chief-operator, and moreover, make sure steam turbine, generator and relevant equipment meet parallel condition (without abnormal alarm signal).

b) Fully inspect CRT graphic display of synchronous parallel operation once; relevant signal indication should be correct and operating switch, change-over switch and synchronous switch should be in correct position.

c) Generator voltage-raising operation is implemented on DCS graphic display by



2×300 MW


means of excitation voltage regulator (AVR) in normal condition.

d) Conditions of generator parallel:

1) Generator voltage is equal to system voltage and maximum error between them should be within 10%.

2) Generator frequency is the same as system frequency.

3) Generator voltage phase is the same as system voltage phase.

4) Generator phase sequence is the same as system phase sequence.

e) Automatic sub-synchronous parallel method is adopted for generator.

f) Precautions

1) Strictly prohibit closing excitation switch to excite generator in the process of raising speed; initial excitation switch should not be started until generator reaches rated speed and parallel conditions are met. Automatically raise generator voltage to excitation voltage value determined according to adjustment and test and then increase excitation slowly according to generator terminal voltage value; during voltage raising, three-phase voltage of generator stator should be balanced and three-phase current should be no-load current value of main transformer; and moreover, generator voltage and excitation current should not exceed relevant rated value under no load, otherwise reduce the voltage immediately and find out and eliminate the reason, then raise the voltage again.

2) Before water feeding and hydrogen filling, generator excitation can not be load on in any case.

3) No matter which mode is adopted for parallel, synchronous block loop can not be released. After synchronizing device is put into operation, when the synchronous meter of local synchronizing device rotates unevenly or stops and bounces, generator parallel is not allowed.

4) During automatic sub-synchronous parallel, if automatic sub- synchronizing device is off normal, it must be handled and tested by electric repairer till returning to normal, and then implement generator parallel operation; prevent generator non-synchronous closing.

5) If the generator CT loop is repaired during stop, relevant generator differential protection should exit before synchronization and should not be put into operation until difference current is acceptable through detection or repair explanation allows after synchronization.

5.2.5.2 Automatic sub-synchronous parallel of generator:

Close the generator outlet knife-switch operating source;

Close the generator outlet knife-switch;



2×300 MW


Inspect that three phases of generator outlet knife-switch are in good closing condition;

Open the generator outlet knife-switch operating source; Close

the generator outlet switch operating source I switch; Close

the generator outlet switch operating source II switch; Close

the DC power switch of generator synchronizing device;

Inspect that steam turbine has been at constant speed;

Inspect that DCS graphic display is free of generator abnormal signal;

Put the excitation state on generator DCS in “automatic” position;

Put the excitation system state on generator DCS in “put-in” position and click on “put-in” function;

Inspect that generator excitation switch is good closing condition and excitation start is

normal;

Inspect that generator outlet voltage rises to rated value and no-load excitation voltage and current are normal;

Inspect that three phases of generator outlet voltage are balanced;

Notify generator steam turbine panel supervisor that DEH adopts “automatic synchronous” mode for synchronization and the conditions are met;

Click on “operation” function key of generator DCS “synchronous control” function;

Click on “put-in” function key (grey-red) of generator DCS “synchronous control” function;

Click on “reset” key of generator DCS “synchronous control” function;

Inspect the displacement (grey-red) of “ACT” function block of generator DCS “synchronous control” function;

Inspect that generator switch closing is in good condition;

Inspect that generator three-phase stator current is balanced and carries initial load;

Click on “general reset” key of generator DCS “synchronous control”;

Remove mis-power on protection strap inside generator protection cabinet A;

Remove mis-power on protection strap inside generator protection cabinet B;

Verify that no voltage is available at both terminals of “closing main steam stop valve” strap inside generator protection cabinet A and then put the strap into operation;

Verify that no voltage is available at both terminals of “closing main steam stop valve” strap inside generator protection cabinet B and then put the strap into operation;

Verify that no voltage is available at both terminals of “closing main steam stop valve” strap inside generator protection cabinet C and then put the strap into operation;



2×300 MW


Open the DC power switch of generator synchronizing device.

5.2.5.3 Inspect that generator stator three-phase current indication is balanced and generator

has carried 5％ initial load (about 15MW).

5.3 Operation Maintenance and Adjustment of Generator and Auxiliaries

5.3.1 Temperature Monitoring

5.3.1.1 Temperature and temperature rise of generator stator and rotor:

When the components of generator are under rated operating parameters, maximum

allowable monitoring temperature should be determined according to temperature rise test result. When the temperature rise test is not conducted on site, the monitored maximum allowable temperature should be lower than manufacturer’s specified value, shown as following table:

Location

Allowable Temperatur e

Rise（）

Maximum Allowable Temperatur

e（）

Test Condition

Test Method

Stator core gear

74

120

Hydrogen pressure 0.31Mpa

hydrogen

temperature 46

Thermocouple method

Stator core gear yoke

74

120


hydrogen

temperature 46

Thermocouple method

Stator coil slot inner layer

40

90 Cooling water

temperature 50

Resistance method

Rotor

64


hydrogen

temperature 46

Resistance method

Water branch outlet

85

Temperature measuring

microcomponent

Main outlet pipe water

31

85

Temperature measuring

microcomponent

5.3.1.2 The generator should operate for long time within the range of the data specified in manufacturer’s nameplate or capability diagram. Before the temperature rise test is not



2×300 MW



conducted, the generator should not operate beyond the range of the data specified in nameplate.

5.3.1.3 Under rated power factor and different hydrogen pressure, the generator current should not exceed the specified value shown as following table:

Hydrogen pressure

（Mpa） 0.31 0.208 0.103

Stator current（A） 10189 9150 8140

5.3.2 Monitoring of Voltage, Frequency, Power Factor and Unbalanced Current

5.3.2.1 It is allowed that stator voltage of generator may vary within the range of ±5％ of rated

value, and here the generator can still guarantee the rated output under rated power factor.

5.3.2.2 When generator stator voltage is lower than 95％ of rated value, stator current should

not be greater than 105％ of rated value.

5.3.2.3 Minimum operating voltage of generator should be determined according to the

requirement of stable operation and should not be lower than 90％ of rated value;

maximum operating voltage should comply with the manufacturer’s specification but

should not be higher than 110％ of rated value.

5.3.2.4 Generator frequency should be 50HZ at all times, when its variation range is within ±0.5HZ, the generator may operate with rated capacity.

5.3.2.5 The generator is allowed to operate under different power factors, but should meet

generator capacity curve and is restricted by the following conditions:

5.3.2.6 When higher than rated power factor, restricted by stator current steam turbine output;

5.3.2.7 When lower than rated power factor, restricted by rotor current;

5.3.2.8 Under leading phase power factor, restricted by stabilization.

5.3.2.9 When the generator operates under different power factors at the same time, stator and rotor current should not exceed the specified value under corresponding hydrogen pressure.

5.3.3 Leading Phase Operation of Generator

5.3.3.1 Requirements of leading phase operation

a) The leading phase operation of generator should comply with dispatching order

(leading phase test must be conducted), after exit of leading phase operation state, report to the dispatcher immediately.

b) In principle, the leading phase operation of generator is only adopted in normal operating state of power plant and system, when the defect of main equipment like generator excitation system has an impact on system safety, the generator should be in lagging phase operation.


2×300 MW


2

c) When the generator is in leading phase operation, the excitation system of generator must be in good condition and its voltage regulator (AVR) and forced excitation must be intact and put into operation; voltage regulator (AVR) operates in “automatic” mode.

d) When generator output is less than 80％ of rated output (240MW), the leading

phase operation is allowed; when generator output is greater than or equal to 80％

of rated output, the generator should be in lagging phase operation; when generator

output is equal to 90％ of rated output or above, the power factor should be less

than 0.99 in lagging phase operation.

5.3.3.2 Precautions of leading phase operation

a) When the generator is in leading phase operation, the monitoring of generator terminal voltage should be enhanced; the temperature rise of each component and generator cooling medium should meet the requirements of field manual and manufacturer.

b) Ensure that auxiliary power busbar voltage of generator in leading phase operation is not less than specified value (5.7kV). During leading phase operation, strengthen monitoring and when once finding out that auxiliary power busbar voltage, generator active and reactive power, current, rotating speed and generator operating state have abnormal phenomena, immediately change generator from leading phase operation to lagging phase operation and report to the dispatcher at once.

5.3.3.3 When the voltage regulator (AVR) is in manual operation mode, the leading phase operation is not allowed and the ratio of active to reactive power should not be greater than 3 all the time.

5.3.3.4 During normal operation, three-phase current of stator should be equal. When three-phase current is asymmetric, allowable continuous unbalanced current of generator should not exceed 10% of rated value during continuous operation under rated parameter and maximum single-phase current should not exceed rated current. During continuous operation below rated load, the current difference between phases may be greater than the above-mentioned specified value, but should be determined according to test. In long-time stable operation, when the current of each phase is not more than rated value, per-unit value of negative sequence current component should not be greater than

8 ％ . The capacity of short-time withstand negative sequence current should meet

I2 ×t≤10.

5.3.3.5 In an emergency, stator overcurrent capacity, rotor overvoltage capacity and allowable time are shown as the following table:

Allowable time（s） 10 30 60 100

Stator overcurrent capacity （rated current of stator％）

226

154

130

116



2×300 MW


Rotor overvoltage capacity （ rated excitation voltage of

rotor ％）

208

146

125

112

(Note: total number of the above emergency overload should not exceed two times every year)

5.3.4 Specification of Insulation Resistance

5.3.4.1 Before generator starting or after stop standby for over one week, the insulation

resistance should be detected.

5.3.4.2 Measurement and specification of insulation resistance of each component of generator:

5.3.4.3 Insulation of generator stator loop

a) Insulation resistance of generator stator winding is measured with 2500V

megameter and it should not be less than 1000MΩ(25 ) through 1min

measurement. Equipment temperature rises 5-15 , and insulation resistance

reduces half approximately.

b) The measured result in different conditions should be converted to the measured value in the last same condition; the value should not be lower than 1/3-1/5 of the last measured value and 60s and 15s absorptance should not be less than 1.3; the result is not used for basis of acceptability of generator insulation, for reference only. Under different temperature, insulation resistance may be converted according to the following formula:

Ｒt=Ｒ75×2(75-t)/10

Ｒt is insulation resistance value at t;

t is the temperature when measuring;

UN is rated voltage (V) of winding;

PN is rated capacity (kVA) of generator;

5.3.4.4 Insulation resistance of rotor loop is measured with 500V megameter and 1min insulation

resistance value should not be less than 10MΩ at 25.

5.3.4.5 Insulation resistance to ground, of all temperature measuring components inside generator is measured with 250V megameter in cold state and it should not be less than 5MΩ.

5.3.4.6 During operation, the repairers should measure, with 500V megameter, the insulation

resistance to ground, of bearing once a month and keep a record. One end of megameter is grounded and other end is connected by turns to each measured terminal

(BEG1 ～ BEG6) to directly measure insulation resistance. Predicated insulation

resistance is more than 1MΩ. When insulation resistance is less than 0.5MΩ, it will cause shaft current conveyance and damage insulation, and here the generator must be stopped. The reduction of insulation resistance shows the insulation is deteriorated, so it must be repaired to reach minimum allowable value before operation.



2×300 MW



When insulation resistance of the above measured object is lower than specified value, it should be restored in time.

5.3.5 Maintenance and Inspection of Generator

5.3.5.1 Routine work of generator system:

a) Strictly monitor generator operating condition and adjust in time to make operating

parameter not exceed specified value.

b) Both increase and reduction of active load of generator are usually controlled by means of unit coordination or adjusted by attendant; and moreover monitor and adjust reactive load and strictly control generator stator voltage and current that should not exceed specified value.

c) During normal operation, transcribe operating parameters of generator hourly and contrast with print report, if any difference, analyze and find out the reason. If specific temperature measuring point is abnormal, strengthen the monitoring of the location and shorten record time, and moreover, report to relevant department for handling according to physical circumstances.

d) During generator operating, put excitation loop grounding detection device in automatic detection mode and check it regularly so as to put into normal operation.

e) Each shift should inspect fully generator, AVR device and relaying protection device once, etc. When any abnormal circumstance is found out, report handling in time and keep a record.

5.3.5.2 Main inspection items during generator operation:

a) Inspection items of central control room and protection cubicle:

1) The display value of each pointer parameter on DCS does not exceed allowable value.

2) The indication of each light signal is normal; the position of each control switch conforms to actual position; CRT graphic display is correct.

3) Relay and automatic device are free of loose contact, sealing off and overheat smoking, etc.

4) The position of each protection strap is correct and conforms to operating condition.

5) Keep records carefully and strengthen monitoring and shorten record time under abnormal circumstance.

6) Inspect that the temperature of generator enclosed busbar casing should be normal.

b) Inspection of generator proper:

1) Generator sound is normal, free of metallic friction sound and impact sound as well as abnormal vibration.


2×300 MW


2) Double-end sealing oil pressure is normal; lubricating oil flow is normal; return oil temperature is not higher than specified value.

3) The perimeter is clean, free of impurities, oil leakage and dewing.

4) The temperature rise of each component of generator does not exceed specified

value, without abnormal heat generation.

5) Fully inspect switch, knife-switch, PT and CT of generator system, etc.

6) The temperature of generator outlet enclosed busbar casing is less than 70.

c) Inspection and maintenance of stator cooling water system

1) Hydrogen pressure of in-service generator should be higher than stator winding cooling water pressure. When hydrogen-water pressure difference is less than 0.035MPa, an alarm is given.

2) Water quality should be acceptable, or an ion exchanger should be put into

operation.

3) Stator cooling water flow should be normal, or the pressure difference between both sides of water filter should be inspected. When the pressure difference is more than 0.2MPa, an alarm is given, and here standby filter should be put into operation.

4) Inspect that stator cooling water temperature should be normal.

5) Each waterway of generator should be unhindered and each water diversion pipe is free of shaking and leakage.

d) Inspection of hydrogen system:

1) Inspect that hydrogen pressure of generator should be within the range of specified value.

2) Inspect that hydrogen purity inside generator is normal (＞96％) and humidity

should be within normal range.

3) Inspect that hydrogen temperature is within allowable range and hydrogen cooler should be in normal operation.

e) Inspection of excitation system is referred to relevant contents of generator excitation system in this manual.

5.3.5.3 Relevant specification of generator insulation overheat monitoring device (FJR-1) operation:

a) The adjustable knobs on device panel are used for repair, adjustment and test, and

operators should not adjust them at will.

b) After the device is put into operation, the operation may not exit unless before unit overhaul and minor maintenance stop or before gas displacement inside generator; the device should be put into operation after the unit speed is stable.



2×300 MW


c) Put-in operation: inspect that ammeter pointer is in zero position and then close the power switch of device, after becoming normal, open gas inlet valve slowly and then open gas outlet valve, and here inspect that monitoring flow of device should be about 2L/min and ammeter indication value should be more than 75A.

d) Stop operation: shut off the gas outlet valve, then shut off the gas inlet valve and finally turn off the power switch (power source may not be shut off in the case of short-time stop).

e) During normal operation, each shift should inspect at least four times that both device detection part and remote control part are in normal operation, without abnormal signal.

5.4 Generator Disconnection

5.4.1 Disconnection Operation

5.4.1.1 Inspect that active load of generator has been minimized and reactive load is reduced

near to zero;

5.4.1.2 Open the generator outlet switch;

5.4.1.3 Inspect that generator outlet switch is in trip position;

5.4.1.4 Inspect that three-phase stator current of generator should be zero;

5.4.1.5 Put the excitation system put-in state on generator DCS graphic display into “exit” function;

5.4.1.6 Inspect that excitation switch MK tripping is in good condition;

5.4.1.7 Open the generator outlet knife-switch;

5.4.1.8 Inspect that generator outlet knife-switch is in trip position;

5.4.1.9 Open the generator outlet knife-switch operating source;

5.4.1.10 Put the generator protection mis-power on (applying voltage suddenly) protection strap;

5.4.1.11 Make generator protection exit and close main steam stop valve protection strap;

5.4.1.12 Open the generator outlet switch operating source I and II switch;

5.4.1.13 Report to shift chief-operator that unit has been disconnected.

5.4.1.14 After disconnected, change the unit to cold reserve according to shift chief-operator’s

order, and moreover,

a) Change generator PT loop to cold reserve;

b) Change voltage regulator (AVR) to cold reserve;

5.4.1.15 If the generator needs changing to repair, safety measures such as ground wire installing should be taken according to the requirement of work sheet, to make unit in repair state.


Sony

Highlight

Potential Transformer=Voltage Transformer


2×300 MW


5.5 Disposal of Generator Fault and Abnormal Condition

5.5.1 Abnormal Operation of Hydrogen Cooling System

5.5.2.1 Hydrogen Pressure Reduction

A. Fault

a) Hydrogen pressure indication descends or an alarm is given.

b) Hydrogen filling amount increases.

c) Density and generator fan differential pressure reduces.

d) Stator cooling water tank pressure ascends or steam exhaust pipe flowmeter has gas discharge.

e) Differential pressure between hydrogen and water descends.

B. Fault Source

a) Hydrogen filling regulator is out of order or hydrogen supply system pressure descends.

b) Seal oil pressure reduces.

c) Hydrogen system leaks or is mis-operated.

C. Disposal

a) In case hydrogen pressure reduction is found, find out and handle the source of trouble immediately and increase hydrogen filling to keep generator inner hydrogen pressure in normal condition, and moreover, strengthen the monitoring of hydrogen purity and core temperature.

b) For the hydrogen pressure reduction arising from seal oil pressure drop, handle it according to “seal oil pressure drop”.

c) When stator cooling water tank pressure rises and steam discharge quantity increases, the hydrogen may leak to stator cooling water system, so monitor closely hydrogen and water differential pressure, when necessary, properly lower stator cooling water pressure to prevent stator cooling water leaking in generator.

d) When hydrogen cooling system leaks, report to shift chief-operator and contact with hydrogen station for inspection, and moreover, take fire prevention and explosion protection safety measures.

e) If hydrogen pressure drops and can not keep rated value, contact with shift chief-operator to reduce unit load till stop according to the condition of stator core temperature.

5.5.2.2 Hydrogen Temperature Increase or Reduction



2×300 MW


A. Fault

a) Hydrogen temperature indication increases or reduces.

b) Low or high hydrogen temperature alarm is given.

B. Fault Source

a) Hydrogen cooler cooling water adjusting valve is out of order.

b) Open type water pressure drops.

c) Unit load ascents or descents suddenly.

C. Disposal

a) In case hydrogen temperature increase or reduction is found, find out and eliminate the source of trouble and return to normal operation.

b) Inspect operating condition of hydrogen cooler open type water adjusting valve, if the adjusting valve is out of order, switch to manual adjustment or bypass valve adjustment.

c) Inspect open type water pressure and keep within normal range.

d) Strengthen the monitoring of hydrogen pressure and stator core temperature, if hydrogen temperature increases, report to shift-chief operator and reduce unit load according to the condition of core temperature.

5.5.2.3 High or low generator hydrogen purity alarm: the alarm is given by hydrogen purity

monitoring device. When hydrogen purity is below 90％, low purity alarm signal is made,

and here:

A. Notify hydrogen station to take a sample for analysis.

B. Discharge dirt in hydrogen system and fill generator with acceptable hydrogen to make hydrogen purity inside generator come up to standard.

C. When high hydrogen purity alarm signal is made, it shows that purity meter pointer reaches

100％ or above, and such case shows that detection loop goes out of order or it is caused

by purity fan stop.

5.5.2.4 High Liquid Leak Detector Level

A. Fault: “high liquid leak detector level” signal alarm; oil or water enters into leak detector.

B. Disposal:

a) Inspect all leak detectors (total four ones) and find out the leak detector with liquid that should be discharged, when necessary, take chemical sampling for analysis.

b) Identify as stator cooling water leakage:

1) If stator cooling water seeps slightly, reduce intake water pressure and strengthen the monitoring of stator winding temperature and insulation; report to shift-chief operator and relevant leaders and arrange stop disposal as soon as



2×300 MW


possible.

2) If stator cooling water leaks, report to shift-chief operator and relevant leaders and stop generator immediately.

c) Identify as hydrogen cooler leakage:

1) Inspect that if the dew arising from low water temperature of hydrogen cooler increases water leakage, adjust the water inflow of hydrogen cooler.

2) Inspect that if hydrogen cooler water pipe leaks, reduce load and strengthen the monitoring of hydrogen temperature and humidity; adjust cooling water and ensure hydrogen temperature is greater than cooling water pressure; remove leaky cooler till stop for disposal.

d) If the oil leaks, inspect whether oil hydrogen pressure is normal and adjust it to return to normal. When oil leakage is continuous and can not be treated, apply for stop disposal.

5.5.2 Troubleshooting of Stator Cooling Water System

5.5.2.1 High Stator Winding Water Inlet and Outlet Temperature

A. When water inlet temperature reaches 53, “high water inlet temperature” alarm signal will

be made and here inspect and adjust cooler water outlet temperature, if the cooler is dirty, switch cooler operation.

B. When water outlet temperature reaches 85, “high water outlet temperature” alarm signal

will be made and here inspect generator water inlet temperature, pressure and flow immediately. If water inlet temperature is high, handle it according to “high water inlet temperature”; if all are normal, enhance generator water inlet pressure and increase cooling water flow under the condition of not exceeding maximum allowable operating pressure, so as to reduce generator stator cooling water outlet temperature. When generator stator

winding water outlet temperature exceeds 90, report to shift-chief operator and relevant

leaders and reduce generator load for operation till stop for disposal.

5.5.2.2 When stator cooling pump operation is abnormal and trips arising from failure, standby stator cooling pump should self-start, or start it manually quickly; during unit operation, stator cooling pump interlocking should be put into operation normally.

5.5.2.3 Low stator winding cooling water flow: when the pressure drop of cooling water at both ends of stator winding is 0.035MPa lower than normal value, “low water flow” alarm will be given.

A. Disposal

a) Inspect whether water inlet and outlet valves of differential pressure switch and water discharge valve are normal and observe whether the alarm is caused arising from throttle.

b) Inspect whether stator cooling water inlet pressure is normal; adjust recirculation and increase water flow and water inlet pressure. When necessary, start standby



2×300 MW


pump operation.

c) Inspect whether valves of stator water system are in correct position.

d) Inspect stator cooling water screen differential pressure value. If differential pressure value is over great, switch to standby screen in time for operation.

5.5.3 Troubleshooting of Seal Oil System

5.5.3.1 Main Faults of Seal Oil System

A. Air-side seal oil pump breaks down or air-side seal oil is interrupted.

B. Hydrogen-side seal oil pump breaks down or air-side seal oil is interrupted.

C. Oil-hydrogen differential pressure is low.

D. Defoaming tank oil level is high.

E. Oil level in hydrogen-side return oil control tank is abnormal (high or low).

5.5.3.2 : Reasons for low oil-hydrogen differential pressure:

A. Air-side (hydrogen-side) AC seal oil pump breaks down.

B. Seal oil supply piping leaks.

C. Seal oil screen is choking.

D. Air-side seal oil overpressure valve or differential pressure adjusting valve acting is abnormal.

E. Hydrogen-side seal oil overpressure valve acting is abnormal or recirculation valve opening is over large.

F. Oil level in hydrogen-side return oil control tank is over low.

G. Seal oil system differential pressure adjusting valve or balancing valve is out of order.

H. Misoperation.

5.5.3.3 Disposal in the case of air-side seal oil fault or air-side seal oil interruption and low oil-hydrogen differential pressure

A. When air-side seal oil pump breaks down and inlet-outlet differential pressure reduces to 0.035MPa, “air-side seal oil pump failure” alarm will be given.

B. Report to centralized control chief operator and start high pressure seal oil standby pump;

inspect that outlet pressure of high pressure seal oil pump is normal.

C. When air-side seal oil-hydrogen differential pressure reduces to 0.056MPa, seal oil standby differential pressure adjusting valve should be opened automatically and keeps oil-hydrogen differential pressure as 0.056MPa; when standby differential pressure adjusting valve

refuses operation, start standby oil source bypass valve ＃266 immediately and adjust

oil-hydrogen differential pressure to 0.056MPa.

D. When air-side oil-hydrogen differential pressure continuously reduces to 0.035MPa, an



2×300 MW


alarm will be give, and at the same time air-side DC seal oil pump should self-start to make oil-hydrogen differential pressure return to 0.084MPa, or start it manually and report to centralized control chief operator, and moreover, inspect outlet pressure of high-pressure seal oil standby pump and operating condition of standby differential pressure adjusting valve and inspect whether standby differential pressure adjusting valve and relevant valves are in normal state.

E. If both high-pressure standby oil source and air-side AC and DC seal oil pump break down and air side adopts low-pressure standby oil source for oil supply, report fault stop to shift-chief operator and notify hydrogen generation station to reduce hydrogen pressure to 0.014MPa or below and keep seal oil- hydrogen pressure difference as 0.021MPa.

5.5.3.4 When air-side seal oil is completely interrupted, stop and notify hydrogen station to

discharge station urgently.

5.5.3.5 Disposal in the case of hydrogen-side seal oil pump failure or hydrogen-side seal oil interruption

A. When hydrogen-side seal oil pump breaks down and inlet-outlet differential pressure reduces to 0.035MPa, “hydrogen-side seal oil pump failure” alarm will be given.

B. Report to shift-chief operator and disconnect hydrogen-side seal oil pump, and moreover, contact with repairer to return to normal as soon as possible.

C. Generator sealing pad may operate under the oil supply condition of hydrogen-free side oil pump; during hydrogen-side seal oil pump stop, hydrogen purity descends and humidity ascends, and here strengthen the displacement of hydrogen inside generator and keep

hydrogen purity above 90％, and moreover, increase hydrogen filling to ensure hydrogen

pressure inside generator.

D. Monitor that oil level of hydrogen-side seal oil tank and operation of air-side return oil tank smoke exhaust fan are normal.

5.5.3.6 Rise of Oil Level in Hydrogen-side Seal Oil Tank

A. Fault

a) Oil level gauge indication of hydrogen-side seal oil tank rises.

b) High defoaming tank oil level alarm is given.

B. Fault Source

a) Oil drain valve acting is abnormal (blocking or floating ball break, etc.)

b) Generator inner hydrogen pressure is low.

C. Disposal

a) When oil drain valve misacts, precess the thimble under oil drain valve to open oil drain valve and keep oil level in hydrogen-side seal oil tank in normal condition.

b) Properly turn down oil filling valve, namely precess the thimble above oil filling valve.



2×300 MW


c) When generator inner hydrogen pressure drops, handle it according to hydrogen pressure drop and try to keep normal hydrogen pressure inside generator.

d) When oil level indication of hydrogen-side seal oil tank is full and high defoaming tank

oil level alarm is given, report to shift-chief operator and require stopping hydrogen-side seal oil pump operating, if it is still non-effective, require stopping generator.

e) In treatment process, closely monitor oil level of generator leak detector and make sure whether oil enters into generator, if so, strengthen draining oil in leak detector and report to shift-chief operator.

5.5.3.7 Drop of Oil Level in Hydrogen-side Seal Oil Tank

A. Fault

a) Indication of oil level gauge of hydrogen-side seal oil tank drops.

b) An alarm of low oil level in hydrogen-side seal oil tank is given.

B. Fault Source

a) Oil filling valve misacts (blocking or floating ball break, etc.).

b) Oil drain valve is opened in the wrong way.

C. Disposal

a) When it is found that oil level in hydrogen-side seal oil tank drops, inspect operating condition of oil filling valve, when necessary, precess the thimble under oil filling valve and fill oil to normal oil level.

b) If oil drain valve misacts(blocking or mis-opening), precess the thimble above oil drain valve to close oil drain valve and keep the oil level in hydrogen-side oil tank in normal condition.

5.5.3.8 High Defoaming Tank Oil Level

A. Fault

a) “High defoaming tank oil level” alarm is given.

b) Generator leak detector oil level is high.

B. Fault Source

a) Defoaming tank return oil piping or overflow piping is choking.

b) Hydrogen-side return oil control tank oil level is high (oil filling valve and oil drain valve misact).

c) Sealing pad oil quantity is over great (pad wear).

C. Disposal

a) When high defoaming tank oil level alarm is given, the operator should stop hydrogen-side seal oil pump operation immediately and strengthen the monitoring of



2×300 MW


hydrogen purity.

b) Open defoaming tank oil drain valve to drain oil; a person should be specially assigned to monitor the operation to prevent generator inner hydrogen leaking out.

c) In disposal process, closely monitor the oil level of generator leak detector and strengthen the oil drain of leak detector.

d) After defoaming tank oil level returns to normal, shut off defoaming tank oil drain valve and start hydrogen-side seal oil pump; if high defoaming tank oil level alarm is still given, handle it by the above method and strengthen whether oil enters into generator and report to shift-chief operator.

5.5.4 Reverse Power Operation

5.5.4.1 Fault

a) Generator active meter displays negative value on generator DCS graphic display and

kilowatt-hour meter turns reversely;

b) “Main steam stop valve closed” alarm information is available on generator DCS graphic display and audible emergency alarm is given;

c) Reactive meter display value ascends and stator current display value descends; stator

voltage and excitation loop instrument display values are normal;

d) System cycle may reduce.

5.5.4.2 Disposal

When the generator is in reverse power operation and reverse power protection acts and trips, handle it according to emergency trip; if reverse power protection does not act, manually disconnect generator from system immediately.

5.5.5 Rotor Grounding

5.5.5.1 Fault

a) Excitation current increases; excitation voltage reduces; reactive meter indication

drops;

b) Generating unit has violent oscillatory motion;

c) When generator rotor grounding protection is put into operation, the generator trips.

5.5.5.2 Disposal

a) Before protection acts, disconnect generating unit and suppress field immediately.

b) Measure generator rotor insulation at different speeds;

c) When confirming rotor grounding, stop generator for disposal.



2×300 MW


5.5.6 Loss of Field

5.5.6.1 Fault

a) “Generator field loss” alarm information is available on generator DCS graphic display and audible emergency alarm is given; generator excitation current display value is near to or equal to zero;

b) Reactive display value of generator is negative;

c) Active display value of generator descends; stator voltage drops; stator current rises, with periodic oscillation;

d) Busbar voltage drops and is lower than normal value.

5.5.6.2 Disposal

a) When the generator loses excitation, if excitation loss protection acts and trips, handle it according to emergency trip. If the protection fails to act, disconnect and stop generating unit and report to shift-chief operator, and moreover, find out and eliminate fault source.

b) Allowable load and time in the case of generator excitation loss operation: generator

load should be reduced to 60％ of rated load within 60s as of loss of excitation and

should be reduced to 40％ of rated load within 150s as of loss of excitation; total

allowable time of asynchronous operation of loss of excitation should not exceed 15min.

5.5.7 Stator Grounding

5.5.7.1 Fault

a) Generator stator grounding protection (3U0) may act and generator outlet switch and

field suppression switch trip; main steam stop valve is closed; the indication values of relevant parameters of generating unit, such as stator voltage, stator current, active power, reactive power,rotor voltage and current, are zero.

b) “Electric prewarning” and “electric tripping” alarm windows are on; “stator grounding” signal is made; buzzer makes a sound.

c) Zero sequence voltmeter inside generator protection cabinet has indicated value that

even reaches 100V;

d) Generator zero-sequence voltmeter has indication value;

5.5.7.2 Fault Source

It is grounded completely or incompletely in stator loop and system.

5.5.7.3 Disposal

a) When stator grounding protection acts and trips:

If protection acts and trips, handle it according to stop;



2×300 MW


Inspect the generator; if no evident fault point exists through inspection, raise generator voltage from zero and inspect that no fault exists, and then repeat synchronization.

b) When stator grounding protection makes a signal:

If water leakage alarm is given at the same time, stop generator immediately;

c) Measure that generator zero-sequence voltage is below 10V, handle it by the following methods:

1) Firstly, inspect whether generator loop is grounded;

2) Inspect whether low voltage switch of neutral point voltage transformer is intact or the contact is in good condition;

3) Through inspection, if it is internal fault or no external fault point is found out, report to shift-chief operator and stop generator to handle fault.

5.5.8 Generator Dissymmetrical Operation

5.5.8.1 Fault

The indicated value of generator three-phase stator ammeter has deviation and negative

sequence ammeter has indicated value.


a) Generator stator current loop parameters are unbalanced;

b) The pointer is inaccurate;

c) Load three-phase is asymmetric.

5.5.8.3 Disposal

a) The difference between three phase current of generator should not exceed 8% of rated current, and moreover, the generator may operate continuously when the current of any phase is not more than rated value, or the operator should reduce generator load to meet the above requirements.

b) When unbalance value is greater than the above specified, find out and eliminate fault source; or report to chief engineer who makes a decision on disposal.

c) Asymmetric overload protection of generator may act and trip.

5.5.9 Oscillation and out-of-step

5.5.9.1 Fault

a) Active and reactive meter display values on DCS graphic display oscillate greatly;

b) Stator current display value oscillates violently and exceeds normal value;

c) Stator voltage display vlaue reduces and oscillates;

d) Excitation current and voltage display values oscillates near to normal value;



2×300 MW


e) The generator makes a roar sound and its rhythm is in step with oscillation of the above display values. If the oscillation direction of display value of each generating unit in parallel operation is in full accord, it is caused by system oscillation; if the oscillation direction of display value of one generating unit is opposite to other generating units, the generating unit is out of step.

5.5.9.2 Disposal

5.5.9.2.1 Inspect the display value of each instrument of generator excitation loop; if the oscillation is caused by generator mis-parallel or loss of field, disconnect the generator immediately.

5.5.9.2.2 If system fault causes generator oscillation, increase reactive power of generator as much as possible and enhance system voltage to create the condition of synchronization recovery. During operation in AVR automatic mode, strictly prohibit disturbing voltage regulator operation; during operation in AVR manual mode, increase excitation current as much as possible up to allowable overload value, and here execute in accordance with generator emergency load specification.

5.5.9.2.3 By means of the above measures, if it fails to return to normal within 60s, disconnect the generating unit out of step, and after the system is stable, restore synchronous parallel immediately.

5.5.10 Automatic Trip of Circuit Breaker

5.5.10.1 Fault

Relevant alarm information is available on generator DCS graphic display, and moreover, generator outlet switch and field suppression switch trip; all pointers of generator return to zero; audible emergency alarm is given;

5.5.10.2 Disposal: When in-service generator switch trips automatically, the operator should analyze, inspect and handle it in time according to the conditions of pointer, signal and protection operation.

a) When the generator switch trips, if the excitation switch trips at the same time, inspect whether auxiliary power switching is successful and make relevant treatment.

b) When the generator switch trips, if the excitation switch does not trip, adjust generator cycle and voltage in time and find out and eliminate fault source, and then contact with dispatcher to repeat synchronization.

c) When the generator switch trips, if the excitation switch does not trip, but “main steam stop valve closed” alarm information is available on generator DCS graphic display, stop the generator for disposal immediately.

d) If backup protection act or protection misoperation trip is caused by external fault of generator, make sure trouble shooting or find out misoperation reason, and then release misoperation protection and contact with dispatcher to put generating unit into synchronous operation again.

e) If generating unit tripping is caused by artificial misoperation causes, put generating unit



2×300 MW



into synchronous operation again immediately.

f) If generator protection acts and trips because of internal fault, inspect in detail the appearance of generator and relevant equipment within protection range and inspect whether obvious fault exists, and measure insulation resistance to find out tripping reason, after the fault is eliminated, put into synchronous operation. If no fault is found out, submit to chief engineering for approval, inspect generator by raising voltage from zero, if the voltage increase is normal, contact with dispatcher to put generating unit into synchronous operation; during raising voltage, if abnormal conditions appear, stop the generator for disposal immediately.

5.5.11 Fire and Smoke

5.5.11.1 Fault

a) When the attendant or other personnel find out through inspection: stator end cover

belches out visible smoke and spark or insulation burned taste exists;

b) Generator sound may change suddenly and the generator oscillates;

c) Generator grounding, inter-turn and differential protections act;

d) Relevant pointers of generator may swing abnormally.

e) “Electric alarm” and “electric tripping” alarm windows may be on and the buzzer makes a sound.


Inter-phase, inter-layer or inter-turn short circuit fault may be caused in stator coil.

5.5.11.3 Disposal

a) The operator should disconnect the generator immediately and open field switch to suppress the field.

b) Organize a part of personnel to arrive at scene and extinguish the fire according to fire control regulations.

c) Report to relevant leaders and departments at once and notify fire department to participate in fire extinguishment.

6 Excitation System of Generator

6.1 General Description of Excitation System

6.1.1 Generator excitation system is A5S-O/U231-D3200 type ABB UNITROL 5000

double-channel digital static excitation system produced by Shanghai Power Equipment Research Institute. The overall system consists of four major function blocks:

6.1.1.1 Excitation Transformer Excitation transformer is used to step down generator voltage as input voltage of rectifier and provide power supply for excitation system, and moreover, plays a role in electrical


2×300 MW


isolation between generator terminal and rotor winding.

6.1.1.2 Two Sets of Mutually Independent Excitation Regulators According to the change of generator terminal voltage, two sets of mutually independent excitation regulator are used to correct and change triggering flow angle of silicon controlled rectifier bridge so as to attain the purpose of changing excitation current and stable generator stator voltage.

6.1.1.3 Silicon Controlled Rectifier Unit Silicon controlled rectifier unit is used to convert AC current to controlled DC current.

6.1.1.4 Excitation Starting Unit and Field Suppression Equipment

Excitation starting unit is used to provide primary energy for generator rotor. Field suppression equipment is used to cut off rotor magnetic field loop and release magnetic field energy as quickly as possible.

6.2 Operation of UNITROL 5000 Excitation Regulator

6.2.1 Key Functions and Characteristics

Excitation regulator is a full-redundancy double channel controller and each channel may be

“online” or “standby” mode. Besides automatic voltage regulating function, each channel has PSS, various restriction, protection, monitoring and manual control functions, etc.

1) Operation of Excitation Regulator

In-service Inspection

When excitation regulator works normally, no alarm signal should be made.

Standby channel is free of failure and it is allowable change-over state between main channel and standby channel.

Excitation regulator does not enter restricted state.

Excitation current, generator voltage and reactive power are stable.

Change-over of in-service channel

Two channels are identical and channel 1 or channel 2 may be selected as operating channel freely. Standby channel automatically tracks the operation of operating channel. If standby channel is free of failure, it may manually switch to standby channel for operation.

If a fault is detected in operating channel, automatically switch to the second channel urgently. And then, do not switch to fault channel until the fault is removed.

If both channels break down, urgently switch to manual operating mode. And then, do not switch to automatic mode until the faults are removed.

Put into Operation/Exit of Power System Stabilizer

Power system stabilizer (PSS) can suppress the low frequency oscillation caused by generator or system fluctuation.

When active power of generator reaches set value, PSS is put into operation and



2×300 MW


generator voltage is limited within given range.

PSS may be released manually at any moment, and moreover, if active power and voltage of generator do not reach set value or generator is disconnected with power grid, PSS may be released automatically.

6.2.2 Inspection before Put into Operation of Excitation Regulator

Maintenance work of excitation system has been completed and regulator is idle.

Control and power source cabinets have been got ready and cabinet doors are locked well.

Generator outputs zero load and excitation system is free of grounding and short circuit.

Field suppression switch and regulator power source is normal.

No alarm and failure information is generated.

Excitation system is switched to remote control mode.

Excitation system is switched to automatic mode.

Generator reaches rated speed.

6.2.3 Operation of Excitation Regulator

In-service Inspection

When excitation regulator works normally, no alarm signal should be made.

Standby channel is free of failure and it is allowable change-over state between main channel and standby channel.

Excitation regulator does not enter restricted state.

Excitation current, generator voltage and reactive power are stable.

Change-over of in-service channel

Two channels are identical and channel 1 or channel 2 may be selected as operating channel freely. Standby channel automatically tracks the operation of operating channel. If standby channel is free of failure, it may manually switch to standby channel for operation.

If a fault is detected in operating channel, automatically switch to the second channel urgently. And then, do not switch to fault channel until the fault is removed.

If both channels break down, urgently switch to manual operating mode. And then, do not switch to automatic mode until the faults are removed.

Put into Operation/Exit of Power System Stabilize

Power system stabilizer (PSS) can suppress the low frequency oscillation caused by generator or system fluctuation.

When active power of generator reaches set value, PSS is put into operation and generator voltage is limited within given range.



2×300 MW


PSS may be released manually at any moment, and moreover, if active power and voltage of generator do not reach set value or generator is disconnected with power grid, PSS may be released automatically.

6.3 Operation Instruction of Excitation Regulator Control Panel

6.3.1 Analog Value Display

Digital display

Press the key, and 8 analog signals with channel number, signal name, value and unit will

appear, and moreover, yellow LED is on. More analog signals may be displayed by means of scroll key.

Rectangular bar display

Press he key, and 4 analog signals with channel number, signal name, value and unit as well as combined rectangular display bar will appear, and moreover, yellow LED is on. More analog signals may be displayed by means of scroll key.

Predefined Analog Values

Channel Number Values Unit

Value 1 Generator voltage kV

Value 2 Generator current kA

Value 3 Active power MW

Value 4 Reactive power Mvar

Value 5 Excitation current A-dc

Value 6 Automatic channel set point kV

Value 7 Manual channel set point A-dc

Value 8 Generator voltage value ％

6.3.2 Fault Display and Reset

Fault information includes alarm, protection switching and excitation tripping.

Alarm

Press the key, and if faults exist, the red LED will be on and total 8 fault information may appear. The first fault always appears in the first line and the subsequent faults appear successively in the following lines with fault number. More subsequent faults may be displayed by means of scroll key.

Reset

Most of alarms are stored in control panel and specified alarm is also stored in microprocessor.



2×300 MW


When excitation system signal is reset, first of all, press “reset” on control panel, if the reset fails, select the reset on regulator panel.

Method of resetting on regulator panel: if current communication channel is channel 1,

switch to LOCAL mode and press RESET key to reset, and then switch to remote control mode.

If the signal is not reset, switch communication channel to channel 2. Switching method: press COM/SEL key and press up and down keys to select channel 2; press ACT, and make channel 2 establish communication connection, then switch to LOCAL mode and press RESET key to reset and switch to remote control mode.

6.3.3 Command Key

Local control panel is equipped with keyboard. These keys are allowed to control excitation system in a local way.

Command Local Feedback Indication

Field suppression switch on

FCB ON

√ *

√

Field suppression switch off

FCB OFF

√ *

√

Excitation on EXC ON √ * √

Excitation off EXC OFF √ * √

Channel 1 on CH Ⅰ √ * √

Channel 2 on CH Ⅱ √ * √

Automatic mode AUTO √ * √

Manual mode MANUAL √ * √

Operating regulator set point RAISE √ * Maximum position

Operating regulator set point LOWER √ Minimum position

Reactive power regulator on

PF/Wvar ON

√ *

√

Reactive power regulator off

PF/Wvar OFF

√ *

√

Local control LOCAL √ * √

Remote control REMOTE √ *

Indicator lamp test LAMP TEST √

Enable command RELEASE √



2×300 MW


The items with * show that it will not be valid until both RELAESE enable key and local control key are pressed at the same time.

6.4 Excitation System Fault and Alarm Information

6.4.1 Fault and Alarm Information

In case the following faults happen, the operator should record in detail the fault time system

and generating unit operating state and parameter and inspect and record fault information of excitation system, and moreover, notify relaying protection personnel to make relevant inspection.

Information Text Serial

Number

Information Text Serial

Number

Analog output AI fault 123 Excitation overvoltage 35

Analog input/output brownout fault 149 Fieldbus overtime 60

ARCnet node fault 195 Fieldbus overtime 122

Auxiliary AC power source fault 141 Read initialized data 138

Auxiliary DC power source fault 144 Read initialized dataS2 130

Auxiliary system exit 142 Instantaneous excitation overcurrent 2

Standby unallowed 134 LCP node fault 147

Read backup fault 18 Rectifier power source loss 23

R-phase branch fault 184 Loss of excitation of channel 14

R+ phase branch fault 181 Excitation loss and tripping 5

S-phase branch fault 186 Out of step 140

S+ phase branch fault 183 Generator voltage transformer fault 120

T-phase branch fault 182 MUB fault/power source fault 54

T+ phase branch fault 185 Not configured！ 13

Channel ARCnet fault 55 Out of synchronization! 31

Channel change-over fault 107 Overcurrent 1 inverse time limit 106

Rectifier interface fault 193 Overcurrent 2 inverse time limit 3

Control panel power source fault 1 Overtemperature trip 188

Common standby fault 111 Overtemperature alarm 187

Composite trip 27 Disconnect panel wiring 128

Rectifier block 196 Not set the second parameter setting 132



2×300 MW


Rectifier grade 1 fault 197 Standby RAM fault 108

Rectifier grade 2 fault 198 Rotor grounding fault 52

Rectifier 1．．．8 161-168 Rotor grounding fault 152

Rectifier fault 43 Rotor overtemperature trip 7

Cooler fan alarm 189 Rotor overtemperature alarm 104

Cooling fan trip 190 Surge absorbing device fault 192

Crossover assembly fault 135 Standby alarm 119

Crossover assembly fault 50 Standby trip 137

Current sharing fault 179 Starting external block 146

Current sensor fault 191 Standby ARCnet fault 113

Digital input /output drive fault: X1 32 System restart 110

Digital input /output drive fault:X1 36 Temperature 1 sensor fault 178

Digital input /output node fault:X1 148 Test power source 145

Expansion gate controller fault 153 silicon controlled fuse fault 180

Excitation current transformer fault 159 Transformer overtemperature trip 6

Excitation failure 124 Transformer overtemperature alarm 103

Excitation fault 34 Expansion gate controller trip 53

Excitation internal SC 40 Excitation output SC 41

Excitation overvoltage 118 Excitation channel fault 47

Frequency diagnosis failure 121 Field suppression switch external fault 143

V/Hz fault 46 Field suppression switch fault 127

Excitation starting power source fault

28 Backup write-in alarm

136

7 Transformer operation (220 kV 500 kV 400V)

7.1 Operation Mode

7.1.1 Rated Operation Mode

7.1.1.1 The transformer should operate according to rated nameplate parameters specified by

manufacturer. The transformer may operate according to rated capacity all the year around under rated conditions of use.

7.1.1.2 Allowable temperature of transformer in operation should be monitored according to



2×300 MW


upper-layer oil temperature. When cooling medium temperature drops, the upper-layer oil temperature of transformer should also drop. Maximum upper-layer oil temperature

should not exceed 95. In order to prevent transformer oil deterioration acceleration, the

upper-layer oil temperature should not exceed 85 frequently.

The middle and upper-layer oil temperature and temperature rise of oil immersed transformer in operation with different cooling mode should not exceed the specified value shown as following table:

Cooling Mode

Upper-layer Oil Temperature Rise

Maximum Upper-layer Oil

Temperature

General Upper-layer

Oil Temperature

Oil immersed self-cooling and air cooling

55

95

85

Forced oil circulating air cooling

45

85

75

7.1.1.3 The temperature rise of high and low voltage winding of dry-type transformer (F-class

insulation) should not exceed 100. In operation process, a stress should be laid on

monitoring signal thermometer, because the signal thermometer is protection system of dry-type transformer.

Relevant settings of main machine building dry-type signal thermometer are shown as following table:

Name Factory Settings（） Adjustable Range（）

Fan stop temperature T1 80 60-100

Fan starting temperature T2

100

80-120

Overtemperature alarm temperature T3

130

110-150

Overtemperature trip temperature T4

150

130-170

Note: setting principle is T1＜T2＜T3＜T4.

7.1.1.4 The applied primary voltage of transformer may be higher than rated value, but usually

should not be greater than 105％ of rated voltage of relevant tap. No matter where the

transformer tap is, if the applied primary voltage does not exceed 5% of relevant rated value, secondary side of transformer may be loaded with rated current.

7.1.1.5 The rated capacity of no-load regulating transformer in each tap position should comply

with the manufacturer’ requirements, but within 5％ of rated voltage, if the tap position is

changed, the rated capacity is unchanged. The rated capacity of on-load regulating transformer in each tap position should comply with the manufacturer’ requirements.



2×300 MW


7.1.2 Allowable Overload Operation Mode

7.1.2.1 The transformer may operate in the case of normal overload and emergency overload. Normal overload may be used frequently and its allowable value may be determined according to transformer load curve, cooling medium temperature and transformer-carried load before overloading, etc. Emergency overload is only allowed to be used in an emergency. When the transformer has major defects (e.g. cooling system is off normal; oil leaks severely; chromatographic analysis is abnormal, etc.), overload operation is not allowed.

7.1.2.2 When the transformer operates in the case of overload, all cooling devices should be put into operation, and moreover, strengthen monitoring and inspection and keep records. It should be strictly controlled that upper-layer oil temperature can not exceed allowable value.

z Normal overload and emergency overload operation of dry-type transformer should comply with the manufacturer’s requirements and its emergency overload capacity is shown as following table:

Overcurrent times 1.2 1.3 1.45 1.6 1.75 2.0

Allowable operating

time （min）

60

45

24

5

3

1

Normal overload and emergency overload capacity of oil immersed transformer should comply with the manufacturer’s requirements. In case no manufacturer’s requirements are available, the allowable time of emergency overload of oil immersed transformer may be referred to the following table according to different cooling mode and ambient temperature:

Allowable Operating Time of Oil Immersed Self-cooling Transformer in the Case of Emergency Overload (h: min)

Ambient Temperature（） Overload Times 0 10 20 30 40

1.1 24：00 24：00 24：00 19：00 7：00

1.2 24：00 24：00 13：00 5：50 2：45

1.3 23：00 10：00 5：30 3：00 1：30

1.4 8：30 5：10 3：10 1：45 0：55

1.5 4：45 3：10 2：00 1：10 0：35

1.6 3：00 2：05 1：20 0：45 0：18

1.7 2：05 1：25 0：55 0：25 0：09

1.8 1：30 1：00 0：30 0：13 0：06

1.9 1：00 0：35 0：18 0：09 0：05



2×300 MW



2.0 0：40 0：22 0：11 0：06

Allowable Operating Time of Forced Oil Circulating Cooling Transformer in the Case of Emergency Overload (h: min)


1.1 24：00 24：00 24：00 14：30 5：10

1.2 24：00 21：00 8：00 3：30 1：35

1.3 11：00 5：10 2：45 1：30 0：45

1.4 3：40 2：10 1：20 0：45 0：15

1.5 1：50 1：10 0：40 1：16 0：07

1.6 1：00 0：35 0：16 0：08 0：05

1.7 0：30 0：15 0：09 0：05

7.1.3 Operation Mode of Cooling System

7.1.3.1 Before put into operation and in operating process of transformer, the cooling devices

must be put into operation reliably

7.1.3.2 The forced oil circulating air cooling device of main transformer has double power sources. In normal condition. Double power sources should ensure reliable power supply, and moreover, interlock and are standby mutually according to selected operation mode. The control loop of cooling device should comply with the following requirements:

1) Switch the power source change-over switch to selected operating position, e.g. “loop I standby, loop II operating” or “loop I operating, loop II standby”.

2) During normal operation, switch the 1K switch of cooler automatic put-in control loop to “operation” position and switch the cooler signal loop switch 2K to “operation” position.

3) Each group of cooler power source automatic switch 1ZK-4ZK should be closed and the put-in position of selector switch 1KK-4KK of cooler operation mode should be determined according to the requirement of operation mode. The selector switch has four positions in all:

4) Operation－the cooler is put into operation.

5) Auxiliary－the cooler is put into operation automatically when transformer load rises

to 75% of rated value or upper-layer oil temperature reaches 55. When the load

drops to less than 75% of rated value or upper-layer oil temperature is below 55,

the cooler stops operating automatically.

6) Standby — when the operating cooler or automatic put-in auxiliary cooler breaks down and trips during operation, standby cooler is put into operation.


2×300 MW


7) Stop—the cooler stops operating.

7.1.3.3 Operation Mode of Main Transformer Cooler

1) There are total four groups of main transformer coolers. When three groups are put into operation, the transformer operation with rated load can be met.

2) Both operating and auxiliary coolers should be distributed uniformly and alternately to be beneficial to even cooling of transformer.

3) During normal operation, two groups of coolers are put into operation; one group is auxiliary and the other group is standby.

4) When ambient temperature varies greatly, the operation mode of cooler may be adjusted according to upper-layer oil temperature of transformer.

5) When ambient temperature is relatively high in summer, three groups of coolers may be put into operation according to upper-layer oil temperature of transformer and one group may be put into standby;

6) When ambient temperature is relatively low in winter, one group of operating cooler may be changed to standby according to upper-layer oil temperature of transformer, i.e. two groups are in operation and two groups are standby (but the upper-layer oil

temperature of transformer should not be lower than 75).

7.1.3.4 When the cooling device of main transformer breaks down and all coolers are released (oil pump fans are all stopped):

1) When the upper-layer oil temperature of main transformer reaches 75 and the

duration reach 20min, start up outlet trip;

2) The transformer is allowed to operate for 60min under rated load, when the time reaches 60min, start up outlet trip;

7.1.3.5 Insulation Monitoring

1) Before the transformer is put into operation and after repair or service interruption, the insulation resistance at each side of transformer should be measured. During measurement, the voltage transformer connected to transformer must be disconnected.

2) When the insulation resistance of transformer coil is measured, 2500V megameter should be used for the coil with voltage of above 10kV and 500V megameter should be used for the coil with voltage of below 500V.

3) Before measurement, the measured coil should be grounded to discharge electricity; during measurement, R15″ and R60″ values should be measured and the absorptance R60″/R15″ is calculated according to measured result. After completion of measurement, the electricity should be discharged to the ground.

4) The insulation resistance and absorptance of dry-type transformer are usually not specified.



2×300 MW


5) The insulation resistance value of oil immersed transformer should comply with the following requirements:

The absorptance of above 20kV transformer and below 20kV transformer at 10-30

should not be lower than 1.3 and 1.2 respectively.

The insulation resistance should not be less than the specified value shown as following table.

Allowable Insulation Resistance Value of Oil Immersed Transformer (MΩ)

Temperature

High Voltage

Winding Voltage

10

20

30

40

50

60

70

80

3—10kV 450 300 200 130 90 60 40 25

20—35kV 600 400 270 180 120 80 50 35

60—500kV 1200 800 540 360 240 160 100 70

Note: both medium and low voltage insulation resistance standard of identical transformer is the same as high voltage winding.

When the measured insulation resistance value is unacceptable, report to shift-chief operator in time and contact with repairer to find out and eliminate fault source. After fault removal, restore transformer standby mode and put transformer into operation according to the dispatcher’s order.

7.2 Operation and Maintenance

7.2.1 Preparation before Transformer Put into Operation

Before the transformer is put into operation, the work sheet of relevant electrical connection

loop of transformer should be revoked, and moreover, disconnect ground wire and short circuit wire; make sure the transformer is intact and the loop is complete and meets operating condition, and besides do well the work as follows:

a) Measure that transformer insulation resistance should be acceptable (for the repaired equipment, check electrical repair hand-over record book);

b) Inspect that transformer tap is in correct position; both oil color and oil level of oil conservator are normal; each part of transformer body is free of oil impregnate and leakage;

c) Gas relay valve should be opened and filled with oil; the interior should be free of gas and the covering hood should be intact;

d) Inspect that cooler valve should be opened and each cooling device should be in good condition (after repair, the valve should be opened by repairer); cooler power source



2×300 MW


interlocking and motor trial operation should be normal;

e) Inspect that breather silica gel color should be normal; pressure relief valve should be intact and in reset state; permanent ground wire in each part of transformer should be firm and reliable.

f) Inspect that transformer thermometer wiring is intact and setting temperature meets the requirement.

g) Inspect that secondary loop equipment (control, pointer and protection device, etc.) should be intact; protection devices of transformer during normal operation should be put into operation correctly.

7.2.2 Operation of Transformer

a) The power interruption and transmission operation of transformer not only should

comply with relevant electrical operation and accident treatment regulations but also should comply with the following requirements:

1) The transformer should be charged up from the power source side provided with protection device. In the case of power interruption, the power source-side switch provided with protection device should be disconnected finally.

2) Use fuse to put in or release transformer and strictly prohibit using knife-switch to put in or release transformer.

3) Before the forced oil circulating air cooling transformer is put into operation, start up cooling device first, after operation stop, the cooling device may be put out of operation.

b) After coil replacement and overhaul, main transformer and high-voltage house service transformer must not be put into operation until raising voltage from zero by generator and checking that phase sequence is correct. Starting-standby transformer and low-voltage house service transformer after repair must not be put into operation until checking that phase sequence and charging are normal.

c) The tap position of no-load regulating transformer should be adjusted in the case of taking safety measures after transformer power interruption. Besides, the uniformity of three-phase DC resistance should be measured and the tap change record should be kept.

d) The voltage tap of on-load regulating switch of on-load regulating transformer may be switched during normal operation of transformer. During switching operation, pay attention to the following:

1) Give attention to tapping switch position indication, transformer current and voltage of any other side;

2) In principle, for on-load regulating switch, only operate a gear once and then with an internal of time, adjust the next gear;

3) When the transformer is overloaded, do not operate on-load tapping switch



2×300 MW


frequently;

4) The on-load regulating tapping switch is electrically operated in normal condition. When electric operation is out of order, it may be manually operated, but necessary safety measures should be taken.

7.2.3 When the on-load regulating tapping switch is manually operated, cranking 33 circles by

hand every time is a tap; clockwise is voltage step-up direction and anticlockwise is voltage step-down direction. Operating procedure: take off connecting sleeve cover and switch off the power source of electrically operated mechanism; install the built-in handle crank to worm shaft for operation, after completion of switching, inspect that handle crank is just vertical upward and numerical value display is just right in the middle of indicating piece notch, and finally make connecting sleeve return to original state.

7.2.4 The on-load regulating switch of transformer should be maintained and inspected

according to the following requirements:

a) The defilement degree of oil in change-over switch insulating cylinder should be inspected regularly. Usually, after operating about 1000 times under rated current, the oil sample should be assayed once and withstand voltage value of oil should not be less than 30kV. When withstand voltage value of oil is less than 30kV, it must be replaced with new oil. Even if withstand voltage value of oil exceeds 30kV, it must be also replaced with new oil once a year.

b) The electrically operated mechanism should keep intact at all times.

c) The gas protection and explosion-proof equipment of tapping switch should be intact, after they acts, and find out the reason.

7.2.5 The gas protection of transformer in operation or in hot reserve must be put in “trip”

position and the gas protection of transformer in cold reserve may be put in “signal” position to facilitate monitoring oil level of transformer.

7.2.6 When the oil level indicated on oil level gauge rises abnormally, the reason for oil level

rise should be found out. Before gas protection trip strap is released, the opening of various gas discharge or oil drain plugs is prohibited to clean up moisture absorber or to do any other work so as to prevent gas protection misoperation trip.

7.2.7 When the transformer operates in the following cases, heavy gas protection strap should

be changed to signal from trip, after completion of operation, the gas protection should return to “trip” position.

a) In the case of oil filling, oil filtering or replacing oil submerged pump;

b) In the case of cleaning eyelets of breather or opening valves in any other position to discharge gas, drain oil or feed oil (except oil sampling and gas relay degassing);

c) In the case of operating on gas protection secondary loop.

d) In the above cases, transformer gas protection putting in trip or changing to signal must



2×300 MW


be approved by shift-chief operator.

7.2.8 Operating Maintenance of Forced Oil Air Cooling Device of Transformer

a) Before the forced oil circulating air cooling device is put into operation or during

operation:

1) Inspect that the valves of cooler oil inlet and outlet tube connector should be opened; the radiator air intake is unobstructed and the inlet is clean.

2) Start up and inspect cooling device group by group:

Rotation direction of oil submerged pump is correct and it is free of abnormal noise and

obvious vibration during operation;

Rotation direction of fan motor is correct and vanes are free of friction;

The closing of each switch in cooler control box is in good condition, free of vibration and abnormal sound;

The cooler is free of oil impregnate and leakage.

7.2.9 Inspection of Transformer

a) During transformer operation, the attendant should monitor transformer operating

condition according to pointer indication and should transcribe relevant transformer parameters once a hour in normal case. When the transformer operates in the case of overload or any other abnormal condition, strengthen monitoring the load, upper-layer oil temperature and coil temperature of transformer and reduce transcribing time interval.

b) Inspection of Oil Immersed Transformer in Operation

1) Both oil level and oil color of transformer oil conservator and bushing should be normal; each part of transformer should be free of oil impregnate and leakage;

2) The bushing exterior should be clean, free of breakage crack, discharge track and any other abnormal phenomenon;

3) The sound in each part of transformer should be normal;

4) The temperature in each part of transformer is normal; the opening of oil system valve is correct; fan and oil pump are in normal operation;

5) Each joint of transformer primary loop has sound contact, free of heating;

6) Pressure relief valve or explosion proof pipe is intact; pressure relief valve is in reset state;

7) Gas relay should be free of gas and should be filled with oil; the valve of gas relay access to oil conservator should be opened;

8) Doors and windows of transformer cubicle should be complete; no water leakage and flowage exist in the cubicle, with sound lighting and ventilation;



2×300 MW


9) Inspect that neutral point grounding resistance of transformer is free of overheating;

10) Tapping position of on-load tapping switch and power source indication should be normal;

11) Inspection of transformer neutral point ground resistor:

A. It should be free of impurities in resistor; if there is much of dust, the dust should be cleaned off as soon as possible;

B. Inspect whether the connection between resistor elements are sound;

C. Inspect whether operating condition of insulation supporter is sound;

D. Before the resistor still keep operating after the system breaks down, necessary inspection of resistor should be implemented carefully to remove hidden trouble.

7.2.10 Inspection of dry type transformer in operation:

a) The temperature in each part of transformer should be normal and the temperature

measuring device should be clean and intact.

b) The transformer is free of abnormal sound, burnt odor and abnormal vibration.

c) No water accumulation and leakage exist around the transformer; the casing is clean and free of impurities.

d) Transformer cabinet door should be closed well.

e) Transformer ventilation system is sound and the fan is in good condition.

7.2.11 Special inspection of transformer:

a) After gas and differential protections act, perform inspection immediately; increase

inspection times in the case of abnormal operation.

b) In rainy, snowy or foggy day, inspect whether transformer joints have steaming and melting or whether flashover discharge is serious; the bushing should be free of breakage and burnt track and the insulator has no the icicle causing flashover.

c) In strong wind weather, inspect that upper outgoing line of transformer should be free of severe oscillation and looseness; the top cover and surrounding are free of impurities.

d) When air temperature changes suddenly, perform special inspection of transformer oil level and operating condition of cooling device and inspect whether overheating or icing exists.

e) In the case of overloading, monitor the change of load, oil temperature and oil level; joint contact should be sound and free of overheating; the cooling system should be in normal operation.

f) After short circuit fault, inspect whether relevant joints are deformed and inject oil; inspect whether transformer neutral point or discharging gap has burnt track.



2×300 MW


7.3 Abnormal Operation and Trouble Disposal of Transformer

7.3.1 Disposal of Abnormal Operation of Transformer

a) During transformer operation, in case any abnormal condition is found (such as oil

leakage, inadequate oil conservator level, overheating and abnormal sound), make an attempt to eliminate the abnormal condition as soon as possible and report to higher-level leader. If the abnormal condition can not be eliminated until the transformer is stopped, and has the probability of threatening equipment and system safety, the transformer should be stopped immediately. If standby transformer is available, it should be put into operation as soon as possible.

b) In any case as follows, first of all, contact with repairer and then stop the transformer:

1) The crack, oil seepage, discharge and trace happen.

2) The falling object above transformer endangers safety and can not be removed until the power source is interrupted.

3) The oil leaks severely.

4) The load, ambient environmental temperature and cooling condition have no obvious change, but the temperature of transformer rises abnormally.

5) The transformer oil color changes suddenly; or becomes dark and turbid and the viscosity increases, or the oil is unacceptable through periodical assay.

6) The sound is abnormal, but no discharging sound is made.

7) Each lead terminal is loose, generates heat and turns color.

8) On-load regulating device is out of order; tap adjustment is out of control and the tap can not be manually adjusted to be normal.

9) All main protections of transformer are out of operation.

10) In the above cases, if conditions permit, put standby transformer into operation; if no standby transformer is available, stop transformer operation as soon as possible.

c) Stop the transformer operation immediately in any case as follows:

1) Transformer internal sound is relatively large and uneven, with crackling sound;

2) Under normal load and cooling conditions, transformer temperature is abnormal and is on the rise;

3) Oil conservator or pressure relief valve injects oil;

4) Oil quality change is exaggerated and the oil has been carbonized;

5) The bushing has serious breakage and discharging;

6) The oil leaks heavily and the oil level drops to be lower than indication limit of oil level gauge;

7) The transformer is on fire.



2×300 MW


d) When the oil temperature rise of transformer in operation exceeds allowable value, find out the reason and take measures to reduce oil temperature, and moreover, do well the work as follows:

1) Inspect the load of transformer and temperature of cooling medium and check the due oil temperature value under the load and cooling medium temperature;

2) Check the indicated temperature value of remote and local thermometers of transformer;

3) Inspect whether transformer ventilation and cooling devices are normal.

If the temperature increase is caused by abnormality of cooling system, try to put cooling system into normal operation. If the abnormality of cooling system can not be eliminated during operation, adjust transformer load to relevant capacity according to the specifications of this manual, till the transformer stops to eliminate the defect.

If no problem is found through above inspection, transformer oil temperature is over 10

higher than in normal condition under the same load and cooling temperature, or transformer load does not change, but oil temperature is on the rise, the transformer has had internal fault, so the transformer operation must be stopped immediately.

e) Abnormal oil level of transformer

1) When the oil level of transformer is greatly lower than the oil level corresponding to oil temperature of the time, the oil should be filled immediately according to relevant regulations of this manual.

When the oil level drops quickly due to much of oil leakage, prohibit changing gas protection to only acting on signal and take the measures for stopping oil leakage quickly, and moreover, report to higher-level leader and fill oil immediately. If the oil leakage can not be eliminated and the oil level has been down to lower limit, the transformer should be out of operation.

If transformer oil level drops due to relatively low temperature, in order to avoid dropping to below oil level gauge, the operation mode of cooling device should be adjusted according to the load of the time so as to keep transformer oil temperature and oil level within specified range.

2) When transformer oil level is on the rise because of temperature increase, if the oil level at maximum oil temperature is higher than oil level indicating gauge, the oil should be drained to lower oil level to proper height and avoid oil spill.

When transformer oil level rises abnormally arising from breath sealing system blocking or the oil spills out of breather, immediately notify the repairer and report to higher-level leader, and moreover, take effective measures to eliminate the fault. When the above-mentioned oil level is abnormal and the indication of oil level gauge is false oil level, thus any oil drain is forbidden before transformer breather returns to normal.

3) In case oil level is abnormal, monitor closely the oil level gauge of transformer and the change of oil temperature and report to relevant leader in time.



2×300 MW


7.3.2 Trouble Disposal

7.3.2.1 When transformer gas protection acts and makes a signal, inspect the transformer immediately and find out the reason for gas signaling; inspect whether it is caused by air invasion in transformer, or oil level drop, or secondary loop fault.

When the transformer has no external fault signs, the gas sample in gas relay should be taken for test analysis. If the gas is combustible and the chromatographic analysis is abnormal, it shows that the transformer has internal fault and must be stopped for repair.

During the above disposal, attention should be paid to time interval of gas signaling, if the interval time is shortened successively, it shows that the transformer may trip, and here the gas protection is prohibited to be changed to signal; if standby transformer is available, put it into operation and report to leader immediately to stop the transformer operation.

7.3.2.2 When the gas protection acts and trips, fully inspect transformer and take gas sample for testing. The transformer should not be put into operation until the transformer is inspected fully and the test is acceptable.

7.3.2.3 When the gas protection acts and makes a signal, but the switch does not trip, it usually arises from:

Air enters into transformer due to oil filtering, oil filling or untight cooling system;

Oil level drops slowly due to temperature reduction or oil leakage;

Negative pressure is formed due to breathing system clogging; a little gas is generated due to transformer fault;

It is caused by crossing short circuit fault.

7.3.2.4 After the pressure relief valve of transformer in operation acts, the mechanical-electrical signal of relief valve should be reset manually.

7.3.2.5 Automatic Trip

When the transformer trips, if available, put standby transformer into operation immediately and then inspect protection to find out which protection acts; the tripping reason of transformer may be determined according to operating condition of protection and external conditions (such as external short circuit and transformer overload, etc.) when the transformer trips;

When main protection (such as gas or differential protection) of transformer acts, external inspection of the equipment within protection range must be performed to find out internal fault signs and the insulation resistance of coil should be measured to find out the tripping reason of transformer. If the transformer has internal fault signs, internal inspection should be performed.

If it is ascertained that transformer trip is not caused by internal fault but external fault resulting in overcurrent protection act or secondary loop fault. The external inspection of transformer may not be performed to immediately raise voltage from zero or impact closing and put transformer into operation.

7.3.2.6 Disposal of Transformer Fire



2×300 MW


Immediately cut off power supply and extinguish the fire by use of dry powder, carbon dioxide and 1211 fire extinguishers, and moreover, notify fire department. The liquid is strictly prohibited to be used to extinguish the fire in case the power supply is not cut off.

Stop transformer cooling device.

If transformer top cover catches fire, open emergency oil drain valve to drain oil and make oil level lower than the position on fire, and moreover, the flame can not be gotten out. If it is caused by internal fault of transformer, the oil can not be drained to prevent transformer explosion.



2×300 MW


8 Auxiliaries Electricity System

8.1 Operation Mode of 6kV System

8.1.1 ＃1 and 2 turbine-boiler is a unit system. Each set of turbine-boiler is equipped with A

and B-section 6kV operating busbar and is supplied with electricity respectively by both split windings at low voltage side of high-voltage house service operating transformer. Two

sets of auxiliary equipment of ＃1 and 2 turbine-boiler are tapped to A and B-section

busbar. During normal operation, 6kV operating busbar is supplied with electricity by high-voltage house service operating transformer and standby power source is in hot reserve.

8.1.2 During normal operation, 01# starting-standby transformer is in charging standby state

and used as standby power source of ＃1 and 2 units. Standby power switch of 6kV

busbar is in hot reserve in normal condition.

8.1.3 Before the generator starts, the auxiliary power of ＃1 and 2 turbines are supplied by

high-voltage house service operating transformer of the generator.

8.1.4 When 6kV auxiliary operating power source fails to supply power to the section, the

power is supplied by relevant standby power source.

8.1.5 The common 0A-section operating power switch in ＃1 turbine 6kV1A section, common

0A-section standby power switch in ＃ 2 turbine 6kV2A section, common 0B-section

standby power switch in ＃1 turbine 6kV1B section and common 0B-section operating

power switch in ＃2 turbine 6kV2B section are all in operating state; both operating source

incoming line switch in common 6kV0A section and operating source incoming line switch in common 6kV0B section are in operating state; both standby source incoming line switch in common 6kV0A section and standby source incoming line switch in common 6kV0B section are in hot reserve; common 6kV0A section and common 6kV0B section PT is put into operation.

8.1.6 The desulphurization 1-section operating power switch in ＃1 turbine desulphurization

6kV1A section, desulphurization 1-section standby power switch in ＃ 1 turbine

desulphurization 6kV1B section, desulphurization 2-section operating power switch in ＃2

turbine desulphurization 6kV2A section and desulphurization 2-section standby power

switch in ＃2 turbine desulphurization 6kV2B section are all in operating state; both

operating source incoming line switch in desulphurization 6kV1 section and operating source incoming line switch in desulphurization 6kV2 section are in operating state; both standby source incoming line switch in desulphurization 6kV1section and standby source incoming line switch in desulphurization 6kV2 section are in hot reserve; desulphurization 6kV1 section and desulphurization 6kV2 section PT is put into operation.

8.2 Operation Mode of 400V System



2×300 MW


8.2.1 The auxiliary power of the unit plant is supplied by 6kV operating busbar. 6kV operating busbar of each unit is connected with two steam turbine transformers, two boiler transformers, one lighting transformer and two electric dust collecting transformers. 6kV common busbar of two units is totally connected with two ash handling transformers, two common transformers, two coal handling transformers, two water supply transformers, two circulating water transformers, one ash yard transformer, two chemical water transformers and two administrative zone transformers.

8.2.2 The power source of two steam turbine transformers is respectively connected to 6kV 1

（2）A and 1（2）B section. In normal condition, 400V PC busbar of each steam turbine

is supplied with power by respective steam turbine transformer; in normal condition, two steam turbine transformers are in operation and 400V busbar interconnection switch is in hot reserve. When a steam turbine changes to tripping or stops abnormally, 400V busbar interconnection switch may be put into operation manually to provide power source; two steam turbine transformers may be in parallel operation for short time when their 6kV power source sides are all in a power source system.

8.2.3 The power source of two boiler transformers is respectively connected to 6kV 1（2）A and

1（2）B section. In normal condition, 400V PC busbar of each boiler is supplied with

power by respective boiler transformer; in normal condition, two boiler transformers are in operation and 400V busbar interconnection switch is in hot reserve. When a boiler changes to tripping or stops abnormally, 400V busbar interconnection switch may be put into operation manually to provide power source; two boiler transformers may be in parallel operation for short time when their 6kV power source sides are all in a power source system.

8.2.4 The power source of two electric dust collecting transformers is respectively connected

to 6kV 1（2）A and 1（2）B section. In normal condition, two electric dust collecting

transformers are in operation and 400V busbar interconnection switch is in hot reserve. Two electric dust collecting transformers may be in parallel operation for short time when their 6kV power source sides are all in a power source system.

8.2.5 Each set of turbine-boiler is equipped with one lighting transformer and the power source

is connected to 6kV1（2）A section. In normal condition, each lighting transformer is in

operating state and 400V busbar interconnection switch is in cold reserve. When a lighting transformer changes to tripping or stops abnormally, 400V busbar interconnection switch may be put into operation manually to provide power source. Two lighting transformers may be in parallel operation for short time when their 6kV power source sides are all in a power source system; the parallel operation may be prohibited when their 6kV power source sides are not in a power source system, and here it should be operated by means of power turn-off.

8.2.6 Ash yard PCA section: the power source is supplied by ash yard transformer in 6kV common 0A section;

8.2.7 Common PC section: in normal condition, each common transformer is in operating state

and 400V busbar interconnection switch is in cold reserve. When a common transformer changes to tripping or stops abnormally, 400V busbar interconnection switch may be put



2×300 MW


into operation manually to provide power source. Two common transformers may be in parallel operation for short time when their 6kV power source sides are all in a power source system; the parallel operation may be prohibited when their 6kV power source sides are not in a power source system, and here it should be operated by means of power turn-off.

8.2.8 Ash handling PC section: in normal condition, each ash handling transformer is in operating state and 400V busbar interconnection switch is in cold reserve. When an ash handling transformer changes to tripping or stops abnormally, 400V busbar interconnection switch may be put into operation manually to provide power source. Two ash handling transformers may be in parallel operation for short time when their 6kV power source sides are all in a power source system; the parallel operation may be prohibited when their 6kV power source sides are not in a power source system, and here it should be operated by means of power turn-off.

8.2.9 Chemical water PC section: in normal condition, each chemical water transformer is in operating state and 400V busbar interconnection switch is in cold reserve. When a chemical water transformer changes to tripping or stops abnormally, 400V busbar interconnection switch may be put into operation manually to provide power source. Two chemical water transformers may be in parallel operation for short time when their 6kV power source sides are all in a power source system; the parallel operation may be prohibited when their 6kV power source sides are not in a power source system, and here it should be operated by means of power turn-off.

8.2.10 Coal handling PC section: in normal condition, each coal handling transformer is in operating state and 400V busbar interconnection switch is in cold reserve. When a coal handling transformer changes to tripping or stops abnormally, 400V busbar interconnection switch may be put into operation manually to provide power source. Two coal handling transformers may be in parallel operation for short time when their 6kV power source sides are all in a power source system; the parallel operation may be prohibited when their 6kV power source sides are not in a power source system, and here it should be operated by means of power turn-off.

8.2.11 Water supply PC section: in normal condition, each water supply transformer is in operating state and 400V busbar interconnection switch is in cold reserve. When a water supply transformer changes to tripping or stops abnormally, 400V busbar interconnection switch may be put into operation manually to provide power source. Two water supply transformers may be in parallel operation for short time when their 6kV power source sides are all in a power source system; the parallel operation may be prohibited when their 6kV power source sides are not in a power source system, and here it should be operated by means of power turn-off.

8.2.12 Circulating water PC section: in normal condition, each circulating water transformer is in operating state and 400V busbar interconnection switch is in cold reserve. When a circulating water transformer changes to tripping or stops abnormally, 400V busbar interconnection switch may be put into operation manually to provide power source. Two circulating water transformers may be in parallel operation for short time when their 6kV power source sides are all in a power source system; the parallel operation may be



2×300 MW


prohibited when their 6kV power source sides are not in a power source system, and here it should be operated by means of power turn-off.

8.2.13 Administrative zone management PC section: in normal condition, each administrative

zone management transformer is in operating state and 400V busbar interconnection switch is in cold reserve. When an administrative zone management transformer changes to tripping or stops abnormally, 400V busbar interconnection switch may be put into operation manually to provide power source. Two administrative zone management transformers may be in parallel operation for short time when their 6kV power source sides are all in a power source system; the parallel operation may be prohibited when their 6kV power source sides are not in a power source system, and here it should be operated by means of power turn-off.

8.2.14 The operating power source of 400V safety PC A and B sections are respectively connected to 400V boiler PC A and B sections by means of two sets of switches; a set of switch is available between #1 and 2 turbine 400V safety PC 0 section, to form interconnection loop, and in normal condition, interconnection switch is in cold reserve and diesel-engine generator unit is in hot reserve; the power source may be supplied respectively to safety PC A and B sections by means of 400V safety 0 section.

8.2.15 Normal power supply mode of 400V MCC power control box: all MCC workshop panels (XA) are supplied with power by unit plant auxiliary PC A section and all MCC workshop panels (XB) are supplied with power by unit plant auxiliary PC B section. 400V MCC power control box with double loop power supply operates within open loop in the middle, if no breaker point is available in the middle, one side is used to supply power and the other side is standby.

8.3 Electric Switching Operation

8.3.1 Requirements of switching operation:

a) The switching operation of 500kV and 220kV system and change of operation mode

should be implemented according to the dispatcher and shift-chief operator’s order. The operation of auxiliary power system and change of operation mode should be implemented according to the shift-chief operator’s order and the persons concerned should be notified; .

b) Before the operation order sheet is implemented, it should be checked on DCS or electric system diagram;

c) After the equipment is repaired, the person in charge of repair work must indicate clearly on equipment repair sheet whether the equipment can be put into operation or not, and sign on the sheet, and then the attendant can perform switching operation;

d) Before equipment energization operation, withdraw all work sheets; remove safety measures of repair equipment; restore fixed shade and railings and permanent warning board; fully inspect equipment and affiliated loop to ensure the loop has the conditions of put into operation;

e) All switching operations should strictly comply with relevant requirements of Working



2×300 MW


Regulation of Power Safety and electric switching operation management system;

f) Normal switching operation should not be performed as much as possible during shift handover (trouble disposal and other operations should be performed in time according to specific circumstances).

8.3.2 Principles of switching operation:

a) When the power switching operation is performed between 01# starting-standby

transformer and 1# (2#) high-voltage house service operating transformer, it is only allowed to adopt in-series switching (power interruption switching) mode;

b) During power source switching between 6kV busbar and 400V busbar, when both 6kV busbar and 400V busbar are in synchronous operation, short-time parallel operation is allowed but long-time parallel operation is not allowed for power source switching. And here the operating transformer used for two-section operation should not be overloaded.

c) For the special panel with power source from 400V one and the same busbar, it is allowed to switch power source from special panel side with parallel loop; for the special panel with power source from 400V different-section busbar, the parallel loop is forbidden from special panel. If the power source switching is needed, the turbine-boiler personnel should be notified to adopt instantaneous power interruption method.

d) The loop equipped with SF6, vacuum and air switches must be cut off by means of switch or switch on load current during switch opening and closing operation and the knife switch is forbidden to be used to switch on and off load current; power failure switching-off must be operated in regular sequence of switch, load-side knife-switch and busbar-side knife-switch and the switching-on should be operated to the contrary; Before switching off and switching on, it must be ascertained that the loop switch is in off position (except changeover busbar operation).

e) Actual opening and closing position of switch can not be judged only from the signal displayed on DCS and pointer indication and should be determined according to actual mechanism position of switch; generally, the hand trip with load is forbidden to make 6kV vacuum switch trip;

f) Loop system running in synchronization and running out of synchronization should be

operated by means of switch and the knife-switch is forbidden; for the switching operation, the consideration should be given to the probability of overloading of parallel loop circuit and transformer and whether the operation is reliable and the trouble disposal is convenient;

g) For the transformer and cable newly installed or the work that may change phase sequence and phase has been done, the phase must be checked before energization;

h) In the process of switch opening and closing operation, the indicator light, instrument and relevant signal should be observed carefully to verify the correctness of switch motion;

i) During switching operation, the use of relevant relaying protection and automatic device



2×300 MW


should comply with the requirements in the part of relaying protection and automatic device in this manual;

j) The switch with synchronous closing should be closed after synchronous function is put

into operation. When it is on voltage only at one side of switch, the synchronous block function should not be released until approved by shift-chief operator.

k) Power interruption and energization operation:

1) Before the knife-switch or vacuum switch is opened or closed to interrupt or energize power, it must be inspected that the switch should be in off state;

2) Strictly prohibit opening and closing the knife-switch on load; the installed electrical and mechanical (anti-misoperation) blocking devices should not be put out of operation at random;

3) When the power is interrupted, firstly, open the switch; secondly, open the load-side knife switch; then open the busbar-side knife switch; energization operation sequence is opposite to power interruption;

4) In operation process, when it is found that the knife switch is opened (closed) by mistake, it is not allowed to reclose (reopen) the knife switch that should not be closed (opened) until the safety measures are taken.

n) Looping operation:

1) System looping-in operation must meet the following conditions: the same phase, the same phase sequence, the same frequency and equal voltage;

2) During looping-in operation, for the switch with synchronization checking, the synchronization should be checked before looping in; for the switch without synchronization checking, it should be in ring network state through inspection before looping in;

3) Before looping-off and looping-in operation, voltage fluctuation should not exceed specified value; pay attention to power flow distribution and inspect whether some electric elements are overloaded, etc.

o) Impact closing operation:

4) Before the equipment such as transformer and busbar is installed and put into operation and after overhaul, the full voltage surge should be performed according to relevant regulations. When the conditions permit, it should be charged up by means of raising voltage from zero as much as possible;

5) After the equipment such as transformer and busbar trips out of service, the full voltage surge may be performed according to relevant regulations. When the conditions permit, it should be charged up by means of raising voltage from zero as much as possible;

6) During impact closing operation, the attention should be paid to the following: impact closing switch should have enough breaking capacity and the times of fault trip



2×300 MW


should be within specified range; protection device of impact closing switch should be complete and put into operation and automatic reclosing should be stopped, when necessary, the settings of protection device may be reduced before impact closing; the power source that has a little impact on stability should be selected as much as possible as impact closing power source, when necessary, the interconnection line power flow should be inspected and adjusted; When the transformer in neutral point grounding system is impacted, the neutral point should be grounded.

p) During raising voltage from zero, the attention should be paid to the following:

1) The equipment of which voltage is raised should have complete protection device;

2) When the generator voltage is stepped up, the manual step-up mode should be adopted and the forced excitation device should be stopped;

3) When the voltage of transformer of neutral point grounding system is stepped up, the neutral point must be grounded.

q) Operation allowable by means of knife switch:

1) Open and close the fault-free no-load busbar and the equipment capacitance current of connecting to busbar directly by means of knife switch;

2) Open and close the voltage transformer in fault-free condition;

3) Open and close the impedance-free parallel branch on the principle of equal potential;

4) Open and close the loop equalizing current not more than 70Ａin 10kV and below

system;

5) Open and close the transformer neutral point grounding knife switch when the system has no ground fault;

6) Open and close the no-load transformer with excitation current nor more than 2Ａ

and the no-load line with capacitance current not more than 5Ａ.

r) The double-circuit power source of each MCC, special switchboard and thermal controlled distribution box is not allowed in parallel operation. Only in switching process, short-time parallel operation is allowed when they are in one and the same power source system through inspection;

s) When switching the auxiliary power by means of short-time parallel operation, the following should be met:

1) The voltage difference between 6kV auxiliary power to be switched should not

exceed 10％;

2) During auxiliary power switching, pay attention to system parallel condition to prevent non-synchronous parallel.

3) Put-in and release of standby power source automatic put-in device of auxiliary



2×300 MW


power system: when standby power source is in hot reserve, automatic put-in switch should be in “put-in” position; before standby power source is closed manually or after closed automatically, or before is out of standby, automatic put-in switch should be in “release” position; when 6kV system standby power source is normal, the quick change-over device starting mode button should be switched to “unblock” state; when no standby power source is available, starting mode button should be switched to “block” state.

t) Power interruption and energization operation of 6kV busbar voltage transformer: when the power is interrupted, switch the auxiliary power quick change-over device button of the busbar of the voltage transformer to “block” state; open the low voltage protection DC switch of the busbar of the PT with power to be interrupted and open the low voltage AC switch of the PT with power to be interrupted; pull the PT plug-in car with power to be interrupted, to test or repair position. The operation sequence of energization is opposite to the power interruption.

u) Power interruption operation of 400V busbar voltage transformer: open the low voltage protection DC switch of the busbar; open the switch cabinet of PT; open the secondary switch of PT with power to be interrupted; take of primary-side cutout (according to work demand). The operation sequence of energization is opposite to the power interruption.

v) Open the circuit breaker to make generator running out of synchronization with system or two systems, firstly, inspect load distribution condition and adjust as much as possible to make active and reactive load of circuit breaker running out of synchronization, equal to or near to 0;

w) Open the circuit breaker to interrupt the power of any loop line of double loops, firstly, inspect that the other loop line is not overloaded;

x) Close the circuit breaker to make generator running in synchronization with system or one system running in synchronization with the other system, firstly, put synchronizing device into operation and make parallel after being synchronous through checking or inspect that the system to be switch on (such as double-source line) is no voltage.

y) Sequence of opening and closing of isolators at both sides of circuit breaker: during power interruption, firstly, open the circuit breaker; secondly, open the load-side isolator; finally, open the power source-side isolator. During energization, the sequence is opposite to that of power interruption;

z) Before opening and closing the isolator in unit loop, inspect that circuit breaker is in tripping position; after the isolator is opened, inspect that it has tripped off without doubt; after the isolator is closed, inspect that the closing is in good condition;

aa) The isolator should be closed quickly and decidedly: when the isolator is closed by mistake (e.g. the isolator is closed in the loop with short circuit fault or short circuit line, or non-synchronous system is connected), in any case (no matter one phase, two phases or three phases are closed), it is not allowed to reopen the closed isolator that should not be reopened until the loop is disconnected by circuit breaker or is cross-connected;



2×300 MW


bb) When the isolator is opened manually, the operation should be slow and cautious and particularly when the isolator contact is disconnected just now, and here if violent electric arc arises from wrong opening of isolator, perform reverse operation immediately to close the isolator and stop operation to find out the reason; if the electric arc is caused by switching off the no-load current of no-load line, no-load busbar and small-capacity no-load transformer or the capacitance current of small-capacity no-load capacitor, the isolator should be opened quickly;

cc) When 500kV and 220kV isolator power source is interrupted normally, the isolator is put in during operation and should be opened immediately after operation;

dd) Operation sequence of control power switch: during power interruption, the control power switch should be opened after both circuit breaker and isolator are opened; during energization, the control power switch should be closed before both isolator and circuit breaker are closed;

ee) For the circuit only with cutout and isolator, , firstly, put in cutout; secondly, close the isolator; during power interruption, the operation sequence is opposite to that during energization;

ff) Put-in and release of relaying protection strap: before the equipment (or line) is put in standby or the circuit breaker is closed for energization, inspect that relevant protection strap has been put in; after the equipment (or line) is put out of standby, whether to put protection strap out of operation should be implemented according to relevant regulations of relaying protection and automatic device in this manual or relevant notice, and if no specified regulations are available, the protection strap is usually not put out of operation;

gg) If the voltage transformer must be stopped due to fault or the secondary side low voltage fuse must be taken off (or secondary subswitch must be opened) during operation, it must be approved by shift-chief operator (unless the operation must exit immediately for fault disposal). When the power interruption of the voltage transformer may cause loss of voltage of relevant secondary voltage loop, first of all, the low voltage protection and automatic device (such as low voltage, low voltage overcurrent, distance protection, forced excitation device) of secondary voltage supplied by voltage transformer should be put out of operation before power interruption; after the voltage transformer returns to normal, the above protection and automatic device should be put into operation immediately.

hh) After generator running out of synchronization and stop, if the generator is in hot reserve, the generator outlet switch, excitation switch and generator outlet isolator should be opened; if the generator is in cold reserve, the affiliated voltage transformer should be pulled to repair position and the low voltage subswitch of voltage transformer and excitation starting power source should be opened;

ii) The high voltage auxiliary power source switching operation of unit should be by use of auxiliary power quick change-over device. If the auxiliary power quick change-over device is out of operation due to fault, the auxiliary power source should be switched by the following method: closing before opening when operating auxiliary transformer and



2×300 MW


standby auxiliary transformer are synchronous; opening before closing when they are non-synchronous (generally, strive for synchronous switching as much as possible). During power regulation, the condition of starting-standby transformer with on-load voltage regulating should be utilized to reduce circulating current influence caused by 6kV side voltage difference;

jj) Connection and removal sequence of ground wire (including grounding isolator): the

ground wire is connected after all power-interruption switching operations are completed and no voltage is proved through check; the ground wire is removed before all energization switching operations. Before repair equipment changes to operation (or standby) and after the “safety measures” are removed, the whole energization loop should be free of short circuit connection through inspection. Before the line grounding isolator is opened or closed, an order should be given by the dispatcher;

kk) The MCC power distribution cabinet supplied with power by two power sources should exchange power source by means of power interruption and the parallel operation is forbidden to avoid arc light short circuit when opening the isolator to switch off circulating current. And moreover, opening or closing the knife-switch on load should be prevented to avoid accident.

8.4 Abnormal Conditions and Disposal

8.4.1 General Regulations of Accident Disposal

a) Primary task:

1) Control accident spread as soon as possible; eliminate accident source and remove the danger to equipment and persons.

2) Take measures to ensure auxiliary power and main machine are in normal operation to prevent accident spread.

3) Keep equipment in operation by any possible method to ensure normal power supply for users.

4) Restore power supply for the users with power interruption as soon as possible.

5) When the accident has been controlled and trends to be stable, adjust operation mode to be sound and make system return to normal.

b) During accident disposal, the shift-chief operator is commander of accident disposal and leads all attendants to perform accident disposal and operation.

c) When an accident happens to electrical system, the attendants should judge and treat the accident in the following sequence.

1) Judge the character of accident according to pointer and CRT display, alarm window signal, whether impact oscillation existing in system, operating condition of relaying protection and automatic device, computer print record and equipment exterior sign.

2) Ascertain fault position and scope through full inspection and test of equipment.



2×300 MW


3) If the fault endangers persons and equipment, the measures should be taken immediately to remove the threat. When necessary, the equipment should be stopped; if no threat against persons and equipment exists, every effort should be made to keep and restore normal operation of equipment.

4) Guarantee the safe operation of fault-free equipment. Pay special attention to isolate the equipment not influenced directly; when necessary, start up standby equipment.

5) For the fault equipment, after the fault position and scope are determined, the attendant should take on-site safety measures to facilitate first-aid repair by repairers.

6) In order to prevent accident spread and avoid disorder in disposal process, each process of accident disposal must be initiatively reported to shift-chief operator or higher-level leader quickly and correctly.

d) In order to prevent accident spread and treat the accident quickly, the attendant may perform the following operations in an emergency and then report to shift-chief operator or higher-level leader

1) Cut off the power supply of damaged equipment or the equipment with direct threat against persons and equipment.

2) Isolate the in-service equipment with damage threat.

3) When busbar voltage vanishes, open the switch connected to the busbar.

4) Restore the power supply after auxiliary power is interrupted in part or all.

e) After the busbar fails to operate, the busbar must be inspected and all switches connected to the busbar must be shut off before voltage stepping up or impact test. If some one is working on power distribution switchgear at that time, the person should be notified to leave before voltage stepping up or impacting.

f) The accident must be treated quickly, correctly and unhurriedly with deliberation. Or else, the accident may spread.

g) When accepting an order of accident disposal, the attendant must repeat the order to the person who gives an order; the attendant should ask clearly if not understanding the order or having no notion of intention. The attendant should not execute the order until a disposal order given by the leader that the attendant is familiar to is accepted. After the order is executed, the attendant should report to the person that gives an order immediately.

h) The person that gives an order should be familiar to the person that accepts the order and require the order accepter to repeat the order. If the next order of accident disposal must be determined according to execution condition of the preceding order, the person that gives an order should wait for the report of order accepter in person, which should not be transmitted through the third person, and moreover, it is not allowed to judge the execution condition of order according to pointer indication.

i) When an accident happens, the indication of pointer and signal should be monitored



2×300 MW


carefully. Some one among attendants in main control room should record the execution time of each operation (in particular the precedence order) and the phenomenon relating to accident.

j) When an accident happens during relief of a shift, the shift handover persons should remain in own work post. The shift takeover persons must coordinate to treat the disposal under unified command of shift-chief operator and chief operator. After the accident disposal ends and all returns to normal, the shift-chief operator or department leader gives an order to change the shift in a unified way.

k) After completion of accident disposal, the on-duty person in charge should make the observed phenomenon and the condition of accident disposal filled in log book according to the facts so as to facilitate analyzing accident and finding out the reason.

l) After a switch trips, if the switch is closed manually in a forced way, pay attention to the following:

1) The attention should be paid to voltage, current and system impact condition to facilitate distinguishing whether a fault exists. If a fault happens, the switch closed forcedly should be opened immediately.

2) If it is found that equipment has fault symptom such as smoking, firing and arc light, the forced closing is forbidden.

3) When the tripping switch is closed forcedly, the condition should be given to equipment skip tripping accident.

4) In general principle, the above accident disposal should be executed according to the character of accident and specific circumstances.

8.4.2 Disposal of 6kV Auxiliary Power System Faults and Abnormal Conditions

a) 6kV auxiliary busbar operating power switch trips and standby power switch is

automatically put in successfully

1) Inspect that 6kV auxiliary busbar voltage indication should be normal; reset flash switch and audible signal; remove the quick change-over device of the section of busbar.

2) Inspect protection operating condition and find out fault source, and moreover, perform necessary inspection for tripping switch; if it belongs to misoperation trip, find out misoperation reason and then return to normal.

b) Disposal of 6kV auxiliary busbar power failure

1) Immediately inspect switch tripping reason and protection operating condition and report to shift-chief operator and chief operator; carry unit load according to physical circumstances on site.

2) In case the operating power switch trips and automatic put-in is unsuccessful, and moreover, no branch quick-break and zero sequence overcurrent blocking signal is made, the standby power switch should be closed immediately.



2×300 MW


3) When no standby power source is available or the power is supplied by standby power switch, the power supply switch trips, it is allowed to close forcedly the current power supply switch in case no gas or differential protection acts. Or it should be treated according to busbar power interruption till shutdown.

4) If the power switch trips again after automatic put-in or forced closing, it is not allowed to energize the fault busbar forcedly once more and the fault busbar and affiliated loop should be inspected, and moreover, the insulation of busbar and relevant loop should be measured.

In case an obvious fault point is available, try to remove fault point and restore power supply for busbar, and moreover, notify repairer to rush to repair fault equipment.

In case no obvious fault point is available, open all load switches connected to fault busbar and energize on trial by standby power switch. After trial energization succeeds, energize power- failure load successively; when some loop switch is closed, standby power switch trips again, the loop should be powered off to change to repair; restore the operation mode before 6kV busbar breaks down.

5) When 6kV busbar power fails, auxiliary 400V busbar power failure disposal may comply with requirements of 400V busbar power failure disposal.

Make a report and keep records in time in disposal process.

c) 6kV busbar single-phase grounding

1) When the high voltage house service operating transformer is in operation with a section of 6kV busbar and single-phase grounding happens to 6kV busbar, the operating power switch of 6kV1A(2A) or 1B(2B)-section busbar trips within 1.5s and the auxiliary quick change-over device of relevant section is blocked. And here 6kV busbar with single-phase grounding will lose the power and the fault should be treated according to the circumstances of 6kV busbar power failure.

2) When 01# starting-standby transformer is in operation with 6kV busbar and single-phase grounding happens to 6kV busbar, the branch trips within 3.0s, i.e. 6kV1A(1B)-section standby power switch or 6kV2A(2B)-section busbar standby power switch trips; all are shut off within 3.5s, i.e. high voltage-side switch of 01# starting-standby transformer and 6kV1A(1B)-section busbar standby power switch or 6kV2A(2B)-section busbar standby power switch trip. And here, if 01# starting-standby transformer is in operation with a machine, the 6kV auxiliary power of the machine will vanish entirely; if low voltage branch zero sequence of 01# starting-standby transformer acts within 3.0s, the fault 6kV busbar section may be isolated and then another section is used for energization to ensure auxiliary power; if low voltage branch of 01# starting-standby transformer acts within 3.5s, the diesel-engine generator will be used to provide standby power source for safety PC section.



2×300 MW


8.4.3 Disposal of 400V Auxiliary Power Busbar Fault

a) Disposal of 400V auxiliary busbar power failure

1) Immediately inspect switch tripping reason and protection operating condition and report to shift-chief operator and chief operator; carry unit load according to physical circumstances on site.

2) If it is misoperation tripping, restore power supply for power failure busbar immediately.

3) If 400V busbar power failure arises from 6kV busbar power failure or auxiliary transformer protection act, after inspecting and opening busbar operating power switch, close the 400V busbar interconnection switch and restore power supply for power failure busbar.

4) Inspect power failure busbar and affiliated loop. If no obvious fault point is found out, open all load switches connected to busbar and measure busbar insulation that is normal, and then energize busbar on trial by low voltage transformer, if it is normal, respectively measure branch insulation that is acceptable and then recover power supply for branch load. If an obvious fault point is found out, isolate it immediately and then recover normal operation mode of power failure busbar, and moreover, notify repairers for first-aid repair.

5) If the busbar breaks down and can not recover from fault, each MCC and switchboard on fault busbar may be switched to another busbar for power supply (firstly, switch off normal power supply loop; secondly, switch on standby loop).

6) When 400V boiler PC-section busbar power fails, pay attention to operating condition of 400V safety-section busbar.

9 DC System

9.1 Description

9.1.1 Each unit is provided with two groups of 220V battery installed in electrical building and

one group of common 220V battery installed in central control building. The battery adopts valve-controlled lead-acid battery. 220V storage battery supplies power to hot operation of the unit, electrical control, signal, power of the unit, emergency lighting, UPS system, relaying protection and automatic device, etc. 220V common storage battery supplies power to common relay room, etc.

9.1.2 220V DC system of 1 and 2# units is respectively provided with two high-frequency switch power supply charging devices and 220V common DC system of 1 and 2# units is respectively provided with one high-frequency switch power supply charging device. An interconnection line is installed between two groups of 220V DC system of each unit and between two groups of 220V common DC system of two units. The switching operation of power supply mode may be performed by means of interconnection switch.

9.1.3 220V DC system is provided with DC branch panel in the position with relatively



2×300 MW



centralized load. Branch panel busbar is supplied with power by DC panel main busbar through double loops and any other DC load is supplied with power from DC panel by means of radial feeder line.

9.1.4 220V battery for 1 and 2# units adopts valve-controlled sealed lead-acid battery and operates by means of floating charge. There are 104 220V storage batteries with capacity of 1500Ah in each group for each unit and there are 104 common 220V storage batteries with capacity of 400Ah.


9.2.1 Operation Regulations of DC System

a) Power DC network supplies power radially.

b) Control DC network supplies power by means of ring net.

c) All interconnection switches of control DC network must operate in open circuit in

normal mode; when the power switch at one side fails and trips, the power may be supplied by power switch at the other side through interconnection switch.

d) When any busbar charging device is put out of operation for some reason and the power may be supplied singly by battery within short time, if the time is relatively long, the charging device on another busbar may be put into operation instead to provide power supply for the load on the busbar and charge up battery in a floating way.

e) When DC control busbars are in operation respectively, the parallel loop is forbidden on the side of load that is not in the same busbar.

f) If the power source switching is needed for busbar, the short-time power interruption method should be avoided as much as possible.

g) When DC system is in operation, the insulation monitoring device should be put into operation.

h) Before DC oil pump starts, inspect that DC busbar voltage should be within allowable range; After DC oil pump stops, inspect that DC busbar voltage should be within allowable range.

i) It is not allowed that DC busbar operates singly separating from battery.

j) When in-service high frequency power switch type charging device fails, the battery may provide power supply for load within short time, but the high frequency power switch type charging device (normal) should recover from fault and be put into operation as soon as possible. When the faulty high frequency power switch type charging device can not be put into operation within short time, the charging device on another busbar may be put into operation instead to provide power supply for the load on the busbar and charge up battery in a floating way.

k) Any load with power supply by double loops should operate with open loop no matter whether power source side is in the same busbar; the power is supplied respectively and parallel operation is not allowed.


2×300 MW


l) Any parallel operation of DC system must not be performed until the polarity in parallel point is correct through checking and voltage difference meets the conditions.

m) Generally, the allowable fluctuation range of 220V DC busbar voltage should be within

±5％ of rated value.

n) When the storage battery is in floating charge operating state, the voltage of each

battery should be within 2.15～2.20V.

o) Monitoring and inspection of DC system operation:

1) During normal operation, DC busbar voltage should be within 225～235V.

2) Input voltage of high frequency power switch is within 380V±10％ and 50HZ±0.5Hz.

Output of charging device should meet the requirements of busbar voltage and floating charge current.

3) Periodic charge, discharge and maintenance work of battery should be done by repair technicians.

4) Each DC busbar is provided with a group of insulation inspection device used to monitor the busbar insulation against ground. When the insulation reduces to certain value, “DC busbar insulation reduction” signal will be made, and here the reason should be found out in time.

p) The attendant should inspect the appearance of battery twice when on duty. When the weather changes, the attendant should strengthen inspection at any moment. Inspection items are as follows:

1) Indoor temperature, ventilation and lighting should be in good condition.

2) Battery appearance should be clean; terminal, casing and cover should be free of breakage and overheat trace.

3) It should be clean and free of impurities in battery room.

4) Open flame is forbidden in battery room.

5) When strong sour odor arises in battery room, indoor ventilator should be turned on till the air returns to normal.

q) Inspection of high frequency power switch type charging device, DC panel and insulation monitoring device

1) Inspect that each pointer and signal indication on DC panel should be normal.

2) Measure positive and negative voltage to ground and the insulation should be acceptable.

3) Each knife-switch, switch and button on DC panel should conform to operating state.

4) Inspect that each joint should be free of looseness and overheat; the fuse should be intact.



2×300 MW


5) DC busbar voltage and floating charge current should be normal.

6) Each component of thyristor rectifier device should be free of overheat.

7) Insulation monitoring device should be in normal operation, without abnormal alarm.

r) Inspection of DC system busbar in operation

1) System insulation is sound without grounding and busbar voltage is normal.

2) Indication of each pointer on DC panel is normal.

3) Switches and signaling devices are complete and in good condition.

4) System equipment is sound; each part is clean and free of electric leakage; joint part is free of overheat.


9.3.1 Disposal of high or low DC busbar voltage:

a) Disposal of high voltage:

1) Inspect whether high frequency power switch floating charge current of battery is too

great, if so, reduce output current.

2) If it is caused by abnormality of high frequency power switch, stop the abnormal high frequency power switch and reduce output current of running high frequency power switch.

b) Disposal of low voltage:

1) If DC busbar load is over great, enhance the output of high frequency power switch and make busbar voltage return to normal.

2) When battery voltage reduces relatively greatly, the floating charge operation mode may be changed to equalizing charge operation mode.

3) If it is caused by abnormality of floating charge high frequency power switch, switch to another high frequency power switch for operation.

4) Inspect whether battery outlet switch trips, if so, perform inspection immediately and close the switch after return to normal.

c) DC system grounding

1) Symbol: “DC busbar insulation reduction” signal and alarm sound are made.

2) Disposal

Inspect 220V DC busbar (DC control busbar and DC branch panel) microcomputer DC insulation monitoring device; determine fault busbar and fault line number; clearly distinguish earth electrode.

Ask whether some one works in loop, if any, stop work immediately.



2×300 MW


Contact heat engine whether water leakage, steam leakage and opening device are available; lay stress on inspecting the doubtful part.

Inspect along the line according to fault busbar and fault line number displayed by

microcomputer DC insulation monitoring device.

Open the DC load on trial: firstly, stop non-important load and finally stop protection and hot operating load.

Stop the insulation monitoring device on trial.

Fully inspect busbar and battery and open the charging device on trial.

Open the DC power supply incoming line knife-switch on trial, if the grounding vanishes, it shows that DC power supply incoming line is grounded; if the grounding does not vanish yet, it shows that DC busbar is grounded, and here switch the control DC load to non-grounding busbar for operation and cut off power supply of fault busbar according to the shift-chief operator’s order.

After completion of disposal, return to original mode as soon as possible. Finding grounding time should not exceed 2h.

d) Precautions when finding DC grounding:

1) Have the shift-chief operator’s approval before open the hot operating power source on trial.

2) Notify relevant attendant before open the load on trial.

3) During loop power supply, open the air switch of double-circuit power source side at the same time.

4) With shift-chief operator’s approval, open the protection power source on trial and stop all protections of the DC power source.

5) Grounding operation of DC system should not exceed 2h.

9.3.2 Disposal of fire in battery room:

1) Open the battery outlet switch and close the busbar interconnection switch.

2) Adjust the floating charge current of high frequency power switch device and

maintain busbar voltage.

3) Notify fire department.

4) Put out the fire by use of carbon dioxide or carbon tetrachloride fire extinguisher.

5) Wear gas mask during fire extinguishing.



2×300 MW


10 UPS Power Supply

10.1 Description

10.1.1 The operating power source of hot operation protection, monitoring instruments,

computer and other devices of 2×300MW unit should be single-phase AC 220V uninterrupted power supply. Therefore, a set of inverted uninterrupted power supply (UPS, model: BORRI E2001) is equipped.

Equipment in UPS system: rectifier, inverter, static switch, bypass maintenance switch, load sharing switch and control equipment, etc. These equipment are respectively installed in rectifier cabinet, inverter cabinet, bypass cabinet and load control panel.

a) Main power source:

Main power source, namely operating power source, is transmitted to rectifier cabinet and converted through rectifier (three-phase controllable rectifier bridge) to make three-phase AC voltage change to constant-voltage DC output. DC voltage output of rectifier may be delivered by two circuits; one circuit is used for battery charging and the other circuit is used for input of inverter to supply DC power source to inverter. In order to not influence normal charging of battery in the system by silicon rectifier device in unit plant 220V DC system, a separating diode is installed on one DC voltage output of rectifier charging up battery. When the operating power source or the rectifier fails, or unit plant 220V DC system voltage is higher than rectifier output DC voltage, unit plant 220V DC system provides DC input power source for inverter.

DC voltage output of rectifier or DC power source provided by unit plant 220V DC system is transmitted to inverter cabinet as input of inverter, through inverter control circuit, DC voltage is changed to a series of sine pulse width square wave output, after the higher harmonics are filtered off through filter circuit, it is changed to single-phase AC voltage and then delivered to bypass cabinet through static switch and to load control panel through bypass switch.

b) Standby power source:

Standby power source, through 380/220V isolating transformer and automatic voltage stabilizer, is transmitted to bypass cabinet and then to load control panel through static switch and bypass switch.

c) Power source switching:

Both operating power source and standby power source are transmitted to bypass cabinet and then transmitted to load control panel through bypass switch QIBY and finally the load sharing is realized in load control panel. Both operating power source and standby power source have the switching modes as follows:

1) Power source switching by bypass switch QIBY

Bypass switch QIBY has three position states, namely: normal (I), test (I＋II) and bypass (II).

When bypass switch QIBY switches to another state from one state, each contact of switch is switched in the sequence of switching on before switching off. When operating power source supplies power to UPS system load and standby power source are normal, and moreover,



2×300 MW


operation bypass switch QIBY switches to test (I＋II) or bypass (II) position from normal (I) position, the load power source will switch to standby power source for power supply without interruption; if operating power source is normal and when operation bypass switch QIBY

switches to normal (I) position from bypass (II) or test (I＋II) position, UPS system load power

source will also switch to operating power source for power supply, from standby power source without interruption.

2) Power source switching by static switch making and breaking

When bypass switch QIBY is in normal (I) position, the switching of UPS system load power supply can be realized by means of controlling the making and breaking of static switch. When the inverter breaks down and stops operation automatically or pressing MANUAL TRANSFER manual power source transfer button, operating power source will switch to standby power source to provide power supply for UPS system load; after rectifier and inverter return to normal, press RESET button, and standby power source will switch to operating power source to provide e power supply for UPS system load (both rectifier and inverter are not stopped unartificially and they can start automatically after the cause of stopping their operation is removed. In the case of not pressing MANUAL and TRANSFER button, it needs not press RESET button, and UPS system load power source will automatically switch to operating power source for power supply, from standby power source). The above switching process is interrupted, but interrupted power supply time is very short and it is sufficient for user needs.

3) Power supply tracking:

The device is provided with synchronizer to make AC voltage outputted from inverter to track standby power supply frequency to ensure that interrupted power supply time of load will not increase arising from asynchronous switching of both power supplies when operating power source switches to standby power source to provide power supply for UPS system load. When standby power source fails, the synchronizer releases tracking and operating standby power works continuously by self-excited oscillation frequency 50HZ.

10.1.1.1 Operating condition:

a) Normal state: main power source provides power supply and UPS provides stable AC220V and 50Hz sine wave power supply for load;

b) Fault state: When main power source fails, the inverter is supplied with power

automatically by unit plant battery DC system power source and UPS provides stable AC220V and 50Hz sine wave power supply for load; when battery DC system power source discharges electricity to the limit, UPS inverter will be switched off automatically. When main power source returns to normal, the inverter will automatically recover to be supplied with power by rectifier;

c) Bypass (automatic/manual) state: if output voltage of inverter is abnormal arising from internal fault, static switch may switch the load automatically to standby power source of bypass system. If output voltage of inverter is abnormal arising from maintenance, the bypass switch may be operated manually to switch the load to standby power source of bypass system uninterruptedly and completely insulated with other UPS equipment; during return, the load power source is uninterrupted.



2×300 MW


10.1.1.2 The following signals are available on local main machine cabinet panel of UPS device:

a) Rectifier input low-voltage alarm

b) DC input low-voltage alarm

c) Bypass AC power source low-voltage alarm

d) Inverter input over high/ over low-voltage alarm

e) UPS output alarm: high/low voltage, high/low frequency

f) Rectifier input voltage

g) Inverter input voltage

h) Inverter output voltage

i) Inverter output frequency

j) Bypass AC power source voltage

k) Inverter output current

l) Static quick change-over switch (put in bypass position) alarm

m) Battery running alarm

10.1.1.3 Meanings of UPS alarm signal:

a) Main power source input fault: main power source voltage or frequency is beyond normal range;

b) Battery discharge: the battery is in discharge state (red light flashes); when the battery discharges off, red right is on uninterruptedly.

c) Inverter fault: inverter output voltage is beyond normal range.

Resultant fault signal and battery running and bypass running signals can be displayed on DCS graphic display of unit plant.

10.1.2 Operation and Maintenance

10.1.2.1 Operation Mode and Regulations

a) Normal operation mode of UPS system: operating PC-section power source provides

power supply for UPS system load; safety PC-section power source loop is standby; bypass switch (QIBY) is in “I” (when operating power source fails, standby power source switches automatically) position.

b) Off-normal operation mode of UPS system

Standby power source provides power supply for UPS system load and bypass switch (QIBY) is in large bypass II position.

220V power DC busbar provides power supply for UPS system load.



2×300 MW


When operating power source fails, UPS system may operate in off-normal operation

mode “I＋II” or “II”; when both rectifier and inverter fail or power supply must be interrupted for

repair, UPS system may operate in off-normal operation mode “II”; when both operating and standby power sources fail, UPS system may operate in off-normal operation mode “II”.

c) During normal operation, output voltage of UPS system should maintain within 220V±1

％ and in the case of full load, voltage change should not exceed ±8％; frequency

change should not exceed ±2％, and moreover, it should reach static stability within

40ms recovery time.

d) Bypass switch (QIBY) should be in “I” position in normal condition and the operators should not operate the switch at will. When both rectifier and inverter need to be repaired with power interruption, the bypass switch (QIBY) can not operated to “II” position unless required by repairer who should be present on the scene.

e) During normal operation, it is not allowed to switch UPS operating power source and

standby power source directly by means of operating bypass switch (QIBY) to “I＋II”

or “II” position from “I” position and to “I” position from “I＋II” or “II” position, to prevent

circulating current generated in switching process damaging inverter or bypass switch (QIBY), etc.

f) After rectifier and inverter in cold reserve are put into operation, it is not allowed to operate with load immediately, and firstly they should operate without load for 15min.

g) When both rectifier and inverter restart after stopped and repaired, it is not allowed to switch on unit plant 220V DC power source to provide power supply for inverter, and firstly the rectifier should be started, after becoming normal, the DC power source can only be fed.

h) When UPS device needs to be stopped, it switches to standby power source for power supply by means of manual bypass switch.

10.1.2.2 Startup and Stop Operation of UPS System Device

a) Bypass system operation: Close the bypass isolating transformer input switch kA;

b) Voltage stabilizer operation:

1) Put the voltage stabilizer bypass switch in “stabilization” position;

2) Put the change-over switch on panel in “automatic” position;

3) Close the voltage stabilizer input switch K and observe that output voltage on panel

is 220V (±1％～5％);

4) Press the “stabilization” button on panel;

5) Here bypass voltage outputs to UPS standby input terminal.

a) UPS operation

1) Put the manual bypass switch QIBY in “I” position;



2×300 MW


2) Close the three-phase input switch QIRP and observe that battery voltage on panel

is 250V (240～270V);

3) Close the battery input switch QIB;

4) Inverter starts and static switch outputs;

5) Close the standby input switch QIRA;

6) UPS starts up and inspect that all parameters of UPS device are normal.

d) Switch UPS to standby bypass output from inverted output

1) Open the three-phase input switch QIRP;

2) Open the battery input switch QIB;

3) Inspect that static switch switches automatically inverted output to standby bypass output;

4) Operate manual bypass repair switch QIBY and put in “I” →“II” position;

5) Inspect that UPS output is supplied by bypass and UPS main machine is non-electrified (except terminal RQIBY);

6) Inspect that bypass system is in standby state.

e) UPS restores inverter output

1) Here, bypass system is in output state and manual bypass switch QIBY is in “II” position;

2) Put the manual bypass repair switch QIBY in “I+II” position from “II” position;

3) Inspect that standby-side indicator light of static switch on panel is on and then put

in “I” position from “I+II” position;

4) Close the three-phase input switch QIRP;

5) Inspect that battery voltage on panel is 250V（240～270V）;

6) Close the battery input switch QIB;

7) Inspect that UPS restores inverter output;

8) Inspect that bypass system is in standby state.

f) Inspection before device put-in

1) Inspect that UPS device and loop meet operating condition and UPS room is clean and free of impurities.

2) Inspect whether the connection in UPS cabinet is loose and drops out; push printed panel to final position along guide rail.

3) All switches and knife-switches are in correct position and the fuse is intact.

4) Inspect that UPS cabinet is dry and free of dewing.



2×300 MW


g) UPS stop operation:

1) Make sure that UPS standby power source input green light is on (standby power source is normal);

2) Open the battery input switch QIB;

3) Open the three-phase input switch QIRP, after several minutes, the inverter stops and UPS switches automatically to bypass for operation without interruption;

4) Open the standby input switch QIRA;

5) Open the voltage stabilizer input switch K;

6) Turn off the bypass isolating transformer input switch KA;

7) Inspect that UPS has been shut down.

Note: Switch QIBY switch to I+II position, and standby power source provides power supply for static switch and load;

Switch QIBY switch to II position, and the load is supplied with power by standby power source through bypass.

10.1.3 Abnormal Conditions and Disposal

In the case of abnormal operation, it switches over and give an alarm automatically, therefore timely inspection should be performed when off-normal operation occurs, and after condition recovery, the operation should comply with operation steps of UPS system device according to specific circumstances at that time.

11 Station Motors


11.1.1 General Requirements of Motor Operation

a) The attendant who has jurisdiction over mechanical equipment driven by motor should

master power supply mode of motor. The operation attendant not only should master power supply mode of motor but also should master operation mode of relaying protection and automatic device.

b) The manufacturer’s rated nameplate should be available on the casing of each motor. If the nameplate is lost, it should be made up in time by repairer.

c) The motor casing, ventilating pipe and metal structure should be coated with paint and should be indicated with equipment name and number according to affiliated unit.

d) The motor and motor-driven machine should be set with arrow sign to indicate rotation direction.

e) Motor outgoing line, cable head and exposed rotating part should be installed with firm shade and railings or protective cover.



2×300 MW


f) The casing of motor and starting device should be grounded according to the “technical regulations for grounding” and the work is forbidden on grounding body of running motor.

g) The standby motor can be started at any moment and the periodic alternate running or periodic put-into-operation trial run table of motor should be established. Each attendant should strictly implement periodic alternate running or periodic put-into-operation trial run of motor. In normal condition, the motor with available switching startup condition should be started according to switching period and for the standby motor with unavailable startup condition and with capacity of 50kW and above, and moreover, the standby motor has stopped running for 15 days continuously, the insulation resistance should be measured. In order to prevent standby motor from moisture, for the motor installed in damp place, the trial run for put into operation should be conducted once a week.

h) Requirements of measurement of motor insulation resistance:

1) 6kV high voltage motor insulation is measured with 2500 V megameter; 400V and below low voltage motor insulation is measured with 500V megameter.

2) The insulation resistance of 6kV motor should not be less than 1 megohm/kV; the insulation resistance of 400V and below low voltage motor should not be less than 0.5 megohm (insulation resistance of DC motor should not be less than 0.5 megohm).

3) The insulation resistance of motor must be measured when the loop is in cold

reserve.

4) The insulation resistance is measured as required in special case (e.g. the motor is affected with damp, etc.).

i) The motor with bearing forced lubrication should be provided with lubricating oil interruption signaling device, when necessary, should be installed with lubricating oil interruption or low oil pressure motor trip-off interlocking device.

In normal condition, if it is far away from motor when opening the remote control switch of the motor, a set of emergency switch-off equipment should be installed nearby the motor and when the motor power switch is opened by means of emergency switch-off equipment, the closing operation loop should be blocked.

The emergency switch-off equipment should be set with clear name, number and warning sign as well as the facilities preventing touch and pull by the others by mistake.

The emergency switch-off equipment can only be used in an emergency and it is strictly prohibited to be used for safety measures.

j) For the motor with capacity of 40kW and above or the motor with its driven machine adjusted according to current in production process, an ammeter should be installed in the place of operating motor to monitor the startup and operation.

k) The motor installed indoors with much dust should be cleaned periodically and



2×300 MW


forbidding water dropping on motor; for the air cooling motor, no condensed water should be available on the cooler and the cold air room should be free of water accumulation.

l) The attendant of motor-driven machine should record the startup and stop time of motor and all abnormal conditions arising during motor running in log book in details.

m) All types of fusible equipment (protector, fusible piece and cutout, etc.) used in motor should be inspected before use and they should be intact; rated current should match with motor capacity.

11.1.2 Operation Mode

a) The motor may run according to the specified data on the manufacturer’s nameplate under rated cooling air temperature.

b) Maximum monitoring temperature of engine coil and core should not exceed the temperature in any case according to the manufacturer’s requirements. If no manufacturer’s requirements are available, maximum temperature of motor coil and

core should not exceed 105 and temperature rise should not exceed 65.

c) Generally, the motor may run within －5％～＋10％ of rated voltage and its rated

output is unchanged (5.7～6.6kV, 360～420V). the unbalance value of voltage between

phases during running with rated output should not exceed 5％; the attention should be

paid to overheat and vibration of motor during running with voltage unbalance.

d) During normal running, motor current should not exceed ＋5％ of rated value, when it

exceeds ＋5％～＋10％, the unit attendant should try to reduce it to rated current

within 15min. It is not limited thereof if caused by main machine fault overloading.

e) Motor bearing temperature should comply with the following requirements (if any, should comply with the manufacturer’s requirements):

1) Sliding bearing: ≤80 (temperature rise: 40)

2) Rolling bearing: ≤100 (temperature rise: 60)

11.1.3 Operation of Motors

a) Normal power interruption and supply of auxiliary motor should be operated by operation attendant. The affiliated unit of motor-driven machine needs power interruption and supply, the on-duty person in charge, of affiliated unit should fill in “equipment power interruption and supply contact sheet” for contact.

b) After completion of motor repair, when the work-sheet is concluded, the person in charge of repair work should report equipment condition and insulation resistance value to the operator, if acceptable, and then contact power supply operation.

c) The external inspection of motor should be performed before power supply and the contents and division of work are as follows:

The operation attendant should be in charge of inspecting:



2×300 MW


1) Inspect the integrity of electrical loop and equipment thereof; the work-sheet has been concluded; the protection device is put into operation.

2) The ground wire of motor and cable casing should be intact and firm.

3) Motor wiring hood and fan blade hood should be intact and firm.

4) Whether starting device of wound type motor is oily and inspect the oil level thereof.

5) For the motor cooled by air cooler, cold air room should be free of water

accumulation.

6) Motor and affiliated mechanical equipment are intact; no impurity is available and no one works nearby; the startup conditions are met.

7) The oil in bearing oil ring should be sufficient and the oil cap should be covered well; if it is forced lubrication, the oil system should be put into operation; if the bearing is cooled with water, the cooling water should be turned on.

8) If possible, had better try to rotate the rotor to make sure rotor does not rub against stator and the rotor-driven machine is free of fault.

9) For the motor cooled by air cooler, the cooling water should be supplied.

d) Operation principles of motor power interruption and supply:

1) When supplying electric power to motor primary loop, take turns to operate power fuse, knife-switch and switch; and on the contrary when shutting off power supply.

2) When supplying electric power, firstly, inspect that operation fuse should be put in place (green light is on); secondly, put closing loop fuse in place, and on the contrary when shutting off power supply.

3) The operation mode selector switch on motor switch panel should be put in remote control position.

4) Strictly prohibit using pointer and indicator light as one and only judgment basis of switch on-off.

5) Open and close the knife-switch, if conditions permit, inspect that knife edge is in off or on position.

e) If the motor is by means of remote closing, remote operator should contact with local attendant and then start the motor, and moreover, local attendant should stay beside motor till the motor rises to rated speed. If an ammeter is available, the starting process should be monitored according to ammeter; after the startup ends, the motor body must be inspected according to specific circumstances.

f) Allowable startup number of cage rotor motor should strictly comply with the following requirements:

1) For the motor with capacity of 100kW and above, it is allowed to start up twice in succession in cold state and start up once in hot state; startup interval time should not be less than 5min.



2×300 MW


2) For the motor with capacity of 100kW and below, it is allowed to start up thrice in succession in cold state and start up twice in hot state; startup interval time should not be less than 5min.

3) For the motor with fault disposal and starting time not more than 3s, one startup time may be increased according to the above requirements.

4) When the dynamic balance test is conducted for motor, startup interval time should not be less than 30min.

5) Definition of motor state:

It is cold state as long as motor run-down time is equal to or greater than 30min; it is hot state as long as motor starting current attenuates to minimum or run-down time is less than 30min.

g) The motor should be started one by one and usually it is not allowed to start two or

more motors with relatively large capacity simultaneously in the same busbar. Before starting large capacity motor, the electrical attendant should be contacted to adjust busbar voltage.

h) In normal condition, when the motor starts, the switch refuses closing or trips when starting, the reclosing is strictly prohibited before finding the reason; if starting time exceeds general starting time of the motor and the current does not attenuate to normal value, open the motor power switch immediately and find the reason.

i) When the motor starts, after the switch is closed, if the motor does not run and buzzes or can not reach normal speed, open the motor power switch immediately and find the reason.

11.1.4 Operation Monitoring and Maintenance

a) The attendant of motor-driven machine should be in charge of monitoring of motor during running and exterior cleaning of motor.

b) When the unit attendant discovers an abnormal condition, report to shift-chief operator quickly, when necessary, notify electrical repairer to inspect the motor. When the operation attendant discovers the motor running is abnormal, the operation mode of motor can not be changed unless reported to shift-chief operator.

c) The operation attendant should perform external inspection of running and standby motors according to specified time and period and the contents are as follows:

1) Motor and ambient temperature thereof.

2) Motor and bearing sound; whether there is burnt odor.

3) Indicated value of motor ammeter should not exceed the prescribed limit.

4) Casing ground wire and cable head protective cover should be intact and firm.

5) For DC motor, observe whether slip ring or commutator sparks; protective covers of slip ring and commutator are intact; slip ring handle should not exceed danger sign.



2×300 MW


6) Motor vent hole should be unhindered; air cooler should be in working order and be free of water leakage.

7) Motor appearance should be free of ash deposit and water accumulation or finding

that the impurities such as ash, power and water steam may enter into motor or starting device, the attendant of motor-driven machine should be notified in time to remove the impurities.

d) The monitoring of motor casing and bearing temperature should be compared in the case of the same ambient air temperature. If the temperature rise is abnormal, the source of fault should be found out, when necessary, the measures of strengthening ventilation and reducing load should be taken and the monitoring should be strengthened.


11.2.1 The motor should be stopped immediately in any case as follows:

a) A fatal accident that requires stopping motor immediately happens;

b) The motor and the motor-driven machine are damaged to danger level;

c) The motor catches fire or the insulation has burnt odor;

d) The vibration is violent and the motor or the motor-driven machine makes a metallic

friction sound;

e) Motor temperature or bearing temperature steeply rises and exceed the limit; the rotating speed drops sharply;

f) The motor is submerged.

11.2.2 In any case as follows, for important motors, the standby motor may be started first and then the fault motor is stopped, and moreover, find out the source of fault:

a) The motor sound is abnormal or the insulation has burnt odor;

b) The spark and smoking arise in stator and rotor gap or staring adjusting device;

c) The stator current exceeds normal running value;

d) The motor oscillates violently;

e) The cooling water system of large-sized closed type cooling motor breaks down;

f) The rise of bearing temperature is abnormal;

g) The motor is submerged and on fire danger to insulation safety.

h) When the running motor trips for the protection acts, the tripping reason should be inspected by the attendant generally, and after returning to normal, the motor can be restarted. If it is caused by artificial touch and stop by mistake, the motor may be restarted instantaneously.

When the important auxiliary motor trips, if no standby motor is available or the standby



2×300 MW


motor can not be started quickly, it is allowed to rush to start the tripping motor once in order to prevent great damage to turbine-boiler equipment except in the following cases:

z 6kV busbar subordinate to tripping motor is grounded;

z A fatal accident that requires stopping the motor immediately happens;

z The motor-driven machine is damaged;

z The obvious short circuit or damage phenomenon exists.

i) When the motor catches fire, the power supply should be shut off at once. The special electrical equipment fire extinguisher should be used. When no special fire extinguisher is available, after the power supply is cut off, the fire should be extinguished with spray water. Large-stream water is forbidden to be fed into motor.

j) After the motor switch is closed, if the motor does not run and only make a sound or can not reach normal speed, the possible cause is as follows:

1) One phase in stator loop is broken; one phase of fuse is blown; one phase of cable head, knife-switch or switch is in loose contact;

2) It is disconnected or in loose contact in rotor loop;

3) The motor and the motor-driven machine get stuck;

4) Stator winding connection is wrong;

k) Terminal voltage of motor is relatively low.

Disposal: if the motor does not run within 1-2s after closing, shut off motor power supply at once and fully inspect the loop and load, and moreover, notify the repairer for disposal.

l) When the motor starts or runs, there is spark or smoking in stator and rotor gap and the possible cause is as follows:

1) The center is misaligned or bearing pad is worn to make stator collide with rotor;

2) The cooper (aluminum) bar of cage rotor is broken or in loose contact.

m) The motor protection acts and trips and the possible cause is as follows:

1) The machine gets stuck;

2) The loop breaks down;

3) When the wound rotor motor starts, the slip ring is short-circuited or rheostat is not in initial position;

4) The protection operating current value setting may be too small and the selectivity characteristic is not enough.

n) The motor sound changes suddenly during running and the current rises or drops to zero. The possible cause is as follows:



2×300 MW


1) One phase in stator loop is disconnected (the fuse is blown, etc.);

2) The system voltage drops;

3) The winding inter-turn is short-circuited or the current transformer is open-circuited;

4) The machine breaks down.

o) The current of running motor oscillates periodically and the motor makes a periodical abnormal sound. The possible cause is as follows:

1) The rotor cooper (aluminum) bar is broken;

2) The winding of wound rotor is disconnected or the slip ring device and the rheostat are in loose contact;

3) The load changes unevenly.

p) The motor vibrates violently and the possible cause is as follows:

1) The motor does not align with machine center;

2) The unit is out of balance;

3) The rotating part rubs with static part;

4) The ball and roller bearing or bearing neck is damaged;

5) The motor-driven machine is damaged;

6) The cage rotor end ring has crack or the cooper (aluminum) bar is in loose contact;

7) The motor rotor core is damaged or loose and the rotor axis is bent or cracked;

8) The motor bearing and end cover are loose or the base is not connected with foundation firmly;

9) The stator and rotor air gap is uneven and exceeds specified value.

q) The sliding bearing is overheated and the possible cause is as follows:

1) The lubrication is poor, e.g. the oil is too much, or a little, or very dense, or unclean and the oil is mixed with water or the oil grade is incorrect;

2) The lubricating ring gets stuck or is broken;

3) The orifice on bearing paid is choking or worn flat;

4) The motor reel or bearing is leaned;

5) The bearing cover is too tight or the bearing clearance is too small;

6) The center is misaligned or the dogtooth of the elastic backrest wheel works unevenly.



2×300 MW


12 Power Distribution Device

12.1 Circuit Breaker

12.1.1 Operation monitoring and maintenance of circuit breaker:

a) When the switch is put into operation, the manufacturer’s nameplate indicating basic

parameter should be available; the opening and closing indicator should be observable and the indication should be correct, and besides, the indicator should be set with complete name and number.

b) During SF6 switch operation, the change of SF6 gas pressure should be monitored. The change of SF6 gas pressure should conform to “SF6 gas pressure-temperature change isopycnic”, or the reason should be found out.

c) Normal mechanical life of SF6 switch is 3000 times. When rated current is broken 2000 times or the switch is broken 20 times under rated short circuit current, it should be out of service for repair.

d) Normal operating mechanism life of vacuum circuit breaker is 30000 times, after operated 10000 times each, vacuum circuit breaker should be fully inspected and maintained, and moreover, the routine inspection should be performed at least once a year.

12.1.2 6kV switch cabinet interlocking:

a) The switch car has three positions: operation, test and repair.

b) Interlocking of switch car and switch cabinet high-voltage chamber door: when the

switch is in operation position or between operation and test position, the high-voltage chamber door can not be opened; when the switch is in test position and in opening state, the high-voltage chamber door can be opened; after the high-voltage chamber door is opened, the switch can not be thrust in operation position.

c) Interlocking of high-voltage chamber door and low-voltage plug: when the low-voltage plug is drawn out, the high-voltage chamber door can not be closed.

d) The switch can not be pushed in or out until the switch is in off state and the high-voltage chamber door is closed.

e) Interlocking of grounding knife-switch and switch car: when the switch car is in test or repair position, the grounding knife-switch operating handle jack baffle plate can be opened and here the grounding knife-switch can be operated; when the grounding knife-switch is closed, the switch car can not be pushed in operation position from test position.

f) The switch car can be locked in both test and operation position and a clear indication is available.



2×300 MW



12.1.3 Inspection of SF6 switch in operation:

a) SF6 gas pressure, ambient temperature and compressed air pressure should be recorded regularly every day and the pressure change should be normal contrasting with SF6 gas temperature-pressure change isopycnic.

b) Inspect that each part of switch and piping have no abnormal sound and unusual odor and pipe clamp should be normal.

c) The switch opening and closing indication should conform to the operating condition.

d) The grounding device should be grounded well and the body and there surrounding thereof are free of impurities; the secondary loop of switch should be intact.

e) Both switch mechanism box door and terminal box door should be closed tightly.

f) For the in-service switch, inspect that both casing and insulator are free of crack, discharge and corona and each part is in sound contact and has not abnormal overheat.

12.1.4 Inspection of vacuum circuit breaker in operation:

a) The switch opening and closing indication should conform to the operating condition.

b) The vacuum arc-extinguishing chamber and the switch have no abnormal sound.

c) No discharging sound is made.

d) The switch cabinet blocking device is intact.

e) The switch energy-storing indication is correct.

12.1.5 Operation of circuit breaker:

a) Work before switch energization:

1) Repair work-sheet is concluded; safety measures are removed; the loop is clean.

2) Inspect that both casing and insulator are intact and free of crack.

3) Inspect that switch operating mechanism and protection are intact.

4) Inspect that switch opening and closing indicator pointer is in opening position.

b) Operation principles of SF6 switch:

1) SF6 switch changes to hot reserve from cold reserve:

The power air switch in switch terminal box should be closed.

The power switch in SF6 switch cabinet should be closed.

Inspect that proximity-remote switch of SF6 switch should be put in “remote” position.

Inspect that the indication of switch three-phase SF6 gas pressure gauge

should be normal.


2×300 MW


Inspect that SF6 switch is in off position (subject to actual position of mechanism).

According to the requirements of operation mode, close the SF6 switch busbar

side and load side knife-switch and inspect that the knife-switch should be closed well.

2) SF6 switch changes to cold reserve from hot reserve:

Inspect that SF6 switch is in off state.

Firstly, open the switch load side knife-switch; secondly, open the busbar side knife-switch and inspect that the knife-switch is disconnected.

As required, shut off switch energy-storing power source and switch operating power source.

c) Power outage operation of 6kV vacuum switch (from operation to test position)

1) Inspect that switch opening and closing indicator is in “opening” 0 position (“0” position shows that the switch is in opening state and “1” position shows that the switch is in closing state).

2) Shut off the switch energy-storing power source.

3) Insert the special key for switch operation and turn to “hand cranking” position from “locking operating position” (manual crank handle jack baffle plate is opened).

4) Insert manual crank handle and turn the handle anticlockwise to make the switch

turn to “test” position from “operation” position.

5) Remove manual crank handle and turn the key to “off-position locking” from “hand cranking” position and then draw out the key.

6) Remove the secondary plug-in unit of switch and open the control power switch.

d) Operation of 6kV vacuum switch energization (push to “operation” from “test”):

1) Inspect that switch cabinet door is closed well and the loop is complete and meets operating condition.

2) Inspect that the switch is in “test” position and the proximity-remote switch is in “proximity” position.

3) Inspect that switch opening and closing indicator is in “opening” position (“0”

position).

4) Put in the secondary plug-in unit of switch and close the control power switch.

5) Close the switch energy-storing switch and inspect that energy store is normal, and then open the switch energy-storing switch.

6) After the test switch is opened and closed normally, inspect that the switch is in opening position.



2×300 MW


7) Insert the special key and turn the key to “hand cranking” position from “off-position locking”.

8) Insert manual crank handle and turn the handle clockwise to make the switch turn to

“operation” position from “test” position.

9) Remove manual crank handle and turn the key to “locking operating position and then draw out the key.

10) Turn on switch energy-storing power source and inspect that the energy store is normal.

11) Put (or inspect) proximity-remote switch in “remote” position.

12) Operation of changing 6kV vacuum switch to “test” position from “repair” position.

13) Inspect that switch opening and closing indicator is in “opening” position.

14) Make the special car for repair align with the rail in switch cabinet and lock the car.

15) Push the switch to “test” position and after locked, remove the special car for repair.

16) Close the high-voltage chamber door of switch.

f) Operation of 6kV vacuum switch shifting out of “test” position (repair position):

1) Inspect that the switch is in “opening” position;

2) Open the high-voltage chamber door of switch cabinet;

3) Make the special car for repair align with the rail in switch cabinet and lock the car.

4) Pull the switch along the rail to special car and after locked, remove it.

5) Close and lock the high-voltage chamber door.

g) Precautions of 6kV switch operation:

1) Strictly prohibit energizing and put the unprotected switch into operation.

2) Inspect the operation of switch in hot reserve; the energy-storing power source is intact and the energy store is normal.

3) The control mode of switch should be in “remote” position in normal condition.

4) Strictly prohibit opening and closing the high voltage switch in switch chamber during normal operation.

5) If the synchronization checking is required, the switch can not be closed until the synchronization checking is performed.

h) 400V circuit breaker

1) Switch structure: it is composed of circuit breaker body and drawer cabinet. The body of plug-in circuit breaker is seated on the guide rail in drawer cabinet and switches on main loop by means of upper and lower busbar connection on circuit breaker body and drawer cabinet; the secondary loop is connected by means of



2×300 MW


plug-in type tie-in module.

2) The drawer circuit breaker has three operating positions: “on”, “test” and “off” and the positions shift by means of turning operating handle. When it is in “on” position, main loop and secondary loop are connected; when it is in “test” position, main loop is disconnected and isolated with reliable insulation and only secondary loop is connected; when it is in “off” position, main loop and secondary loop are disconnected.

3) A mechanical interlocking device is available between drawer circuit breaker body and drawer cabinet. The circuit breaker can be closed when in “on” and “test” position, but can not be closed when in the middle position of “on” and “test”.

4) Maximum phase current of main loop is displayed on the display screen on tripper panel of circuit breaker in normal state.

12.1.6 Abnormal conditions and disposal:

a) When the attendant discovers any abnormal condition (e.g. SF6 gas pressure drops, or

an abnormal sound is made, or opening and closing position indication is incorrect, etc.) during switch operation, the abnormal condition should be eliminated in time, if not, report to the higher-level leader, and besides, record in relevant operation log book and enter the equipment defect management system.

b) When the attendant discovers that the equipment has the defect that threatens power network safety but can not be eliminated if the power supply is uninterrupted, report to the dispatcher on duty and apply for power outage disposal in time, and moreover, report to the higher-level leader. The switch power supply should be shut off at once for disposal in any case as follows:

1) The casing is badly damaged or discharges electricity.

2) SF6 gas chamber is leaky severely and an operation blocking signal is made.

3) The vacuum switch makes a hissing sound of vacuum breakage.

4) The insulation burnt odor arises in switch.

5) The pneumatic machinery is no-voltage suddenly.

6) An accident danger to persons or equipment safety happens.

c) When the switch generates abnormal heat, strengthen the monitoring and find out the source of fault; if the conditions permit, take temporary temperature reduction measures. If the abnormal heat is caused by overloading, with the shift-chief operator’s approval, reduce the through load current and report to divisional director.

d) When SF6 switch explodes or severe gas leakage arises, the operator should be cautious when approaching the equipment and should approach the equipment from the “windward” as much as possible, and when necessary, should wear gas mask and protective clothing.

e) Abnormal SF6 switch gas pressure



2×300 MW


1) SF6 switch gas pressure drops:

For the in-service switch, when the control room makes an “abnormal SF6 switch gas pressure” signal, arrive on the spot in time and inspect whether SF6 gas pressure is lower than 0.56 MPa; if the pressure drops below 0.56MPa, notify the repairer at once to make up the gas and strengthen the monitoring of SF6 switch gas pressure.

2) When both “abnormal SF6 gas pressure” and “control loop disconnection” alarm signals are made (namely tripping and closing loops have been blocked), SF6 gas pressure should be inspected: if SF6 gas pressure has been lower than 0.54 MPa or below, open the switch operating DC switch and here strictly prohibit any operation of switch, and moreover, report to relevant leader in time and supply auxiliary power by starting-standby transformer instead, and make fault switch run out of synchronization by means of higher-level switch.

3) Under the same temperature, if the difference between SF6 gas pressure values

transcribed two times successively is 0.01 ～ 0.03MPa, the abnormal condition

should be analyzed at once, and when necessary, the repairer should be notified to detect and eliminate the leakage; if heavy gas leakage is discovered, report to relevant leader immediately and make fault switch run out of synchronization by means of higher-level switch.

f) When the switch is out of order and the opening is not allowed in itself, transfer the load as much as possible and open the switch operating DC switch, and besides, make fault switch out of service for repair by means of higher-level switch.

g) When the switch refuses operation and the skip tripping is caused, change the switch that refuses operation to repair; the switch should not be put into operation until the fault is found out and eliminated.

h) Requirements of switch emergency tripping times:

1) After the high-voltage switch trips in an emergency, the switch emergency tripping clause, protection operating condition and tripping times should be recorded.

2) The emergency tripping times of high-voltage switch should not exceed allowable tripping times. When the tripping times have reached specified allowable value, it is not allowed to put the switch into operation again and the switch should be repaired as soon as possible; if the switch needs to be put into operation, an order should be given by the dispatcher or higher-level leader.

3) After the high-voltage switch is repaired, the tripping times should be added up from zero according to repair notice and be registered in high-voltage switch emergency tripping log book.

i) SIEMENS low-voltage circuit breaker

1) When the contact generates heat and the temperature inside casing exceeds 80,

the tripper can give an alarm and open the circuit breaker when the current is relatively small.



2×300 MW


2) When the tripper breaks down, The “E” error display or alarm can be given and here the circuit breaker may be opened.

3) Faults and disposal methods (seed the following table):

Faults Fault Source Disposal Methods

Failure to store energy manually

Mechanical fault of energy-storing device, contact with repairer for disposal

Failure to store energy

Failure to store energy electrically:

1. Mechanical fault of energy-storing device;

2. Control power supply voltage of electric

energy-storing device is less than 85％Us.

1. Mechanical fault of energy-storing device, contact with repairer for disposal;

2. Inspect whether undervoltage tripper power supply voltage is more

than 85％Us.

1. Whether undervoltage tripper power

supply voltage is more than 70％Us;

2. Undervoltage tripper control power supply fails.

1. Inspect that undervoltage tripper power supply voltage must be more

than 70％Us;

2. Replace undervoltage tripper control power supply.

Secondary loop is in bad contact

Pull out circuit breaker and then turn to “on” position and inspect whether secondary loop is on state.

Failure to switch on

1. Rated power supply voltage of closing

electromagnet is less than 85％Us;

2. Closing electromagnet fails.

1. Inspect that power supply voltage of closing electromagnet must be

more than 85％Us;

2. Replace the closing electromagnet.

Failure to trip

1. The operation machine breaks down;

2. Whether the control power supply voltage

of shunt excitation tripper is less than 70％

Us;

3. The shunt excitation tripper is damaged.

1. Inspect the operation machine mechanism, if not press hard, contact with the repairer for disposal;

2. Inspect whether the control power supply voltage of shunt excitation

tripper is more than 70％Us;

3. Replace the shunt excitation tripper.

The handle fails to insert in circuit

The guide rail or circuit breaker body does not enter into drawer rack completely.

Push the guide rail and circuit breaker to the end.



2×300 MW



breaker

The circuit breaker body can not be drawn out in off position

1. The crank handle does not be drawn out;

2. The circuit breaker does not reach “off”position.

1. Draw out the crank handle;

2. Turn circuit breaker to “off” position correctly.

The circuit breaker fails to turn to “on” position

1. Foreign impurity falls into drawer seat to press cranking machine hard or clench mechanism tooth skips;

2. The shell grade rated current of circuit breaker body does not match with that of drawer seat.

1. Inspect and remove foreign impurity, if still failing to turn to “on” position, contact with the repairer for disposal;

2. Select and match up the circuit breaker body and drawer with the same shell grade rated current.

The intelligent electronic tripper screen has no display available

1. The intelligent electronic tripper does not be energized.

1. Whether AC power source of electronic tripper is closed, if not, close it at once;

2. Open the AC power source of electronic tripper and after energizedagain, if the fault still exists, contact with the repairer for disposal.

The intelligent electronic tripper fault light is on and it is still on after pressing the light clearance button

The intelligent electronic tripper is faulty.

Open the AC power source of electronic tripper and after energized again, if the fault still exists, contact with the repairer for disposal.

The circuit breaker tripping indicator light is on

The overload circuit breaker trips (Lindicator light is on).

1. Inspect operating time on electronic tripper and analyze fault source;

2. Remove the overload in time; if actual operating current does not

Date: 2008-09-16 No.:QN1-SEC-G-04-TP-004 maPtcahgwe i-th11lo0n-g time deRlaeyvo. p: eArating current setting, modify it according to


2×300 MW



practical situation; 3. Press reset button and reclose circuit breaker.

The overload circuit breaker trips (G indicator light is on).

4. Inspect operating time and current value on electronic tripper and analyze fault source;

5. If an earth fault exists, inspect and handle the fault;

6. If no earth fault exists, inspect whether earth fault current setting value matches with actual protection;

7. Modify the earth fault current setting value of electronic tripper;

8. Press reset button and reclose circuit breaker.

The circuit breaker trips after closed (fault indicator light is on)

1. Circuit breaker closing is at fault;

2. Transient current is large when closing;

3. Circuit breaker closing is at overload fault.

1. Inspect operating time and current value on electronic tripper and analyze fault source;

2. If a short circuit fault exists, inspect and handle the fault;

3. If it is overload, inspect and handle it or adjust setting value;

4. Modify the current setting value of intelligent electronic tripper

5. Press reset button and reclose circuit breaker.

12.2 Disconnect Switch

12.2.1 Operation Inspection and Operation of Knife-switch

a) Inspection before the knife-switch is put into operation:

1) The equipment is complete and the safety measures are removed.

2) The loop joint connection is firm and the operating mechanism is intact.

3) The knife-switch block is complete and the interlocking between main knife-switch

and earthing knife-switch or switch is reliable.



2×300 MW


4) The support insulator is free of crack and damage and the driving mechanism is normal.

5) The contact surface of moving and static contacts is clean and free of burnt trace.

6) The equipment name and number are clear and correct.

b) The following items should be inspected besides the above items during in-service

inspection:

1) The insulator is intact and free of flashover and electric discharge.

2) Each joint is free of looseness, drop-off, vibration and overheat.

3) The doors of control box and driving mechanism box are closed well, free of water accumulation.

4) The indication of knife-switch position conforms to local state.

5) All blocking devices are in good condition.

c) Inspection in special case:

1) When the short circuit fault happens, all knife-switches of through short circuit current should be inspected.

2) In heavy fog and rain weather, the insulator casing should be free of abnormal discharge and flashover.

3) In high wind weather, inspect that the knife-switches should be stable and free of impurity and discharge.

4) After snowing, inspect that through current part is free of melting or vaporization and free of ice coating and discharge.

d) The knife-switch is not used to clear the circuit and only used to isolate voltage. It is strictly prohibited to use knife-switch to cut off load current, line and transformer no-load current; the knife-switch should be closed before the switch is closed and the knife-switch should be opened after the switch is disconnected.

e) The knife-switch should be operated correctly, quickly and decidedly. When the knife-switch is closed in faulty loop, it is not allowed to open the closed knife-switch in any case, or the accident will spread and a threat will be caused to operator and guardian.

f) For the knife-switch of worm wheel drive operating mechanism, inspect whether abnormal electric arc occurs when moving and static contacts are just separated in opening process, if any, change the rotating direction at once to close the knife-switch so as to avoid malignant accident of opening the knife-switch with load.

g) For the knife-switch with blocking pin, the knife-switch should be pinned after opened and closed.

h) After the knife-switch operation is completed, the operating condition should be



2×300 MW


inspected carefully. After closing, inspect that moving and static contacts are in sound contact without deflection, or the contact part should not be too few; after opening, inspect that the space between moving and static contacts should meet the requirements of safety regulation.

i) Strictly prohibit opening and closing the knife-switch on load; when no switch is available in loop, it is allowed to perform the following operation by means of knife-switch:

1) Open and close the fault-free no-load busbar and the capacitance current of equipment directly connected to busbar.

2) Open and close the voltage transformer when no fault happens.

3) Open and close the lightning arrester when no lightning strike happens.

4) Open and close the transformer neutral point grounding knife-switch when no grounding exists.

5) Open and close the no-load transformer with excitation current not more than 2Ａ

and the no-load line with capacitance current not more than 5Ａ and voltage not

more than 10kV.

6) Open and close the loop equalizing current with voltage below 10kV and current

below 70Ａ.

7) On the principle of equal potential, open and close the impedance-free parallel branch, such as switching of busbar knife-switch when double busbars are in parallel operation; for the knife-witch connected with switch in parallel, when the switch accesses, open and close the bypass current of switch, etc.

j) Before closing the grounding knife-switch, inspect that power outage part is in cold reserve and check that no voltage is available; strictly prevent closing the grounding knife-switch in live state.

k) The special operation by means of knife-switch should be performed under the conditions of fine weather, low air humidity and favorable wind direction as much as possible.

l) The knife-switch operated by means of remote control should not be eclectically operated on the spot usually, if the remote control operation is out of order, which is acknowledged, and with the shift-chief operator’s approval, the local electric operation is allowed, but hand cranking operation is strictly prohibited.

m) Strictly prohibit releasing blocking device without approval in the operation process of all blocking devices (including mechanical lock) put into operation. The removal or release of blocking device should be approved by the shift-chief operator.

12.2.2 Abnormal conditions of knife-switch and disposal:

a) Abnormal conditions and disposal:

1) When the knife-switch generates heat, the load current should be adjusted to make



2×300 MW


temperature reach allowable value (below 70); if it is of no effect, the power supply must be shut off for disposal.

2) When the knife-switch can not be closed or opened, it should not be closed or

opened forcedly; inspect whether DC or AC operating power source is normal.

3) Strictly prohibit opening and closing the knife-switch on load. When the knife-switch is opened or closed by mistake, it should be handled on the following principle:

When the knife-switch is closed by mistake, strictly prohibit opening the knife-switch once closed. The knife-switch should be opened after the switch is opened.

When the knife-switch is opened by mistake, before the knife-switch does not go out of knife edge, restore original state of knife-switch at once. If the knife-switch has gone out of knife edge and relatively large discharge sound and arc light occur, and here open the knife-switch quickly and strictly prohibit reclosing to prevent accident spread.

12.3 Busbar and Cables

12.3.1 Busbar

a) The full chain type enclosed busbar is used for generator main busbar and auxiliary

branch busbar, with self-cooing mode.

b) The conductor of enclosed busbar adopts circular tube aluminum busbar and positive Y insulator support mode and the busbar to casing (ground) is not less than 240mm; the casing adopts aluminum circular tube and the neutral point adopts busbar chamber structure; the bulk life time of enclosed busbar should not be less than 30 years.

c) Inspection before busbar energization:

1) The work-sheet of the loop subordinate to busbar is concluded; safety measures are removed; the busbar is clean.

2) The busbar insulation is acceptable (subject to repair notice).

3) The busbar insulator is free of crack and deformation and the screws of components are complete and fastened.

4) The casing short-circuit grounding and casing grounding of enclosed busbar are firm and sound.

d) Inspection of busbar in operation:

1) The busbar and insulator as well as conductor joint are free of heat generation, color change and burnt odor.

2) The support insulator is free of breakage and deformation and the casing grounding of enclosing busbar is sound.

3) The connecting screws are free of looseness and abnormal vibration.



2×300 MW


4) No water accumulation and water shut-off exist inside the casing of enclosed busbar.

5) The enclosed busbar is free of abnormal heat generation.

e) The busbar temperature is high and the busbar has obvious heat generation, color

change or burnt odor; the disposal method is as follows:

1) Inspect whether busbar current exceeds rated value.

2) Adjust operation mode and reduce busbar current, and if the conditions permit, strengthen external cooling.

3) If the above disposal is of on effect, apply to the dispatcher for shutdown and repair.

f) Disposal of abnormal vibration:

1) If the vibration is caused by loose casing screw and support insulator, try to eliminate it in time.

2) If the vibration is caused by conductor body, it should be shut down for inspection and disposal.

12.3.2 Power Cable

a) Generally, normal operating voltage of cable should not exceed 15％ of rated voltage.

b) The long-time allowable temperature of cable conductor should not exceed the values listed as the following table (if the values diverge from the manufacturer’s specified values, the manufacturer’s specified values prevail). Unit: .

Voltage Cable type

3kV and below

6kV

10kV

Rubber insulation 65 65

Polyvinyl chloride (PVC) insulation 65 65

Polyethylene (PE) insulation 70 70

Cross-linked polyethylene insulation 90 90 90

c) The long-time allowable current-carrying capacity of cable during normal operation should be calculated and determined according to the operating temperature of cable conductor, loss and thermal resistance of each part of cable, laying mode, ambient temperature and heat dissipation conditions, etc. In principle, cable overload is not allowed, even if the overload arises from fault disposal, normal current should be restored quickly.

In an emergency, short-time overload is allowed for cable and the following requirements should be complied with:

1) 1) 10％overload for 2h continuously is allowed for 380V cable.



2×300 MW


2) 2) 15％overload for 2h continuously is allowed for 6kV cable.

3) 3) After the specified time of overload ends, normal load should be restored at once. For the intermittent overload, the overload once again is not allowed until after the

last overload ends 10～12h.

d) Before the cable with power outage more than one week but less than one method is put into operation again, the insulation resistance should be measured with megameter. If any doubt, the high voltage test must be conducted to inspect whether the insulation is sound. For the cable with power outage more than one month but less than one year, the DC high voltage test must be conducted. For the cable with power outage exceeding test period, the cable must be tested according to preventive test standby items.

The insulation resistance of 6kV cable, measured with 2500Ｖmegameter for 60s

should not be less than 6ＭΩ and the insulation resistance of 380Ｖcable, measured

with 500Ｖmegameter for 60s should not be less than 0.5ＭΩ.

The standby power cable should be charged up for operation as much as possible.

e) The cable for metal box type busbar is insulated with ethylene-propylene rubber and provided with chlorosulfonated polyethylene fire-retardant sheath; the resin toughened glass material is used for cable supporter. The pressure type joint is used for cable joint and the contact surface is silvered; maximum operating temperature of spiral

connection joint should not exceed 105.

f) For the arrangement and laying of cable in box, the equalizing of conductor current

distribution should be considered; the in-phase should not exceed 4 ％ and the

phase-phase should not exceed 5％.

g) Inspection of cable in operation:

1) Cable channel cover plate should be complete and cable channel is free of water accumulation, oil accumulation or other impurities.

2) For each cable line laid in the ground, inspect whether road surface is normal; whether there is excavation trace; whether line marking stake is intact, etc.

3) Forbid stacking up rubble, slag, building material, heavy workpiece, acid and

alkaline excrement or build lime pit by piling bricks, clay, stones on cable line, etc.

4) The cable head does not generate heat and the bushing is free of breakage and discharge trace.

5) The ventilation, drainage and lighting facilities in cable channel or cable tunnel should be complete and in particular, the fire control facilities should be complete.

6) The cable sheath temperature should not exceed allowable normal value and the load current should not exceed allowable value.

h) The special inspection of water level in cable channel should be performed in thunder storm weather in summer.

i) The power supply must be cut off immediately in the case as follows:



2×300 MW


1) The cable insulation is broken down as a result that the cable is grounded to discharge electricity.

2) The cable sheath is ruptured and the shielding layer has been damaged, which has

a strong impact on correctness of operation measurement and control.

3) The cable catches fire and generates smoke.

12.4 Current Transformer (CT) and Potential Transformer (PT)

12.4.1 The secondary side of PT in operation should not be short-circuited and the secondary

side of CT should not be open-circuited.

12.4.2 After repaired, PT should not be put into operation until it passes the test conducted by

tester. Inspection before put into operation:

a) PT high voltage side neutral point, casing and secondary side grounding are in good condition.

b) No short circuit line and impurity hindering operation exist.

c) Each part is clean and free of oil seepage and both oil level and oil color are normal.

d) The bushing and insulator are complete and free of crack, etc.

e) The screw of each part should be fastened.

12.4.3 After CT is repaired, the insulation should be acceptable. Inspection before put into

operation:

a) Secondary connection is firm and secondary loop has no obvious open circuit.

b) Each part is clean and no impurity hindering operation exists.

c) The bushing and insulator are complete and free of crack, etc.

d) The casing and the secondary ground wire are intact.

e) The screw of each part should be fastened.

12.4.4 Inspection of PT in operation:

a) Oil level is normal; oil color is transparent; no oil seepage exists.

b) The bushing and insulator are clean and free of crack and electric discharge sign.

c) High voltage side neutral point, casing and secondary side ground wires are intact and

sound; the breakdown assurance should be normal.

d) PT cubicle should be intact and closed well, and moreover, the humidity should not be too large.



2×300 MW


12.4.5 Inspection of CT in operation:

a) The bushing and insulator are free of crack and discharge sound as well as abnormal sound.

b) The screw of each part is fastened and free of looseness, discharge spark and abnormal heat generation.

c) The casing and the secondary grounding are sound.

12.4.6 PT secondary switch tripping (cutout blown) or loop disconnection

a) Faults:

1) When the pointer and AVR PT secondary switch trips (cutout blown) or the loop is disconnected, the indication of relevant voltmeter, cycle counter and active and reactive meters is not normal; if I it is in “2” channel operation before fault, it switches to “1” channel operation automatically.

2) When AVR PT is disconnected, AVR will switch to “manual” mode from “automatic” mode and make an “AVR PT blackout” signal; if I it is in “1” channel operation before fault, it switches to “2” channel operation automatically.

3) When the protection PT secondary switch trips or the loop is disconnected, relevant “voltage loop disconnection” alarm window is sent out.

4) PT high voltage cutout is blown and a ground signal may be made, but here normal

phase indication of phase-to-ground voltmeter is normal.

b) Disposal:

1) No matter which PT secondary switch trips or loop is disconnected, the time should be recorded accurately and the reading of kilowatt-hour meter should be recorded as much as possible respectively when the secondary switch trips and recovers.

2) When the protection PT secondary switch trips or the loop is disconnected, in order to prevent protection misact, contact with the dispatcher and then stop the protection.

3) When the generator PT secondary switch trips or is disconnected, the requirements in generator part of this manual should be complied with.

4) When the auxiliary power busbar PT secondary switch trips, stop the auxiliary power quick change-over device and open the busbar low-voltage DC secondary switch.

5) Replace cutout: when the high voltage cutout is blown, open the PT knife-switch (pull out PT cabinet body) and open the low voltage secondary switch; put on insulation tools and replace the blown phase cutout.

6) After replaced, if the cutout is blown again, stop the replacement and find out the fault source further, if the operator can not handle the fault, report to relevant leader in time. If the fault has relatively great impact and can not be eliminated within short time, follow the shift-chief operator’s order to change the operation mode of relevant



2×300 MW


equipment and then handle the fault.

7) After return to normal through disposal, restore normal operation mode in time.

12.4.7 PT is generally operated by means of knife-switch and is stopped and put into operation

along with busbar in normal condition. When the in-service PT must be stopped singly, relevant protection and automatic device should switch over or be stopped. If a fault happens, the power supply of PT busbar should be cut off by means of switch and then the fault PT should be isolated.

12.4.8 CT secondary loop is open-circuited:

a) Faults:

1) The pointer CT secondary side is open-circuited and the indication of relevant

ammeter and active and reactive meters is not normal.

2) The differential protection CT secondary side is disconnected, and relevant “differential disconnection” signal is made.

3) When serious, CT makes an abnormal sound; electric discharge, smoking, burnt

odor and even primary loop fault may be caused.

b) Disposal:

1) When the differential protection CT secondary side is disconnected, stop the differential protection.

2) After safety measures are taken for fault CT, the secondary short connection work may be conducted, if possible, reduce fault CT primary current or disconnect primary side for disposal by protector.

12.4.9 Both PT and CT should be stopped in any case as follows:

a) The interior has serious discharge sound and abnormal noise as well as violent

vibration.

b) The smoking, fire or burnt odor is discovered.

c) PT high voltage cutout is blown twice continuously.

d) The bushing is damaged and oil leakage causes no oil level indication.

e) Discharge electricity between leading wire and casing.

f) The transformer temperature is too high.

g) It is very danger to personal and equipment safety.

12.4.10 Fire disposal of CT and PT:

a) Shut off power supply immediately by means of switch.

b) Use carbon tetrachloride or carbon dioxide and 1211 fire extinguishers to put out the fire



2×300 MW


and do not use foam fire extinguisher or water to put out the fire.

12.5 Lightning Arrester

12.5.1 The lightning arrester should be put into operation in normal condition. It must pass the

test before the lightning arrester is put into operation.

12.5.2 After lightning storm, inspect whether lightning arrester exterior has discharge trace and

whether lightning recorder acts.

12.5.3 Inspection of lightning arrester:

a) It should be clean around lightning arrester and the exterior insulator should be intact,

clean and free of crack and discharge trace.

b) The grounding flat iron should be intact; the lightning recorder should be connected well and inspect whether lightning recorder acts.

c) Each joint connection of combined lightning arrester is firm and free of incline.

d) When the lightning happens, forbid approaching grounding lead-down wire of lightning arrester.

12.5.4 The lightning arrester should be stopped immediately in any case as follows:

a) Lightning arrester insulating bush explodes, or broken, or discharges electricity

severely.

b) There is discharge sound inside lightning arrester.

c) Lightning arrester ground wire is loose and broken off.

d) Lightning arrester connecting lead wire is loose and broken off, which may cause grounding.

e) When the lightning arrester is in operation, if there is smoking and fire, or the bushing is badly damaged, or there is electric discharge, or the single-phase grounding or phase-to phase fault will be caused, stop the lightning arrester immediately by means of switch.

12.6 Special Inspection

12.6.1 After the system goes out of order within short time and the forced excitation acts, a full

inspection should be performed for generator and other main equipment.

12.6.2 Special inspection of outdoor power distribution device:

a) Before strong wind, inspect whether there are weeds and other things that are blown away by strong wind to cause short circuit, around busbar and power distribution device; inspect whether the lightning rod above power distribution device is skew or may be



2×300 MW


blown down by wind.

b) In light rain and fog day, outdoor equipment bushing and insulator should not be free of discharge or flashover.

c) In snowy day, inspect that the conductor should not be coated with too thick ice or the long icicle should not be generated; inspect that the falling snow in connection joint should not be melted immediately.

d) After lightning storm, inspect whether the lightning arrester has exterior discharge trace and whether the lightning recorder acts.

e) In lightning storm day, a special inspection should be performed for water level in cable channel.

f) When the air temperature changes suddenly, the oil conservator and the oil level of oil filled bushing should be inspected. When the air temperature drops sharply, the switch heating device should be put into operation in good time according to the circumstances of air temperature drop and should be stopped after the temperature rises.

13 Diesel Generator and Emergency Power Supply

13.1 Equipment Specification

13.1.1 Specification of Diesel Generator Equipment (table 1)

Table 1 Specification of Diesel Generator Equipment

Items（OWER） Nominal Parameter

（PRZME） Maximum Parameter

（STANDBY）

Model AG850-4

Manufacturer MTU Company (Germany)

Power（RATED （kw） 680

Power factor（POWER FACTOR） 0.8

Current（RATED CURRENT）（A） 1231

Voltage（VOL AGE） 400/230

Frequency（FREQUENCY）（Hz） 50

Rotating speed （ ROTATING

SPEED）（R/MIN）

1500

Battery voltage（BATTERY VOLTS） 24

Gross weight（GENSE MAXMASS）

（kg）

6600



2×300 MW


Control system（CONTRL SYSTEM） PLC

Excitation mode Brushless self-excitation

Fuel oil specification ＃0 diesel oil

Fuel oil consumption rate g/kW.h ≤194

Lubricating oil specification 15W40CD（Shell or Mobil）

Cooling mode Water cooling

Starting mode Electric starting

Neutral point grounding mode Neutral point solid ground

13.2 Interlocking Logic Description of D/G and Emergency Power

13.2.1 Automatic Startup

Besides automatic control mode, the unit is provided with two manual control modes,

namely local control cabinet control and remote control in central control room.

Normal switching of power source is attained by means of mutual interlocking between unit feeder circuit breaker and operating power source incoming line circuit breaker in AC emergency safety section. When the safety-section busbar voltage is lost, after 3-6s time delay (avoid automatic put-in time of relaying protection and standby power source), the diesel generating unit starts up automatically by means of linkage of safety-section busbar voltage monitoring relay and auxiliary relay; when the frequency and voltage of diesel generating unit reach the setting value, the outlet switch of diesel generating unit is closed and here the interlocking safety-section operating power source incoming line circuit breaker trips and the safety-section diesel generating unit feeder circuit breaker is closed, and then the unit begins to supply power to safety-section busbar. When the safety-section operating power source recovers, the stop command is given manually according to program and the unit trips and stops automatically.

During normal standby, the safety (A and B)-section busbar voltage should be monitored by means of real-time online. When the busbar voltage is lower than setting value and after certain time delay (may be set), the “startup” command is not received or the command is received, but the unit fails to start up, and here an alarm should be given to the operator in central control room at once and the operator is allowed to give a startup command by means of emergency button on control board. The command channel should be independent of normal program starting channel, i.e. the unit program start should adopt dual channel.

The local manual mode is used for shutdown. After shutdown, the outlet circuit breaker is disconnected automatically and the two-way switch value is respectively outputted to safety A and B-section safety source circuit breaker to switch off it. In addition, the local emergency shutdown button should be installed. The local control is used for test, adjustment and normal maintenance of unit and here the unit is usually in no-load operation.

When the on-load test needs to be conducted for unit, the starting process is the same as “automatic”. Only “startup” command is given by means of local manual operation. And here the



2×300 MW



transient parallel is available to unit and power plant source and then switches to unit power supply; when the test is completed, the unit should also be in transient parallel with power plant source and finally switches to power plant source. The automatic adjusting device should ensure stable switching of load power supply.

If the self-starting of diesel generator all fails thrice, the shutdown signal is made, and moreover, the block self-starts loop.

13.3 Normal Operation, Maintenance and Notice

14.3.1 In normal condition, the diesel generator should be put in hot reserve and the no-load

local manual starting test should be conducted once respectively on the 10th day and 25th

day of every month for the diesel generator in hot reserve, but the no-load running time should not exceed 10min every time.

14.3.2 Inspection items of diesel generator in hot reserve:

a) Inspect that all switches, knife-switches and control switches are in correct position and meet self-starting conditions;

b) Inspect that diesel generator outlet switch and safety power switch are normal;

c) Inspect that special 24V battery voltage and floating charge current should be normal:

24V DC power source for diesel generator starting motor is provided by 2×12V special battery (200Ah); the special battery should be fully charged normally and the voltage is not less than 27V; the battery is charged by external charger that is put into “automatic” floating change operation normally;

d) Inspect that no abnormal signal is made on control panel of diesel generator body, with correct state;

e) Inspect that no abnormal signal is made on PLC control cabinet of diesel generator, with correct state;

f) Inspect that the diesel generator and its surrounding are clean and free of impurities;

g) The diesel generating unit is free of oil leakage and water leakage; the oil level in oil tank of diesel generator is normal; the oil way valve is opened.

14.3.3 It is strictly prohibited that the diesel generator is in parallel operation with system. When 380V safety-section busbar switches to normal power supply manually from diesel generator power supply, the short-time power outage mode should be adopted;

14.3.4 After the diesel generator is started and shut down each time, the reset button must be pressed for resetting once;

14.3.5 During operating period, some one must be on the spot to monitor the operating condition of diesel generator and the prescribed requirements should be met. The operating parameters such as voltage, current, vibration, frequency and temperature of diesel generator should not exceed allowable value and no abnormal alarm signal is made on control panel;


2×300 MW



14.3.6 After the diesel generator is overhauled, the self-starting on-load test must be conducted and the diesel generator should not be put into operation until it returns to normal;

14.3.7 The unit may operate stably for long time under rated power; the allowable operating

time is 1h under 1.1 times of rated power and the allowable operating time is 10s under 3.0-times short-time overload;

14.3.8 After the diesel generator is stopped by clapping emergency shutdown button manually

on the spot, the emergency shutdown button must be drawn outward and then can be reset;

14.3.9 When the air temperature is below 0 in winter, the diesel generator water heater

should be put into operation;

14.3.10 The fire-extinguishing apparatus in diesel generator room should be all complete.

14.3.11 Protection configuration and operating condition of diesel generator

a) Unit overspeed protection: shut down and close oil valve, audible and visual alarm;

b) Over low lubricating oil pressure: shut down and close oil valve, audible and visual alarm;

c) Diesel generator self-starting failure: shut down and close oil valve, audible and visual alarm;

d) Diesel generator cooling water overtemperature: shut down and close oil valve, audible and visual alarm;

e) Diesel generator protection outlet CB protection act: shut down and close oil valve, audible and visual alarm;

f) Namely: low voltage block overcurrent protection, reverse power protection and automatic voltage regulator protection;

g) Diesel generator emergency tripping: audible and visual alarm;

h) Low diesel generator lubricating oil: audible and visual alarm;

i) Low diesel generator cooling water level: audible and visual alarm;

j) Low oil level in oil tank of diesel generator: audible and visual alarm;

k) High diesel generator cooling water temperature: audible and visual alarm;

l) Diesel generator single-phase grounding protection: audible and visual alarm;

m) Diesel generator overload protection: audible and visual alarm;

n) Low diesel generator battery voltage: audible and visual alarm;


13.4.1 Off-normal starting and abnormal operation of diesel generator

a) Source of starting failure:


2×300 MW


1) No fuel oil or fuel oil is short;

2) The motor cylinder cooling water temperature is low;

3) The battery voltage is low;

4) The injecting oil pump is filled with air;

5) The starting motor breaks down;

6) The control loop fails.

b) Disposal:

1) Inspect according to the above circumstances, and when necessary, heat up or fill oil;

2) Inspect diesel generator starting battery voltage. If the voltage is low, the battery

must be charged; if the connection is poor, it should be fastened;

3) Inspect whether fuel oil piping and filter are choking;

4) Inspect injecting oil pump and loosen screw plug to discharge air;

5) If battery voltage is over low, the battery should be charged by equalizing, if starting motor is faulty, perform relevant inspection and disposal;

6) Inspect relevant control loop and clear relevant fault;

7) If the gas exhaust system generates white smoke, it shows that fuel oil has entered into motor, and inspect whether solenoid valve is in working order.

13.4.2 Diesel generator generating white smoke

a) Source of fault:

1) Exhaust smoke contains moisture;

2) After the generator starts, the loading up is excessively quick;

3) The oil injector is off-normal.

b) Disposal:

1) Inspect whether fuel oil contains water and eliminate water leakage source;

2) If it is still of no effect through the above disposal, the oil injection distributor and the component that may goes out of order should be inspected and repaired by repairer.

13.4.3 Diesel generator generating blue smoke

a) Source of fault:

1) The motor runs without load for long time;

2) The exhaust smoke is mixed with lubricating oil;

3) The operating condition of motor piston ring is bad.



2×300 MW


b) Disposal:

1) Increase motor load as much as possible;

2) Inspect lubricating oil seepage point;

3) Repair the motor piston ring and the component that may goes out of order by repairer.

13.4.4 Diesel generator is under capacity or generates block smoke

a) Source of fault:

1) Air filter is too dirt;

2) Oil nozzle is faulty;

3) Fuel oil valve is faulty and valve opening is not enough;

4) Injecting oil pump breaks down;

5) Oil injection distributor is off-normal;

6) Turbocharger is too dirt or faulty.

b) Disposal:

1) Inspect and clean air filter;

2) Make relevant disposal by repairer.

13.4.5 Diesel generator overheating

a) Source of fault:

1) Water circulating piping ring is choking;

2) Water piping is not filled with water or there is air;

3) Water level in water tank is lower;

4) Radiator is blocked;

5) Cooling water temperature regulator goes wrong;

6) Water pump breaks down.

b) Disposal:

1) Inspect whether cooling water piping and radiator are blocked, when necessary, clean them;

2) Fill water pipe with water and discharge air in pipe;

3) Inspect whether water level in water tank is normal, when necessary, fill water;

4) Make relevant disposal by repairer;

5) Inspect ventilation condition of machine house;



2×300 MW


6) Inspect whether ambient temperature is within diesel generator design range.

13.4.6 Diesel generator overloading

a) Disposal:

If it is found that the diesel generator is overloaded during operation, relevant electrical loop should be inspected at once. If no abnormal condition is found out, remove unit part load and then inspect operating condition of generator.

13.4.7 The diesel generator rotates at high speed and the rotating speed can not drop:

a) Source of fault: the speed control system is out of order;

b) Disposal: emergency shut down and cut off fuel oil.

13.4.8 Faults and disposal

When the following serious faults happen to diesel generator and the protection does not

act, and immediately clap the emergency shutdown button manually on the spot to stop diesel generator:

a) The generator generates smoke and catches fire;

b) Generator coil temperature rises to limit value;

c) Generator stator is grounded;

d) Generator voltage drops to limit value;

e) Generator voltage rises to limit value;

f) The unit speed exceeds limit value;

g) Cooling water temperature rises to limit value;

h) Lubricating oil pressure drops to limit value.



2×300 MW


14 110 kV system operation

14.1 110 kV system operation mode

14.1.1 Electrical Wring

110 kV station transformer (TD11) is connected to Hoanh Bo—Giap Khan overhead line （ “T”

type） by means of a 110kV circuit breaker (131) and connection switch( 131-3,131-7).

14.1.2 Grounding Mode

High-voltage side of Station transformer is grounded directly; low-voltage side grounding via a resistance of 3.8 Ω.

14.1.3 Normal operation mode of 110 kV system

In normal case, The 110 kV system as the standby power supply for all 6.6 kV section bus bar. Beside relay protection tripping or the order form A0, the 110 kV system is forbidden to be power cut without permission!

14.1.4 Technical Specification of 110 kV station transformer

Name of Equipment standby transformer


Model SFZ-CY-50000/115TH


Rated capacity 50000/31500-25000-31500kVA

Rated voltage （115±10×1.0％）/6.8—6.8kV

Rated current 251.02/2674.49A

Cooling mode ONAN

Wiring category YNyn0yn0d11

No-load loss 33.6kW

Load loss 160kW


Impedance voltage 19％


Wire type Staition transformer is selected as split transformer with balance coil.



2×300 MW


14.1.5 Rated Operation Mode

14.1.1.1 The station transformer should operate according to rated nameplate parameters specified by manufacturer. The transformer may operate according to rated capacity all the year around under rated conditions of use.

14.1.1.2 Allowable temperature of transformer in operation should be monitored according to upper-layer oil temperature. When cooling medium temperature drops, the upper-layer oil temperature of transformer should also drop. Maximum upper-layer oil temperature

should not exceed 95. In order to prevent transformer oil deterioration acceleration, the

upper-layer oil temperature should not exceed 85 frequently.

The middle and upper-layer oil temperature and temperature rise of oil immersed transformer in operation with different cooling mode should not exceed the specified value shown as following table:

Cooling Mode

Upper-layer Oil Temperature Rise

Maximum Upper-layer Oil

Temperature

General Upper-layer

Oil Temperature

Oil immersed self-cooling and air cooling

55

95

85

Forced oil circulating air cooling

45

85

75

14.1.1.3 The applied primary voltage of transformer may be higher than rated value, but usually

should not be greater than 105％ of rated voltage of relevant tap. No matter where the

transformer tap is, if the applied primary voltage does not exceed 5% of relevant rated value, secondary side of transformer may be loaded with rated current.

14.1.6 Allowable Overload Operation Mode

14.1.2.1 The station transformer may operate in the case of normal overload and emergency

overload. Normal overload may be used frequently and its allowable value may be determined according to transformer load curve, cooling medium temperature and transformer-carried load before overloading, etc. Emergency overload is only allowed to be used in an emergency. When the transformer has major defects (e.g. cooling system is off normal; oil leaks severely; chromatographic analysis is abnormal, etc.), overload operation is not allowed.

Normal overload and emergency overload capacity of oil immersed transformer should comply with the manufacturer’s requirements. In case no manufacturer’s requirements are available, the allowable time of emergency overload of oil immersed transformer may be referred to the following table according to different cooling mode and ambient temperature:

Allowable Operating Time of Oil Immersed Self-cooling Transformer in the Case of Emergency Overload (h: min)



2×300 MW



1.1 24：00 24：00 24：00 19：00 7：00

1.2 24：00 24：00 13：00 5：50 2：45

1.3 23：00 10：00 5：30 3：00 1：30

1.4 8：30 5：10 3：10 1：45 0：55

1.5 4：45 3：10 2：00 1：10 0：35

1.6 3：00 2：05 1：20 0：45 0：18

1.7 2：05 1：25 0：55 0：25 0：09

1.8 1：30 1：00 0：30 0：13 0：06

1.9 1：00 0：35 0：18 0：09 0：05

2.0 0：40 0：22 0：11 0：06

14.1.7 Insulation Monitoring

1) Before the transformer is put into operation and after repair or service interruption,

the insulation resistance at each side of transformer should be measured. During measurement, the voltage transformer connected to transformer must be disconnected.

2) When the insulation resistance of transformer coil is measured, 2500V megameter should be used for the coil with voltage of above 10kV and 500V megameter should be used for the coil with voltage of below 500V.

3) Before measurement, the measured coil should be grounded to discharge electricity; during measurement, R15″ and R60″ values should be measured and the absorptance R60″/R15″ is calculated according to measured result. After completion of measurement, the electricity should be discharged to the ground.

4) The insulation resistance value of oil immersed transformer should comply with the following requirements:

The absorptance of above 20kV transformer and below 20kV transformer at 10-30

should not be lower than 1.3 and 1.2 respectively.

The insulation resistance should not be less than the specified value shown as following table.

Allowable Insulation Resistance Value of Oil Immersed Transformer (MΩ)



2×300 MW


Temperature

High Voltage

Winding Voltage

10

20

30

40

50

60

70

80

3—10kV 450 300 200 130 90 60 40 25

20—35kV 600 400 270 180 120 80 50 35

60—500kV 1200 800 540 360 240 160 100 70

Note: both medium and low voltage insulation resistance standard of identical transformer is the same as high voltage winding.

When the measured insulation resistance value is unacceptable, report to shift-chief operator in time and contact with repairer to find out and eliminate fault source. After fault removal, restore transformer standby mode and put transformer into operation according to the dispatcher’s order.

14.2 110 kV system operation

14.2.1 Preparation before Station Transformer Put into Operation

Before the transformer is put into operation, the work sheet of relevant electrical connection

loop of transformer should be revoked, and moreover, disconnect ground wire and short circuit wire; make sure the transformer is intact and the loop is complete and meets operating condition, and besides do well the work as follows:

a) Measure that transformer insulation resistance should be acceptable (for the repaired equipment, check electrical repair hand-over record book);

b) Inspect that transformer tap is in correct position; both oil color and oil level of oil conservator are normal; each part of transformer body is free of oil impregnate and leakage;

c) Gas relay valve should be opened and filled with oil; the interior should be free of gas and the covering hood should be intact;

d) Inspect that cooler valve should be opened and each cooling device should be in good condition (after repair, the valve should be opened by repairer); cooler power source interlocking and motor trial operation should be normal;

e) Inspect that breather silica gel color should be normal; pressure relief valve should be intact and in reset state; permanent ground wire in each part of transformer should be firm and reliable.

f) Inspect that transformer thermometer wiring is intact and setting temperature meets the requirement.

g) Inspect that secondary loop equipment (control, pointer and protection device, etc.) should be intact; protection devices of transformer during normal operation should be put into operation correctly.



2×300 MW



14.2.2 Operation of Transformer

a) The power interruption and transmission operation of transformer not only should comply with relevant electrical operation and accident treatment regulations but also should comply with the following requirements:

1) The transformer should be charged up from the power source side provided with protection device. In the case of power interruption, the power source-side switch provided with protection device should be disconnected finally.

2) Use fuse to put in or release transformer and strictly prohibit using knife-switch to put in or release transformer.

b) After coil replacement and overhaul, Station transformer and low-voltage house service transformer after repair must not be put into operation until checking that phase sequence and charging are normal.

c) The voltage tap of on-load regulating switch of on-load regulating transformer may be switched during normal operation of transformer. During switching operation, pay attention to the following:

1) Give attention to tapping switch position indication, transformer current and voltage of any other side;

2) In principle, for on-load regulating switch, only operate a gear once and then with an internal of time, adjust the next gear;

3) When the transformer is overloaded, do not operate on-load tapping switch frequently;

4) The on-load regulating tapping switch is electrically operated in normal condition. When electric operation is out of order, it may be manually operated, but necessary safety measures should be taken.

14.2.3 When the on-load regulating tapping switch is manually operated, cranking 33 circles by

hand every time is a tap; clockwise is voltage step-up direction and anticlockwise is voltage step-down direction. Operating procedure: take off connecting sleeve cover and switch off the power source of electrically operated mechanism; install the built-in handle crank to worm shaft for operation, after completion of switching, inspect that handle crank is just vertical upward and numerical value display is just right in the middle of indicating piece notch, and finally make connecting sleeve return to original state.

14.2.4 The on-load regulating switch of transformer should be maintained and inspected

according to the following requirements:

a) The defilement degree of oil in change-over switch insulating cylinder should be inspected regularly. Usually, after operating about 1000 times under rated current, the oil sample should be assayed once and withstand voltage value of oil should not be less than 30kV. When withstand voltage value of oil is less than 30kV, it must be replaced with new oil. Even if withstand voltage value of oil exceeds 30kV, it must be also replaced with new oil once a year.


2×300 MW


b) The electrically operated mechanism should keep intact at all times.

c) The gas protection and explosion-proof equipment of tapping switch should be intact, after they acts, and find out the reason.

14.2.5 The gas protection of transformer in operation or in hot reserve must be put in “trip”

position and the gas protection of transformer in cold reserve may be put in “signal” position to facilitate monitoring oil level of transformer.

14.2.6 When the oil level indicated on oil level gauge rises abnormally, the reason for oil level

rise should be found out. Before gas protection trip strap is released, the opening of various gas discharge or oil drain plugs is prohibited to clean up moisture absorber or to do any other work so as to prevent gas protection misoperation trip.

14.2.7 When the transformer operates in the following cases, heavy gas protection strap should

be changed to signal from trip, after completion of operation, the gas protection should return to “trip” position.

a) In the case of oil filling, oil filtering or replacing oil submerged pump;

b) In the case of cleaning eyelets of breather or opening valves in any other position to discharge gas, drain oil or feed oil (except oil sampling and gas relay degassing);

c) In the case of operating on gas protection secondary loop.

d) In the above cases, transformer gas protection putting in trip or changing to signal must be approved by shift-chief operator.

14.2.8 Inspection of Transformer

a) During transformer operation, the attendant should monitor transformer operating

condition according to pointer indication and should transcribe relevant transformer parameters once a hour in normal case. When the transformer operates in the case of overload or any other abnormal condition, strengthen monitoring the load, upper-layer oil temperature and coil temperature of transformer and reduce transcribing time interval.

b) Inspection of Oil Immersed Transformer in Operation

1) Both oil level and oil color of transformer oil conservator and bushing should be normal; each part of transformer should be free of oil impregnate and leakage;

2) The bushing exterior should be clean, free of breakage crack, discharge track and any other abnormal phenomenon;

3) The sound in each part of transformer should be normal;

4) The temperature in each part of transformer is normal; the opening of oil system valve is correct; fan and oil pump are in normal operation;

5) Each joint of transformer primary loop has sound contact, free of heating;



2×300 MW


6) Pressure relief valve or explosion proof pipe is intact; pressure relief valve is in reset state;

7) Gas relay should be free of gas and should be filled with oil; the valve of gas relay

access to oil conservator should be opened;

8) Doors and windows of transformer cubicle should be complete; no water leakage and flowage exist in the cubicle, with sound lighting and ventilation;

9) Inspect that neutral point grounding resistance of transformer is free of overheating;

10) Tapping position of on-load tapping switch and power source indication should be normal;

11) Inspection of transformer neutral point ground resistor:

A. It should be free of impurities in resistor; if there is much of dust, the dust should be cleaned off as soon as possible;

B. Inspect whether the connection between resistor elements are sound;

C. Inspect whether operating condition of insulation supporter is sound;

D. Before the resistor still keep operating after the system breaks down, necessary inspection of resistor should be implemented carefully to remove hidden trouble.

14.2.9 Special inspection of transformer:

a) After gas and differential protections act, perform inspection immediately; increase

inspection times in the case of abnormal operation.

b) In rainy, snowy or foggy day, inspect whether transformer joints have steaming and melting or whether flashover discharge is serious; the bushing should be free of breakage and burnt track and the insulator has no the icicle causing flashover.

c) In strong wind weather, inspect that upper outgoing line of transformer should be free of severe oscillation and looseness; the top cover and surrounding are free of impurities.

d) When air temperature changes suddenly, perform special inspection of transformer oil level and operating condition of cooling device and inspect whether overheating or icing exists.

e) In the case of overloading, monitor the change of load, oil temperature and oil level; joint contact should be sound and free of overheating; the cooling system should be in normal operation.

f) After short circuit fault, inspect whether relevant joints are deformed and inject oil; inspect whether transformer neutral point or discharging gap has burnt track.

14.3 Abnormal Operation and Trouble Disposal of Transformer

14.3.1 Disposal of Abnormal Operation of Transformer

a) During transformer operation, in case any abnormal condition is found (such as oil



2×300 MW


leakage, inadequate oil conservator level, overheating and abnormal sound), make an attempt to eliminate the abnormal condition as soon as possible and report to higher-level leader. If the abnormal condition can not be eliminated until the transformer is stopped, and has the probability of threatening equipment and system safety, the transformer should be stopped immediately. If standby transformer is available, it should be put into operation as soon as possible.

b) In any case as follows, first of all, contact with repairer and then stop the transformer:

1) The crack, oil seepage, discharge and trace happen.

2) The falling object above transformer endangers safety and can not be removed until the power source is interrupted.

3) The oil leaks severely.

4) The load, ambient environmental temperature and cooling condition have no obvious change, but the temperature of transformer rises abnormally.

5) The transformer oil color changes suddenly; or becomes dark and turbid and the viscosity increases, or the oil is unacceptable through periodical assay.

6) The sound is abnormal, but no discharging sound is made.

7) Each lead terminal is loose, generates heat and turns color.

8) On-load regulating device is out of order; tap adjustment is out of control and the tap can not be manually adjusted to be normal.

9) All main protections of transformer are out of operation.

10) In the above cases, if conditions permit, put standby transformer into operation; if no standby transformer is available, stop transformer operation as soon as possible.

c) Stop the transformer operation immediately in any case as follows:

1) Transformer internal sound is relatively large and uneven, with crackling sound;

2) Under normal load and cooling conditions, transformer temperature is abnormal and is on the rise;

3) Oil conservator or pressure relief valve injects oil;

4) Oil quality change is exaggerated and the oil has been carbonized;

5) The bushing has serious breakage and discharging;

6) The oil leaks heavily and the oil level drops to be lower than indication limit of oil level gauge;

7) The transformer is on fire.

d) When the oil temperature rise of transformer in operation exceeds allowable value, find



2×300 MW


out the reason and take measures to reduce oil temperature, and moreover, do well the work as follows:

1) Inspect the load of transformer and temperature of cooling medium and check

the due oil temperature value under the load and cooling medium temperature;

2) Check the indicated temperature value of remote and local thermometers of transformer;

3) Inspect whether transformer ventilation and cooling devices are normal.

If the temperature increase is caused by abnormality of cooling system, try to put cooling system into normal operation. If the abnormality of cooling system can not be eliminated during operation, adjust transformer load to relevant capacity according to the specifications of this manual, till the transformer stops to eliminate the defect.

If no problem is found through above inspection, transformer oil temperature is over 10

higher than in normal condition under the same load and cooling temperature, or transformer load does not change, but oil temperature is on the rise, the transformer has had internal fault, so the transformer operation must be stopped immediately.

e) Abnormal oil level of transformer

1) When the oil level of transformer is greatly lower than the oil level corresponding to oil temperature of the time, the oil should be filled immediately according to relevant regulations of this manual.

When the oil level drops quickly due to much of oil leakage, prohibit changing gas protection to only acting on signal and take the measures for stopping oil leakage quickly, and moreover, report to higher-level leader and fill oil immediately. If the oil leakage can not be eliminated and the oil level has been down to lower limit, the transformer should be out of operation.

If transformer oil level drops due to relatively low temperature, in order to avoid dropping to below oil level gauge, the operation mode of cooling device should be adjusted according to the load of the time so as to keep transformer oil temperature and oil level within specified range.

2) When transformer oil level is on the rise because of temperature increase, if the oil level at maximum oil temperature is higher than oil level indicating gauge, the oil should be drained to lower oil level to proper height and avoid oil spill.

When transformer oil level rises abnormally arising from breath sealing system blocking or the oil spills out of breather, immediately notify the repairer and report to higher-level leader, and moreover, take effective measures to eliminate the fault. When the above-mentioned oil level is abnormal and the indication of oil level gauge is false oil level, thus any oil drain is forbidden before transformer breather returns to normal.

3) In case oil level is abnormal, monitor closely the oil level gauge of transformer and the change of oil temperature and report to relevant leader in time.



2×300 MW


14.3.2 Trouble Disposal

14.3.2.1 When transformer gas protection acts and makes a signal, inspect the transformer immediately and find out the reason for gas signaling; inspect whether it is caused by air invasion in transformer, or oil level drop, or secondary loop fault.

When the transformer has no external fault signs, the gas sample in gas relay should be taken for test analysis. If the gas is combustible and the chromatographic analysis is abnormal, it shows that the transformer has internal fault and must be stopped for repair.

During the above disposal, attention should be paid to time interval of gas signaling, if the interval time is shortened successively, it shows that the transformer may trip, and here the gas protection is prohibited to be changed to signal; if standby transformer is available, put it into operation and report to leader immediately to stop the transformer operation.

14.3.2.2 When the gas protection acts and trips, fully inspect transformer and take gas sample for testing. The transformer should not be put into operation until the transformer is inspected fully and the test is acceptable.

14.3.2.3 When the gas protection acts and makes a signal, but the switch does not trip, it usually arises from:

Air enters into transformer due to oil filtering, oil filling or untight cooling system;

Oil level drops slowly due to temperature reduction or oil leakage;

Negative pressure is formed due to breathing system clogging; a little gas is generated due to transformer fault;

It is caused by crossing short circuit fault.

14.3.2.4 After the pressure relief valve of transformer in operation acts, the mechanical-electrical signal of relief valve should be reset manually.

14.3.2.5 Automatic Trip

When the transformer trips, inspect protection to find out which protection acts; the tripping reason of transformer may be determined according to operating condition of protection and external conditions (such as external short circuit and transformer overload, etc.) when the transformer trips;

When main protection (such as gas or differential protection) of transformer acts, external inspection of the equipment within protection range must be performed to find out internal fault signs and the insulation resistance of coil should be measured to find out the tripping reason of transformer. If the transformer has internal fault signs, internal inspection should be performed.

If it is ascertained that transformer trip is not caused by internal fault but external fault resulting in overcurrent protection act or secondary loop fault. The external inspection of transformer may not be performed to immediately raise voltage from zero or impact closing and put transformer into operation.

14.3.2.6 Disposal of Transformer Fire



2×300 MW


Immediately cut off power supply and extinguish the fire by use of dry powder, carbon dioxide and 1211 fire extinguishers, and moreover, notify fire department. The liquid is strictly prohibited to be used to extinguish the fire in case the power supply is not cut off.

Stop transformer cooling device.

If transformer top cover catches fire, open emergency oil drain valve to drain oil and make oil level lower than the position on fire, and moreover, the flame can not be gotten out. If it is caused by internal fault of transformer, the oil can not be drained to prevent transformer explosion.



2×300 MW


14.4 110 kV system switching operation procedures

Reminder:

Voltage transformer: PT

110 kV Station transfromer: 110 kV TD11

Circuit breaker: CB

Ground wire : GW

Working power supply: WS

Standby power supply: SS

Connection switch：CS

Earthing switch：ES

14.4.1 Maintenance state to cold standby state of 110 kV staition transfromer （TD11）

√ NO. Part 1: Dangerous point precontroal 1.0 Dangerous point 1 False switching operation 2 CS/ES is not on it’s correct position 3 The load supplied power with ground wire or earthing switch 2.0 Precontroal measures 1 Check the name/number/position earnestly of equipments before operation 2 Forbidden changing the order of operation without permited

3 If the CS or ES is not on correct position, whether can put into operation must

accept the maintenance supervisor’s wirtten suggestions Part 2: Switching operation procedures 1 Get shift director order: maintenance state to cold standby state of 110 kV TD11

2 Check all work permit sheet have been over , the TD11 on power transmission

condition 3 Check 6.6 kV section 1A SS CB 631A in open state 4 Check 6.6 kV section 1A SS CB 631A on outside switchgear position

5 Check 6.6 kV section 1A SS incoming branch PT 631A9 on outside switchgear

position 6 Remove the GW ( NO. ) at TD11 side of 6.6kV section 1A SS CB 631A 7 Check 6.6 kV section 1B SS CB 631B in open state 8 Check 6.6 kV section 1B SS CB 631B on outside switchgear position

9 Check 6.6 kV section 1B SS incoming branch PT 631B9 on outside switchgear

position 10 Remove the GW ( NO. )at TD11 side of 6.6kV section 1B SSCB 631B 11 Check 6.6 kV section 2A SS CB 632A in open state 12 Check 6.6 kV section 2A SS CB 632A on outside switchgear position


position 14 Remove the GW ( NO. ) at TD11 side of 6.6kV section 2A SS CB 632A



2×300 MW


15 Check 6.6 kV section 2B SS CB 632B in open state 16 Check 6.6 kV section 2B SS CB 632B on outside switchgear position


position 18 Remove the GW ( NO. ) at TD11 side of 6.6kV section 2B SS CB 632B 19 Check 110 kV TD11 CB 131 in open state 20 Check 110 kV TD11 property is normal，SF6 compressure indicator shows normal 21 Check 110 kV TD11 CS 131-7 at line side on disconnection position 22 Check 110 kV TD11 CS 131-3 at TD11 side on disconnection position 23 Open the ES 131-38 of TD11 24 Check the ES 131-38 of TD11 on disconnection position 25 Open the ES 131-38 of TD11 CB 131 at TD11 side 26 Check the ES 131-35 of TD11 CB 131 at TD11 side on disconnection position 27 Open the ES 131-75 of TD11 CB 131 at line side 28 Check the ES 131-75 of TD11 CB 131 at line side on disconnection position 29 Check the ES 131-75 of 110 kV line on disconnection position 30 Check the CT TI131 of TD11 CB 131 at line side is normal

31 Check 110 kV TD11 property is normal， terminals box / oil level / oil stain shows

normal

32 Check the On-Load Tap-Changer device of TD11 is normal, tapping position

accord with the requirements of A0 33 Check earthing resistance of TD11 is normal 34 Check the circuit of TD11 has no GW

14.4.2 110kV station transformer (TD11) energized and 5 times closing surge test

√ NO. Part 1: dangerous point precontroal 1.0 dangerous point 1 False switching operation 2 CS/ES is not on it’s correct position 3 The load supplied power with ground wire or earthing switch 4 Violate dispatcher’s discipline 2.0 precontroal measures 1 Check the name/number/position earnestly of equipments before operating 2 Forbid to changing the order of switching operation without permited

3 If the CS or ES is not on correct position, whether can put into operation must

accept the maintenance supervisor’s wirtten suggestions

4

Forbid adopting the followings method to operation : remove the mechanical interlock、operating the contactor maunuly operating the

switch by force 5 Before energize, personnle are in the safe area



2×300 MW


Part 2: switching operation procedures 1 Get shift director order：110 kV TD11 energized and 5 times closing surging test

2 Check all work permit sheet have been over , the TD11 on power transmission

condition

3 Check the surge arrestors CS131 of 110 kV line is normal, the indicator of surge

indicator shows normal

4 Check the PT TU131 of 110 kV line is normal, PT oil level shows normal,

terminals box is normal, secondary voltage switch on it’s proper position

5 Close the secondary DC power supply air switch F11/F12/F13/F14/F15 of 110 kV

line protection panel

6

Check the secondary DC power supply air switch of 110 kV line relay protection

panel no abnormal, changeover switch on it’s proper position, all module no

abnormal signal

7 Check all Protection linking piece in 110 kV line relay protection panel on it’s

proper position accord with the requirements by A0 and relevant regulations

8 Close the secondary DC power supply air switch F11/F12/F13/F14/F15 of 110 kV

TD11 protection panel A

9 Check the secondary power supply of 110 kV TD11 protection panel A is normal,

changeover switch on it’s proper position, all module no abnormal signal

10 Check all Protection linking piece in 110 kV TD11 protection panel A on it’s proper

position accord with the requirements by A0 and relevant regulations

11 Close the DC supply switch F11/F12/F13/F14/F15 of 110 kV TD11 relay

protection panel B

12 Check the DC supply of 110 kV TD11 relay protection panel B is normal,

changeover switch on it’s proper position, all module no abnormal signal

13 Check all relay protection linking piece in 110 kV TD11 protection panel B on it’s

proper position accord with the requirements by A0 and relevant regulations

14 Check the temporary relay protection set point of device T35 in 110 kV TD11

protection panel A has been set for TD11 energized and closing surge test

15 Check the high-speed bus power transfer system of 6.6 kV section 1A in stopped

using sate

16 Check the high-speed bus power transfer system of 6.6 kV section 1B in stopped

using sate 17 Check 6.6 kV section 1A SS CB 631A in open state 18 Check 6.6 kV section 1A SS CB 631A on outside switchgear position


position 20 Check 6.6 kV section 1B SS CB 631B in open state 21 Check 6.6 kV section 1B SS CB 631B on outside switchgear position


position 23 Check the high-speed bus power transfer system of 6.6 kV section 2A in stopped



2×300 MW


using sate


using sate 25 Check 6.6 kV section 2A SS CB 632A in open state 26 Check 6.6 kV section 2A SS CB 632A on outside switchgear position


position 28 Check 6.6 kV section 2B SS CB 632B in open state 29 Check 6.6 kV section 2B SS CB 632B on outside switchgear position


position 31 Check 110 kV TD11 CB 131 in open state

32 Check 110 kV TD11 CB 131 property is normal, SF6 compressure indicator shows

normal 33 Check 110 kV TD11 CS 131-3 at TD11 side on disconnection position 34 Check the ES 131-38 of TD11 on disconnection position 35 Check the ES 131-35 of TD11 CB 131 at TD11 side on disconnection position 36 Check the CS 131-7 of TD11 CB 131 at line side on disconnection position 37 Check the ES 131-75 of TD11 CB 131 at line side on disconnection position 38 Check the ES 131-76 of 110 kV line on disconnection position 39 Check the PT TU131 of 110 kV line is normal, PT oil level and color shows normal

40 Check the surge arrestors CS131 of 110 kV line is normal, the indicator of surge

shows normal

41

Check the TD11 property is normal, oil level and color shows normal, the On-Load

Tap-Changer device of TD11 is normal, tapping position accord with the

requirements of A0

42 Check the CT TI131 property of 110 kV TD11 CB 131 at line side is normal, CT oil

level and color shows normal

43 Close the control power supply and power supply air switch of the CS 131-7 of

110 kV TD11 CB 131 at line side 44 Close the CS 131-7 of TD11 CB 131 at line side remotely 45 Check the CS 131-7 of TD11 CB 131 at line side on connection position

46 Open the control supply and power supply air switch of the CS 131-7 of 110 kV

TD11 CB 131 at line side

47 Close the control supply and power supply air switch of the CS 131-3 of 110 kV

TD11 CB 131 at TD11 side 48 Close the CS 131-3 of TD11 CB 131 at TD11 side remotely 49 Check the CS 131-7 of TD11 CB 131 at TD11 side on connection position

50 Open the control supply and power supply air switch of the CS 131-3 of 110 kV

TD11 CB 131 at TD11 side


position, fuse plug in good state



2×300 MW


52 Rack the truck of 6.6 kV section 1A SS incoming branch PT 631A9 manually from

outside switchgear position to test position

53 Connect the secondary control wire plug of 6.6 kV section 1A SS incoming branch

PT 631A9

54

Close the control supply and secondary voltage air switch B1（4DK）、B2（5ZK）、

B3（1DK）、B4（2DK）、B5（3DK）of the 6.6 kV section 1A SS incoming branch

PT 631A9

55 Rack the truck of 6.6 kV section 1A SS incoming branch PT 631A9 manually from

test position to operation position


position, fuse plug in good state

57 Rack the truck of 6.6 kV section 1B SS incoming branch PT 631B9 manually from


58 Connect the secondary control wire plug of 6.6 kV section 1B SS incoming branch

PT 631B9

59


B3（1DK）、B4（2DK）、B5（3DK）of 6.6 kV section 1B SS incoming branch PT

631B9

60 Rack the truck of 6.6 kV section 1B SS incoming branch PT 631B9 manually from

test position to operation position

61 Get the shift director order: close the 110 kV TD11 CB 131 remotely

Closing time: hh mm

62 Check the 110 kV TD11 CB 131 in closing state, voltage of 6.6 kV section 1B SS

incoming branch shows normal 63 Check temperature and voice of TD11 is normal , porcelain insulator is normal

64 Get the shift director order: open the 110 kV TD11 CB 131

Open time: hh mm 65 Check the energies circuit of 110 kV is normal.


Closing time: hh mm 67 Check temperature and voice of TD11 is normal , porcelain insulator is normal

68 Get the shift director order: open the 110 kV TD11 CB 131 remotely

Open time: hh mm 69 Check the energies circuit of 110 kV is normal.




Open time: hh mm 73 Check the energies circuit of 110 kV is normal


Closing time: hh mm



2×300 MW


75 Check temperature and voice of TD11 is normal , porcelain insulator is normal


Open time: hh mm 77 Check temperature and voice of TD11 is normal , porcelain insulator is normal



14.4.3 Maintenance state to cold standby state of 6.6kV section 1A, 1B

√ NO. Part 1 Dangerous point precontroal 1.0 Dangerous point 1 False switching operation 2 CS/ES is not on it’s correct position The load supplyed power with ground wire or earthing switch 2.0 precontroal measures 1 Check the name/number/position earnestly of equipments before operation 2 Forbid to changing the order of operation without permited Part 2 operation procedures

1 Get shift director order：maintenance state to cold standby state of 6.6 kV section

1A,1B

2 Check all work permit sheet have been over , 6.6 kV section 1A,1B on power

transmission condition 3 Check 6.6 kV section 1A SS CB 631A in open state 4 Check 6.6 kV section 1A SSCB 631A on outside switchgear position

5 Check 6.6 kV section 1A SS incoming branch PT 631A9 on operation position,

voltage shows normal 6 Check 6.6 kV section 1A WS CB 641A in open state 7 Check 6.6 kV section 1A WS CB 641A on outside switchgear position

8 Check 6.6 kV section 1A WS incoming branch PT 641A9 on outside swichgear

position 9 Check all load CB of 6.6 kV section 1A（C61A ）on outside switchgear position 10 Check 6.6 kV section 1A PT C61A9 on outside switchgear position 11 Identifying three phase of 6.6 kV section 1A has no voltage

12

Measure three phase to ground Isolation and alternate Isolation separately of 6.6

kV section 1A

A-B： MΩ，B-C： MΩ，C-A： MΩ

A-ground： MΩ，B- ground： MΩ, C- ground： MΩ

13 Check 6.6 kV section 1A PT C61A9 is normal, on outside switchgear position，

fuse plug in good state

14 Rack the truck of 6.6 kV section 1A PT C61A9 manually from outside switchgear

position to test position



2×300 MW


15 Check the control selector switch “QK” of 6.6 kV section 1A SS CB 631A on

“SWBD” position 16 Check 6.6 kV section 1A SS CB 631A in open state

17

Measure contacts to ground Isolation and alternate Isolation of contacts

separately of 6.6 kV section 1A SS CB 631A



18

Rack the truck of 6.6 kV section 1A SS CB 631A manually from outside

switchgear position to test position 19 Check 6.6 kV section 1B SS CB 631B in open state 20 Check 6.6 kV section 1B SS CB 631B on outside switchgear position

21 Check 6.6 kV section 1B SS incoming branch PT 631B9 on operation position,

voltage shows normal 22 Check 6.6 kV section 1B WS CB 641B in open state 23 Check 6.6 kV section 1B WS CB 641B on outside switchgear position

24 Check 6.6 kV section 1B WS incoming branch PT 641B9 on outside switchgear

position 25 Check all load CB of 6.6 kV section 1B (C61A ) on outside switchgear position 26 Check 6.6 kV section 1B PT C61B9 on outside switchgear position 27 Identifying three phase of 6.6 kV section 1B C61B has no voltage

28

Measure three phase to ground Isolation and alternate Isolation separately of 6.6

kV section 1A



29 Check 6.6 kV section 1B PT C61B9 is normal, on outside switchgear position，


30 Rack the truck of 6.6 kV section 1B PT C61B9 manually from outside switchgear


31 Check the control selector switch “QK” of 6.6 kV section 1B SS CB 631B on

“SWBD” position 32 Check 6.6 kV section 1B SS CB 631B in open state

33

Measure contacts to ground Isolation and alternate Isolation of contacts

separately of 6.6 kV section 1B SS CB 631B



34 Rack the truck of 6.6 kV section 1B SS CB 631B manually from outside

switchgear position to test position 35 Check the circuit of 6.6 kV section 1A, 1B （C61A、C61B）has no GW



2×300 MW


14.4.4 6.6kV seciton 1A, 1B energized （C61A、C61B）

√ NO. Part 1 Dangerous precontroal 1.0 dangerous point 1 False switching operation 2 False order 3 Operating in the wrong HV cubicle 4 Violate dispatcher’s discipline 2.0 precontroal measures 1 Check the name/number/position earnestly of equipments before operating 2 Forbidden changing the operation order by oneself without permited 3 Forbid to operating equipments without permited that administrated by A0

4

forbid adopting the followings method to operation : remove the mechanical interlock、operation the contactor maunuly operating the

switchby force Part 2 operation procedures 1 Get the shift director order： 6.6 kV section 1A,1B energized

2 Check all work permit sheet have been over , the 6.6 kV section 1A,1B on power

transmission condition

3

Check the protection supply of 110 kV TD11 protection panel A is normal, each

protection module no abnormal signal, changeover switches on it’s proper

position

4 Check all Protection linking piece in 110 kV TD11 protection panel A on it’s proper

position accord with the requirements by A0 and relevant regulations

5 Check the temporary relay protection set point of device T35 in 110 kV TD11

protection panel A has been set for closing surge test

6

Check the protection power supply of 110 kV TD11 protection panel B is normal,

each protection module no abnormal signal, changeover switch on it’s proper

position

7 Check all Protection linking piece in 110 kV TD11 protection panel B on it’s proper

position accord with the requirements by A0 and relevant regulations 8 Check 110 kV TD11 operation normal


using state


using state


using state


using state 13 Check 6.6 kV section 1A SSCB 631A in open state 14 Check 6.6 kV section 1A SSCB 631A on test position



2×300 MW


15

Check 6.6 kV section 1A SS incoming branch PT 631A9 on operation position,

voltage shows normal 16 Check 6.6 kV section 1A WSCB 641A on outside switchgear position 17 Check 6.6 kV section 1A SSCB 641A on operation position

18 Check 6.6 kV section 1A WS incoming branch PT 641A9 on outside switchgear

position 19 Check all load CB of 6.6 kV section 1A C61A on outside switchgear position 20 Check 6.6 kV section 1A PT C61A9 on test position 21 Connect the secondary control wire plug of 6.6 kV section 1A PT C61A9

22

close the control power supply and secondary voltage air switch B1（3DK）、B2

（5ZK）、B3（1DK-1）、B4（1DK-2）、B5（1DK-3）、B6（2DK）of 6.6 kV section

1A PT C61A9

23 Rack the truck of 6.6 kV section 1A PT C61A9 manually from test position to

operation position

24 Check the control selector switch “QK” of 6.6 kV section 1A SSCB 631A on

“SWBD” position 25 Check 6.6 kV section 1A SSCB 631A in open state 26 Check 6.6 kV section 1A SSCB 631A on test position 27 Connect the secondary control wire plug of 6.6 kV section 1A SSCB 631A

28 close the control power supply air switch B1（1ZK）、B2（2ZK）、B3（3ZK）、B4

（5ZK）of 6.6 kV section 1A SSCB 631A 29 opening/closing test for 6.6 kV section 1A SSCB 631A, check no abnormal 30 Check 6.6 kV section 1A SSCB 631A in open state 31 Rack the truck of 6.6 kV section 1A SSCB 631A from test to operation position 32 Check the position indicator of 6.6 kV section 1A SSCB 631A shows normal 33 Check the electrification indicator of three phase has no light

34 Turn the control selector switch “QK” of 6.6 kV section 1A SSCB 631A on “PCR”

position 35 Check 6.6 kV section 1B SSCB 631B in open state 36 Check 6.6 kV section 1B SSCB 631B on outside switchgear position

37 Check 6.6 kV section 1B SS incoming branch PT 631B9 on operation position,

voltage shows normal 38 Check 6.6 kV section 1B SSCB 641B in open state 39 Check 6.6 kV section 1B SSCB 641B on outside switchgear position

40 Check 6.6 kV section 1B WP incoming branch PT 641B9 on outside switchgear

position 41 Check all load CB of 6.6 kV section 1B (C61B )on outside switchgear position 42 Check 6.6 kV section 1B PT C61B9 on test position 43 Connect the secondary control wire plug of 6.6 kV section 1B PT C61B9

44

Close the control power supply and secondary voltage air switch B1（3DK）、B2


1B PT C61B9



2×300 MW


45

Rack the truck of 6.6 kV section 1B PT C61B9 manually from test position to

operation position

46 Check the control selector switch “QK” of 6.6 kV section 1B SSCB 631B on

“SWBD” position 47 Check 6.6 kV section 1B SSCB 631B in open state 48 Check 6.6 kV section 1B SSCB 631B on test position 49 Connect the secondary control wire plug of 6.6 kV section 1B SSCB 631B

50 Close the control supply air switch B1（1ZK）、B2（2ZK）、B3（3ZK）、B4（5ZK）

of 6.6 kV section 1B SSCB 631B 51 Opening/closing test for 6.6 kV section 1B SSCB 631B, check no abnormal 52 Check 6.6 kV section 1B SSCB 631B in open state

53 Rack the truck of 6.6 kV section 1B SSCB 631B manually from test position to

operation position 54 Check the position indicator of 6.6 kV section 1B SSCB 631B shows normal 55 Check the electrification indicator of three phase has light

56 Turn the control selector switch “QK” of 6.6 kV section 1B SSCB 631B on “PCR”

position 57 Get shift director order: close the 6.6 kV section 1A SSCB 631A remotely

58 Check the 6.6 kV section 1A SSCB 631A in closing state, voltage of 6.6 kV section

1A shows normal. Report these results to shift director 59 Check the energies circuit of 6.6 kV section 1A no abnormal. 60 Get shift director order: close the 6.6 kV section 1B SSCB 631B remotely

61 Check the 6.6 kV section 1B SSCB 631B in closing state, voltage of 6.6 kV

section 1B shows normal. Report these results to shift director 62 Check the energized circuit of 6.6 kV section 1B no abnormal.

14.4.5 Maintenance state to cold standby state of 6.6kV section 0A, 0B（C60A、C60B）

√ NO. Dangerous point precontroal 1.0 Dangerous point 1 False switching operation 2 CS/ES is not on it’s correct position 3 The load supplyed power with ground wire or earthing switch 2.0 Precontroal measures 1 Check the name/number/position earnestly of equipments before operation 2 Forbidden changing the operation order without permited Part 2 operation procedures

1 Get shift director order：maintenance state to cold standby state of 6.6 kV section

0A,0B（C60A、C60B）

2 Check all work permit sheet have been over , 6.6 kV section 0A,0B on power

transmission condition 3 Check 6.6 kV section 0A SSCB 631A-1（connect with 6.6kV section 2A directly）



2×300 MW


on outside switchgear position

4 Check 6.6 kV section 0B SSCB 630B-1（connect with 6.6kV section 2B directly）


5 Check 6.6 kV section 0A WSCB 640A-1（connect with 6.6kV section 1A directly）


6 Check 6.6 kV section 0B WSCB 640B-1（connect with 6.6kV section 1B directly）


7 Check 6.6 kV section 0A WSCB 640A-2 （connect with 6.6kV section 0A directly）

in open state 8 Check 6.6 kV section 0A WSCB 640A-2 on outside switchgear position

9 Check 6.6 kV section 0A WS incoming branch PT 640A9 on outside switchgear

position

10 Check 6.6 kV section 0A SSCB 630A-2（connect with 6.6kV section 0A directly）

in open state 11 Check 6.6 kV section 0A SSCB 630A-2 on outside switchgear position


position 13 Check all load CB of 6.6 kV section 0A（C60A）on outside switchgear position 14 Check 6.6 kV section 0A PT C60A9 on outside switchgear position 15 Identifying three phase of 6.6 kV section 0A has no voltage

16

measure three phase to ground Isolation and alternate Isolation separately of 6.6

kV section 0A



17 Check 6.6 kV section 0A PT C60A9 is normal, on outside switchgear position,


18 Rack the truck of 6.6 kV section 0A PT C60A9 manually from outside switchgear


19 Check the control selector switch “QK” of 6.6 kV section 0A WSCB 640A-2 on

“SWBD” position 20 Check 6.6 kV section 0A WSCB 640A-2 in open state

21

measure contact to ground Isolation and alternate Isolation separately of 6.6 kV

section 0A WSCB 640A-2


A-ground： MΩ，B- ground： MΩ, C- ground：

22 Rack the truck of 6.6 kV section 0A WSCB 640A-2 manually from outside

switchgear position to test position

23 Check 6.6 kV section 0A WS incoming branch PT 640A9 is normal, on outside

switchgear position, fuse plug in good state

24 Rack the truck of 6.6 kV section 0A WS incoming branch PT 640A9 manually from

outside switchgear position to test position 25 Check 6.6 kV section 0B WSCB 640B-2 in open state

26 Check 6.6 kV section 0B WSCB 640B-2 on outside switchgear position

Date: 2008-09-16


Page - 149 -

Rev. : A


2×300 MW


27

Check 6.6 kV section 0B WS incoming branch PT 640B9 on outside switchgear

position 28 Check 6.6 kV section 0B SSCB 630B-2 in open state 29 Check 6.6 kV section 0B SSCB 630B-2 on outside switchgear position


position 31 Check all load CB of 6.6 kV section 0B (C60B) on outside switchgear position 32 Check 6.6 kV section 0B PT C60B9 on outside switchgear position 33 Identifying three phase of 6.6 kV section 0B has no voltage

34

measure three phase to ground Isolation and alternate Isolation separately of 6.6

kV section 0B



35 Check 6.6 kV section 0B PT C60B9 is normal, on outside switchgear position,


36 Rack the truck of 6.6 kV section 0B PT C60B9 manually from outside switchgear


37 Check the control selector switch “QK” of 6.6 kV section 0A WSCB 640B-2 on

“WSBD” position 38 Check 6.6kV section 0B WSCB 640B-2 in open state

39

Measure contact to ground Isolation and alternate Isolation separately of 6.6 kV

section 0B WSCB 640B-2



40 Rack the truck of 6.6 kV section 0B WSCB 640B-2 manually from outside


41 Check 6.6 kV section 0B WS incoming branch PT 640B9 is normal, on outside

switchgear position, fuse plug in good state

42 Rack the truck of 6.6 kV section 0B WS incoming branch PT 640B9 manually from



“SWBD” position 44 Check 6.6 kV section 0A WSCB 640A-1 in open state

45

measure contact to ground Isolation and alternate Isolation separately of 6.6 kV

section 0A WSCB 640A-1



46 Rack the truck of 6.6 kV section 0A WSCB 640A-1 manually form outside


47 Check the control selector switch “QK” of 6.6 kV section 0B WSCB 640B-1

on ”SWBD” position 48 Check 6.6 kV section 0B WSCB 640B-1 in open state

49 Measure contact to ground Isolation and alternate Isolation separately of 6.6 kV

Date: 2008-09-16


Page - 150 -

Rev. : A


2×300 MW


section 0B WSCB 640B-1



50 Rack the truck of 6.6 kV section 0B WSCB 640B-1 manually form outside

switchgear position to test position 51 Check the energizied circuit of 6.6 kV section 0A, 0B（C60A、C60B） has not GW

14.4.6 6.6kV section 0A,0B (C60A、C60B）energized

√ NO. Part 1 Dangerous point precontroal 1.0 dangerous point 1 False switching operation 2 Violate dispatcher’s discipline 3 Operating in the wrong HV cubicle 2.0 precontroal measures 1 Check the name/number/position earnestly of equipments before operating 2 Forbid to changing the switching operation order by oneself without permited 3 Forbid to operating equipments without permited that administrated by A0

4

Forbid adopting the followings methods to operating :

remove the mechanical interlock,operating the contactor maunuly, operating the

switch by force Part 2 Operation procedures 1 Get shift director order： 6.6 kV section 0A,0B（C60A、C60B）energized

2 Check all work permit sheet have been over , the 6.6 kV section 0A,0B on power

transmission condition 3 Check 6.6 kV section 0A SS CB 630A-1 on outside switchgear position 4 Check 6.6 kV section 0B SS CB 630B-1 on outside switchgear position 5 Check 6.6 kV section 0A WS CB 640A-1 on test position 6 Check 6.6 kV section 0B WSCB 640B-1 on test position


using state


using sate 9 Check 6.6 kV section 0A SS CB 630A-2 in open state 10 Check 6.6 kV section 0A SS CB 630A-2 on outside switchgear position


position 12 Check 6.6 kV section 0A WS CB 640A-2 in open state 13 Check 6.6 kV section 0A WS CB 640A-2 on test position 14 Check 6.6 kV section 0A WS incoming branch PT 640A9 on test position 15 Check all load CB of 6.6 kV section 0A (C60A) on outside switchgear position 16 Check 6.6 kV section 0A PT C60A9 on test position 17 Connect the secondary control wire plug of 6.6 kV section 0A PT C60A9



2×300 MW


18


B3（1DK-1）、B4（1DK-2）、B5（1DK-3）、B6（2DK）of 6.6 kV section 0A PT C60A9

19 Rack the truck of 6.6 kV section 0A PT C60A9 manually form test position to

operation position


“SWBD” position 21 Check 6.6 kV section 0A WS CB 640A-2 in open state 22 Check 6.6 kV section 0A WSCB 640A-2 on test position 23 Connect the secondary control wire plug of 6.6 kV section 0A WS CB 640A-2

24 Close the DC control supply air switch B1（1ZK）、B2（2ZK）、B3（3ZK）、B4（5ZK）

of 6.6 kV section 0A WS CB 640A-2

25 Check the relay protection device of 6.6 kV section 0A WS CB 640A-2 shows

normal 26 Opening/closing test for 6.6 kV section 0A WS CB 640A-2, check no abnormal 27 Check 6.6 kV section 0A WSCB 640A-2 in open state 28 Rack the truck of 6.6 kV section 0A WS CB 640A-2 from test to operation position 29 Check the position indicator of 6.6 kV section 0A WS CB 640A-2 shows normal 30 Check the electrification indicator of three phase no light

31 Turn the control selector switch “QK” of 6.6 kV section 0A WSCB 640A-2 on

“PCR” position 32 Check 6.6 kV section 0A WS incoming branch PT 640A9 on test position

33 Connect the secondary control wire plug of 6.6 kV section 0A WS incoming

branch PT 640A9

34

Close the DC control supply and secondary voltage air switch B1（3DK）、B2


0A WS incoming branch PT 640A9

35 Rack the truck of 6.6 kV section 0A WS incoming branch PT 640A9 from test

position to operation position 36 Check 6.6 kV section 0B SS CB 630B-2 in open state 37 Check 6.6 kV section 0B SS CB 630B-2 on outside switchgear position


position 39 Check 6.6 kV section 0B WS CB 640B-2 in open state 40 Check 6.6 kV section 0B WS CB 640B-2 on test position 41 Check 6.6 kV section 0B WS incoming branch PT 640B9 on test position 42 Check all load CB of 6.6 kV section 0B (C60B) on outside switchgear position 43 Check 6.6 kV section 0B PT C60B9 on test position 44 Connect the secondary control wire plug of 6.6 kV section 0B PT C60B9

45

Close the DC control supply and secondary voltage air switch B1（3DK）、B2


0B PT C60B9 46 Rack the truck of 6.6 kV section 0B PT C60B9 manually form test position to



2×300 MW


operation position

47 Check the control selector switch “QK” of 6.6 kV section 0B WSCB 640B-2 on

“SWBD” position 48 Check 6.6 kV section 0B WS CB 640B-2 in open state 49 Check 6.6 kV section 0B WS CB 640B-2 on test position 50 Connect the secondary control wire plug 6.6 kV section 0B WS CB 640B-2

51 Close the DC supply air switch B1（1ZK）、B2（2ZK）、B3（3ZK）、B4（5ZK）

of 6.6 kV section 0B WSCB 640B-2

52 Check the relay protection device of 6.6 kV section 0B WS CB 640B-2 shows

normal 53 Opening/closing test for 6.6 kV section 0A WSCB 640A-2, check no abnormal 54 Check 6.6 kV section 0B WSCB 640B-2 in open state 55 Rack the truck of 6.6 kV section 0B WSCB 640B-2 from test to operation position 56 Check the position indicator of 6.6 kV section 0B WS CB 640B-2 shows normal 57 Check the electrification indicator of three phase no light

58 Turn the DC control selector switch “QK” of 6.6 kV section 0B WS CB 640B-2

on “PCR” position 59 Check 6.6 kV section 0B WS incoming branch PT 640B9 on test position

60 Connect the secondary control wire plug of 6.6 kV section 0B WS incoming

branch PT 640B9

61

Close the secondary voltage and DC control supply air switch B1（3DK）、B2


0B WS incoming branch PT 640B9

62 Rack the truck of 6.6 kV section 0B WS incoming branch PT 640B9 form test to

operation position


“SWBD” position 64 Check 6.6 kV section 0A WS CB 640A-1 in open state 65 Check 6.6 kV section 0A WS CB 640A-1 on test position 66 Connect the secondary control wire plug 6.6 kV section 0A WSCB 640A-1

67 Close the secondary DC control supply air switch B1（1ZK）、B2（2ZK）、B3（3ZK）、

B4（5ZK）of 6.6 kV section 0A WS CB 640A-1

68 Check the relay protection device of 6.6 kV section 0A WS CB 640A-1 shows

normal 69 Closinging/opening test for 6.6 kV section 0A WS CB 640A-1 is normal 70 Check 6.6 kV section 0A WS CB 640A-1 in open state 71 Rack the truck of 6.6 kV section 0A WS CB 640A-1 form test to operation position 72 Check the position indicator of 6.6 kV section 0B WS CB 640A-1 shows normal 73 Check the electrification indicator of three phase no light

74 Turn the control selector switch “QK” of 6.6 kV section 0A WS CB 640A-1 on

“PCR” position 75 Check the control selector switch “QK” of 6.6 kV section 0B WS CB 640B-1 on



2×300 MW


“SWBD” position 76 Check 6.6 kV section 0B WS CB 640B-1 in open state 77 Check 6.6 kV section 0B WS CB 640B-1 on test position 78 Connect the secondary control wire plug 6.6 kV section 0B WS CB 640B-1

79 Close the secondary DC control supply air switch B1（1ZK）、B2（2ZK）、B3（3ZK）、

B4（5ZK）of 6.6 kV section 0B WS CB 640B-1

80 Check the relay protection device of 6.6 kV section 0B WS CB 640B-1 shows

normal 81 Opening/closing test for 6.6 kV section 0B WS CB 640B-1 is normal 82 Check 6.6 kV section 0B WS CB 640B-1 in open state 83 Rack the truck of 6.6 kV section 0B WS CB 640B-1 form test to operation position

84 Check the position indicator of 6.6 kV section 0B WS CB 640B-1 shows normal 85 Check the electrification indicator of three phase no light

86 Turn the control selector switch “QK” of 6.6 kV section 0B WSCB 640B-1 on ”

PCR” position 87 Get shift director order: close the 6.6 kV section 0A WSCB 640A-1 remotely

88 Check 6.6 kV section 0A WS CB 640A-1 in closing state, voltage of 6.6 kV section

0A WS incoming branch shows normal. Report these results to shift director 89 Get shift director order: close the 6.6 kV section 0A WS CB 640A-2 remotely

90 Check the 6.6 kV section 0A WS CB 640A-1 in closing state, voltage of 6.6 kV

section 0A shows normal. Report these results to the shift director 91 Check the energied circuit of 6.6 kV section 0A no abnormal 92 Get shift director order: close the 6.6 kV section 0B WS CB 640B-1 remotely

93 Check the 6.6 kV section 0B WS CB 640B-1 on closing state, voltage of 6.6 kV

section 0B shows normal. Report these results to the shift director 94 Get shift director order: close the 6.6 kV section 0B WS CB 640B-2 remotely

95

Checking the 6.6 kV section 0B WSCB 640B-2 in closing state, voltage of 6.6 kV

section 0B WS incoming branch shows normal. Report these results to shift

director 96 Check the energied circuit of 6.6 kV section 0B no abnormal



2×300 MW


15 Relay Protection and Automatic Device

15.1 Management Regulations on Operation of Relay Protection and Automatic Device

15.1.1 Operation principle of relay protection and automatic device:

a) Generally, it is not allowed that electrical equipment operates without protection; when

necessary, part protection may be stopped after examining and approving formalities

have been gone through, but main protection can not be stopped at the same time.

During operation, forbid opening the door of protection device cabinet and forbid using

mobile telephone and other devices with radio transmission function in relay protection

cubicle in central control room.

b) The repair and test work of relay protection and automatic device should be conducted

coordinating equipment power outage once. The relay protection and automatic device of

uninterrupted power equipment can be stopped for operation only in the case as follows:

1) Above two kinds of main protection devices are available;

2) When the special main protection is in operation, the short-time stop of standby

protection is allowed;

3) If the conditions permit, a standby protection is put into operation instead of the

protection out of operation;

4) For gas and differential protections of transformer, it is allowable that one set is

stopped for short time;

5) The dispatcher approves putting relay protection and automatic device out of

operation.

c) The wiring correctness inspection must be performed by means of load current;

short-time stop is allowable in case relevant measures are taken and weather condition is

normal.

d) Take strict precautions against CT secondary open circuit and PT secondary short circuit.

e) The put-in and stoppage of relay protection and automatic device of operating equipment

as well as mode change must take orders from dispatcher or shift-chief operator and

comply with shift-chief operator’s written order, and moreover, the operation content

should be recorded in Operation Log in detail. When it is ascertained that relay protection

and automatic device are in danger of misoperation, the attendant is entitled to release

the protection device first and then report to higher-level leaders step by step.

f) Generally, AC power source of protection device must be from protection equipment itself

or TV of the same loop of protection equipment and TV stoppage is conducted

coordinating main equipment (loop) repair or standby state.



2×300 MW



g) The stoppage of single busbar PT can be allowed only in case normal operation of

protection device in not influenced.

h) Strictly prohibit stopping DC power source of protection device. If the DC power source

needs to be stopped due to fault disposal, it must be submitted to chief engineer for

approval, and moreover, relevant safety measures and accident anticipation should be

taken.

15.1.2 Division of jurisdiction of protection dispatcher

a) Dispatcher’s jurisdiction:

1) 500kV, 220kV and 110kV line protection and reclosing;

2) Main transformer 500kV and 220kV side zero sequence protection and

starting-standby transformer 110kV side zero sequence protection;

3) 500kV, 220kV and 110kV fault recorders.

b) The company dispatcher’s jurisdiction:

1) Generator protection (excl. main transformer 500kV and 220kV side zero sequence

protection);

2) Starting-standby transformer protection (excl. starting-standby transformer 110kV side

zero sequence protection);

3) 6kV operation branch, standby branch and feeder protection;

4) Each low-voltage house service transformer and 380V operation branch and standby

branch protection;

5) Auxiliary high voltage and low voltage motor protection;

6) DC charging device and synchronizing device;

7) Auxiliary power source quick change-over and standby power source automatic put-in

device.

15.1.3 Central control operators should be familiar with and master:

a) Operating principle and configuration of relay protection and automatic device;

b) Mounted position and capacity of relay protection fuse; function and operation method of

strap and control switch, etc.

c) Be able to settle the accident correctly according to operating condition of relay

protection;

d) Be able to make analysis and disposal according to abnormal condition of relay

protection.


2×300 MW


15.1.4 Regulations of operation on relay protection loop

a) Regulations on secondary loop repair work:

1) During equipment repair, the attendant should be in charge of checking whether

safety measures of relay protection in work sheet are appropriate and complete;

2) During repair of relay protection and automatic device, the operator should set up

“working here” sign board in front and back of relevant control panel and protection

panel and the red identification strip should be set to distinguish the boundary line and

scope of repair and operating equipment;

3) After the repair work of relay protection and automatic device is completed, the

repairer must restore all equipment and loops to normal operation state. After the

completion of site cleaning, the repairer should launch into a detailed site explanation

to operator combining concluding work sheet and the repair condition should be

recorded in relay protection work log book; main record contents are: setting value

change and change report, secondary wiring change, settled and unsettled problems

and defects, operation precautions and whether equipment can be put into operation,

etc. The operation attendant should carefully perform inspection and acceptance

check and then both parties should sign relay protection work log book;

4) In order to prevent protection misoperation of operating equipment, the boring and

other work with relatively great vibration are not allowed on or nearby in-service

control panel and protection panel;

5) The test and other testing work are not allowed on non-stopped protection device. It is

also not allowed to use test button of device to conduct the test in case the protection

is not stopped.

b) Regulations on secondary loop operation:

1) When changing the operation mode of primary system, the consideration should be

given to coordination of secondary equipment and relay protection device, i.e. when

writing the operation sheet of primary equipment, the adjustment operation relating to

relay protection and secondary loop should be written in at the same time;

2) When working on in-service PT or CT secondary loop, PT secondary loop short circuit

and CT secondary loop open circuit should be prevented.

3) For all protection devices of operation adjustment, the electrical repairer should put

forward detailed adjustment operation requirements;

4) If the relay protection setting value needs to be adjusted or the secondary operation

mode needs to be changed due to change of operation mode, it should be executed

by operator only when changing the operation mode of relay protection or automatic

device by means of clamping strap and switch and other changes are made by



2×300 MW


repairer; the operation attendant should clearly explain the above operation to the shift

takeover attendant;

5) For the switching of CT secondary loop terminal, if it is double-layer clamping strap,

the break-before-make method must be adopted; if it is single-layer clamping strap, it

must switch when relevant primary equipment power supply is cut off and the operator

should wear cotton gloves during switching operation;

c) During operation, the setting value should be changed in sequence as follows:

1) Check whether dispatcher’s order or original setting value on setting notice complies

with actual setting value;

2) Disconnect clamping strap and adjust and recheck it under the guardianship;

3) Measure that no voltage is available at both ends of clamping strap and then put the

strap into operation;

4) Keep a record after the setting values are changed.

15.2 Inspection of Relay Protection Device

15.2.1 Inspection items before put into operation:

a) A written notice of “allowing putting into operation” should be given by relay protector;

b) Each relay component, clamping strap and test component should be in correct position;

the setting values should comply with setting notice or dispatcher’s order;

c) The indication of each signal lamp on protection device should be correct;

d) The voltage at both ends of clamping strap in tripping loop is zero by measuring with high

internal resistance voltmeter or multimeter and then put the strap into operation.

15.2.2 Inspection items during operation:

a) The switch, knife-switch, fuse, test component plug and clamping strap subordinate to

device should be put into sound operation and in correct position.

b) The attendant should clean relay protection panel surface regularly. During cleaning, do

not vibrate relay to avoid misoperation, and moreover, forbid washing the equipment on

relay protection panel with water and wet cloth.

c) The attendant should perform patrol inspection for relay protection device once a shift.

Inspection items include: protection device power supply, signal indication, contact

position, clamping strap position, whether relay being out of axis or not, heating element

temperature rise, whether rotating elements being normal or not, whether resistance or

coil being burned out, changing color, generating smoke and disconnected obviously, etc.

The operating equipment protection panel door should be closed.



2×300 MW


d) The attendant should inspect regularly the operating condition of signaling set such as

emergency acoustics, alarm bell and lamp light and inspect whether DC insulation

against ground and DC voltage are normal, etc.

15.3 Action of Relay Protection and Automatic Device

15.3.1 Record actuating switch (tripping and self-closing, etc), protection signal drop or display

and action precedence time and sequence.

15.3.2 Inspect the actuating condition of fault recorder.

15.3.3 When relay protection acts and trips, report fault information to shift-chief operator or

dispatcher in time; the protection actuating signal can not be reset until rechecked by the

second person.

15.3.4 When the protection acts to make switch trip, if the forced energization or trial energization

is needed, the protection actuating signal should be reset first.

15.3.5 If the protection misacts, hold original state as much as possible and notify relay personnel

for disposal.

15.3.6 When switching off PT or settling PT loop fault, the protection of PT power supply or

tripping action or automatic function of automatic device should be released and the

automatic block action of some element should not be deemed to be reliable without

measures available.

15.4 Principle Summary and Operation Specification

15.4.1 01 starting-standby transformer protection adopts T35, D30 and T60 type (imported from

America) transformer protection device produced and provided by Shanghai Relay Co.,

Ltd. The protection cabinet includes E and F cabinets.

E

cabinet Starting/standby transformer protection cabinet, including: 1

1 T35 E00 HCH F8N H6C M8L digital transformer management relay includes

the following protection: (starting/standby transformer T35)

Starting/standby transformer differential (three sides) Starting/standby transformer high-voltage side zero-sequence

overcurrent

Starting/standby transformer low-voltage side zero-sequence overcurrent

(two) Starting/standby transformer low-voltage side branch current (two)

1



2×300 MW


2 D30 E00 HCH F8L H6U digital transformer management relay includes the

following protection: (starting/standby transformer D30)

Starting/standby transformer distance

1 set




Automatic air subswitch (Siemens), etc.

4 Protection supervisor 1 set

F

cabinet Starting/standby transformer protection cabinet, including: 1

1 T60 E00 HCH F8N H6U M8L digital transformer management relay includes

the following protection: (starting/standby transformer T60)

Starting/standby transformer differential (three sides) Starting/standby transformer high-voltage side overcurrent

Starting/standby transformer high-voltage side zero-sequence differential

Starting/standby transformer low-voltage side zero-sequence differential

(two) Starting/standby transformer low-voltage side branch current (two)

1

2 Starting/standby transformer non-power output 1 set




Automatic air subswitch (Siemens), etc.

15.4.2 MFC2000-2 Type Microcomputer Auxiliary Power Quick Change-over Device

a) The company’s 6kV auxiliary power quick change-over device adopts MFC2000-2 type

microcomputer auxiliary power change-over device produced by Wiscom System Co.,

Ltd.

b) Basic functions of MFC2000-2 type microcomputer auxiliary power quick change-over



2×300 MW


device: real-time monitoring and display of operating parameter and operation mode,

mutual switching of operating and standby power sources, low-voltage load reduction,

block alarm and emergency disposal, acceleration protection after starting, emergency

review, wave recording, print, communication and GPS comparing the time, etc.

c) The device has four switching modes: 1. manual switching 2. emergency switching 3.

no-voltage starting 4. switch mistrip.

1) The bi-directional switching is all available during manual switching, including parallel

automatic, parallel semi-automatic and synchronous switching. When the parallel

automatic is selected, the device will close the standby switch automatically, after

certain time delay, will trip off the standby switch automatically. When the parallel

semi-automatic is selected, the device will close the standby switch automatically and

the tripping operation of operating switch is completely manually. After starting, if the

parallel switching conditions can not be met, the device will block signaling and enter

into waiting for resetting state;

2) When the synchronous switching is selected, the tripping order is released first; when

the switching condition is met, the order of closing standby switch is released. During

switching, three switching conditions are available (as long as any one condition is

met): quick, synchronous catch and residual voltage; when the quick condition is not

met, it switches to synchronous catch or residual voltage mode;

3) The device has decoupling function, i.e. during synchronous switching or parallel

switching, if the switch that should trips off fails to trip off, both power sources will be

in parallel. And here, the device will execute decoupling function and trip off the switch

closed just now;

4) The emergency switching is started by protection outlet and it has no option but to

switch to standby power source from operating power source; firstly, the operating

power switch trips, after make sure that the operating power switch trips off and the

switching condition is met, close the standby power switch. The switching condition is

the same as that of synchronous switching;

5) No-voltage starting: when auxiliary busbar power source is lost and three-phase

voltage is all lower than setting value, and moreover, the time exceeds setting time

delay, the device will execute emergency switching automatically;

6) Switch mistrip starting: when the operating power switch mistrips by various reasons

(including artificial misoperation), the device will execute emergency switching

automatically.

d) Operation mode of MFC2000-2 type microcomputer auxiliary power quick change-over

device:

1) When the power switch of device is closed, the device panel indicator light +15V, -15V



2×300 MW


and +24V power indicator light is on;

2) During normal operation, the panel “operation” indicator light flashes thrice per

second approximately. The operating parameter and operation mode of equipment

are displayed on liquid crystal screen;

3) When the switching operation is executed on the spot, the panel “local” indicator light

is on; when it is executed remotely, the panel “local” indicator light is off;

4) When the operating power switch is in closing position, the panel “operation” indicator

light is on; when it is in opening position, the indicator light is off;

5) When the standby power switch is in closing position, the panel “standby” indicator

light is on; when it is in opening position, the indicator light is off;

6) After completion of device switching operation, the panel “action” indicator light is on,

after reset, the indicator light is off. If the device does not perform switching operation,

the “action” indicator light is off;

7) When the device is in blocking state (including device blocking and outlet blocking),

the panel “block” indicator light is on and the “operation” indicator light flashes slowing

down approximately once per 2 seconds. When the device is in unblocking state, the

“block” indicator light is off;

8) When the device sends a signal to DCS, the panel “communication 1” indicator light is

on, or it is off;

9) When the device receives a signal from DCS, the panel “communication 2” indicator

light is on, or it is off;

e) Setup mode of device: the mode setting of 6kV quick change-over device during normal

operation is as follows:

1 Control mode Remote

2 Protection switching mode Series connection

3 No-voltage switching mode Series connection

4 Local manual switching mode Parallel automatic

5 Remote parallel switching Automatic

6 No-voltage starting Put in service

7 Quick switching Put in service

8 Synchronous catch phase lead angle Put out of service

9 Synchronous catch lead time Put in service



2×300 MW


10 Residual voltage switching Put in service

11

Low voltage switching auxiliary

machine

Put out of service

12 Standby power loss Put in service

13 Outlet put-in or put out of service Put in service

f) Device alarm and disposal:

1) When auxiliary power system and device are in normal operation, no abnormal and b

blocking signals will be made, if any, it shows that the operating state is abnormal and

it should be disposed according to different circumstances, and after disposal, the

alarm window may be reset by means of pressing resetting button;

2) “Device power loss”: inspect the DC power source voltage of device, including quick

change-over cabinet DC power source incoming wire fuse and whether the air switch

above cabinet back and the device power source plug-in unit switch are closed, etc;

g) When the device sends a blocking signal, it may be divided into A and B types according

to difference of disposal method:

1) A: 1. Switch position is blocked abnormally (6kV busbar PT isolator is turned on;

operating and standby switches are fully opened; when any one condition of

operating and standby switches being fully closed is met, the signal is sent out); 2.

Device self checking is abnormal; 3. The protection is blocked (such as operating

branch overcurrent, etc); 4. One phase or two phases of 6kV busbar PT is or are

disconnected; 5. Standby power source is lost; 6. After primary switching;

2) B: 1. External outlet is blocked (close the outlet); 2. The outlet is put out of service in

“mode setup”; 3. All switching modes are put of service (quick switching/residual

voltage, lead time, phase lead angle);

3) When the foregoing block A conditions happen, the device enters into waiting

resetting state and in such state, the device will not respond to any operation and

starting signal and the resetting cannot be otherwise than released manually (before

resetting, the quick change-over device should switch to “closing outlet”, and after

return to normal, put in “protection starting”). If the block or fault still exists and the

signal after reset is as before, contact with repairer for inspection in time, and besides,

get done with accident anticipation of auxiliary power trip;

4) The block B can be reset automatically and the device does not enter into waiting

resetting; the blocking source vanishes and the device is put into operation

automatically.

h) Inspection of device in normal operation:



2×300 MW


1) Inspect that device panel indicator light +15V, -15V, +24V power indicator light is on

and “operation” indicator light flashes approximately thrice per second;

2) The indication of “operating power source” and “standby power source” indicator light

should be in conformity with actual operation mode; when the device is not in

“protection blocking”, no blocking signal should be made;

3) Protection strap of quick change-over device should be put in correct position.

i) Precautions

1) When the operating power source (standby power source) conducts standby power

source (operating power source) switch closing and opening test during operation,

before “manual switching” or put in “protection starting”, the block should be reset

manually, or the device can not perform any operation;

2) When the operating power source is put into operation, if standby power source is lost

and the device can not detect standby power source, after recovery, the block should

be reset manually in time, or the device can not perform any operation.

15.4.3 Operation Manual of LBD-WLB8000 Fault Recorder

a) General description:

Device description:

Model: LBD- WLB8000

Manufacturer: Baoding LBD Electric Co., Ltd.

b) Device function:

The device is mainly used for the record of voltage and current data of electric system

fault or abnormal operating condition and the record of relevant protection and safety

automatic device actuating sequence, and used to reproduce electrical quantity variance

process during fault and abnormal operation and complete comprehensive analysis of

fault recording data, and moreover, provide the basis for determining fault source,

correctly analyzing and evaluating the action of protection and automatic device.

The device can realize the data acquisition of 64-channel analog value and 128-channel

switch value.

The starting mode of device includes analog value starting, switch value starting and

manual starting.

Operating environment requirement of device

Ambient temperature: -5~+45

Relative humidity: ≤90％



2×300 MW


c) Description of device panel

1) Description of indicator light

z Power indicator light: the light is on when power supply is normal;

z Operation indicator light: the light flashes when the device is in normal operation;

the device operation is abnormal, the light is on or off constantly;

z Data uploading indicator light: the light is on when recording data is transmitted ;

z Record starting indicator light: the light is on when the device starts recording;

z Self-check fault indicator light: the light is on once the device goes out of order;

z Device abnormal indicator light: the light is on when the device does not receive

the patrol inspection or mutual inspection order released according to the fixed

time within specified time period;

z Communication fault indicator light: the light is on when the communication in

main machine system goes out of order;

z Test and adjustment indicator light: the light is on when the device enters into test

and adjustment state.

2) Description of button

z Master clear button: used to reset each alarm relay and indication thereof

manually.

z Description of air switch

z 1DK: device DC power source, providing switch value module operating power

source;

z 2DK: device DC power source, providing analog value module operating power

source;

z 3DK: device AC power source, providing industrial personal computer, display

and socket power source.

d) Device put-in

1) Put the industrial personnel computer and display power source into operation;

2) Put the device AC power switch 3DK into operation;

3) Put the device DC power switch 1DK and 2DK into operation;

4) Observe that the indication of device panel “power indication” and “operation

indication” signal is normal, without abnormal alarm signal;



2×300 MW


5) If an abnormal signal exists, press “master clear button” to reset signal.

6) When the device is put out of service, open the device DC power switch 1DK and

2DK;

e) Operation maintenance

When the device is in normal operation, the panel should have no any abnormal

alarm signal and only the device “power indicator light” and “operation indicator light” are

on.

During normal operation, when “self-check fault”, “device abnormal” and

“communication fault” indicator lights among device panel signal indicator lights are on,

the repairer should be notified for disposal; when the “power indication” indicator light is

not on, firstly, inspect whether device power source is normal, if the power source is

normal, the repairer should be notified for disposal; when the “operation” indicator light is

not on, firstly, inspect whether any other alarm signal exists in the device and press

“master clear button” to observe whether the signal can be reset, if not, the repairer

should be notified for disposal;

15.4.4 Description of Low-voltage Auxiliary Power Protection Operation

Guangning Thermal Power Co., Ltd. adopts WISCOM WDZ-440 low-voltage transformer

integrated protection monitoring and control device, WDZ-430 motor integrated protection

monitoring and control device, WDZ-431 motor differential protection device and WDZ-410 feeder

microcomputer integrated protection monitoring and control device. The device not only can

complete normal protection control function but also can directly output the standard 4-20mA

analog value of current measurement and the pulse value required for electric energy

measurement.

a) keyboard and signal indication of WDZ-400 serial auxiliary power integrated protection

monitoring and control device WDZ-400 protection device panel is configured with a

128×64-lattice Chinese character LCD, eight LED indicator lights, nine press keys and

two change-over switch.

Keyboard

1) “←”, “→”, “↑”, “↓” keys are respectively “left”, “right”, “up”, “down” shift keys.

2) The “plus” and “minus” keys are number add-subtract and protection put-in and

out-of-service keys.

3) The “enter” key is used to confirm current operation and enter the next operation.

When the graphic display is default, press the key to enter main menu.

4) The “cancel” key is used to cancel current operation and return to superior menu.

5) The “reset” key is used to reset protection actuating signal and device alarm signal.



2×300 MW


6) Pressing “cancel” and “reset” keys at the same time can reset the device.

7) Pressing “↑”without release and then pressing “+” key can increase the contrast of

liquid crystal; pressing “↓” without release and then pressing “-” key can reduce the

contrast of liquid crystal.

2LED indicator light

1) “Alarm” indicator light: the light is on when an alarm signal is made in case the device

goes out of order by self checking or PT is disconnected and control loop is

disconnected; the light is off after the signal is reset.

2) “Trip” light: the light is on when the circuit breaker is cut off and the “close” light is off.

3) “Close” light: the light is on when the circuit breaker is closed and the “trip” light is off.

4) “Remote” light: the light is on when the remote/local/test and adjustment change-over

switch on panel is switched to remote position and here remote control is put in

service; when switched to local or test and adjustment position, the light is off and

here remote control is put out of service.

5) “Send” light: the light is on when the device sends message text to network.

6) “Receive” light: the light is on when the device receives message text from network.

7) “Operation” indicator light: the light flashes in operation state and here the block

setting value is modified. The flicker frequency is accelerated in test and adjustment

state.

8) “Action” indicator light: the light is on when the protection acts and the light is off after

the protection actuating signal is reset.

Change-over switch

1) Manual trip/manual closing change-over switch

2) Test and adjustment/local/remote state change-over switch

Device put-in and out-of-service

1) Put in microcomputer protection power switch in switch cabinet; inspect that device

‘operation’ indicator light is on; ‘close’ and ‘trip’ indicator lights correspond to switch

position; ‘remote’ and ‘local’ indicator lights correspond to the state of change-over

switch on device panel.

2) Device stoppage: shut off microcomputer protection power switch in switch cabinet.

Central (DCS) signal

1) Protection operation: microcomputer protection operating outlet.



2×300 MW


2) Device fault: microcomputer protection software and hardware fault, notify relay

protection personnel for disposal.

b) Directions for menu operation of WDZ-440 low-voltage transformer microcomputer

integrated protection monitoring and control device

1) The menu is tree-structured and has multilevel submenu. In the process of menu

operation, move the cursor by means of “↑”, “↓”, “←”, “→” keys; enter the

corresponding submenu by pressing “enter” key; exit the corresponding submenu by

pressing “cancel” key.

2) Main graphic display during device operation

3) Display when the device is normal: protection real-time clock, current setting value

area digit, device address, protection device model, real-time displayed AC quantity

sampling value.

4) Main menu during device operation

5) Under main graphic display, press “enter” key to enter main menu; eight submenus

are available under main menu.

Menu Structure

Main Menu Submenu Contents

State value

display Display the information of state value such as

telesignalisation, etc. in a real-time way

Measured value

display Display measured voltage, measured current, active power,

reactive power, power factor and frequency

Electric energy

pulse display Display active electric energy pulse and reactive electric

energy pulse

Electric energy

display

Display active electric energy and reactive electric energy

Complex number

display

Display complex representation of voltage, measured

current and protection current. The former is real part and

the latter is imaginary part

Phase angle

display Display the phase angle of voltage, measured current and

protection current

Measured

value display

Protection value

display Display protection voltage, protection current and zero

sequence current

Report display Operation report

Display operating time, protection event, fault phase, fault



2×300 MW



value, etc.

Self-check report

Display error message, time, setting value area digit and

report number

Telesignalisation

displacement

report

Display displacement time, displacement message and

report number

Remote order Display remote order message, time and report number

Statistical report

Display protection trip times, remote control trip times, reset

times, protection closing times and remote control closing

times

Device power-on

message After the device is energized, if the mantissa of digits

displayed in message is odd, the device is normal

Network N1

monitoring

Network N2

monitoring

Debugging port

monitoring

Communication

monitoring

Electric energy

board monitoring

Protection

analogy

Simulate protection operation of the device

Switch control Simulate remote operation of the device

Relay control Relevant relay in operating device (see note 1)

Starting fault

recording

The fault recording may be started artificially

Test and

adjustment

operation

Electric energy

board test and

adjustment

Adjust electric energy gain and bias and clear electric

energy accumulation

Edition

message

Display edition message of the device



2×300 MW



Clear all reports Clear all reports stored in device

Clear operating

report

Clear all operating reports stored in device

Clear self-check

report

Clear all self-check reports stored in device

Clear

telesignalisation

report

Clear all telesignalisation reports stored in device

Report clearing

Clear remote

control report

Clear all remote control report stored in device

Time setting Set the year, month, day, hour, minute and second in device

Protection setting

area digit

Set current operating setting area digit

Protection setting

Complete protection setting and protection control word

put-in and out-of-service according to setting list

Protection

accuracy

coefficient

Add protection AC value and adjust protection value Uab,

Ubc, Uca, Ia, Ib, Ic and Io by means of adjusting protection

accuracy coefficient

Measurement

accuracy

coefficient

Add measurement AC value and adjust measurement value

MUab, Mubc, Muca, Mia, Mic, P and Q by means of

adjusting measurement accuracy coefficient

Electric energy

board accuracy

coefficient

Adjust active electric energy PE

Communication

protocol Set the protocol and baud rate of network N1, N2 and

debugging port

Electric energy

pulse setting Set initial value integer and initial value decimal of pulse 1

and pulse 2 and pulse number per word

Setting setup

System

parameter

Set device address, password, screen protection time, CT

transformation ratio, PT transformation ratio, network N1

and N2, debugging port communication put-in and

out-of-service and built-in electric energy put-in and

out-of-service



2×300 MW



Signal drive

selection

Including signal 1 selection and signal 2 selection. By

setting relevant protection put-in and out-of-service, add

signal outlet contact when the protection acts.

Call initial setting

Call initial setting to avoid device giving the alarm of setting

self-check fault again

Note 1: ACT：actuating signal relay; FLT：fault signal relay; WARN1：signal relay 1

WARN2：signal relay 2; YH：remote closing relay; YT： remote tripping relay

BCH：reclosing relay; DO1：shunt tripping relay 1; DO2：shunt tripping relay 2

DO3：shunt tripping relay 3; DO4：shunt tripping relay 4; BT：protection tripping relay

c) Protection configuration of WDZ-440 low-voltage transformer integrated protection

monitoring and control device

1) High-voltage side current quick-break protection

2) High-voltage side current specified time quick-break protection

3) High-voltage side overcurrent protection

4) High-voltage side overload protection

5) High-voltage side negative-sequence overcurrent section I protection

6) High-voltage side negative-sequence overcurrent section II protection

7) High-voltage side grounding protection

8) Low-voltage side zero-sequence overcurrent protection

9) Non-electric quantity protection

10) Fault recording function

d) Protection configuration of WDZ-430 motor integrated protection monitoring and control

device

1) Current quick-break protection

2) Negative-sequence overcurrent section I protection

3) Negative-sequence overcurrent section II protection

4) Grounding protection

5) Overheating protection

6) Locked rotor protection



2×300 MW


7) Long starting protection

8) Positive-sequence overcurrent protection

9) Overload protection

10) Undervoltage protection

e) Protection configuration of WDZ-431motor differential microcomputer protection device

1) Differential quick-break protection

2) Split phase ratio differential protection

The device and WDZ-430 form a complete protection of the motor with power more

than 2000kW.

f) Protection configuration of WDZ-410 feeder microcomputer integrated protection

monitoring and control device

1) Overcurrent section I protection

2) Overcurrent section II protection

3) Overcurrent section III protection

4) Overload protection

5) Grounding protection

6) Post-acceleration protection

15.4.5 SID-2CM Type Microcomputer Synchronizing Device

a) General description: the company’s generator adopts SID-2CM type microcomputer

synchronizing device provided with built-in test and detecting unit and the routine test of

controller, fault detection and external circuit correctness check can be conducted without

any other apparatus.

b) Panel description:

1) A 128×64-lattice LCD with backlight is available on the top left of panel and it is used

to display menu and setting parameter and display parallel point code, system

frequency, system voltage, generator frequency, generator voltage, circuit breaker

closing time and any other information.

2) It is synchronism indicator composed of luminotron on the lower left and the indicator

is used to indicate the phase difference between waiting parallel side and system side

voltage in synchronization process. The “frequency difference and power angle” and

“voltage difference” indicator lights are green beyond upper limit during difference

frequency synchronization and are red beyond lower limit; the frequency difference



2×300 MW


light is also red during cofrequency and is off when not exceeding limits. The “closing”

indicator light is on (red) during the period that the controller releases closing order.

3) A down-openable cover plate is available on right side of panel. After the cover plate is

opened, the operation mode selector switch and the operation mode indicator light

can be seen on the left; three operation modes used to set controller are “operation”,

“test” and “set” modes. The operation (red), test (green) and set (yellow) indicator

lights above operation mode selector switch respectively correspond to the three

operation modes.

z The “operation” mode is used for generator or line synchronization; the “test”

mode is used for field test or controller hardware test; the “set” mode is used for

setting parameter and data query;

z 7 press keys are available above operation mode selector switch, namely, left

key, right key, up key, down key, enter key, exit key and reset key. Both left and

right keys are used to select setting parameter; both up and down keys are

used to select menu item or change parameter value; the “enter” key is used to

select function or store parameter; the “exit” key is used to exit current operation

program; the “reset” key is used to reset the program;

z It is operating and indicating unit of test module on the right of panel. The test

module is used to generate voltage transformer voltage at both sides of waiting

parallel point, simulate relevant input switch value signal and indicate the state

of control signal relating to controller output. The “remote reset” key is used to

simulate remote reset order from control board and make controller program

reset. The “auxiliary contact” key is used to simulate the auxiliary contact of

parallel point circuit breaker and reflect whether circuit breaker is closed, and

roughly measure circuit breaker closing loop time;

z 12 parallel point selector switches in the middle of panel are used to simulate

the synchronizing switch state of 12 (1-8 are valid for SID-2CM) parallel points;

if the switch is turned upward, it shows the parallel point is selected. SM, PO

and NV are respectively synchronizing meter and voltage transformer

disconnection; signal input is confirmed by no-voltage closing and turning

upward is valid;

z 8 switches in lower part of panel are used to simulate secondary disconnection

of voltage transformer at both sides of waiting parallel point circuit breaker; SF,

SA, SB and SC are system side fuse fore and three-phase voltage transformer

disconnection test switches and the switch turning front upward means

disconnection;

z VS and VG potentiometers are used to adjust the secondary voltage of input

representative system and waiting parallel side voltage transformer when



2×300 MW


××××

Fs

××.×××

－i

+δ

Fg

××.×××

－i

Vs

×××.×

detecting controller and the voltage value can be measured with AC voltmeter

on VS, VG and common port testing column. The PT secondary voltage may be

selected as line voltage (UL) or phase voltage (UΦ) by means of PT secondary

voltage selector switch;

z RS-232 serial communication interface is available on the lower left of panel

and it is 9-pin D type socket and used to connect with RS-232 communication

interface of notebook computer on the spot. The RS-485 interface of backboard

can also be used to communicate with remote upper computer;

z 7 relay state indicator lights are available in upper part of panel and used to

display corresponding relay state: step-down relay (green), step-up relay (red),

decelerating relay (green), accelerating relay (red), closing relay (red), alarm

relay (yellow) and closing block relay (yellow);

z When the controller works in “set” mode, the closing output loop may be

disconnected automatically by means of SL closing block relay, therefore, the

controller can set the parameter on site and no mis-closing will occur.

c) Description of synchronization control

progress and display screen:

1) The ×××× is parallel point code

number in the first line and the

following is system side frequency

(Hz), waiting parallel side frequency

(Hz), system side voltage (V) and

waiting parallel side voltage (V) in

proper order; Tc is actually measured

closing time (ms) of switch and Tc is

displayed after closed. Both “－i” and

“－0” symbols are available on the

right of Fs and Fg; －i means using

Vg ×××.× Remote

Control Tc ×××

internal signal and －0 means using external signal. If the internal-generated waiting

parallel side signal is used, both “” and “” keys may be used to adjust waiting

parallel side voltage and frequency.

2) “+δ” on the right of FS means that system side voltage signal turns lag angle

30°compared with original input voltage signal inside controller; “-δ” angle means that

system side voltage signal turns lead angle 30° inside controller; if no “+δ” or “-δ”

prompt message is available, the system side voltage signal does not turn. The

bottom line is state display line and the following message may appear at both left

and right ends:



2×300 MW


z Higher voltage: it means that waiting parallel side voltage is higher than system

side voltage and the voltage difference exceeds allowable voltage difference;

z Lower voltage: it means that waiting parallel side voltage is lower than system

side voltage and the voltage difference exceeds allowable voltage difference;

When the above two prompt messages appear, whether to regulate voltage

depends on the setup of “automatic voltage regulation” among channel

parameters. When the “automatic voltage regulation” is set as NO, even though

voltage difference exceeds allowable voltage difference, the voltage is not nor

regulated. The strength of voltage regulation depends on voltage equalizing

control coefficient;

z Higher frequency: it means that waiting parallel side frequency is higher than

system side frequency and the frequency difference exceeds allowable

frequency difference;

z Lower frequency: it means that waiting parallel side frequency is lower than

system side frequency and the frequency difference exceeds allowable

frequency difference;

When the above two prompt messages appear, whether to regulate frequency

depends on the setup of “automatic frequency modulation” among channel parameters.

When the “automatic frequency modulation” is set as NO, even though frequency

difference exceeds allowable voltage difference, the frequency is not nor modulated. The

strength of frequency modulation depends on frequency equalizing control coefficient. In

addition, if generator frequency is less than 49HZ or more than 51HZ and the frequency

displayed on display screen is lower or higher, but the frequency is not modulated;

z Cofrequency: it means that waiting parallel side frequency is consonant with or

very close to system side frequency. In such a case, the controller will modulate

waiting parallel side frequency higher automatically to destroy the stalemate.

The strength of frequency modulation depends on “cofrequency modulation

pulse width” parameter; the larger the cofrequency modulation pulse width is,

the larger the frequency modulation positive pulse width is;

z Waiting parallel side low-voltage blocking: the controller is blocked when waiting

parallel side voltage is lower than blocking voltage;

z System side low-voltage blocking: the controller is blocked when system side

voltage is lower than blocking voltage;

z Generator overvoltage: generator voltage exceeds overvoltage protection value

and here the controller continues voltage reduction control;

z Larger power angle: the power angle exceeds allowable power angle during

cofrequency synchronization and the synchronization condition is not met;



2×300 MW


z Larger voltage difference: the voltage difference exceeds allowable voltage

difference during cofrequency synchronization and the synchronization

condition is not met;

z After synchronization, the controller detects whether auxiliary contact of circuit

breaker is displaced, if displaced, the overall time of circuit breaker closing loop

is displayed, or the “circuit breaker unclosed” is displayed. During false

synchronization, the closing loop operating time is measured roughly by means

of displacement of circuit breaker auxiliary contact; the measured time during

real synchronization (difference frequency synchronization) is just accurate

actual value.

d) Connection between SID-2CM type controller and upper computer

Users may be in communication with upper computer by means of RS-232 or

RS-485 serial interface. When no person is on duty on site, the mode selector switch of

controller should be put in “operation” state, after upper computer feeds relevant signal

and power supply to controller and releases the order of “putting synchronizing device

into operation”, the controller begins to communicate with upper machine. After

completion of synchronization, upper computer may release the order of “putting

synchronizing device out of operation” and may also make controller live all the time.

16 Appendix

16.1 Characteristics Curve of Generator

Characteristics Curve Of Generator (1)



2×300 MW


1.0PF 10189A

0.85PF 10189A

定

子

电

流

A

定子电压 KV

28

26

24

22

20

18

16

14

12 12000

10 10000

8 8000

6 6000

4 4000

2 2000

0 500 1000 1500 2000 2500 3000 3500 转子电流 A

Chinese English

定子电压 KV Stator voltage KV

空载特性 No-load characteristic

短路载特性 Short circuit load characteristic

零功率因数负载特性 Zero power factor load characteristic

定子电流 A Rotor current A

转子电流 A Stator current A



2×300 MW


0.70 0.75

0.80 0.85

0.90 0.95

3200

Characteristics Curve of Generator (2)

定子电流 A

1000 3000 5000 7000 9000 11000 13000

0

最小转子电流 A

400

800

0.25

0.5 0.60

1600

转子电

2000

流 A

0.21 （氢压）

0.31 （氢压）

1.0

0.95

2800

0.90

3600

4000

Chinese English

定子电流 A Stator current A

最小转子电流 A Minimum rotor current A

最大允许转子电流 A Maximum allowable rotor current A

0.0PF 欠激 0.0PF underexcitation



2×300 MW


0.0PF 过激 0.0PF overexcitation

转子电流 A Rotor current A

氢压 Hydrogen pressure



2×300 MW


欠

激

无功

功率

MVA

R 过

激

Characteristics Curve of Generator (3)

250 氢压0.31MPa

氢压0.21MPa

0.7PF

0.8PF

0.85PF

200

0.9PF

150

100

0.95PF

50

有功功率 MW 0

1.0PF

50 100 150 200 250 300

50

100

0.95PF

150 0.85PF

0.9PF

200 0.7PF

0.8PF

250

Chinese English

氢压 Hydrogen pressure

过激 Overexcitation

无功功率 MVAR Reactive power MVAR

有功功率 MW Active power MW



2×300 MW


欠激 Underexcitation

16.2 Layout of Generator Temperature Elements

Stator coil water output Stator coil interlayer Tour

gauging

table

No.

Panel No.

Device position (upper-layer

coil slot number )

Panel No.

Device position

1 69 10 1 1

2 70 11 2 2

3 71 12 3 3

4 72 13 4 4

5 73 14 5 5

6 74 15 6 6

7 75 16 7 7

8 76 17 8 8

9 77 18 9 9

10 78 19 10 10

11 79 20 11 11

12 80 21 12 12

13 81 22 13 13

14 82 23 14 14

15 83 24 15 15

16 84 25 16 16

17 85 26 17 17

18 86 27 18 18

19 87 28 19 19

20 88 29 20 20

21 89 30 21 21



2×300 MW



gauging

table

No.

Panel No.


coil slot number )

Panel No.

Device position

22 90 31 22 22

23 91 32 23 23

24 92 33 24 24

25 93 34 25 25

26 94 35 26 26

27 95 36 27 27

28 96 37 28 28

29 97 38 29 29

30 98 39 30 30

31 99 40 31 31

32 100 41 32 32

33 101 42 33 33

34 102 43 34 34

35 103 44 35 35

36 104 45 36 36

37 105 46 37 37

38 106 47 38 38

39 107 48 39 39

40 108 49 40 40

41 109 50 41 41

42 110 51 42 42

43 111 52 43 43

44 112 53 44 44

45 113 54 45 45



2×300 MW



gauging

table

No.

Panel No.


coil slot number )

Panel No.

Device position

46 114 1 46 46

47 115 2 47 47

48 116 3 48 48

49 117 4 49 49

50 118 5 50 50

51 119 6 51 51

52 120 7 52 52

53 121 8 53 53

54 122 9 54 54

Note: temperature measuring element is copper resistance 50Ω/0 and 71.4Ω/100.


Generator Operation Manual QN1 SEC G 04 TP 004

Documents

automatic voltage regulator

auxiliaries operation manual

automatic device

excitation system

relay protection

transformer unit

generator

trouble disposal