1 1 Introduction & Application of Generator Protection Relay Type SEL700G Relay (Part2) Kamin Dave Business Development Manager [email protected]Schweitzer Engineering Laboratories, India www.selinc.com KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE 2 Generator Protections: Measuring Principal Measuring Principals: Power System Protections:- Current Based Protection: Current Based Protection: Current Based Protection: Current Based Protection: Three Phase Currents, Single Current Three Phase Currents, Single Current Three Phase Currents, Single Current Three Phase Currents, Single Current Measurement Measurement Measurement Measurement Voltage Based Protection: Voltage Based Protection: Voltage Based Protection: Voltage Based Protection: Three Phase Voltages, Single Voltage Three Phase Voltages, Single Voltage Three Phase Voltages, Single Voltage Three Phase Voltages, Single Voltage Measurement Measurement Measurement Measurement Frequency Based Protection: Frequency Based Protection: Frequency Based Protection: Frequency Based Protection: Three Phase Frequency Measurement Three Phase Frequency Measurement Three Phase Frequency Measurement Three Phase Frequency Measurement Power Based Protection: Power Based Protection: Power Based Protection: Power Based Protection: Three or Single Phase Power Measurement Three or Single Phase Power Measurement Three or Single Phase Power Measurement Three or Single Phase Power Measurement Impedance Based Protection: Impedance Based Protection: Impedance Based Protection: Impedance Based Protection: Ph Ph Ph Ph-Ph, Ph Ph, Ph Ph, Ph Ph, Ph-G & 3 G & 3 G & 3 G & 3-Ph Impedance Measurement Ph Impedance Measurement Ph Impedance Measurement Ph Impedance Measurement Control Functions: Control Functions: Control Functions: Control Functions: 3 Generator Protections: Measuring Principal Measuring Principal: Power System Protections KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
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Introduction & Application of Generator Protection Relay Type
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
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Generator Protections: Measuring Principal
Measuring Principals: Power System Protections:-
Current Based Protection:Current Based Protection:Current Based Protection:Current Based Protection:Three Phase Currents, Single Current Three Phase Currents, Single Current Three Phase Currents, Single Current Three Phase Currents, Single Current MeasurementMeasurementMeasurementMeasurement
Voltage Based Protection:Voltage Based Protection:Voltage Based Protection:Voltage Based Protection:Three Phase Voltages, Single Voltage Three Phase Voltages, Single Voltage Three Phase Voltages, Single Voltage Three Phase Voltages, Single Voltage MeasurementMeasurementMeasurementMeasurement
Frequency Based Protection:Frequency Based Protection:Frequency Based Protection:Frequency Based Protection:Three Phase Frequency Measurement Three Phase Frequency Measurement Three Phase Frequency Measurement Three Phase Frequency Measurement
Power Based Protection:Power Based Protection:Power Based Protection:Power Based Protection:Three or Single Phase Power MeasurementThree or Single Phase Power MeasurementThree or Single Phase Power MeasurementThree or Single Phase Power Measurement
Impedance Based Protection:Impedance Based Protection:Impedance Based Protection:Impedance Based Protection:PhPhPhPh----Ph, PhPh, PhPh, PhPh, Ph----G & 3G & 3G & 3G & 3----Ph Impedance MeasurementPh Impedance MeasurementPh Impedance MeasurementPh Impedance Measurement
Control Functions:Control Functions:Control Functions:Control Functions:
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Generator Protections: Measuring Principal
Measuring Principal: Power System Protections
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Generator Protections: Measuring Principal
Measuring Principal; Power System ProtectionsImpedance (Z=V/I):Impedance (Z=V/I):Impedance (Z=V/I):Impedance (Z=V/I):Back up Impedance Back up Impedance Back up Impedance Back up Impedance ----21212121Voltage Controlled Voltage Controlled Voltage Controlled Voltage Controlled –––– 51VC51VC51VC51VCVoltage Restrain Voltage Restrain Voltage Restrain Voltage Restrain –––– 51VR51VR51VR51VRLoss of Excitation Loss of Excitation Loss of Excitation Loss of Excitation –––– 40G40G40G40GPole Slipping (dz/dt) Pole Slipping (dz/dt) Pole Slipping (dz/dt) Pole Slipping (dz/dt) ---- 78787878Line Distance Protection Line Distance Protection Line Distance Protection Line Distance Protection ---- 21 21 21 21
3.3.3.3. Over Voltage Protection (59)Over Voltage Protection (59)Over Voltage Protection (59)Over Voltage Protection (59)
4.4.4.4. Over all GeneratorOver all GeneratorOver all GeneratorOver all Generator----Transformer differential Transformer differential Transformer differential Transformer differential Protection (87GT)Protection (87GT)Protection (87GT)Protection (87GT)
6.6.6.6. Protection against Stator winding over Protection against Stator winding over Protection against Stator winding over Protection against Stator winding over Heating & over loading (51O/L) Heating & over loading (51O/L) Heating & over loading (51O/L) Heating & over loading (51O/L)
Generator Protections: Stator Protections
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2.2.2.2. Stator Unbalanced current Stator Unbalanced current Stator Unbalanced current Stator Unbalanced current Protection Protection Protection Protection (NPS(NPS(NPS(NPS----46)46)46)46)
3.3.3.3. Loss of Excitation Protection (LOFLoss of Excitation Protection (LOFLoss of Excitation Protection (LOFLoss of Excitation Protection (LOF----40G)40G)40G)40G)
Generator Protections: Rotor Protections
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1.1.1.1. Reverse Power Protection (32R)Reverse Power Protection (32R)Reverse Power Protection (32R)Reverse Power Protection (32R)
2.2.2.2. Low forward Power Protection (37L/32L))Low forward Power Protection (37L/32L))Low forward Power Protection (37L/32L))Low forward Power Protection (37L/32L))
3.3.3.3. Under Frequency Protection (81U/F)Under Frequency Protection (81U/F)Under Frequency Protection (81U/F)Under Frequency Protection (81U/F)
4.4.4.4. Over Frequency Protection (81O/F)Over Frequency Protection (81O/F)Over Frequency Protection (81O/F)Over Frequency Protection (81O/F)
5.5.5.5. Out of Step or PoleOut of Step or PoleOut of Step or PoleOut of Step or Pole----Slip Protection (78)Slip Protection (78)Slip Protection (78)Slip Protection (78)
6.6.6.6. Generator Over Speeding ProtectionGenerator Over Speeding ProtectionGenerator Over Speeding ProtectionGenerator Over Speeding Protection
Generator Protections
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• Other Miscellaneous Protections:Other Miscellaneous Protections:Other Miscellaneous Protections:Other Miscellaneous Protections:----
1.1.1.1. Generator Generator Generator Generator –––– Transformer Over fluxing Transformer Over fluxing Transformer Over fluxing Transformer Over fluxing Protection (24)Protection (24)Protection (24)Protection (24)
2.2.2.2. Restricted E/F Protection if it required Restricted E/F Protection if it required Restricted E/F Protection if it required Restricted E/F Protection if it required
3.3.3.3. Back up Impedance Protection or Back up Back up Impedance Protection or Back up Back up Impedance Protection or Back up Back up Impedance Protection or Back up Protection using Voltage Dependent Protection using Voltage Dependent Protection using Voltage Dependent Protection using Voltage Dependent (Voltage restrain / Voltage controlled) over (Voltage restrain / Voltage controlled) over (Voltage restrain / Voltage controlled) over (Voltage restrain / Voltage controlled) over current unit (21/51V)current unit (21/51V)current unit (21/51V)current unit (21/51V)
4.4.4.4. Breaker Flash over ProtectionBreaker Flash over ProtectionBreaker Flash over ProtectionBreaker Flash over Protection
Where; Where; Where; Where; TT: Turbine TripTT: Turbine TripTT: Turbine TripTT: Turbine TripGCB: Generator Control BreakerGCB: Generator Control BreakerGCB: Generator Control BreakerGCB: Generator Control BreakerFB: Field BreakerFB: Field BreakerFB: Field BreakerFB: Field Breaker
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W / O LOSS OF FIELD W / O LOSS OF FIELD W / O LOSS OF FIELD W / O LOSS OF FIELD
WITH LOSS OF FIELDWITH LOSS OF FIELDWITH LOSS OF FIELDWITH LOSS OF FIELD
• REVERSE POWER REVERSE POWER REVERSE POWER REVERSE POWER
LONG TIME (STAGELONG TIME (STAGELONG TIME (STAGELONG TIME (STAGE----1) 1) 1) 1)
SHORT TIME (STAGESHORT TIME (STAGESHORT TIME (STAGESHORT TIME (STAGE----2) 2) 2) 2)
(OPERATES ONLY AT TT)(OPERATES ONLY AT TT)(OPERATES ONLY AT TT)(OPERATES ONLY AT TT)
Tripping Criteria: Generator – Turbine Unit
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Where; Where; Where; Where; TT: Turbine TripTT: Turbine TripTT: Turbine TripTT: Turbine TripGCB: Generator Control BreakerGCB: Generator Control BreakerGCB: Generator Control BreakerGCB: Generator Control BreakerFB: Field BreakerFB: Field BreakerFB: Field BreakerFB: Field Breaker
• OVER EXCITATION OVER EXCITATION OVER EXCITATION OVER EXCITATION
Where; Where; Where; Where; TT: Turbine TripTT: Turbine TripTT: Turbine TripTT: Turbine TripGCB: Generator Control BreakerGCB: Generator Control BreakerGCB: Generator Control BreakerGCB: Generator Control BreakerFB: Field BreakerFB: Field BreakerFB: Field BreakerFB: Field Breaker
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SEL700GSEL700GSEL700GSEL700G
Generating Station Protections:
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Relay Details: SEL700G
• Numerical Generator Protection Relay– Under & Over Voltage Protection
(27/59)
– Negative sequence Protection (46)
– Reverse & Low Forward Power Protection (32)
– Over Excitation Protection (24)
– Over & Under Freq. Protection (81O/81U)
– Under Impedance Protection (21)
– Loss of Excitation Protection (40G)
– 100% Stator E/F Protection (27TN/64G2)
– Rotor E/F Protection by using injection Principal
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Relay Details: SEL700G• Out of Step Protection (78)
message format allows up to 8 current & 8 voltages synchronized measurement
� Metering Parameters � Disturbance Recorder� Export file in COMTRADE format� 16 nos. of configurable LEDs� IEC61850 Station bus compliance� Compact device & less weight
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Relay Details: SEL700G
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Relay Details: SEL700G
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Generator Protection Scheme: Small Size Machine
G D Y
GTGen Set
333 3 3 3
51O/L51O/L51O/L51O/L
51V51V51V51V
32R & 32L32R & 32L32R & 32L32R & 32L87G87G87G87G
87GT87GT87GT87GT
46464646
YYYY
YYYY
81U/F & 81U/F & 81U/F & 81U/F & O/FO/FO/FO/F
60606060
3
87T87T87T87T
3
59GN59GN59GN59GN
NGT with NGRNGT with NGRNGT with NGRNGT with NGR
51G51G51G51G
3
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Generator Protection Scheme: Direct connected Small Size Machine
G
Gen Set
33 3 3
51O/L51O/L51O/L51O/L
51V51V51V51V
32R & 32L32R & 32L32R & 32L32R & 32L87G87G87G87G
46464646
YYYY
YYYY
81U/F & O/F81U/F & O/F81U/F & O/F81U/F & O/F
60606060
59GN59GN59GN59GN
NGRNGRNGRNGR
51G51G51G51G
3
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Generator Protection Scheme: Medium Size Machine
G D Y
GTGen Set
333 3 3 351O/L51O/L51O/L51O/L
21212121
32R & 32L32R & 32L32R & 32L32R & 32L87G87G87G87G
87GT87GT87GT87GT
40G40G40G40G
46464646
YYYY
YYYY
81U/F & O/F81U/F & O/F81U/F & O/F81U/F & O/F
27/5927/5927/5927/59
60606060
24242424
3
87T87T87T87T
359GN59GN59GN59GN
NGT with NGRNGT with NGRNGT with NGRNGT with NGR
51G51G51G51G
3
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Generator Protection Scheme: Large Size Machine
G D Y
GTGen Set
333 3 3 3
51O/L51O/L51O/L51O/L
21212121
32R & 32L32R & 32L32R & 32L32R & 32L87G87G87G87G
87GT87GT87GT87GT
40G40G40G40G
78787878
46464646
YYYY
YYYY
81U/F & O/F81U/F & O/F81U/F & O/F81U/F & O/F
27/5927/5927/5927/59
60606060
24242424
3
87T87T87T87T
3
27N 27N 27N 27N & & & &
59GN59GN59GN59GN
NGT with NGRNGT with NGRNGT with NGRNGT with NGR
51G51G51G51G
3
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
Rotor E/FRotor E/FRotor E/FRotor E/F
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Relay Details: SEL700G
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Front port communication
Push button for Trip/Close
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Relay Details: SEL700G
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
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SEL700G: IEC61850 Certificate
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
KEMA Certificate for IEC61850
Protocol compliance
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SEL700G: IEC61850 Certificate
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
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�Protection Functions require Protection Functions require Protection Functions require Protection Functions require to to to to set based on Machineset based on Machineset based on Machineset based on Machine & & & & Power system parametersPower system parametersPower system parametersPower system parameters
�Do notDo notDo notDo not follow thumb rule follow thumb rule follow thumb rule follow thumb rule blindly for settings of blindly for settings of blindly for settings of blindly for settings of Protection FunctionsProtection FunctionsProtection FunctionsProtection Functions
Generator Protection: General Terminology
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Under Impedance Under Impedance Under Impedance Under Impedance Function (21)Function (21)Function (21)Function (21)
Generator Protection: SEL700G
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Under Impedance Protection (21)
• Generally Offered as a Backup Protection of Generally Offered as a Backup Protection of Generally Offered as a Backup Protection of Generally Offered as a Backup Protection of MachineMachineMachineMachine
• Conceptually itConceptually itConceptually itConceptually it’’’’s a Impedance relay (i.e. s a Impedance relay (i.e. s a Impedance relay (i.e. s a Impedance relay (i.e. Z = V/IZ = V/IZ = V/IZ = V/I))))
• Easy to coEasy to coEasy to coEasy to co----ordinate with Transmission Line ordinate with Transmission Line ordinate with Transmission Line ordinate with Transmission Line Impedance relaysImpedance relaysImpedance relaysImpedance relays
• Impedance & Time CoImpedance & Time CoImpedance & Time CoImpedance & Time Co----ordination is require to ordination is require to ordination is require to ordination is require to check between Under Impedance & Loss of check between Under Impedance & Loss of check between Under Impedance & Loss of check between Under Impedance & Loss of Excitation functionsExcitation functionsExcitation functionsExcitation functions
• Coordination Concerns:Coordination Concerns:Coordination Concerns:Coordination Concerns: Must be coordinate with Transmission line Protection. Undesired operation for system conditions; especially stressed voltage situations and power swings.
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Under Impedance Protection (21): (NERC)
• Coordination Concerns:Coordination Concerns:Coordination Concerns:Coordination Concerns: Must be coordinate with Transmission line Protection. Undesired operation for system conditions; especially stressed voltage situations and power swings.
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Under Impedance Protection (21): (NERC)• Coordination Concerns:Coordination Concerns:Coordination Concerns:Coordination Concerns: Must be coordinate with
Transmission line Protection. Undesired operation for system conditions; especially stressed voltage situations and power swings.
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• Protection measures Impedance (Z=V/I) at the generator end.
Under Impedance Protection (21)
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Impedance Function (21): Relay measures impedance via CT & PT inputs & will trips if impedance falls within pre-determined
characteristics. It is applicable for Line & Generator.
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IF
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G D Y
GTGen Set
3 3 3
21212121
YYYY
YYYY
3 3
27N 27N 27N 27N & & & &
59GN59GN59GN59GN
NGT with NGRNGT with NGRNGT with NGRNGT with NGR
51G51G51G51G
3
DDDD YYYY
IVT
Note: Interposing VT for Vector Matching
Under Impedance Protection (21): Circuit
IVT Configurations to compensate 30 deg. Phase shiftIVT Configurations to compensate 30 deg. Phase shiftIVT Configurations to compensate 30 deg. Phase shiftIVT Configurations to compensate 30 deg. Phase shift–––– Delta/StartDelta/StartDelta/StartDelta/Start
YND1YND1YND1YND1
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
IF
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G D Y
GTGen Set
3 3 3
21212121
YYYY
YYYY
3 327N 27N 27N 27N & & & &
59GN59GN59GN59GN
NGT with NGRNGT with NGRNGT with NGRNGT with NGR
51G51G51G51G
3
DDDD YYYY
IVT
Note: Interposing VT for Vector Matching
Under Impedance Protection (21): Circuit
CT Location on Phase side & Fault in generator CT Location on Phase side & Fault in generator CT Location on Phase side & Fault in generator CT Location on Phase side & Fault in generator wdgwdgwdgwdg
YND1YND1YND1YND1
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
IF
IF
Example:-1
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Under Impedance Protection (21): Setting Criteria
RRRR---- RRRR
XXXX
---- XXXX
ZZZZSetSetSetSet@Ang@Ang@Ang@AngOOOO
Note:Note:Note:Note:XXXXdddd’’’’: Generator Impedance: Generator Impedance: Generator Impedance: Generator ImpedanceZZZZTRTRTRTR: GT impedance: GT impedance: GT impedance: GT impedanceZZZZTLTLTLTL: Transmission Line : Transmission Line : Transmission Line : Transmission Line ImpedanceImpedanceImpedanceImpedance
XXXXdddd’’’’ZZZZTRTRTRTR
ZZZZTLTLTLTL
G D Y
ZZZZTRTRTRTR
ZZZZTLTLTLTL
AngAngAngAng
XXXXdddd’’’’
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Require to set offset impedance in reverse direction also
Example:-1 for wound rotor machine
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G D Y
GTGen Set
3 3 3
21212121
YYYY
YYYY
3 3
27N 27N 27N 27N & & & &
59GN59GN59GN59GN
NGT with NGRNGT with NGRNGT with NGRNGT with NGR
51G51G51G51G
3
DDDD YYYY
IVT
Note: Interposing VT for Vector Matching
Under Impedance Protection (21): Circuit
YND1YND1YND1YND1
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
IF
CT Location on Neutral side & Fault in generator CT Location on Neutral side & Fault in generator CT Location on Neutral side & Fault in generator CT Location on Neutral side & Fault in generator wdgwdgwdgwdg
Example:-2
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Under Impedance Protection (21): Setting Criteria
RRRR---- RRRR
XXXX
---- XXXX
Note:Note:Note:Note:XXXXdddd’’’’: Generator Impedance: Generator Impedance: Generator Impedance: Generator ImpedanceZZZZTRTRTRTR: GT impedance: GT impedance: GT impedance: GT impedanceZZZZTLTLTLTL: Transmission Line : Transmission Line : Transmission Line : Transmission Line ImpedanceImpedanceImpedanceImpedance
X”d + ZTR + Z+ Z+ Z+ ZTLTLTLTL
AngAngAngAng
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
Do not Require to set offset impedance in reverse direction also
Example:-2 for wound rotor machine
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Under Impedance Protection (21): Setting Criteria
RRRR---- RRRR
XXXX
---- XXXX
Note:Note:Note:Note:XXXXdddd’’’’: Generator Impedance: Generator Impedance: Generator Impedance: Generator ImpedanceZZZZTRTRTRTR: GT impedance: GT impedance: GT impedance: GT impedanceZZZZTLTLTLTL: Transmission Line : Transmission Line : Transmission Line : Transmission Line ImpedanceImpedanceImpedanceImpedance
Zone2: X”d + ZTR + Z+ Z+ Z+ ZTLTLTLTL
AngAngAngAng
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
Do not Require to set offset impedance in reverse direction also
Example:-2 for wound rotor machine
Zone1: X”d + ZTR
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Under Impedance Protection (21): Setting Criteria
RRRR---- RRRR
XXXX
---- XXXX
Note:Note:Note:Note:XXXXGGGG’’’’: (: (: (: (XXXX””””dddd + X+ X+ X+ X””””q)/2q)/2q)/2q)/2ZZZZTRTRTRTR: GT impedance: GT impedance: GT impedance: GT impedanceZZZZTLTLTLTL: Transmission Line : Transmission Line : Transmission Line : Transmission Line ImpedanceImpedanceImpedanceImpedance
Zone2: XG + ZTR + Z+ Z+ Z+ ZTLTLTLTL
AngAngAngAng
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
Do not Require to set offset impedance in reverse direction also
Example:-2 for salient pole machine
Zone1: XG + ZTR
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Generator Protection (SEL700G): Backup Impedance Function (21)
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
Impedance Function Range
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Generator Protection (SEL700G): Backup Impedance Function (21)
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Impedance Characteristic with Load Encroachment
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Generator Protection (SEL700G): Backup Impedance Function (21)
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Select function “DC”
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Generator Protection (SEL700G): Backup Impedance Function (21)
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Zone1 Threshold value
Zone1 Offset
Time Delay of Zone1
Zone1 Threshold value
Zone2 Offset = 0 ohms
Time Delay of Zone1
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Generator Protection (SEL700G): Backup Impedance Function (21)
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Z1 & Z2 Circle Characteristic
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Generator Protection (SEL700G): Backup Impedance Function (21)
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Zone1 Threshold value
Zone1 Offset
Time Delay of Zone1
Zone1 Threshold value
Zone2 Offset = 5 Ohms
Time Delay of Zone1
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Generator Protection (SEL700G): Backup Impedance Function (21)
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Offset Mho
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Generator Protection (SEL700G): Backup Impedance Function (21)
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Relay Trip Logic for Backup Impedance Function
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Over Excitation Function Over Excitation Function Over Excitation Function Over Excitation Function (24)(24)(24)(24)
Generator Protection: SEL700G
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Generator-Transformer Over Fluxing Protection (24)
Rotor Field current increasesRotor Field current increasesRotor Field current increasesRotor Field current increases
Stator current increasesStator current increasesStator current increasesStator current increases
Active Power Constant Active Power Constant Active Power Constant Active Power Constant (MW) due to Constant (MW) due to Constant (MW) due to Constant (MW) due to Constant speed of Turbinespeed of Turbinespeed of Turbinespeed of Turbine
Reactive Power Reactive Power Reactive Power Reactive Power (MVAR) Increases or (MVAR) Increases or (MVAR) Increases or (MVAR) Increases or DecreasesDecreasesDecreasesDecreases
� Generator will Overexcite due to Armature reactionGenerator will Overexcite due to Armature reactionGenerator will Overexcite due to Armature reactionGenerator will Overexcite due to Armature reaction
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Generator-Transformer Over Fluxing Protection (24)
• Causes:Causes:Causes:Causes:
– Generator Regulator ProblemGenerator Regulator ProblemGenerator Regulator ProblemGenerator Regulator Problem
• AVR or Voltage Regulator FailsAVR or Voltage Regulator FailsAVR or Voltage Regulator FailsAVR or Voltage Regulator Fails
• Operating Error during off line manual Operating Error during off line manual Operating Error during off line manual Operating Error during off line manual regulator operationregulator operationregulator operationregulator operation
• Loss of VT supply of AVRLoss of VT supply of AVRLoss of VT supply of AVRLoss of VT supply of AVR
• Speed controller (Governor) fails or not Speed controller (Governor) fails or not Speed controller (Governor) fails or not Speed controller (Governor) fails or not functioning properlyfunctioning properlyfunctioning properlyfunctioning properly
– System ProblemSystem ProblemSystem ProblemSystem Problem
• Unit Load Rejection: Full Load or Unit Load Rejection: Full Load or Unit Load Rejection: Full Load or Unit Load Rejection: Full Load or –––– Partial Partial Partial Partial LoadLoadLoadLoad
• Power System Islanding during Major Power System Islanding during Major Power System Islanding during Major Power System Islanding during Major disturbances in Griddisturbances in Griddisturbances in Griddisturbances in Grid
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Generator-Transformer Over Fluxing Protection (24)
• Excitation current increases to increase flux Excitation current increases to increase flux Excitation current increases to increase flux Excitation current increases to increase flux density. The increased excitation current is density. The increased excitation current is density. The increased excitation current is density. The increased excitation current is made up of higher harmonic. made up of higher harmonic. made up of higher harmonic. made up of higher harmonic.
Flux density (IEC60034):Flux density (IEC60034):Flux density (IEC60034):Flux density (IEC60034):
• The maximum flux density in any part of the The maximum flux density in any part of the The maximum flux density in any part of the The maximum flux density in any part of the core and yoke at normal voltage and frequency core and yoke at normal voltage and frequency core and yoke at normal voltage and frequency core and yoke at normal voltage and frequency should be such that the flux density in over should be such that the flux density in over should be such that the flux density in over should be such that the flux density in over voltage / flux conditions does not exceed 1.9 voltage / flux conditions does not exceed 1.9 voltage / flux conditions does not exceed 1.9 voltage / flux conditions does not exceed 1.9 Tesla / 19000 lines per cmTesla / 19000 lines per cmTesla / 19000 lines per cmTesla / 19000 lines per cm2222....
– Flux increases when System voltage rises at Flux increases when System voltage rises at Flux increases when System voltage rises at Flux increases when System voltage rises at Rated FrequencyRated FrequencyRated FrequencyRated Frequency
– Flux increases when System Frequency fall Flux increases when System Frequency fall Flux increases when System Frequency fall Flux increases when System Frequency fall at Rated Voltageat Rated Voltageat Rated Voltageat Rated Voltage
• Saturation of Magnetic Core of the GT due to Saturation of Magnetic Core of the GT due to Saturation of Magnetic Core of the GT due to Saturation of Magnetic Core of the GT due to exceeded the V/Hz ratiosexceeded the V/Hz ratiosexceeded the V/Hz ratiosexceeded the V/Hz ratios
• 5555thththth Harmonic current generate Negative seq. Harmonic current generate Negative seq. Harmonic current generate Negative seq. Harmonic current generate Negative seq. componentscomponentscomponentscomponents
• Serious Over heating will occur in bolts & Serious Over heating will occur in bolts & Serious Over heating will occur in bolts & Serious Over heating will occur in bolts & support structure of machine which destroys support structure of machine which destroys support structure of machine which destroys support structure of machine which destroys their own insulation as well as coil insulation if their own insulation as well as coil insulation if their own insulation as well as coil insulation if their own insulation as well as coil insulation if the phenomenon persist for longer duration the phenomenon persist for longer duration the phenomenon persist for longer duration the phenomenon persist for longer duration
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
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Generator-Transformer Over Fluxing Protection (24)
Core Heating as a Function of Magnetic fluxCore Heating as a Function of Magnetic fluxCore Heating as a Function of Magnetic fluxCore Heating as a Function of Magnetic flux
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
68
Generator-Transformer Over Fluxing Protection (24)
Over fluxing withstand Over fluxing withstand Over fluxing withstand Over fluxing withstand curvescurvescurvescurves
69
Generator-Transformer Over Fluxing Protection (24)
• Protection measures a Ratio of Voltage to Frequency at the generator terminals.
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
24
70
Generator-Transformer Over Fluxing Protection (24)
• Phase to PhasePhase to PhasePhase to PhasePhase to Phase Voltage Voltage Voltage Voltage Measurement
• VLL = 110V
• FN = 50Hz
• V/Hz set value = 1.1PU
• V/Hz Measured = (VLL Measured in Volt) / (F Measured in Hz)
• V/Hz set value = {(VLL)/(FN)} * {1.1} = (2.2)*(1.1) = 2.422.422.422.42V/HzV/HzV/HzV/Hz
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
71
Generator-Transformer Over Fluxing Protection (24)
• Phase to GroundPhase to GroundPhase to GroundPhase to Ground Voltage Voltage Voltage Voltage Measurement
• VLL = 110/1.7325 = 63.5V
• FN = 50Hz
• V/Hz set value = 1.1PU
• V/Hz Measured = (VLN Measured in Volt) / (F Measured in Hz)
• V/Hz set value = {(VLN)/(FN)} * {1.1} = (1.1)*(1.1) = 1.21 V/Hz1.21 V/Hz1.21 V/Hz1.21 V/Hz
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
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Generator-Transformer Over Fluxing Protection (24)
• Specific Over Fluxing Protection is Specific Over Fluxing Protection is Specific Over Fluxing Protection is Specific Over Fluxing Protection is not not not not MandatoryMandatoryMandatoryMandatory & It is generally offered as an & It is generally offered as an & It is generally offered as an & It is generally offered as an optional by other Protection like Over Voltage. optional by other Protection like Over Voltage. optional by other Protection like Over Voltage. optional by other Protection like Over Voltage. Protection should be in circuit whenever field Protection should be in circuit whenever field Protection should be in circuit whenever field Protection should be in circuit whenever field CB is closed CB is closed CB is closed CB is closed
• IEEE C50.13 Generator should continuous IEEE C50.13 Generator should continuous IEEE C50.13 Generator should continuous IEEE C50.13 Generator should continuous withstand withstand withstand withstand 105% of rated105% of rated105% of rated105% of rated excitation at full load excitation at full load excitation at full load excitation at full load
• Normally Inverse & DMT type relays are used Normally Inverse & DMT type relays are used Normally Inverse & DMT type relays are used Normally Inverse & DMT type relays are used for application for application for application for application
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
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• Setting CriteriaSetting CriteriaSetting CriteriaSetting Criteria: Based on : Based on : Based on : Based on Generator V/Hz with stand Generator V/Hz with stand Generator V/Hz with stand Generator V/Hz with stand capability Curvecapability Curvecapability Curvecapability Curve
• Normally, Inverse Characteristic Normally, Inverse Characteristic Normally, Inverse Characteristic Normally, Inverse Characteristic element is used for element is used for element is used for element is used for StageStageStageStage----1111 (1.05 to (1.05 to (1.05 to (1.05 to 1.2 V/Hz for Alarm/Trip for 451.2 V/Hz for Alarm/Trip for 451.2 V/Hz for Alarm/Trip for 451.2 V/Hz for Alarm/Trip for 45----50s)50s)50s)50s)
• Definite Time element is used for Definite Time element is used for Definite Time element is used for Definite Time element is used for StageStageStageStage----2222 for Tripping (1.2 to 1.4 for Tripping (1.2 to 1.4 for Tripping (1.2 to 1.4 for Tripping (1.2 to 1.4 V/Hz for 2s V/Hz for 2s V/Hz for 2s V/Hz for 2s ---- 6s) 6s) 6s) 6s)
Generator-Transformer Over Fluxing Protection (24)
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74
Generator-Transformer Over Fluxing Protection (24)
� IEC60076IEC60076IEC60076IEC60076----1 1 1 1 shows withstand capacity of GT for over shows withstand capacity of GT for over shows withstand capacity of GT for over shows withstand capacity of GT for over voltage shoot up should be 1.4 times for 5svoltage shoot up should be 1.4 times for 5svoltage shoot up should be 1.4 times for 5svoltage shoot up should be 1.4 times for 5s
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
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Generator-Transformer Over Fluxing Protection (24)
� IS: 2026_1IS: 2026_1IS: 2026_1IS: 2026_1 shows withstand capacity of GT for over shows withstand capacity of GT for over shows withstand capacity of GT for over shows withstand capacity of GT for over voltage shoot up should be 1.4 times for 5svoltage shoot up should be 1.4 times for 5svoltage shoot up should be 1.4 times for 5svoltage shoot up should be 1.4 times for 5s
26
76
Generator Protection (SEL700G): Over Excitation Function (24)
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
Over Excitation Function Range
77
Generator Protection (SEL700G): Over Excitation Function (24)
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
Select “DD” option for definite time trip
78
Generator Protection (SEL700G): Over Excitation Function (24)
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
Definite time characteristic Mode (DD)
Stage1 Setting Stage2 Setting
27
79
Generator Protection (SEL700G): Over Excitation Function (24)
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
Select “ID” option for Inverse definite time trip
80
Generator Protection (SEL700G): Over Excitation Function (24)
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
Inverse Definite time characteristic Mode (ID)
Stage1 Setting in Definite time mode
Stage2 Setting in Inverse time mode
81
Generator Protection (SEL700G): Over Excitation Function (24)
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
Select “I” option for Inverse time trip
28
82
Generator Protection (SEL700G): Over Excitation Function (24)
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
Select Curve “0.5” option for Inverse time trip
83
Generator Protection SEL700G): Over Excitation Function (24)
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
Curves “0.5” on various time dial values
84
Generator Protection: Over Excitation Function (24)
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
Select Curve “1.0” option for Inverse time trip
29
85
Generator Protection (SEL700G): Over Excitation Function (24)
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
Curves “1.0” on various time dial values
86
Generator Protection (SEL700G): Over Excitation Function (24)
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
Select Curve “2.0” option for Inverse time trip
87
Generator Protection (SEL700G): Over Excitation Function (24)
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
Curves “2.0” on various time dial values
30
88
Generator Protection (SEL700G): Over Excitation Function (24)
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
Curve “0.5”, “1.0” & “2.0”on time dial value “1.0”
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
Generator Protection: SEL700G
92
Check Synchronizing Function (25): SEL700G
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
G D Y
GTGen Set
333 3 3 3
YYYY
YYYY
3 3
27N 27N 27N 27N & & & &
59GN59GN59GN59GN
NGT with NGRNGT with NGRNGT with NGRNGT with NGR
51G51G51G51G
3
Sys
YYYY
YYYY
25
GCB
93
Check Synchronizing Function (25): SEL700G
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
G D Y
GTGen Set
333 3 3 3
YYYY
YYYY
3 3
27N 27N 27N 27N & & & &
59GN59GN59GN59GN
NGT with NGRNGT with NGRNGT with NGRNGT with NGR
51G51G51G51G
3
Sys
YYYY
YYYY
25
30 deg. Vector compensation
GCB
32
94
Check Synchronizing Function (25): SEL700G
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
G D Y
GTGen Set
333
YYYY
YYYY
3
27N 27N 27N 27N & & & &
59GN59GN59GN59GN
NGT with NGRNGT with NGRNGT with NGRNGT with NGR
51G51G51G51G
3
Sys25
YYYY
YYYY
GCB
95
Check Synchronizing Function (25): SEL700G
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
G D Y
GTGen Set
333
YYYY
YYYY
3
27N 27N 27N 27N & & & &
59GN59GN59GN59GN
NGT with NGRNGT with NGRNGT with NGRNGT with NGR
51G51G51G51G
3
Sys25
30 deg. Vector compensation
GCB
YYYY
YYYY
96
Check Synchronizing Function (25): SEL700G
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
G D Y
Gen Set1
333
YYYY
YYYY
3
25
YYYY
YYYY
GCB1
G
Gen Set2
333 3
GCB2
BC
D Y
D Y
D Y
33
97
Check Synchronizing Function (25): SEL700G (Connection Diagram)
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
98
Check Synchronizing Function (25): SEL700G
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
Voltage difference (DV) setting
Slip frequency (DF) setting
Angle difference (DØ) setting
Advance CB closing angle setting
Vector Compensation setting
99
Check Synchronizing Function (25): SEL700G
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34
100
Check Synchronizing Function (25): SEL700G
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
101
Generator Auto Generator Auto Generator Auto Generator Auto Synchronizing Function Synchronizing Function Synchronizing Function Synchronizing Function
(25)(25)(25)(25)
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
Generator Protection: SEL700G
102
Auto Synchronizing Function (25): SEL700G
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
G D Y
GTGen Set
333 3 3 3
YYYY
YYYY
3 3
27N 27N 27N 27N & & & &
59GN59GN59GN59GN
NGT with NGRNGT with NGRNGT with NGRNGT with NGR
51G51G51G51G
3
Sys
YYYY
YYYY
25
GCB
STG Speed Controller
Frequency – Raise/Low
RPM-Increase/Decrease
35
103
Auto Synchronizing Function (25): SEL700G
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
Steam flow control through Mechanical Governor
104
Auto Synchronizing Function (25): SEL700G
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
Steam flow control through Hydraulic Governor
105
Auto Synchronizing Function (25): SEL700G
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
Frequency ramp rate in Hz/s
Pulse Interval in s
Function ON
36
106
Auto Synchronizing Function (25): SEL700G
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
Freq pulse output
0
0.2
0.4
0.6
0.8
1
1.2
0 2 4 6 8 10 12
Time in s
Pulse width Pulse width Pulse width
Pulse interval Pulse interval
107
Auto Synchronizing Function (25): SEL700G
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
G D Y
GTGen Set
333 3 3 3
YYYY
YYYY
3 3
27N 27N 27N 27N & & & &
59GN59GN59GN59GN
NGT with NGRNGT with NGRNGT with NGRNGT with NGR
51G51G51G51G
3
Sys
YYYY
YYYY
25
GCB
AVR Controller
Voltage – Raise/Low
Field voltage Increase/Decrease
E
108
Auto Synchronizing Function (25): SEL700G
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
Voltage ramp rate in Volt/s
Pulse Interval in s
37
109
Auto Synchronizing Function (25): SEL700G
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
Voltage pulse output
0
0.2
0.4
0.6
0.8
1
1.2
0 2 4 6 8 10 12
Time in s
Pulse width Pulse width Pulse width
Pulse interval Pulse interval
110
Under Voltage Function (27)Under Voltage Function (27)Under Voltage Function (27)Under Voltage Function (27)
Generator Protection: SEL700G
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
111
Under Voltage Protection (27):
• Typically Provides Typically Provides Typically Provides Typically Provides alarm and supervision for other alarm and supervision for other alarm and supervision for other alarm and supervision for other protection using generator terminal voltage. protection using generator terminal voltage. protection using generator terminal voltage. protection using generator terminal voltage. Rarely used to trip the generator directly.Rarely used to trip the generator directly.Rarely used to trip the generator directly.Rarely used to trip the generator directly.
• Provides detection of low voltage that may result Provides detection of low voltage that may result Provides detection of low voltage that may result Provides detection of low voltage that may result in reduction in stability limit, excessive reactive in reduction in stability limit, excessive reactive in reduction in stability limit, excessive reactive in reduction in stability limit, excessive reactive power drawn from the system, and malfunction of power drawn from the system, and malfunction of power drawn from the system, and malfunction of power drawn from the system, and malfunction of voltage sensitive devices and equipment.voltage sensitive devices and equipment.voltage sensitive devices and equipment.voltage sensitive devices and equipment.
• GeneratorGeneratorGeneratorGenerator----Turbine Auxiliaries are effected by low Turbine Auxiliaries are effected by low Turbine Auxiliaries are effected by low Turbine Auxiliaries are effected by low voltagevoltagevoltagevoltage– Motor Tripping (BFP, CWP etc.) on Low voltage Motor Tripping (BFP, CWP etc.) on Low voltage Motor Tripping (BFP, CWP etc.) on Low voltage Motor Tripping (BFP, CWP etc.) on Low voltage
can Shutdown Machine can Shutdown Machine can Shutdown Machine can Shutdown Machine • Coordination Concerns:Coordination Concerns:Coordination Concerns:Coordination Concerns: Coordinate with any Coordinate with any Coordinate with any Coordinate with any
system undersystem undersystem undersystem under----voltage protection, system fault voltage protection, system fault voltage protection, system fault voltage protection, system fault conditions, and stressed system voltage situations conditions, and stressed system voltage situations conditions, and stressed system voltage situations conditions, and stressed system voltage situations for which the system is designed to survive.for which the system is designed to survive.for which the system is designed to survive.for which the system is designed to survive.
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
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112
• Protection measures Voltage at the generator terminals.
Under Voltage Protection (27)
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
113
Under Voltage Protection (27)
• Normally, Inverse Characteristic Normally, Inverse Characteristic Normally, Inverse Characteristic Normally, Inverse Characteristic element is used for element is used for element is used for element is used for StageStageStageStage----1 1 1 1 for for for for Alarm/delayed Trip (Say: 80% to 70% Alarm/delayed Trip (Say: 80% to 70% Alarm/delayed Trip (Say: 80% to 70% Alarm/delayed Trip (Say: 80% to 70% of Un for 5s to 10s)of Un for 5s to 10s)of Un for 5s to 10s)of Un for 5s to 10s)
• Definite Time / Instantaneous element Definite Time / Instantaneous element Definite Time / Instantaneous element Definite Time / Instantaneous element is used for is used for is used for is used for StageStageStageStage----2222 for Tripping (30% for Tripping (30% for Tripping (30% for Tripping (30% to 25% for Inst. / 500ms ). to 25% for Inst. / 500ms ). to 25% for Inst. / 500ms ). to 25% for Inst. / 500ms ).
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
114
Generator Protection (SEL700G): Under Voltage Function (27)
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
Under Voltage Function Range
39
115
Generator Protection (SEL700G): Under Voltage Function (27)
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
Under Voltage Tripping Logic
116
Under Voltage Protection (27): SEL700G
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
Stage1 Settings Under VStage1 Settings Under VStage1 Settings Under VStage1 Settings Under VLNLNLNLN
Stage1 Settings Under VStage1 Settings Under VStage1 Settings Under VStage1 Settings Under VLLLLLLLL
Stage2 Settings Under VStage2 Settings Under VStage2 Settings Under VStage2 Settings Under VLNLNLNLN
Stage2 Settings Under VStage2 Settings Under VStage2 Settings Under VStage2 Settings Under VLLLLLLLL
117
Under Voltage Protection (27): Generator Auxiliary Power Systems
• PPPProtection rotection rotection rotection measures auxiliary system voltage.
• Provides Provides Provides Provides alarming or tripping, automatic transfer to backup supply, starting emergency generation.
• Coordination Concerns:Coordination Concerns:Coordination Concerns:Coordination Concerns: Coordinate with
– Any system under-voltage protection,
– System fault conditions and stressed system voltage situations for which the system is designed to survive.
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
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118
Reverse Power (Reverse Power (Reverse Power (Reverse Power (ActiveActiveActiveActive) Protection ) Protection ) Protection ) Protection (32R)(32R)(32R)(32R)
Generator Protection: SEL700G
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
119
What is Reverse Power???What is Reverse Power???What is Reverse Power???What is Reverse Power???
Generator Protection: SEL700G
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
Machine Act as a Induction MotorMachine Act as a Induction MotorMachine Act as a Induction MotorMachine Act as a Induction Motor
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
122
• Causes:Causes:Causes:Causes:
– Two or more machines are Two or more machines are Two or more machines are Two or more machines are running running running running in parallel & Primein parallel & Primein parallel & Primein parallel & Prime----movermovermovermover of one of of one of of one of of one of the machine fails. Turbine has the machine fails. Turbine has the machine fails. Turbine has the machine fails. Turbine has Problems; exhaust hood Problems; exhaust hood Problems; exhaust hood Problems; exhaust hood temperature on steam turbinestemperature on steam turbinestemperature on steam turbinestemperature on steam turbines
– Sometimes the condition appear Sometimes the condition appear Sometimes the condition appear Sometimes the condition appear during synchronizationduring synchronizationduring synchronizationduring synchronization of machine, of machine, of machine, of machine, if incoming machine frequency is if incoming machine frequency is if incoming machine frequency is if incoming machine frequency is lesser than bus frequency lesser than bus frequency lesser than bus frequency lesser than bus frequency
Reverse Active Power Protection (32R)
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
123
Reverse Active Power Protection (32R)
Fails
Fails
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
42
124
Reverse Active Power Protection (32R): Example1
G D Y
GT
GCB
Gen Set
G D Y
GT
GCB
Gen Set
CB1
CB2
CB3
CB4
CB
5
TL Line
TL Line
MW
MW
Healthy Prime-mover
Failed Prime-mover
MVAR
MVAR
E
E
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
125
Reverse Active Power Protection (32R): Example2
G D Y
GT
GCB
Gen Set
G D Y
GT
GCB
Gen Set
CB1
CB2
CB3
CB4
CB
5
TL Line
TL Line
MW
MW
Healthy Prime-mover
Failed Prime-mover
MVAR
MVAR
E
E
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
126
Reverse Active Power Protection (32R): Example3
G D Y
GT
GCB
Gen Set
CB1 CB3
CB
5
TL Line
MW
Failed Prime-mover
MVAR
E
Active Power Import from Grid sourcesActive Power Import from Grid sourcesActive Power Import from Grid sourcesActive Power Import from Grid sources
GridGridGridGrid
GridGridGridGridMW
MW
MW
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
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127
Reverse Active Power Protection (32R): Example4
G
D Y
TR1
GCB
Gen Set
Failed Prime-mover
MVAR
E
Only Reactive Power Export to LoadsOnly Reactive Power Export to LoadsOnly Reactive Power Export to LoadsOnly Reactive Power Export to Loads
CB1CB1CB1CB1 CB2CB2CB2CB2
D Y
TR2
CB3CB3CB3CB3 CB4CB4CB4CB4
MMMM
CB
5C
B5
CB
5C
B5
CB6CB6CB6CB6
Loads
Loads
Loads
Loads
Loads
Loads
Loads
Loads
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
128
• Protection against the Protection against the Protection against the Protection against the motoring actionmotoring actionmotoring actionmotoring action of of of of the generator while the generator looses the generator while the generator looses the generator while the generator looses the generator while the generator looses itititit’’’’s Primes Primes Primes Prime----mover inputmover inputmover inputmover input
• Protection is applied for Protection is applied for Protection is applied for Protection is applied for PrimePrimePrimePrime----movermovermovermover
• Normally, Protection is applied only when Normally, Protection is applied only when Normally, Protection is applied only when Normally, Protection is applied only when machines are operating in parallel with machines are operating in parallel with machines are operating in parallel with machines are operating in parallel with each other as well as Power Grideach other as well as Power Grideach other as well as Power Grideach other as well as Power Grid
• Generator unaffected by reverse power, Generator unaffected by reverse power, Generator unaffected by reverse power, Generator unaffected by reverse power, but act as a but act as a but act as a but act as a Synchronous MotorSynchronous MotorSynchronous MotorSynchronous Motor(Exporting Reactive Power & Importing (Exporting Reactive Power & Importing (Exporting Reactive Power & Importing (Exporting Reactive Power & Importing Active Power) as long as field on Active Power) as long as field on Active Power) as long as field on Active Power) as long as field on
Reverse Active Power Protection (32R)
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
• Steam turbine tends to overheat, when Steam turbine tends to overheat, when Steam turbine tends to overheat, when Steam turbine tends to overheat, when steam supply is cut off and the turbine still steam supply is cut off and the turbine still steam supply is cut off and the turbine still steam supply is cut off and the turbine still rotates as the generator runs as motor. rotates as the generator runs as motor. rotates as the generator runs as motor. rotates as the generator runs as motor. Steam turbine, act as a pump and the Steam turbine, act as a pump and the Steam turbine, act as a pump and the Steam turbine, act as a pump and the steam is trapped. The turbulence losses in steam is trapped. The turbulence losses in steam is trapped. The turbulence losses in steam is trapped. The turbulence losses in the trapped steam may then built up a high the trapped steam may then built up a high the trapped steam may then built up a high the trapped steam may then built up a high temperature in lowtemperature in lowtemperature in lowtemperature in low----pressure stage. pressure stage. pressure stage. pressure stage. Hence, the turbine blades are overheated Hence, the turbine blades are overheated Hence, the turbine blades are overheated Hence, the turbine blades are overheated due to due to due to due to windagewindagewindagewindage or air friction. However, or air friction. However, or air friction. However, or air friction. However, the heat caused by turbulence of the the heat caused by turbulence of the the heat caused by turbulence of the the heat caused by turbulence of the trapped steam can detrapped steam can detrapped steam can detrapped steam can de----temper turbine temper turbine temper turbine temper turbine runner. runner. runner. runner.
Reverse Active Power Protection (32R)
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
• In case of hydro turbine, the flow of water In case of hydro turbine, the flow of water In case of hydro turbine, the flow of water In case of hydro turbine, the flow of water starts reducing or complete cut off and starts reducing or complete cut off and starts reducing or complete cut off and starts reducing or complete cut off and hence bubbles are formed causing hence bubbles are formed causing hence bubbles are formed causing hence bubbles are formed causing cavitations in the turbine resulting to cavitations in the turbine resulting to cavitations in the turbine resulting to cavitations in the turbine resulting to damage turbine runner.damage turbine runner.damage turbine runner.damage turbine runner.
• In case of diesel driven set, loss of motive In case of diesel driven set, loss of motive In case of diesel driven set, loss of motive In case of diesel driven set, loss of motive power is likely to be cause by some power is likely to be cause by some power is likely to be cause by some power is likely to be cause by some mechanical failure, such as bearing over mechanical failure, such as bearing over mechanical failure, such as bearing over mechanical failure, such as bearing over heating leading to closure of fuel valves, heating leading to closure of fuel valves, heating leading to closure of fuel valves, heating leading to closure of fuel valves, and continued running is likely to cause and continued running is likely to cause and continued running is likely to cause and continued running is likely to cause several damages in engine.several damages in engine.several damages in engine.several damages in engine.
Reverse Active Power Protection (32R)
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
131
Reverse Power Active Protection (32R): Allowable limit
1% to 3% of rated power1% to 3% of rated power1% to 3% of rated power1% to 3% of rated powerHydro turbine
0.5% to 7.5% of rated power0.5% to 7.5% of rated power0.5% to 7.5% of rated power0.5% to 7.5% of rated powerSteam turbine
10% to 15% of rated power10% to 15% of rated power10% to 15% of rated power10% to 15% of rated powerGas turbine (Double shaft)
100% of rated powerGas turbine (Single shaft)
15% of rated powerDiesel (Four cycle-4
25% of rated powerDiesel (Two cycle-2 stroke) stroke)
Allowable limit of %P of Reverse Power
Prime Mover
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
132
• Protection measures Reverse Power (-PRW)at the generator end.
Reverse Active Power Protection (32R)
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
45
133
Reverse Active Power Protection (32R)
G D Y
GT
GCB
Gen Set
MW
Failed Prime-mover
MVAR
EYYYY
YYYY
3
32R32R32R32R
PPPPSet Set Set Set = 1.7325*V= 1.7325*V= 1.7325*V= 1.7325*VLLLLLLLL*I*I*I*ILLLL****COSphiCOSphiCOSphiCOSphiOperate: Operate: Operate: Operate: ----PPPPMeasureMeasureMeasureMeasure > > > > ----PPPPSetSetSetSet
SysSysSysSys
MVARMW
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
134
• Setting Criteria:Setting Criteria:Setting Criteria:Setting Criteria: As the overheating of the As the overheating of the As the overheating of the As the overheating of the turbine blade does not occur instantaneously turbine blade does not occur instantaneously turbine blade does not occur instantaneously turbine blade does not occur instantaneously while the generator starts motoring, so it is not while the generator starts motoring, so it is not while the generator starts motoring, so it is not while the generator starts motoring, so it is not required to trip instantaneously. required to trip instantaneously. required to trip instantaneously. required to trip instantaneously.
– Set Point 1:Set Point 1:Set Point 1:Set Point 1:
• ----P<0.5% for Steam Turbine GeneratorP<0.5% for Steam Turbine GeneratorP<0.5% for Steam Turbine GeneratorP<0.5% for Steam Turbine Generator
• Operating Time 10sOperating Time 10sOperating Time 10sOperating Time 10s
– Set Point 2:Set Point 2:Set Point 2:Set Point 2:
• ----P<0.5% for Steam Turbine GeneratorP<0.5% for Steam Turbine GeneratorP<0.5% for Steam Turbine GeneratorP<0.5% for Steam Turbine Generator
• Operating Time 2sOperating Time 2sOperating Time 2sOperating Time 2s
• Class1 CT can use for Accurate PowerClass1 CT can use for Accurate PowerClass1 CT can use for Accurate PowerClass1 CT can use for Accurate Powermeasurement for Reverse Power operationmeasurement for Reverse Power operationmeasurement for Reverse Power operationmeasurement for Reverse Power operation
Reverse Active Power Protection (32R)
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
135
• Reverse Power is Three Balanced Reverse Power is Three Balanced Reverse Power is Three Balanced Reverse Power is Three Balanced Phenomena so Phenomena so Phenomena so Phenomena so single phase single phase single phase single phase measurement can be Adequatemeasurement can be Adequatemeasurement can be Adequatemeasurement can be Adequate
• Three Phase measurement Three Phase measurement Three Phase measurement Three Phase measurement preferred preferred preferred preferred to watch power phenomenon in each to watch power phenomenon in each to watch power phenomenon in each to watch power phenomenon in each phase.phase.phase.phase.
• Connect current coil/circuit of relay Connect current coil/circuit of relay Connect current coil/circuit of relay Connect current coil/circuit of relay through Metering core of CT to get through Metering core of CT to get through Metering core of CT to get through Metering core of CT to get accurate measurementaccurate measurementaccurate measurementaccurate measurement of Power (i.e. of Power (i.e. of Power (i.e. of Power (i.e. CL1.5, CL1.0 etc.). CL1.5, CL1.0 etc.). CL1.5, CL1.0 etc.). CL1.5, CL1.0 etc.).
Reverse Active Power Protection (32R)
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
46
136
• Directional Power relay will work effectively Directional Power relay will work effectively Directional Power relay will work effectively Directional Power relay will work effectively for larger machine. for larger machine. for larger machine. for larger machine. Power setting is Power setting is Power setting is Power setting is constantconstantconstantconstant
Reverse Active Power Protection (32R)
MWMWMWMW---- MWMWMWMW
MVARMVARMVARMVAR
---- MVARMVARMVARMVAR
Opera
ting R
egio
nO
pera
ting R
egio
nO
pera
ting R
egio
nO
pera
ting R
egio
n
---- PPPPSet Set Set Set >>>>
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
– In Sequential Tripping Mode; Turbine In Sequential Tripping Mode; Turbine In Sequential Tripping Mode; Turbine In Sequential Tripping Mode; Turbine Valves are tripped First Valves are tripped First Valves are tripped First Valves are tripped First
– Used on Steam Turbine Generator to Used on Steam Turbine Generator to Used on Steam Turbine Generator to Used on Steam Turbine Generator to Prevent OverspeedPrevent OverspeedPrevent OverspeedPrevent Overspeed
– This trip mode only used for This trip mode only used for This trip mode only used for This trip mode only used for boiler/reactor or turbine mechanical boiler/reactor or turbine mechanical boiler/reactor or turbine mechanical boiler/reactor or turbine mechanical problemsproblemsproblemsproblems
– This trip mode primarily used for steam This trip mode primarily used for steam This trip mode primarily used for steam This trip mode primarily used for steam turbineturbineturbineturbine
Reverse Active Power Protection (32R)
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
• Abnormal Turbine/Boiler/Reactor condition is Abnormal Turbine/Boiler/Reactor condition is Abnormal Turbine/Boiler/Reactor condition is Abnormal Turbine/Boiler/Reactor condition is detecteddetecteddetecteddetected
– Step 2:Step 2:Step 2:Step 2:• Turbine Valves closed; Generator allowed to Turbine Valves closed; Generator allowed to Turbine Valves closed; Generator allowed to Turbine Valves closed; Generator allowed to
briefly briefly briefly briefly ““““MotorMotorMotorMotor”””” (i.e. Importing Active Power (i.e. Importing Active Power (i.e. Importing Active Power (i.e. Importing Active Power from Grid)from Grid)from Grid)from Grid)
– Step 3:Step 3:Step 3:Step 3:• A Reverse Power relay in Series with Turbine A Reverse Power relay in Series with Turbine A Reverse Power relay in Series with Turbine A Reverse Power relay in Series with Turbine
Valves position switches confirms all Valves Valves position switches confirms all Valves Valves position switches confirms all Valves Valves position switches confirms all Valves have closedhave closedhave closedhave closed
Reverse Active Power Protection (32R)
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
– Step 4:Step 4:Step 4:Step 4:• Generator is required to Isolate from Generator is required to Isolate from Generator is required to Isolate from Generator is required to Isolate from
Power SystemPower SystemPower SystemPower System
– ConsiderConsiderConsiderConsider
• Export High MVARsExport High MVARsExport High MVARsExport High MVARs
Reverse Power (Reactive) Protection Reverse Power (Reactive) Protection Reverse Power (Reactive) Protection Reverse Power (Reactive) Protection (32R)(32R)(32R)(32R)
Generator Protection: SEL700G
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
– Set Point 1:Set Point 1:Set Point 1:Set Point 1:• ----P<5% for Steam Turbine GeneratorP<5% for Steam Turbine GeneratorP<5% for Steam Turbine GeneratorP<5% for Steam Turbine Generator
• Operating Time 10sOperating Time 10sOperating Time 10sOperating Time 10s
– Set Point 2:Set Point 2:Set Point 2:Set Point 2:• ----P<0.5% for Steam Turbine GeneratorP<0.5% for Steam Turbine GeneratorP<0.5% for Steam Turbine GeneratorP<0.5% for Steam Turbine Generator
• Operating Time 2sOperating Time 2sOperating Time 2sOperating Time 2s
• Class1 CT can useClass1 CT can useClass1 CT can useClass1 CT can use for Accurate Power for Accurate Power for Accurate Power for Accurate Power measurement for Reverse Power operationmeasurement for Reverse Power operationmeasurement for Reverse Power operationmeasurement for Reverse Power operation
Low forward Power Protection (32L)
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
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157
Power Protection (32L): SEL700G
KNOWLEDGE IS POWER BUT IMMAGINATION IS MORE IMPORTANT THAN KNOWLEDGE
Select number of stages (Max. 4 nos.)Select number of stages (Max. 4 nos.)Select number of stages (Max. 4 nos.)Select number of stages (Max. 4 nos.)
Two stages can be used for Reverse Two stages can be used for Reverse Two stages can be used for Reverse Two stages can be used for Reverse Power (Active) ProtectionsPower (Active) ProtectionsPower (Active) ProtectionsPower (Active) Protections
Two stages can be used for Two stages can be used for Two stages can be used for Two stages can be used for LowforwardLowforwardLowforwardLowforward Power (Active) Power (Active) Power (Active) Power (Active) ProtectionsProtectionsProtectionsProtections