01a SR Principle

7/18/2019 01a SR Principle

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PSDPSD--FTPFTP 11

Power SystemPower System – – Fast TrainingFast Training

ProgramProgram

Inst. Ahmed M.Inst. Ahmed M.

A/Hafeez A/Hafeez



PSDPSD--FTPFTP 22

SR4 PrincipleSR4 PrincipleT0T0 T1T1 T2T2 T3T3

Field

L3

L4

Stator

Diode

L1

Field

L2

Armature



PSDPSD--FTPFTP 33

T0T0 T1T1 T2T2 T3T3

Field

L3

L4

Stator

Diode

L1

Field

L2

Arm ature

T0T0 T1T1 T2T2 T3T3

Field

L3

L4

Stator

Diode

L1

Field

L2

Arm atur e

Self exitedSelf exited

Remaining magnetismRemaining magnetism

PermanentPermanent

magnetmagnet

Permanent magnetismPermanent magnetism

L5L5

Self exited or Permanent magnetSelf exited or Permanent magnet



PSDPSD--FTPFTP 44

L4L4

L3L3

--

L2L2

L1L1

RFARFA

T0T0 T1T1 T2T2 T3T3

FieldL3

L4

Stator

Diode

L1

Field

L2

Arm ature

Self exited schematicSelf exited schematic

++



PSDPSD--FTPFTP 55

If the generator rotating field (L3) or the exciterIf the generator rotating field (L3) or the exciter

field (L1) have a loss of residual magnetism thefield (L1) have a loss of residual magnetism themagnetism can be put back bymagnetism can be put back by flashingflashing the exciterthe exciterfield winding with a direct current source.field winding with a direct current source.

DYNAMIC FLASHINGDYNAMIC FLASHING

(ENGINE RUNNING)(ENGINE RUNNING)With the engine stopped , connect a voltmeter to terminal 20 andWith the engine stopped , connect a voltmeter to terminal 20 and

22 . Connect the22 . Connect the positivepositive

cable ofcable ofthe DC source to terminalthe DC source to terminal F1.F1. Start the engine and run at low idle rpm . Put theStart the engine and run at low idle rpm . Put the negativenegative

cable ofcable ofthe DC source on terminalthe DC source on terminal F2F2

while reading the voltmeter. AS SOON AS THE VOLMETER HASwhile reading the voltmeter. AS SOON AS THE VOLMETER HASAND INDICATION OF VOLTAGE, REMOVE THE NEGATIVE CABLE FROM TERMINAND INDICATION OF VOLTAGE, REMOVE THE NEGATIVE CABLE FROM TERMINAL F2AL F2

STATIC FLASHINGSTATIC FLASHING

(ENGINE STOPPED)(ENGINE STOPPED)With the engine stopped , disconnect exciter filed (L1) wires fWith the engine stopped , disconnect exciter filed (L1) wires from terminal F1 and F2 of therom terminal F1 and F2 of thevoltage regulator. Connect the positive cable of the DC source tvoltage regulator. Connect the positive cable of the DC source to wire F1 and negative too wire F1 and negative towire F2 for NO MORE THAN ONE OR TWO SECONDS. Repeat 2 or three twire F2 for NO MORE THAN ONE OR TWO SECONDS. Repeat 2 or three t imes.imes.

According to theory this method has the effect of putting residuAccording to theory this method has the effect of putting residual magnetism back in theal magnetism back in theexciter.exciter.

Flashing the fieldFlashing the field


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Permanent magnet schematicPermanent magnet schematicT0T0 T1T1 T2T2 T3T3

Field

L3

L4

Stator

Diode

L1

Field

L2

Arm ature

L5L5

L4

++L3L3 --

L2L2

L1L1

RFARFA

L5L5

S

N



Now comingNow coming …………. AREP PRINCIPLE. AREP PRINCIPLE

STATOR

WINDING

ALTERNATING

CURRENTDIRECT

CURRENT

ROTOR

WINDING

RECTIFIERSEXCITER FIELD

AVR



Rectifier blockRectifier block

AC2

AC1 AC3

CR1

CR2

CR3

CR4

CR7

CR5

CR6

VaristorVaristor

AC -+

A C

-

+

AC -+

CR7CR7

AC3

AC2

AC1

+-



DIODESDIODES

i

i

V+V-

I+

I -



AC2

AC1 AC3

CR1

CR2

CR3

CR4

CR7

CR5

CR6

Time

Rectifier Rectifier blockblock

-+-

- ++

Voltage



Zener Zener diodediode

V+V-

I+

I -

Also called Surge suppression diode, is used to

protect the rectifier from high reverse voltage

pulses.

-+



AC3

AC2

AC1

+-

1-

Multimeter

on range

2-

Remove all wires from block

5-Black test lead on Neg..Neg..

terminal

AC1Red lead on AC2

AC3

Measure OL

4-

Reverse leads : Measure OL

on all position

6-

Varistor

test: Measure resistance between Pos. & Neg. : Measure 15K or more

3-Black

test lead on Pos.Pos.

terminal

AC1Red lead on AC2

AC3

Measure between

0.4 & 1.0 volt

Rectifier block testRectifier block test



SoSo……we have the generator and the exciter we have the generator and the exciter …….what else we need?.what else we need?

T0T0 T1T1 T2T2 T3T3

FieldL3

L4

Stator

Diode

L1

Field

L2Armature

Output Voltage controlOutput Voltage control…………..Voltage regulator ..Voltage regulator

Output frequency controlOutput frequency control…………..Speed governor ..Speed governor

Monitor ing and securit iesMonitoring and securities

……control panels, relays,control panels, relays,

etcetc



01a SR Principle

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