The document discusses various aspects of power system protection. It describes different types of electrical faults that can occur, such as phase-to-phase short circuits and phase-to-ground faults. The key tasks of a protection system are to protect electrical equipment from unnecessary damage, protect personnel near faults, and enable continued service in unaffected areas. Protection schemes aim to operate abnormally but securely, maintaining normal operation until a fault occurs. Requirements for protection systems include speed, selectivity, sensitivity, reliability and simplicity. The document outlines protection schemes and relay logic for generators, transformers, feeders and busbars.

1. PROTECTION OF POWER SYSTEMPREPARED BY TRAINEE ENGINEER MUDDASIR MASOOD

2. WHAT DOES PROTECTION MEANSEVERY THING IN THIS WORLD NEEDS PROTECTION AGAINST THREATS SO DOES ELECTRICAL EQUIPMENTSINTERNAL THREATSEXTERNAL THREATSDAMAGEDPOWER SYSTEMCRITICAL ELECTRICAL EQUIPMENT

3. TYPES OF ELECTRICAL THREATS/FAULTSPHASE TO PHASE SHORT CIRCUITPHASE TO GROUND FAULTSHUNT FAULTSSERIES FAULTOPEN CIRCUIT

4. TASK OF THE PROTECTION SYSTEMPROTECT THE ELECTRICAL EQUIPMENT AGAINST UNESISSARY DAMAGEPROTECT THE PERSONAL IN THE VICINITYOF THE ELECTRICAL FAULTENABLE CONTINUED SERVICE IN THE UNTROUBLED AREA OF THE NETWORK

5. PHILOSPHY OF THE PROTECTION SYSTEMABNORMAL BUT SECURE OPERATIONNORMAL NETWORK OPERATIONFAULT CONDITIONABNORMAL NETWORK OPERATION

6. REQUIREMENT OF THE PROTECTION SYSTEMSPEEDYSELECTIVITYSENSITIVITYRELIABILITYSIMPLICITY

7. PROTECTION SCHEME FOR THE POWER SYSTEMPROTECTION SYSTEM IS DIVIDED INTO ZONESPROTECTION ZONES ARE DECIDED BY THE LOCATION OF CTPRIMARY PROTECTIONBACKUP PROTECTIONEARTH FAULT PROTECTIONDIFFERENTIAL PROTECTIONGT-1CIRCUIT BREAKERPOWER TRANSFORMERGENERATORCURRENT TRANSFORMER132KV BUSBAR

8. TYPICAL PROTECTION SCHEMETRIP COIL-1 TRIPPING MECHANISMTRIP COIL-2DC SUPPLYTRIP CIRCUITPROTECTION RELAY-1DC SUPPLYTRIPING MATRIXPROTECTION RELAY-2

9. BREAKER FAILURE SCHEMEINTEGRATED POWER SYSTEMGPROTECTIVE RELAYTRIP ALL PARALLEL CBMBREAKER FAILURETIME DELAY

10. TYPE OF EARTHING SYSTEMLITTLE FAULT CURRENTEXTREME OVERVOLTAGEUNEARTHED NEUTRALLARGE FAULT CURRENTNO OVERVOLTAGEDIRECTLY EARTHEDLESS FAULT CURRENTLESS OVERVOLTAGEINDUCTOR/ TRANSFORMER GROUNDING

11. GENERATOR PROTECTIONVOLTAGE RISE PROTECTIONROTOR EARTH FAULT PROTECTIONDIFFERENTIAL PROTECTIONIMPEDENCE PROTECTIONGUNDEREXCITATION PROTECTIONREVERSE POWER PROTECTIONNEGATIVE PHASE SEQUENCE PROTECTION80% STATOR EARTH FAULTR100% STATOR EARTH FAULT

12. UNIT STEPUP TRANSFORMER PROTECTIONUNIT TRANSFORMER BUCHHOLZ TRIPPRESSURE RELIEF OLTC TRIPYOIL TEMPERATURE TRIPYBAT∆∆TRANSFORMER EARTH FAULT PROTECTIONWINDING TEMPERATURE TRIPGENERATORTRANSFORMER DIFFERENTIAL PROTECTIONPOWER TRANSFORMER OTHER PROTECTIONS∆GYBBTYYR

13. PROTECTION LOGIC ADOPTED AT BLOCK-1TWO INDEPENDANT TRIP COILSTRIP SUPERVISORY CKT220 OR 24 VOLTPOWER SUPPLYTRIPPING MATRIX+24PROTECTION RELAYTRIP CIRCUITTRIP RELAYOPENING MECHANISM OF CBTRIP CIRCUIT SUPERVISIONTRIP ANNUNCIATIONTRIP COMMAND REGISTER

14. TRIPPING MATRIXOVERCURRENT TIME PROTECTION EXCT. TRAFOUNDER EXCITATION PROTECTION WITH 2 STEPUNIT AUXILIARY TRANSFORMER DIFFERENTIAL PROTECTIONLOSS OF EXCITATION PROTECTIONUNIT TRANSFORMER BUCHOLZ OVERTEMP.100% EARTH FAULT PROTECTIONUNDEREXCITATION PROTECTIONUNBALANCED LOAD PROTECTIONREVERSE POWER PROTECTION WITH TIME DELAYEXCITATION TRANSFORMER BUCHOLZ TRIPFREQUENCY DROP PROTECTIONSS TRANSFORMER BUCHOLZ OVERTEMP.OVERFLUXING PROTECTIONIMPEDENCE PROTECTION T1 IMPEDENCE PROTECTION TE UNIT TRANSFORMER DIFFERENTIAL PROTECTIONTRANSFORMER EARTH FAULT PROTECTIONSS TRAFO OVERCURRENTTIME PROTECTIONROTOR EARTH FAULT PROTECTION80% EARTH FAULT PROTECTIONFREQUENCY RISEGENERATORDIFFERENTIALPROTECTIONSFC EARTH FAULTREVERSE POWER PROTECTIONVOLTAGE RISE PROTECTIONSFC FAILURESYNC BREAKER-1SYNC BREAKER-2ST SERVICE SUPPLY BREAKEREMERGENCY TRIPDE-EXCITATIONSFC BREAKEREXCIT. BREAKERUNIT AUXILIARY CHANGEOVERLOCAL INDICATIONREMOTE SIGNALRESET

15. POWER SUPPLY CIRCUIT BREAKERTRIP COILSL+220VL-

16. GENERATOR DIFFERENTIAL PROTECTION 7TD43GIS=I1=I2IA=0NO TRIPPING I1 RACTIFIERIA TRIPPING TRANSFORMERRACTIFIERIS I2 STABILIZING TRANSFORMERTMSYNCH BREAKER-1DE-EXCITATION BREAKERSFC BREAKERUNIT AUX CHANGOVERST SERVICE SUPPLY BREAKEREMERGENCY TRIPSYNCH BREAKER-2

17. GENERATOR DIFFERENTIAL PROTECTIONPROTECTION AGAINST PHASE TO PHASE FAULTPROTECTION AGAINST PHASE TO EARTH FAULTPROTECTION ZONE DEFINED BY THE LOCATION OF CTSINSENSITIVE TO INTERTURN FAULTSINOPERATIVE TO EXTERNAL FAULTSEARTH FAULT SENSITIVITY DEPEND UPON GROUNDING SYSTEM

18. GENERATOR DIFFERENTIAL PROTECTIONBLOCKUs/UnTRIPUa/UnPICKUP CHARACTERISTIC FOR THE SINGLE INFEED FAULT

19. 100% EARTH FAULT PROTECTION 7ue21 20 HZ FREQUENCY GENERATORCTSYNCH BREAKERTRIP MATRIXDE-EXCITATIONRACTIFIERSERVICE STATIONTRIPEMERGENCY TRIPMEASURING CURRENT Im COMPARATORCOMPENSATING CURRENTIc SFCLIMIT VALUE SETTERAUXILLARY CHANGEOVERIC>Im TIMMERTRIP SIGNAL

20. 100% EARTH FAULT PROTECTIONEARTH FAUTL DUE TO INSULATION DAMAGESHORT CIRCUIT DUE TO THE PHASE WITH THE CORE EARTH FAULT PROTECTIONHIGHLY SENSITIVEDETECTION OF THE EARTH FAULT AT ANY LOCATION

21. 80% EARTH FAULT PROTECTIONVOLTAGE INPUT MODULE 7TM36VOLTAGE TRIGGER MODULE 7TU12PICKUPTIMMER 7TT10TRIP

22. ROTOR EARTH FAULT PROTECTION 7UR20UNGROUNDED FIELD WINDINGSINGLE EARTH FAULT CAUSE LITTLE CURRENTDOUBLE EARTH FAULT/ MAGNETIC UNBALANCEHIGH CURRENT AT THE FAULT LOCATIONELECTRICAL STRESS INCREASESEXCITATION SYSTEMIE

23. ROTOR EARTH FAULT CONT.DETECT BEFORE IT EFFECTSCOUPLING RESISTER RvSET VALUEReRcLOW PASS FILTERWAIT FOR THE STEADY STATELIMIT VALUE GENERATORSQUARE WAVERmUM ALARM<80KΩTRIPPING<5KΩSYNCH BREAKER-1 AND 2DE-EXCITATION BREAKERSERVICE STATION BREAKEREMERGENCY TRIPSFCAUXILLIARY CHANGEOVERTRIPPING SIGNALTRIPPING MATRIX

24. UNDEREXCITATION PROTECTIONCAUSEHIGHLY CAPACITIVE LOADTOO LOW EXCITATION/FIELD CIRCUIT FAULTEFFECTROTOR OVERHEATINGASYNCHRONOUS OPERATIONSTEADY STATE STABILITY OF THE GENERATOR

25. UNDER-EXCITATION PROTECTION

26. UNDER-EXCITATION PROTECTIONCURRENT INPUT 7TM16TRANSDUCER 7TL41T3ANGLE TRIGGER(A)TRIPT2TRIPANGLE TRIGGER (C)VOLTAGE INPUT 7TM36AC VOLTAGE MONITOR 7TU127TU14 EXCITER VOLTAGE MONITORT1TRIPANGLE TRIGGER (B)SYNCH BREAKER-1SYNCH BREAKER-2DE-EXCITATIONEMERGENCY TRIPSERIVCE STATIONAUXILLIARY CHANGEOVER

27. NEGATIVE PHASE SEQUENCE PROTECTIONCAUSEaZERO SEQUENCEbcUNEVEN LOADSERIES FAULTSHUNT FAULT POSITIVE SEQUENCEEFFECTROTOR OVERHEATINGROTOR DISTORTIONNEGATIVE SEQUENCEHEAVY VIBRATION

28. NEGATIVE PHASE SEQUENCE PROTECTIONPOWER SUPPLY 15V2-17.5%8-70%2*(0.1-6.4)CURRENT INPUT MODULE 7TM16LIMIT VALUE TRIGGER 7TP12SEQUENCE FILTER 7TF20TIMER 7TT11TRIPTHERMAL REPLICA/ INVERSE TIME CHARACTERISTICTRIPUNBALANCE LOAD MONITORINGTRIPTRIPPING MATRIXSYNCH BREAKER-1 AND 2

29. REVERSE POWER PROTECTIONCAUSEFAILURE OF DRIVING TURBINEMOTORING OF GENERATOREFFFECTCOMPRESSOR LOADSYSTEM OVERLOADEDSTEAM TURBINE BLADE OVERHEATING

30. REVERSE POWER PROTECTION/ DIRECTIONAL POWER RELAYCURRENT INPUT MODULE 7TM17VOLTAGE INPUT MODULE 7TM37POWER TRIGGER 7TM28TRIPCOUPLING MODULE 7TR20TIMER 7TT11TRIPTRIPPING MATRIXSYNCH BREAKER 1-2TRIP T1SERVICE STATION BREAKERDE-EXCITATIONTRIP WITH LONG TIMEUNIT AUXILLIARY CHANGEOVER

31. Frequency protectionCAUSEOVER LOAD SYSTEM (UNDER FREQUENCY)LOAD SHEDDING (OVER FREQUENCY)FAULTY FREQUENCY RAGULATOREFFECTGENERATOR/TRANSFORMER OVERHEATING

32. BUSBAR PROTECTION SCHEMEIT IS IMPORTANT AT FIRST TO HAVE A KNOW HOW OF BUSBAR ARRANGMENT

33. BUSBAR PROTECTIONHERE ARE SOME OF THE PROTECTION ADOPTED AT OUR SWITCHYARDTIME OVERCURRENT AND EARTH FAULT PROTECTION (IKT943)STATIC BUSBAR PROTECTION (INX5)STATIC DISTANCE RELAY (LZ92)FOR THE PROTECTION OF STEPUP TRANSFORMER, STARTUP TRANSFORMER AND AUTO TRANSFORMERELECTROMECHANICAL DISTANCE RELAY (LH1)OVERCURRENT/UNDERVOLTAGE (IUX159)DIRECTIONAL EARTH FAULT (RE91-10)

34. PROTECTION LAYOUT OF THE FEEDERSIDEFEEDERDISTANCE PROTECTION(LZ92)DISTANCE RELAY(LH1)BUSBAR PROTECTION(INX5)DIRECTIONAL EARTH FAULT(RE91-10)MEASUREMENTOVERCURRENT/UNDERVOLTAGE(IUX159)BUSBAR BBUSBAR A

35. DISTANCE PROTECTION(LZ92)CAUSEOVERHEAD LINES SERIES/SHUNT FAULTEXTERNAL THREAT TO THE POWER UNITEFFECTSUSEPTEBLE TO HIGH SHORT CIRCUIT CURRENTOUT OF STABILITYIMPLEMENTATIONMEASURE THE IMPEDENCE OF THE FEEDING ENDZONE DEFINED

36. TRANSMISSION LINELINE IMPEDENCELOADDISTANCE RELAY(Zl)GSOURCE IMPEDENCE ZsFAULT IMPEDENCE ZfUrefSELECTION CIRCUITCONSTANT TIME CURVEVTRIPANDRESISTANCEUfIREACTANCEIfI>/Z<TIMER

37. LINE CB TRIP COIL 1-2AUTO RECLOSUREDISTANCE RELAY F11TRIP SUPERVISION 1-2CONSTANT CURRENT CHARACTERISTIC

38. THE ENDGOD BLESS U ALL