400kv protection

400KV PROTECTIONPREPARED BYGOPALA KRISHNA PALEPUADE/MRT(PROTECTION)[email protected], Mobile:9440336984

BASICS OF ONE AND HALF CIRCUIT BREAKER SCHEMEPREPARED BYGOPALA KRISHNA PALEPUADE/MRT(PROTECTION)

ONE & HALF BREAKER DESCRIPTIONBUS-1BUS-2BUS-1BUS-21. IN THIS TWO BUSES ARE PRIOVIDED.

ONE & HALF BREAKER DESCRIPTIONBUS-1BUS-2BUS-1BUS-22. THESE TWO BUSES ARE INTER-CONNECTED BY THREE CIRCUIT BREAKERS.

ONE & HALF BREAKER DESCRIPTIONBUS-1BUS-2BUS-1BUS-21-52 CB2-52 CB3-52 CB1-52 CB2-52 CB3-52 CB3. THEY ARE DESIGNATED AS 1-52 CB, 2-52 CB, 3-52 CB.

ONE & HALF BREAKER DESCRIPTIONBUS-1BUS-2BUS-1BUS-21-52 CB2-52 CB3-52 CB1-52 CB2-52 CB3-52 CBLINE-1LINE-2LINE-1LINE-24. LINE - 1 IS CONNECTED IN BETWEEN 1-52 CB & 2-52 CB.5. LINE - 2 IS CONNECTED IN BETWEEN 3-52 CB & 2-52 CB.

ONE & HALF BREAKER DESCRIPTIONBUS-1BUS-2BUS-1BUS-21-52 CB2-52 CB3-52 CB1-52 CB2-52 CB3-52 CBLINE-1LINE-2LINE-1LINE-26. LINE-1 HAVING TWO FEEDING PATHS i.eA. VIA BUS-1 & 1-52 CBB. VIA BUS-2, 3-52 CB & 2-52 CB7. LINE-2 HAVING TWO FEEDING PATHS i.eA. VIA BUS-2 & 3-52 CBB. VIA BUS-1, 1-52 CB & 2-52 CB

ONE & HALF BREAKER DESCRIPTIONBUS-1BUS-2BUS-1BUS-21-52 CB2-52 CB3-52 CB1-52 CB2-52 CB3-52 CBLINE-1LINE-2LINE-1LINE-28. FOR INTURUPTING LINE-1 THE 1-52CB AND 2-52CB IS TO BE TRIPPED.9. FOR INTURUPTING LINE-2 THE 3-52CB AND 2-52CB IS TO BE TRIPPED.

ONE & HALF BREAKER DESCRIPTIONBUS-1BUS-2BUS-1BUS-21-52 CB2-52 CB3-52 CB1-52 CB2-52 CB3-52 CBLINE-1LINE-2LINE-1LINE-210. FOR ANY PROBLEM IN LINE-1 OR LINE-2 ALONG WITH MAIN BREAKER THE MIDDLE BREAKER OR SAY TIE BREAKER (2-52 CB) MUST TRIP.

ONE & HALF BREAKER DESCRIPTIONBUS-1BUS-2BUS-1BUS-21-52 CB2-52 CB3-52 CB1-52 CB2-52 CB3-52 CBLINE-1LINE-2LINE-1LINE-213. SO THESE TWO FEEDERS CONTROLLED BY THREE CIRCUIT BREAKERS IT IS CALLED ONE & HALF BREAKER SYSTEM.11. NORMALLY IN ALL TYPES OF BUSBAR CONFIGUARATIONS ONE BREAKER IS SUFFICIENT FOR ONE FEEDER.12. HERE TWO FEEDERS ARE CONTROLED BY THREE BREAKERS.

ONE & HALF BREAKER DESCRIPTIONBUS-1BUS-2BUS-1BUS-21-52 CB2-52 CB3-52 CB1-52 CB2-52 CB3-52 CBLINE-1LINE-2LINE-1LINE-214. THE BAY BETWEEN BUS-1 & LINE-1 IS CALLED MAIN BAY FOR FEEDER-1. MAIN BAY(1ST BAY) FOR FEEDER-1MAIN BAY(1ST BAY) FOR FEEDER-1

ONE & HALF BREAKER DESCRIPTIONBUS-1BUS-2BUS-1BUS-21-52 CB2-52 CB3-52 CB1-52 CB2-52 CB3-52 CBLINE-1LINE-2LINE-1LINE-2MAIN BAY(1ST BAY) FOR FEEDER-1MAIN BAY(1ST BAY) FOR FEEDER-115. THE BAY BETWEEN LINE-1 & LINE-2 IS CALLED TIE BAY FOR FEEDER-1 & 2. TIE BAY (2ND BAY ) FOR FEEDER-1 & 2TIE BAY (2ND BAY ) FOR FEEDER-1 & 2.

ONE & HALF BREAKER DESCRIPTIONBUS-1BUS-2BUS-1BUS-21-52 CB2-52 CB3-52 CB1-52 CB2-52 CB3-52 CBLINE-1LINE-2LINE-1LINE-2MAIN BAY(1ST BAY) FOR FEEDER-1MAIN BAY(1ST BAY) FOR FEEDER-1TIE BAY (2ND BAY ) FOR FEEDER-1 & 2TIE BAY (2ND BAY ) FOR FEEDER-1 & 2.MAIN BAY(3RD BAY) FOR FEEDER-216. THE BAY BETWEEN BUS-2 & LINE-2 IS CALLED MAIN BAY FOR FEEDER-2. MAIN BAY(3RD BAY) FOR FEEDER-2

ONE & HALF BREAKER DESCRIPTIONBUS-1BUS-2BUS-1BUS-21-52 CB2-52 CB3-52 CB1-52 CB2-52 CB3-52 CBLINE-1LINE-2LINE-1LINE-2MAIN BAY(1ST BAY) FOR FEEDER-1MAIN BAY(1ST BAY) FOR FEEDER-1TIE BAY (2ND BAY ) FOR FEEDER-1 & 2TIE BAY (2ND BAY ) FOR FEEDER-1 & 2.MAIN BAY(3RD BAY) FOR FEEDER-2MAIN BAY(3RD BAY) FOR FEEDER-217. IN THIS SYSTEM FULL DIA MEANS 2 FEEDERS CONTROLLED BY 3 CBs.18. HALF DIA MEANS 1 FEEDER CONTROLLED BY 2 CBs. (Nothing but Double CB System)

ONE & HALF BREAKER DESCRIPTIONBUS-1BUS-2BUS-1BUS-21-52 CB2-52 CB3-52 CB1-52 CB2-52 CB3-52 CBLINE-1LINE-2LINE-1LINE-2MAIN BAY(1ST BAY) FOR FEEDER-1MAIN BAY(1ST BAY) FOR FEEDER-1TIE BAY (2ND BAY ) FOR FEEDER-1 & 2TIE BAY (2ND BAY ) FOR FEEDER-1 & 2.MAIN BAY(3RD BAY) FOR FEEDER-2MAIN BAY(3RD BAY) FOR FEEDER-2GOPALA KRISHNA PALEPU ADE/MRT/ T&C/400KV SS/O/O CE/400KV / L&SS/ VSAPTRANSCO, [email protected]: 9440336984

SUBSTATION DESIGN/LAYOUT (I-CONFIGUARATION)FEEDER2FEEDER4FEEDER6FEEDER8FEEDER10FEEDER12FEEDER1FEEDER3FEEDER5FEEDER7FEEDER9FEEDER11BUS-2BUS-1BAY1BAY2BAY3BAY4BAY5BAY6BAY7BAY8BAY9BAY10BAY11BAY12BAY13BAY14BAY15BAY16BAY17BAY18DIA1DIA2DIA3DIA4DIA5DIA6

SUBSTATION DESIGN/LAYOUT(D-CONFIGUARATION)BUS-2BUS-1FEEDER3FEEDER4FEEDER7FEEDER8FEEDER11FEEDER12FEEDER1FEEDER2FEEDER5FEEDER6FEEDER9FEEDER10BAY1BAY2BAY3BAY4BAY5BAY6BAY7BAY8BAY9BAY10BAY11BAY12BAY13BAY14BAY15BAY16BAY17BAY18DIA1DIA2DIA3DIA4DIA5DIA6

SUBSTATION DESIGN/LAYOUT(DOUBLE BUS & DOUBLE BREAKER SYSTEM)FEEDER1BAY1BAY2BAY3BAY4FEEDER2FEEDER3BAY5BAY6BAY7BAY8FEEDER4FEEDER1BUS-2BUS-1BAY1BAY2BUS-2BUS-1FEEDER2BAY3BAY4FEEDER3BAY5BAY6BAY7BAY8FEEDER4FOR ECONOMICAL& RELIABULITY PURPOSE THIS SYSTEM ADOPTED IN 800KV SYSTEM

MESH / RINGLAYOUTFEEDER 1FEEDER 2FEEDER 3FEEDER 4FEEDER 5FEEDER 6FEEDER 7FEEDER 81-52 CB2-52 CB3-52 CB4-52 CB5-52 CB6-52 CB8-52 CB7-52 CB

SUBSTATION DESIGN/LAYOUT(DOUBLE MAIN BUS & TRANSFER BUS SYSTEM)FEEDER1BUS-2BUS-1FOR ECONOMICAL& RELIABULITY PURPOSE THIS SYSTEM ADOPTED IN 400 & 220 KV SYSTEMFEEDER2TRANSFER BUS COUPLERT/F-1T/F-2BUS COUPLERTRANSFER BUSFEEDER3FEEDER4BAY1BAY2BAY3BAY4BAY5BAY6BAY7BAY8

SUBSTATION DESIGN/LAYOUT(DOUBLE MAIN BUS & CB BYPASS ISO SYSTEM)FEEDER1BUS-2BUS-1FOR ECONOMICAL& RELIABULITY PURPOSE THIS SYSTEM ADOPTED IN 220KV SYSTEMT/F-1BUS COUPLERFEEDER2T/F-2FEEDER3FEEDER4BAY1BAY2BAY3BAY4BAY5BAY6BAY7WHEN ANY CB PROBLEM OR FOR PREVENTIVE MAINTANENCE THEN ALL OTHER FEEDERS SHIFTED TO ANOTHER BUS OF FAULTED CB BUS AND CLOSE THE BYPASS ISOLATOR, THEN PROTECTION IS SHIFTED TO BUS COUPLER AND OPEN THE FAULTY CB.

SUBSTATION DESIGN/LAYOUT(SINGLE BUS & TRANSFER BUS SYSTEM)FEEDER1BUS-1TRANSFER BUSFOR ECONOMICAL& RELIABULITY PURPOSE THIS SYSTEM ADOPTED IN 220 & 132 KV SYSTEMFEEDER2TRANSFER BUS COUPLERT/F-1T/F-2FEEDER3FEEDER4BAY1BAY2BAY3BAY4BAY5BAY6BAY7

CT METHODS IN ONE AND HALF CIRCUIT BREAKER SCHEMEPREPARED BYGOPALA KRISHNA PALEPUADE/MRT(PROTECTION)

DIFFERENT CT METHODS OF ONE & HALF BREAKER SYSTEM3 CT METHOD4 CT METHOD6 CT METHOD6 CT METHODLINELINELINELINECBCBCBCBCBCBCBCBCBCBCBCBAT/FAT/FAT/FAT/F5 CT METHODLINECBCBCBAT/F6 CT METHODLINECBCBCBAT/F

ONE & HALF BREAKER SYSTEMLINE 11-891-89A1-52CB3-893-89A3-52CB2-52CB2-89A2-89B1-89L3-89TBUS-1BUS-2T/F-11-CT3-CT2-CT(3CT METHOD)

ONE & HALF BREAKER SYSTEMLINE 11-891-89A1-52CB3-893-89A3-52CB2-52CB2-89A2-89B1-89L3-89TBUS-1BUS-2T/F-11-CT3-CT2-ACT2-BCT(4CT METHOD)

ONE & HALF BREAKER SYSTEM

LINE 11-89A1-52CB1-CT3-893-89A3-52CB3-CT2-52CB1L-CT2-CT2-89A2-89B1-89L3-89TBUS-1BUS-2T/F-13T-CT1-89(5CT METHOD)


LINE 11-89A1-52CB1B-CT3-893-89A3-52CB3B-CT2-52CB2B-CT2-89A2-89B1-89L3-89TBUS-1BUS-2T/F-11-891A-CT2A-CT3A-CT(6CT METHOD)


LINE 11-89A1-52CB1-CT3-893-89A3-52CB3-CT2-52CB2B-CT2-89A2-89B1-89L3-89TBUS-1BUS-2T/F-11-891L-CT2A-CT3T-CT(6CT METHOD)

TYPICAL ONE & HALF BREAKER SYSTEM ADOPTED IN GISDS : DISCONNECTOR SWITCH, GS: GROUNDING SWITCH, CT: CURRENT TRANSFORMER, VD: VOLTAGE DIVIDER

CORE WISE APLICATION OF CTs INONE AND HALF CIRCUIT BREAKER SCHEMEPREPARED BYGOPALA KRISHNA PALEPUADE/MRT(PROTECTION)

CURRENT TRANSFORMER CONNECTIONS IN 3CT METHOD

CURRENT TRANSFORMER CONNECTIONS IN 6CT METHOD (GIS or AIS with DEAD TANK CBs)

CT CORES CONEECTION DIAGRAMS IN ONE AND HALF CIRCUIT BREAKER SCHEMEPREPARED BYGOPALA KRISHNA PALEPUADE/MRT(PROTECTION)

SINGLE BUS SYSTEM1-52CB1-891-89LBUS BAR PROTECTIONBUS BAR CHECKUP PROTMETERINGMAIN-2/BACKUP PROTECTIONMAIN-1 PROTECTIONBUS1-CVTBB-EVT/ CVT

ONE & HALF BREAKER ( 3 CT METHOD) WITH PROTECTION SCHEMECVTCVTVBB1VBB2VBB2VL2 / VL1OR VBB1VL1 / VL2OR VBB2VBB1FEEDER1 / LINE1FEEDER2 / LINE2CVTVL2CVTVL1VL1BUSBAR-1BUSBAR-2MAIN-1MAIN-2PROTECTION OF LINE2(OR TRANSFORMER, IF APPLICABLE)VL1VL1 / VBB1VL2 / VBB2FOR TRANSFORMER PROTECTION & METERING VOLTAGE SELECTION RELAYS FOR BUS-1, BUS-2& LINE ARE PROVIDED .

ONE & HALF BREAKER ( 4 CT METHOD) WITH PROTECTION SCHEMECVTCVTVBB1VBB2VBB2VL2 / VL1OR VBB1VL1 / VL2OR VBB2VBB1FEEDER1 / LINE1FEEDER2 / LINE2CVTVL2CVTVL1VL1BUSBAR-1BUSBAR-2MAIN-1MAIN-2PROTECTION OF LINE2(OR TRANSFORMER, IF APPLICABLE)VL1FOR TRANSFORMER PROTECTION & METERING VOLTAGE SELECTION RELAYS FOR BUS-1, BUS-2& LINE ARE PROVIDED .

ONE & HALF BREAKER ( 6 CT METHOD) WITH PROTECTION SCHEMECVTCVTVBB1VBB2VBB2VL2 / VL1OR VBB1FEEDER1 / LINE1FEEDER2 / LINE2CVTVL2CVTVL1VL1BUSBAR-1BUSBAR-2MAIN-1MAIN-2PROTECTION OF LINE2(OR TRANSFORMER, IF APPLICABLE)VL1FOR TRANSFORMER PROTECTION & METERING VOLTAGE SELECTION RELAYS FOR BUS-1, BUS-2& LINE ARE PROVIDED .

ONE & HALF BREAKER ( 5 CT METHOD) WITH PROTECTION SCHEMECVTCVTVBB1VBB2VBB2VL2 / VL1OR VBB1VL1 / VL2OR VBB2VBB1FEEDER1 / LINE1FEEDER2 / LINE2CVTVL2CVTVL1BUSBAR-1BUSBAR-2MAIN-1MAIN-2PROTECTION OF LINE2(OR TRANSFORMER, IF APPLICABLE)VL1 / VBB1VL2 / VBB2..FOR TRANSFORMER PROTECTION & METERING VOLTAGE SELECTION RELAYS FOR BUS-1, BUS-2& LINE ARE PROVIDED .

ONE & HALF BREAKER ( 6 CT METHOD) WITH PROTECTION SCHEMECVTCVTVBB1VBB2VBB2VL2 / VL1OR VBB1VL1 / VL2OR VBB2VBB1FEEDER1 / LINE1FEEDER2 / LINE2CVTVL2CVTVL1BUSBAR-1BUSBAR-2MAIN-1MAIN-2PROTECTION OF LINE2(OR TRANSFORMER, IF APPLICABLE)..FOR TRANSFORMER PROTECTION & METERING VOLTAGE SELECTION RELAYS FOR BUS-1, BUS-2& LINE ARE PROVIDED .

ONE & HALF BREAKER ( 6 CT METHOD) WITH PROTECTION SCHEMECVTCVTVBB1VBB2VL1 / VL2OR VBB2VBB1FEEDER1 / LINE1FEEDER2 / LINE2CVTVL2CVTVL1BUSBAR-1BUSBAR-2MAIN-1MAIN-2PROTECTION OF LINE2(OR TRANSFORMER, IF APPLICABLE)FOR TRANSFORMER PROTECTION & METERING VOLTAGE SELECTION RELAYS FOR BUS-1, BUS-2& LINE ARE PROVIDED .

COMPARISION BETWEEN DIFFERENT CT METHODS

400KV C.T. INFORMATIONP1P2EYE BOLT DESIGNHAIRPIN / U SHAPE DESIGNDEAD TANK DESIGN

PRIMARY CONNECTIONS : P1 P2CURRENT RATING : 2000 AMPSCORESCLASSPURPOSESECONDARY CONNECTIONSCURRENT RATING : 1A2000/ 1A1000/ 1A500/ 1ACORE-1PSBUSBAR PROTECTION1S1 1S31S1 1S21S2 1S3__

CORE-2PSBUSBAR CHECKUP PROTECTION2S1 2S32S1 2S22S2 2S3__CORE-30.5 / 0.2METERING3S1 3S43S1 3S33S4 3S23S1 3S23S4 3S3CORE-4PSMAIN-2 PROTECTION4S1 4S44S1 4S34S4 4S24S1 4S24S4 4S3CORE-5PSMAIN-1 PROTECTION5S1 5S45S1 5S35S4 5S25S1 5S25S4 5S3

MAIN-1, MAIN-2PROTECTION & METERINGFOR LINE ADOPTED IN ONE AND HALFCIRCUIT BREAKER SCHEMEPREPARED BYGOPALA KRISHNA PALEPUADE/MRT(PROTECTION)

NORMS OF PROTECTION FOLLOWED IN APTRANSCO FOR TRANSMISIION LINES & DISTRIBUTION LINES ( FEEDER / LINE PROTECTION )

Sr.NoVOLTAGE MAIN- 1 PROTECTIONMAIN-2 PROTECTION/ BACKUP PROTECTION1.11 KV LINES2 O/L + E/F ( 51 + 51N )-2.33 KV LINES3 O/L + E/F ( 51 + 51N )-3.66 KV LINESSWITCHED DISTANCE SCHEME OR NUMERICAL DISTANCE SCHEME (21P+ 21N)DIRECTIONAL O/L & E/F RELAYS WITH HIGH SET ( 67 + 67N )4.132 KV LINES5.220 KV LINESNON SWITCHED DISTANCE SCHEME OR NUMERICAL DISTANCE SCHEME (21P + 21N)SWITCHED DISTANCE SCHEME OR NUMERICAL DISTANCE SCHEME (21P+ 21N)6.400 KV LINESNUMERICAL DISTANCE SCHEME (21P + 21N) + in BUILT DEF RELAY(67N)NUMERICAL DISTANCE SCHEME (21) OR LINE DIFFERENTIAL SCHEME (87L) WITH 67N7.765 KV LINESNUMERICAL DISTANCE SCHEME (21P + 21N) + in BUILT DEF RELAY(67N)NUMERICAL DISTANCE SCHEME (21) OR LINE DIFFERENTIAL SCHEME (87L) WITH 67NIF MAIN-1 & MAIN-2 ARE NUMERICAL RELAYS, BOTH SHOULD BE SEPARATE MEASURING PRINCIPLES (CHARECTERESTICS), MODELS AND ALGORITHAMS (SHOULD NOT BE DUPLICATED) AND ALL FEATURES SHOULD BE AVAILABLE IN BOTH SCHEMES AND BOTH RELAYS SHOULD BE 100% REDENDENCY IN ALL ASPECTS ( COMPLEMENTARY TO EACH OTHER ) . DISSIMILAR CARRIER SCHEMES ARE TO BE SELECTED ( POTT & PUTT or BLOCK & UNBLOCK). OTHER WISE MAIN-2 MAY BE DIFFERENT MAKE OR PHASE COMPARISION PROTECTION/LINE DIFFERENTIAL PROTECTION WITH BACKUP DISTANCE PROTECTION IS TO BE ADOPTED. BOTH M1 & M2 SHOULD CONTAIN DIRECTIONAL EARTH FAULT PROTECTION (67N) WITH DIRECTIONAL COMPARISION PICKUP SCHEME AS INBUILT FUNCTION.ZONE-1: 80% OF MAIN LINEZONE-2: 100% OF MAIN LINE + 50% OF SHORTEST LINE AT OTHER ENDZONE-3: 100% OF MAIN LINE + 100% OF SHORTEST LINE AT OTHER ENDZONE-4: 100% OF MAIN LINE + (100% OF SHORTEST LINE + 20% OF LONGEST LINE) AT OTHER END.

MAIN-1 PROTECTION FOR LINE (4CT METHOD)CEDISPLAYACTIVESTARTTRIPREL 521333333IR5 / A511IY5 / A531IB5 / A551IN5 / A5711-CTCORE-5CTR: 2000-1000-500/1ACLASS: PS2-BCTCORE-5CTR: 2000-1000-500/1ACLASS: PS

5S45S45S45S25S25S2P2P2P2CT MBCT MBP2P2P2

5S45S45S45S25S25S2VR11 / E111VY11 / E131VB11 / E151VN11 / E1711-CVTCORE 1200VACLASS: 3P3 CT METHOD : 1-CT & 2-CT4 CT METHOD : 1-CT & 2-BCT6 CT METHOD : 1-ACT & 2-BCT

MAIN-1 PROTECTION FOR LINE (4CT METHOD) (NEW DEVELOPMENT)333333IR5 / A511IY5 / A531IB5 / A551IN5 / A5711-CTCORE-5CTR: 2000-1000-500/1ACLASS: PS2-BCTCORE-5CTR: 2000-1000-500/1ACLASS: PS


5S45S45S45S25S25S2VR11 / E111VY11 / E131VB11 / E151VN11 / E1711-CVTCORE 1200VACLASS: 3PIR5 / A511IY5 / A531IB5 / A551IN5 / A5713 CT METHOD : 1-CT & 2-CT4 CT METHOD : 1-CT & 2-BCT6 CT METHOD : 1-ACT & 2-BCT

MAIN-1 PROTECTION FOR LINE (5CT METHOD)CEDISPLAYACTIVESTARTTRIPREL 521333IR5 / A511IY5 / A531IB5 / A551IN5 / A5711-LCTCORE-5CTR: 2000-1000-500/1ACLASS: PS

5S45S45S45S25S25S2P2P2P2CT MBVR11 / E111VY11 / E131VB11 / E151VN11 / E1711-CVTCORE 1200VACLASS: 3P

MAIN-2 PROTECTION FOR LINE(4CT METHOD)CEDISPLAYACTIVESTARTTRIPREL 316333333IR4 / C411IY4 / C431IB4 / C451IN4 / C4711-CTCORE-4CTR: 2000-1000-500/1ACLASS: PS2-BCTCORE-4CTR: 2000-1000-500/1ACLASS: PS


4S44S44S44S24S24S2VR21 / E211VY21 / E231VB21 / E251VN21 / E2711-CVTCORE 2200VACLASS: 3PLBB / BFRRAICALBB / BFRRAICA50ZT50Z3 CT METHOD : 1-CT & 2-CT4 CT METHOD : 1-CT & 2-BCT6 CT METHOD : 1-ACT & 2-BCT

MAIN-2 PROTECTION FOR LINE(4CT METHOD) ( NEW DEVELOPMENT)333333IR4 / C411IY4 / C431IB4 / C451IN4 / C4711-CTCORE-4CTR: 2000-1000-500/1ACLASS: PS2-BCTCORE-4CTR: 2000-1000-500/1ACLASS: PS


4S44S44S44S24S24S2VR21 / E211VY21 / E231VB21 / E251VN21 / E2711-CVTCORE 2200VACLASS: 3PIR4 / C411IY4 / C431IB4 / C451IN4 / C4713 CT METHOD : 1-CT & 2-CT4 CT METHOD : 1-CT & 2-BCT6 CT METHOD : 1-ACT & 2-BCT

MULTI FUNCTION NUMERICAL RELAY FOR MULTI BREAKER, MULTI CT & CVT/PT APPLICATION (NEW APPLICATION) (ONE & HALF BREAKER SYSTEM or RING BUS SYSTEM)1-52 CB2-52 CB3-52 CB33LINE1-52,2-52: MAIN & TIE CIRCUIT BREAKER21P: PHASE DISTANCE PROTECTION21N: GROUND DISTANCE PROTECTION27: UNDER VOLTAGE RELAY67: DIRECTIONAL RELAY50: INST OVER CURRENT RELAY51: TIME OVER CURRENT RELAY59: OVER VOLTAGE RELAY64: EARTH FAULT RELAY50BF-1: LBB/BFR OF MAIN CB50BF-2: LBB/BFR OF TIE CB79-1,2: AUTO RECLOSURE RELAY OF MAIN & TIE CB25-1,2: CHECK SYNCHRONISAM RELAYFOR MAIN & TIE CB67P50 BF-150 BF-221N79-121P50P51P275933BUS-1 PTBUS-2 PTLINE CVT25-179-225-267N50N51N

MAIN-2 PROTECTION FOR LINE (5CT METHOD)CEDISPLAYACTIVESTARTTRIPREL 316333IR4 / C411IY4 / C431IB4 / C451IN4 / C4711-LCTCORE-4CTR: 2000-1000-500/1ACLASS: PS

4S44S44S44S24S24S2P2P2P2CT MBVR21 / E211VY21 / E231VB21 / E251VN21 / E2711-CVTCORE 2200VACLASS: 3P

MULTI FUNCTION PANEL METERING & ENERGY METER (4CT METHOD)333333IR3 / D311IY3 / D331IB3 / D351IN3 / D3711-CTCORE-3CTR: 2000-1000-500/1ACLASS: 0.52-BCTCORE-3CTR: 2000-1000-500/1ACLASS: 0.5

3S43S43S43S23S23S2P2P2P2CT MBCT MB

3S43S43S43S23S23S2VR31 / E311VY31 / E331VB31 / E351VN31 / E3711-CVTCORE 3100VACLASS: 0.5/0.2P2P2P23 CT METHOD : 1-CT & 2-CT4 CT METHOD : 1-CT & 2-BCT6 CT METHOD : 1-ACT & 2-BCT

MULTI FUNCTION PANEL METERING & ENERGY METER (5CT METHOD)333IR3 / D311IY3 / D331IB3 / D351IN3 / D3711-LCTCORE-3CTR: 2000-1000-500/1ACLASS: 0.5/0.2

3S43S43S43S23S23S2P2P2P2CT MBVR31 / E311VY31 / E331VB31 / E351VN31 / E3711-CVTCORE 3100VACLASS: 0.5/0.2

LBB & BUSBARPROTECTIONSCHEMES ADOPTED INONE AND HALFCIRCUIT BREAKER SCHEMEPREPARED BYGOPALA KRISHNA PALEPUADE/MRT(PROTECTION)

BASICS OF LBB/BFR PROTECTIONLOCAL BREAKER BACKUP PROTECTION A PROTECTION WHICH IS DESIGNED TO CLEAR A SYSTEM FAULTY BY INITIATING TRIPPING OTHER CIRCUIT BREAKER(S) IN THE CASE OF FAILURE TO TRIP OF THE APPROPRIATE CIRCUIT BREAKER.IN MODERN NETWORKS THE CRITICAL FAULT CLEARING TIME MAY BE LESS THAN 200ms. HENCE, IF THE FAULT IS NOT CLEARED DUE TO FAILURE OF THE PRIMARY PROTECTIVE RELAYS OR THEIR ASSOCIATED CIRCUIT BREAKER, A FAST ACTING BACK-UP PROTECTIVE RELAY MUST CLEAR THE FAULT.THERE ARE TWO BASIC FORMS.REMOTE BACK-UP.LOCAL BACK-UP.REMOTE BACK-UPPROVIDES BACK-UP PROTECTION FOR THE BOTH THE RELAYS (MAIN-1 & MAIN-2) AND BREAKERS AT REMOTE SUBSTATION.LOCAL BACK-UPLOCAL BACK-UP PROTECTION CAN BE DEVIDED INTO TWO CATAGORIES.RELAY BACK-UPBREAKER BACK-UP

RELAY BACK-UPDUPLICATE PRIMARY PROTECTION. i.e ONE IS NON SWITCHED DISTANCE PROTECTION AND ANOTHER IS SWITCHED DISTANCE SCHEME OR OTHER WISE BOTH SCHEMES CHARECTERSTICS ARE DIFFERENT (QUADRALATERAL, MHO CIRCULAR, TAMOTO & OPTICAL ) OR DIFFERENT MANUFACTURERS(ABB, ALSTOM, SIEMENS, EASUN REYROLL, SEL, GE, NXT PHASE OR BASLER) OR DIFFERENT METHODS (i.e ELECTROMECHANICAL, STATIC, NUMERICAL{MICROPROCESSOR &DSP}). IF MAIN-1 & MAIN-2 ARE NUMERICAL RELAYS BOTH SHOULD BE SEPARATE CHARECTERESTICS AND SEPARATE MODELS AND ALL FEATURES SHOULD BE AVAILABLE IN BOTH SCHEMES AND BOTH RELAYS SHOULD BE 100% REDENDENCY IN ALL ASPECTS. TO INCREASE THE SECURITY, THE CIRCUIT BREAKER HAS TWO TRIP COILS, ONE IS CONNECTED TO MAIN-1 PROTECTION AND ANOTHER IS CONNECTED TO MAIN-2 PROTECTION.BREAKER BACK-UPBECAUSE OF THE HIGH COST OF HIGH VOLTAGE CIRCUIT BREAKERS, IT IS NOT FEASIBLE TO DUPLICATE THEM.IN CASE OF A BREAKER FAILURE THE OTHER CIRCUIT BREAKERS CONNECTED TO THE SAME BUS AS THE FAULTED BREAKER MUST THERE FORE BE TRIPPED.

LBB/BFR FLOW CHARTMAIN PROTECTIONOPERATEDYESYESTRIP MAINBREAKERINITIATE BFRWAIT FOR FAULT CLEARENCEANDFAULT CLEAREDYESNORESET BREAKER FAILURE SCHEMETRIP BACK-UP/Adjacent BREAKERSThe Breaker Failure Protection (LBB/BFR) can operate single-stage/two-stage. When used as single-stage protection, the Bus trip command is given to the adjacent Circuit Breakers if the protected feeder Breaker fails. When used as two-stage protection, the first stage can be used to repeat the trip command to the relevant feeder Breaker, normally on a different trip coil, if the initial trip command from the feeder protection is not successful. The second stage will result in a Bus trip to the adjacent Breakers, if the command of the first stage is not successful.RETRIP

LBB/BFR TIME CO-ORDINATION CHARTFAULT OCCURSNORMAL CLEARINGINOPERATIVEBREAKERBREAKER INTURUPTING TIMEPROTECTIVE RELAYFOR EX: DISTANCE RELAYNORMAL CLEARING TIMEBREAKER FAILURE RELAY STARTMARGINRESETTING TIME OF THE CURRENT MEASURING UNITSSET TIME OF THE TIME MEASURING UNITTRIPPING RELAYTIMEBACK-UP BREAKERINTERUPTING TIME TOTAL CLEARING TIME OF THE BREAKER FAILURE RELAYMARGINMAXIMUM FAULT CLEARING TIME BEFORE SYSTEM INSTABILITY~30ms~60ms

LBB/BFR LOGICPHASE L1PHASE L2/EPHASE L3CURRENT INPUTS~|||A/DCONVERTER&I > ISETI > ISETPHASE CURRENT SET POINTEARTH CURRENT SET POINT&CIRCUIT BREAKER FAILURE INITIATEBINARY INPUTOUT PUT OF DISTANCE RELAY OR SHORT CIRCUIT CURRENT RELAY> 1TIMING/OUTPUT STAGETIME STAGE T1TIME STAGE T2TIME STAGE T2SWITCHED OFF&&&O> 1LEDCB FAILURE INITIATELEDTRIP T2 RELAYALARM T1 RELAYLEDTRIP T1 RELAYLED(PHASE START)LED(EARTH START)ALARM RELAY(PHASE START)ALARM RELAY(EARTH START)

LBB/BFR PROTECTION1-52CB2-52CB3-52CBBUS-1BUS-2LINE1AT/F-150Z50Z LBB/BFR IS LOCAL BREAKER BACKUP PROTECTION/ BREAKER FAILURE RELAY. 1No RELAY IS PROVIDED FOR EACH BREAKER. THIS IS CURRENT OPERATED RELAY. THIS RELAY IS ENERGISED WHEN MASTER TRIP RELAY(86-A OR/AND 86-B) OPERATES OR SINGLE PHASE TRIP RELAYS OPERATES AND GIVEN SIGNAL TO BREAKER FOR TRIP. IN THIS RELAY TIME DELAY IS PROVIDED. THIS RELAY OPERATES WHEN THE BREAKER IS UNDER TROUBLE/ FAILS TO OPERATE. AFTER ENERGISED THE RELAY AND TIME DELAY COMPLETES, EVEN CURRENT IS THERE THIS THINKS BREAKER FAIL TO OPERATE AND GIVEN SIGNAL AS PER SCHEME DESCRIBED NEXT PRESENTATION. NEW CONCEPT: Normally the CT connections for LBB/BFR relay is in series with Main-2 Protection. In case of Numerical Distributed LBB/BFR and Centralized Bus-Bar System, the CT connections for Bus-Bar are terminated at LBB/BFR and Centralized Bus-Bar is interconnected by Fiber-Optic cable. 50ZT

1-52 CB LBB/BFR OPERATIONBUS-1BUS-21-52CB3-52CB2-52CB86-A86-BABBREL521MAIN-1ABBREL316MAIN-286-A86-BTC-1TC-2BUSBAR-1 PROTECTION OPTDAND BUSBAR-1 ISOLATEDDIRECT TRIP 1&2VIA CARRIER TOOTHER ENDTC-1TC-250ZTO 86-B TRIP RELAYOF TIE CB(2-52CB)

2-52 CB LBB/BFR OPERATIONBUS-1BUS-21-52CB3-52CB2-52CBABBREL521MAIN-1ABBREL316MAIN-286-A86-BTC-1TC-2ABBRET521MAIN-1ABBRET316MAIN-2TO 86-B TRIP RELAYOF LINE CB(1-52CB)DIRECT TRIP 1&2VIA CARRIERTO OTHER ENDTO 86-B TRIP RELAYOF AT/F(ICT) CB (3-52CB)INTER TRIP TOLVCB & TBCCB50ZT

3-52 CB LBB/BFR OPERATIONBUS-1BUS-21-52CB3-52CB2-52CB86-A86-BABBRET521MAIN-1ABBRET316MAIN-286-A86-BTC-1TC-2TC-1TC-2BUSBAR-2PROTECTION OPTDAND BUSBAR-2 ISOLATEDINTER TRIP TO LV CB & TBC CB 50ZTO 86-B TRIP RELAYOF TIE CB(2-52CB)

BASICS OF BUSBAR PROTECTIONNEED FOR BUSBAR PROTECTION IN ITS ABSENCE FAULT CLEARING TAKES PLACE IN ZONE-2 OF DISTANCE RELAY BY REMOTE END TRIPPING. THIS MEANS SLOW AND UNSELECTIVE TRIPPING AND WIDE SPREAD BLACKOUT.EFFECT OF DELAYED CLEARENCE GREATER DAMAGE AT FAULT POINT. INDIRECT SHOCK TO CONNECTED EQUIPMENT LIKE SHAFTS OF GENERATOR AND WINDINGS OF TRANSFORMER.BASIC THEORY KIRCHOFFs CURRENT LAW STATES THAT THE SUM OF THE CURRENTS ENTERING A GIVEN NODE MUST BE EQUAL TO THE CURRENTS LEAVING AT THAT NODE.BUS BAR PROTECTION SYSTEMS1. HIGH IMPEDENCE DIFFERENTIAL PROTECTION 2. MODERATE-IMPEDENCE DIFFERENTIAL PROTECTION3. LOW-IMPEDENCE DIFFERENTIAL PROTECTION4. NUMERICAL BUS DIFFERENTIAL PROTECTIONHIGH IMPEDENCE DIFFERENCIAL PROTECTION THE HIGH IMPEDENCE PROTECTION SCHEME, ON THE OTHER HAND, IS A GOOD SOLUTION FOR SINGLE BUSBAR ARRANGEMENTS , ONE & HALF BREAKER SYSTEMS OR RING BUSBARS, PROVIDING THAT APPROPRIATE DEDICATED CT CORES ARE AVAILABLE FOR THIS USE ALONE. IT IS SENSTIVE, STABLE & FAST PROTECTION. HOWEVER, SPECIAL CT REQUIREMENTS, ADDITIONAL HIGH VOLTAGE DEVICE PROTECTION, DEMANDING MAINTANENCE etc PUT RESTRICTIONS IN ITS APPLICATIONS. A MEASURING CIRCUIT COMPRISES A HIGH-IMPEDENCE STABILIZING RESISTOR CONNECTED ACROSS THE CIRCULATING CURRENT ARRANGEMENT OF ALL THE CTs IN PARALLEL. THE VALUE OF THE STABILIZING RESISTOR IS CHOOSEN SUCH THAT THE VOLTAGE DROP ACROSS THE RELAY CIRCUIT IS INSUFFICIENT TO OPERATE THE FAULTS OUTSIDE THE PROTECTED ZONE.

LIMITATIONS OF CONVENTIONAL HIGH IMPEDENCE DIFFERENTIAL RELAYPUTS STRINGENT REQUIREMENTS ON CTs. Class X for all CT Cores.NEED FOR DEDICATED CT CORES. Separate CT Cores for BUSBAR and CHECK ZONE Protection.IDENTICAL CT RATIO, MAGNETISING IMPEDENCE.AUX CTs RATIO CORRECTIONS UNACCEPTABLE.IN ABILITY TO COPE WITH INCREASING FAULT CURRENT.SLOW RESPONSE.Advantage of Numerical Protection Technology (e.g. Fault recording, Communication etc) not available.BASIC OPERATING TIME EXCLUDING RELAY TIME IS 15 20ms.THIS RELAY REQUIRES CHECK ZONE FEATURE. THE TRIP COMMAND IS ONLY GIVEN WHEN BOTH A DISCRIMINATING & CHECK ZONE SYSTEM OPERATES.MEDIUM IMPEDENCE DIFFERENTIAL PROTECTION MANY OF THE LIMITATIONS OF HIGH IMPEDENCE PROTECTION CAN BE OVERCOME USING MODERATE MEDIUM IMPEDENCE PROTECTION (OR STABILIZED HIGH-IMP SCHEME), WHICH IS A COMBINATION OF THE NORMAL HIGH-IMP AND STABILIZED DIFFERENTIAL SCHEMES.LOW IMPEDENCE DIFFERENTIAL PROTECTION LOW IMPEDENCE PROTECTION(PERCENTAGE BIASED BUS DIFFERENTIAL RELAY) IS MOST SUITABLE PROTECTION SCHEME FOR DOUBLE AND MULTIPLE BUSBAR SYSTEMS (WITH OR WITHOUT TRANSFER BUS) WITH FEEDERS BEING SWITCHED BETWEEN SECTIONS OF BUSBAR, WHICH OPERATES WITH FULL SELECTIVITY FOR ALL POSSIBLE BUSBAR CONFIGUARATIONS.ADVANTAGES FREE OF ANY NEED FOR MATCHED CT CHARACTERESTICS OR RATIOs, LOW LEAKAGE REACTANCE OR RESISTANCE. OTHER PROTECTIVE RELAYS CAN BE INCLUDED IN THE SAME CIRCUIT. STABLE FOR INFINITE FAULT LEVELS. INSENSITIVE TO CT SATURATION. DETECTS FAULTS WITHIN 1 2ms & INITIATES TRIPPING WITHIN 5 7ms.

BASICS OF BUS BAR PROTECTIONBASIC THEORYEXTERNAL FAULTKIRCHOFFs CURENT LAW STATES THAT THE SUM OF THE CURRENTS ENTERING A GIVEN NODE MUST BE EQUAL TO THE CURRENTS LEAVING THAT NODEI6I4I2I5I3I1IFIF= I6= I1+I2+I3+I4+I5INTERNAL FAULTI6I4I2I5I3I1IFIF= I1+I2+I3+I4+I5+I6

HIGH IMPEDENCE BUSBAR PROTECTION87BBM87BBC52 CIRCUIT BREAKERTRIP COIL+ VE- VE96 BBC : BUSBAR CHECK TRIPPING RELAY 96 BBM : BUSBAR MAIN TRIPPING RELAY A varistor is normally applied across the relay input terminals to limit the voltage to a value safely below the insulation voltage of the secondary circuits

LOW IMPEDENCE BUSBAR PROTECTION52 CIRCUIT BREAKERTRIP COIL-VE+VEOVER CURRENT COILRESTRAINTCOILOPERATING COIL96 BUS BARTRIPPING RELAYOVER CURRENT STARTER RELAYS.IdIs

DIFFERENCE BETWEEN BUSBAR SCHEMES

BUS BAR MAIN & CHECHUP PROTECTION (ANY CT METHOD)

CEDISPLAYACTIVESTARTTRIPREB 521333333IR1 / B111IY1 / B131IB1 / B151IN1 / B1711-CTCORE-1CTR: 2000-1000/1ACLASS: PS3-CTCORE-1CTR: 2000-1000/1ACLASS: PS


1S31S31S31S11S11S1CEDISPLAYACTIVESTARTTRIPRED 521BUS BAR PROTECTION FOR BUS-1BUS BAR PROTECTION FOR BUS-2IR1 / B111IY1 / B131IB1 / B151IN1 / B171

BUS BAR PROTECTION87 BB1 BUS BAR-1 PROTECTION87 BB2 BUS BAR-2 PROTECTIONBUS-2BUS-11-522-523-521-CT3-CT10-5211-5212-5210-CT12-CT13-5214-5215-5213-CT15-CT16-5217-5218-5216-CT18-CT19-5220-5221-5219-CT21-CT

BUSBAR-1 PROTECTION TRIPPING SCHEME+VEBUSBAR PANEL

BUSBAR-2 PROTECTION TRIPPING SCHEMECEDISPLAYACTIVESTARTTRIPREB 670+VEBUSBAR PANEL

DISTRIBUTED LBB & NUMERICAL CENTRALISED BUS BAR PROTECTION

LATEST DEVELOPMENT IN NUMERICAL CENTRALISED BUS BAR PROTECTIONMAIN -1MAIN -2MAIN -1MAIN -2MAIN -1MAIN -2MAINB/UMAINB/UMAINB/U

MISCELENEOUSRELAYS & PROTECTIONSADOPTED FOR LINE INONE AND HALF CIRCUIT BREAKERSCHEME (STUB, TEED AND AUTO RECLOSURE FUNCTIONS)

PREPARED BYGOPALA KRISHNA PALEPUADE/MRT(PROTECTION)

STUB-1/ STUB-2 PROTECTION1-52CB2-52CB3-52CBBUS-1BUS-23333LINE-1AT/F-1STUB-1&2(BAY 1&2)WHEN A LINE IS SUPPLIED VIA TWO CIRCUIT BREAKERS IN A ONE & HALF CIRCUIT BREAKER ARRANGEMENT, THE LINE PROTECTION INCLUDES THE AREA BETWEEN THE TWO CTs. HOWEVER, WHEN THE LINE ISOLATOR IS OPEN THE LINE CVTs FOR THE DISTANCE PROTECTION ARE CONNECTED TO THE LINE AND CANNOT PROVIDE THE CORRECT VOLTAGE FOR THE STUB END.(i.e THE AREA BETWEEN THE LINE ISOLATOR AND CTs) (STUB = DEAD END)TO PROVIDE PROTECTION FOR A FAULT IN THIS AREA, REL 521/ REL 316 IS PROVIDED WITH A STUB PROTECTION WHICH GIVES AN BUS OVER CURRENT TRIP IF THE LINE ISOLATOR IS OPEN AND THE CURRENT EXCEEDS THE SET VALUE IN ANY PHASE. 1-89LREL 521REL 316DISTANCE / ATF RELAYS CONVERTED TO STUB/BUS OVER LOAD RELAYS WHEN LINE ISOLATOR OPENS3-89TRET 521RET 316STUB-3&2(BAY 3&2)

TEED-1/ TEED-2 PROTECTION1-52CB2-52CB3-52CBBUS-1BUS-233333LINE-1AT/F-1TEED-1&2(BAY 1&2)TEED-1&2(BAY 2&3)TEED PROTECTION IS BASED ON KIRCHOFFS CURRENT LAW. THREE SETS OF CTS ARE CONNECTED IN STAR FASHION. SOME OF THE CURRENTS MUST BE ZERO. IF ANY UNBALANCE CURRENTS ARE NOTICED THEN IMMEDIATELY TEED PROTECTION OPERATES. IF TEED PROTECTION BAY 1&2 OPERATED THEN IT TRIPS 1-52CB & 2-52CB. SIMILARLY IF TEED PROTECTION BAY 2&3 OPERATED THEN IT TRIPS 2-52CB & 3-52CB.

TEED-1 PROTECTION {BAY1&2}(5CT METHOD)CEDISPLAYACTIVESTARTTRIPRADHA3333331-CTCORE-5CTR: 2000-1000-500/1ACLASS: PS1-LCTCORE-1CTR: 2000-1000/1ACLASS: PS

P2P2P2P1P1P13332-CTCORE-5CTR: 2000-1000-500/1ACLASS: PSP1P1P1P2P2P2P1P1P1P2P2P2

5S45S45S45S25S25S2

5S45S45S45S25S25S2

1S31S31S31S21S21S2IT WORKS ON CIRCULATING CURRENT PRINCIPLE AND IT IS HIGH IMPEDENCE DIFFERENTIAL RELAY. TEED-1 PROTECTION FOR BAY 2&3 IS ALSO SAME AS ABOVE AND THE FOLLOWING CTs & CORES ARE USED3-CT(CORE-5), 2-CT(CORE-1) & 3-TCT(CORE-1) ARE STARRED AND CONNECTED TO TEED-1 PROTECTIONIR5IY5IB5IN5IR5IY5IB5IN5IR1IY1IB1IN1

TEED-2 PROTECTION {BAY1&2}(5CT METHOD)3333331-CTCORE-4CTR: 2000-1000-500/1ACLASS: PS1-LCTCORE-2CTR: 2000-1000/1ACLASS: PS


2S22S22S22S32S32S33332-CTCORE-4CTR: 2000-1000-500/1ACLASS: PS

4S24S24S24S44S44S4P2P2P2CT MBCEDISPLAYACTIVESTARTTRIPRADSBRAICALBB/BFRRAICALBB/BFRTEED-2 PROTECTION FOR BAY 2&3 IS ALSO SAME AS ABOVE AND THE FOLLOWING CTs & CORES ARE USED. 3-CT(CORE-4), 2-CT(CORE-2) & 3-TCT (CORE-2) ARE CONNECTED TO TEED-2 PROTECTION.IT WORKS ON KIRCHOFFS CURRENT PRINCIPLE & IT IS PERCENTAGE BIASED LOW IMPEDENCE DIFFERENTIAL RELAY

TEED PROTECTION TRIP SCHEMEBUS-1BUS-21-52CB3-52CB2-52CB86-AMTR/HSTRABB REL521MAIN-186-BMTR/HSTR86-BMTR/HSTR86-AMTR/HSTR86-BMTR/HSTR86-AMTR/HSTRABBRADHATEED-1ABBRADSBTEED-2ABBRADHATEED-1ABBRADSBTEED-2TRIP COIL-1TRIP COIL-1TRIP COIL-1TRIP COIL-2TRIP COIL-2TRIP COIL-286-A : GROUP-A MASTER TRIP RELAY / HIGH SPEED TRIP RELAY 86-B : GROUP-B MASTER TRIP RELAY / HIGH SPEED TRIP RELAY(BAY 1&2)(BAY 1&2)(BAY 2&3)(BAY 2&3)ABBREL521STUB-1ABBREL316STUB-2(BAY 1&2)ORABBRET521STUB-1ORORABBRET316STUB-2ORLINE/TRANSFORMER ISOLATOR OPENS THIS INTERLOCK WILL INITIATE MAIN-1 REL 521/ RET 521 & MAIN-2 REL 316/ RET 316 CONVERTED STUB-1 & 2 PROTECTION

AUTO RECLOSURE BASICS FAULTS ARE THREE TYPES1. TRANSIENT FAULT: These are cleared by the immediate tripping of Circuit Breakers and do not reoccur when the line is re-energized. 2. SEMI-PERMANENT FAULTS: These require a time interval to disappear before a line is charged again.3. PERMANENT FAULTS: These are to be located and repaired before the line is re-energized. About 80-90% of the faults occurring are transient in nature. Hence the Automatic Reclosure of breaker (after tripping on Fault) will result in the line being successfully re-energized. ADVANTAGES:A. Decreasing outage time.B. Improving Reliability.C. Improving system stability.D. Reduce fault damage and Maintenance Time. DEAD TIME: The time between the Auto-reclosing Scheme being energized and the operation of the contacts which energize the Circuit Breaker closing circuit. RECLAIM TIME: The Time Following a successful closing operation measured from the instant the Auto-Reclosing relay closing contacts make which must elapse before the Auto-Reclosing relay initiates another reclosing attempt. In other words, it may be said to be the time between 1st and 2nd Auto-Reclosure.

TYPES OF AUTO-RECLOSING SCHEMES:1. BASED ON PHASEA. THREE PHASE AUTO-RECLOSING: This type of Auto-Reclosing causes an immediate drift part of the two systems and hence no interchange of synchronizing power can take place during the dead time. B. SINGLE PHASE AUTO-RECLOSING: In this, only the faulty phase(only SLG Faults) is reclosed without causing interruption in interchange synchronizing power between two systems through other two healthy phases.2. BASED ON ATTEMPTS OF RECLOSUREA. SINGLE SHOT AUTO-RECLOSING: In this scheme, Breaker is reclosed only once on a given fault before lockout of Circuit Breaker Occurs. High-Speed Auto-Reclosing for EHT System is invariably Single Shot.B. MULTI-SHOT AUTO-RECLOSING: In this scheme, more than one reclosing attempts made for a given fault before lockout of Circuit Breaker occurs.B.I. DISADVANTAGES: Repeated closure attempts has with high fault level would seriously affect the Circuit Breaker, Equipment and System Stability.B.ii. CIRCUIT BREAKER LIMITATIONS: Ability of Circuit Breaker to Perform several Trip Close operations in quick succession. B. iii. SYSTEM CONDITIONS: In the percentage of the semi-Permanent faults (which could be burnt out) is moderate, For example on the lines through the forest, multi shot Auto-Reclosing is followed.3. DEPENDING ON SPEED: A. HIGH-SPEED AUTO-RECLOSING: This aids in fast restoration of supply but should be done by taking into account the following factors.I. System disturbance time can be tolerated without loss of system stability.ii. Characteristics of Protection Schemes and Circuit Breaker. B. LOW SPEED OR DELAYED AUTO RECLOSING: This is suitable for highly inter-connected systems where the loss of a single line is unlikely to cause two sections of the system to drift apart and loose synchronism.

METHOD OF ADOPTION IN ONE AND HALF BREAKER SYSTEM: The Auto-Reclosure Functions used for the Bus Breakers 1-52CB & 3-52CB are set as Masters and one for the Center Breaker 2-52CB(TIE) as Follower. Co-ordination is required between the Auto-Reclosure Functions. A Synchrocheck function is also loaded in each Relay to permit 3 pole Auto-Reclosing.Each Line Protection relays starts both MAIN & TIE Circuit Breakers to trip for the Concerned line. After a Successful reclosure of the Main Breaker, The Tie Breaker will be reclosed after a supplementary time delay. Should the Main CB Auto-Reclosure relay not be successful in its reclosing attempts, the Tie CB Auto-Reclosure is blocked. If the Main CB is Open or its Auto-Reclosure Relay is not ready or Out of service, The TIE CB Auto-Reclosure will reclose The TIE Breaker after its own dead time without any supplementary time delay. CHOICES OF EHV SYSTEM:1. CHOICE OF DEAD TIME: A. Lower limit is decided by deionising of Circuit Breaker.B. Upper Limit is decided by Transient Stability and Synchronism.C. Longer Transmission Lines Require Longer dead Time.D. The dead time for High Speed Auto-Reclosing scheme with EHV System is 0.3 to 1.2 sec.2. CHOICE OF RECLAIM TIME:This should not be set to such a low value that the operating cycle of Breaker is exceeded when two faults incident occurs close together. The reclaim time will be in the range of 10 to 30 sec., depending the breaker opening and closing mechanisms.3. CHOICE OF ZONE:This should normally kept in Zone-1. It is a Zone-1 fault and SLG fault only auto-reclosure is comes in to picture. In other zones the auto reclosure is blocked.

AUTO-RECLOSURE FOR ONE & HALF BREAKER SCHEME1-52CB2-52CB3-52CBLINE-1LINE-279 (A/R)+ 25(SYNC) RAAAMRASC79 (A/R)+ 25(SYNC) RAAAMRASC79 (A/R)+ 25(SYNC) RAAAMRASC TRIP COMMANDS AUTO RECLOSURE COMMANDS21 MAIN-1REL 52121 MAIN-2REL 31621 MAIN-1REL 52121 MAIN-2REL 316

AUTO RECLOSING TIMING CHARTTIMEAUTO RECLOSERELAYINSTANT OF FAULTPROTECTIONCIRCUIT BREAKERTRANSIENT FAULTPERMANENT FAULTPROTECTIONCIRCUIT BREAKEROPERATING TIMEOPERATING TIMEOPERATESOPERATESTRIP COILENERGISEDCONTACTSSEPARATEARCEXTINGUISHEDCONTACTS FULLY OPENRESETSTRIP COILENERGISEDCONTACTSSEPARATEARCEXTINGUISHEDCONTACTS FULLY OPENRESETSOPENING TIMEARCING TIMEOPERATING TIMEOPENING TIMEARCING TIMEOPERATING TIMECLOSING COILENERGISEDCONTACTS MAKECONTACTSFULLY CLOSEDCLOSINGTIMEDEAD TIMECLOSING COILENERGISEDCONTACTS MAKECONTACTSFULLY CLOSEDCLOSINGTIMEDEAD TIMERECLOSE ON TO FAULTOPERATESTRIP COILENERGISEDCONTACTSSEPARATEARCEXTINGUISHEDCONTACTS FULLY OPENRESETSSYSTEM DISTURBANCE TIMERECLOSE INITIATED BY PROTECTIONDEAD TIMECLOSING PULSE TIMERECLAIM TIMERELAY READY TO RESPONDTO FURTHER FAULT INCIDENTS(AFTER SUCEESFUL RECLOSRE)

CARRIER INTERTRIPPING SCHEMESADOPTED IN ONE AND HALFCIRCUIT BREAKER SCHEME PREPARED BYGOPALA KRISHNA PALEPUADE/MRT(PROTECTION)

TYPES OF CARRIER TRIPPING SCHEMESPERMISSIVE TRIPPINGPermissive trip commands are always monitored by a protection relay. The circuit breaker is tripped when receipt of the command coincides with operation of the protection relay at the receiving end responding to a system fault. The receipt of an incorrect signal must coincide with operation of the receiving end protection for a trip operation to take place. Normally, the risk of a spurious trip is lesser. The intention of these schemes is to speed up tripping for faults occurring within the protected zone.BLOCKING SCHEMEBlocking commands are initiated by a protection element that detects faults external to the protected zone. Detection of an external fault at the local end of a protected circuit results in a blocking signal being transmitted to the remote end. At the remote end, receipt of the blocking signal prevents the remote end protection operating if it had detected the external fault. Loss of the communications channel is less serious for this scheme than in others as loss of the channel does not result in a failure to trip when required. However, the risk of a spurious trip is higher.

TYPES OF CARRIER TRIPPING SCHEMESConventional time-stepped distance protection has One of the main disadvantages is that the instantaneous Zone 1 protection at each end of the protected line cannot be set to cover the whole of the feeder length and is usually set to about 80%. This leaves two 'end zones', each being about 20% of the protected feeder length. Faults in these zones are cleared in Zone 1 time by the protection at one end of the feeder and in Zone 2 time (typically 0.25 to 0.5 seconds) by the protection at the other end of the feeder. This situation cannot be tolerated in some applications, for two main reasons:I). Faults remaining on the feeder for Zone 2 time may cause the system to become unstable.II). Where high-speed auto-reclosing is used, the non-simultaneous opening of the circuit.Breakers at both ends of the faulted section results in no 'dead time' during the autoreclose cycle for the fault to be extinguished and for ionized gases to clear. This results in the possibility that a transient fault will cause permanent lockout of the circuit breakers at each end of the line section.Even where instability does not occur, the increased duration of the disturbance may give rise to power quality problems, and may result in increased plant damage.Unit schemes of protection that compare the conditions at the two ends of the feeder simultaneously positively identify whether the fault is internal or external to the protected section and provide high-speed protection for the whole feeder length. This advantage is balanced by the fact that the unit scheme does not provide the back up protection for adjacent feeders given by a distance scheme.The most desirable scheme is obviously a combination of the best features of both arrangements, that is, instantaneous tripping over the whole feeder length plus back-up protection to adjacent feeders. This can be achieved by interconnecting the distance protection relays at each end of the protected feeder by a communications channel. The purpose of the communications channel is to transmit information about the system conditions from one end of the protected line to the other, including requests to initiate or prevent tripping of the remote circuit breaker. The former arrangement is generally known as a 'transfer tripping scheme' while the latter is generally known as a 'blocking scheme'. However, the terminology of the various schemes varies widely, according to local custom and practice.

TYPES OF CARRIER TRIPPING SCHEMES1.ZONE 1 EXTENSION SCHEME (Z1X SCHEME)2.TRANSFER TRIPPING SCHEMESI. DIRECT UNDER REACH TRANSFER TRIP SCHEME (DUTT)II.PERMISSIVE UNDER REACH TRANSFER TRIP SCHEME (PUTT)III.PUTT FWD SCHEMEIV.PERMISSIVE UNDER REACH ACCELERATED SCHEMEV.PERMISSIVE OVER REACH TRANSFER TRIP SCHEME (POTT)VI.WEEK IN FEED CONDITIONS.3.BLOCKING OVER REACHING SCHEMESI.BLOCKING OVER-REACHING PROTECTION SCHEME USING ZONE 2. OR DIRECTIONAL COMPARISION BLOCKING SCHEMEII. BLOCKING OVER-REACHING PROTECTION SCHEME USING ZONE 1. III. WEEK IN FEED CONDITIONS.4.DIRECTIONAL COMPARISON UNBLOCKING SCHEME

PROPERTIES OF COMMAND PROTECTION SYSTEMS

PREFFERED APPLICATIONS OF TELE/ CARRIER TRIPPING SCHEMES

COMPARISION OF TELE/ CARRIER TRIPPING SCHEMES

ADVANTAGES & DRAWBACKS OF TELE/ CARRIER TRIPPING SCHEMES

PROTECTION COUPLER PANEL

CEDISPLAYACTIVESTARTTRIPNSD 50/ NSD 70

PROTECTION COUPLERS FOR 400KV LINEFOR EACH LINE 2Nos PROTECTION COUPLER PANELS PROVIDED.FOR EACH LINE 1NO CARRIER SPEECH PANEL PROVIDED.SO, ONE LINE REQUIRES TOTAL 3 PANELS.CARRIER SPEECH PANEL PURELY FOR VOICE COMMUNICATION BETWEEN TWO SUBSTATIONS, i.e THE LINE CONNECTED SUBSTATIONS.THE VOICE COMMUNICATION ARE TWO METHODS PROVIDED.ONE IS HOTLINE COMMUNICATION/DEDICATED/ LIFT&TALK METHOD.ANOTHER IS DIAL METHOD.IN PROTECTION COUPLER PANEL-1 TOTAL 3 CARDS ARE IMPORTANT FOR SENDING & RECEIVING TRIP SIGNALS.ONE CARD FOR ALARM i.e G4AA. ONE CARD FOR PERMISSIVE/PROTECTION TRIP i.e G4AC & ANOTHER CARD FOR DIRECT TRIPS i.e G4AD.IN PROTECTION COUPLER-2 PANEL ALSO 3 CARDS ARE PROVIDED SIMILAR TO PROTECTION COUPLER-1 PANEL.THE PROTECTION COUPLER PANEL DRAWING IS SHOWN IN PREVIOUS MENU.1SET TX & RX FOR PERMISSIVE/ PROTECTION TRIP(G4AC)1SET TX & RX FOR BACKUP FOR PERMISSIVE/ PROTECTION IN ANOTHER PANEL(G4AC).1SET TX & RX FOR DIRECT TRIP CHANNEL-1( G4AD).1SET TX & RX FOR SPARE UNDER EMERGENCY(G4AD).THE ABOVE ARRANGEMENT SIMILAR FOR PROTECTION COUPLER PANEL-2.G4AA CARD FOR ALARM.

MAIN-1 PROTECTION CARRIER INTER TRIPPINGABB REL521CRCS-VECARRIER RECEIVECARRIER SENDALARMINABBNSD 50OUTPANEL-1PANEL-2G4AC V9LC 1G4AC V9LC 2G4AC V9LC 5G4AC V9LC 6G4AA V9LB 5G4AA V9LB 6ABBNSD 50G4AC V9LC 10G4AC V9LC 14G4AC V9LC 9G4AC V9LC 13THIS IS BACKUP FOR PERMISSIVE/ PROTECTION TRIPAND CONNECTED IN ANOTHER PANEL+VE-VE

MAIN-2 PROTECTION CARRIER INTER TRIPPINGABB REL316CRCS-VECARRIER RECEIVECARRIER SENDALARMINABBNSD 50OUTPANEL-2PANEL-1G4AC V9LC 1G4AC V9LC 2G4AC V9LC 5G4AC V9LC 6G4AA V9LB 5G4AA V9LB 6ABBNSD 50G4AC V9LC 10G4AC V9LC 14G4AC V9LC 9G4AC V9LC 13THIS IS BACKUP FOR PERMISSIVE/ PROTECTION TRIPAND CONNECTED IN ANOTHER PANEL+VE-VE

DIRECT TRIP SEND CARRIER CHANNEL-1T N CMAIN CB(1-52CB)T N CTIE CB(2-52CB)CONTROL PANEL87 BUSBAR TRIP (ZONE-1)87 BUSBAR TRIP (ZONE-2)96 BUSBAR PROT-1 PANEL96 BUSBAR PROT-2 PANELRYBRYBTIE CB (2-52 CB)MAIN CB (1-52 CB)50 LBB/BFR FOR MAIN CB / RAICA59L1 / OVER VOLTAGE STAGE-1 59L2 / OVER VOLTAGE STAGE-250 LBB/BFR FOR TIE CB / RAICAABBNSD 50DC +VE FROM PANELG4AD V9LC 2DC VE FROM PANELG4AD V9LC 1PANEL-1 87 HZ / TEED-1 PROTECTION 87 LZ / TEED-2 PROTECTION CONDITIONS FOR DIRECT TRIPTIE CB OPEN CONDITION + MAIN CB REMOTE HAND TRIP GIVEN.MAIN CB OPEN CONDITION + TIE CB REMOTE HAND TRIP GIVEN.TIE CB OPEN CONDITION + 96 BUSBAR-1 OPERATED.MAIN CB OPEN CONDITION + 96 BUSBAR-2 OPERATED (FOR HALF DIA ONLY).MAIN CB 50 LBB/BFR OPERATED.TIE CB 50 LBB/BFR OPERATED. 59L1 OVER VOLTAGE STAGE-1 OPERATED.59L2 OVER VOLTAGE STAGE-2 OPERATED.87 HZ TEED-1 PROTECTION OPERATED87 LZ TEED-2 PROTECTION OPERATED.

DIRECT TRIP SEND CARRIER CHANNEL- 2T N CMAIN CB(1-52CB)T N CTIE CB(2-52CB)CONTROL PANEL87 BUSBAR TRIP (ZONE-1)87 BUSBAR TRIP (ZONE-2)96 BUSBAR PROT-1 PANEL96 BUSBAR PROT-2 PANELRYBRYBTIE CB (2-52 CB)MAIN CB (1-52 CB)50 LBB/BFR FOR MAIN CB / RAICA59L1 / OVER VOLTAGE STAGE-1 59L2 / OVER VOLTAGE STAGE-250 LBB/BFR FOR TIE CB / RAICAABBNSD 50DC +VE FROM PANELG4AD V9LC 2DC VE FROM PANELG4AD V9LC 1PANEL-287 HZ / TEED-1 PROTECTION 87 LZ / TEED-2 PROTECTION CONDITIONS FOR DIRECT TRIPTIE CB OPEN CONDITION + MAIN CB REMOTE HAND TRIP GIVEN.MAIN CB OPEN CONDITION + TIE CB REMOTE HAND TRIP GIVEN.TIE CB OPEN CONDITION + 96 BUSBAR-1 OPERATED.MAIN CB OPEN CONDITION + 96 BUSBAR-2 OPERATED (FOR HALF DIA ONLY).MAIN CB 50 LBB/BFR OPERATED.TIE CB 50 LBB/BFR OPERATED. 59L1 OVER VOLTAGE STAGE-1 OPERATED.59L2 OVER VOLTAGE STAGE-2 OPERATED.87 HZ TEED-1 PROTECTION OPERATED87 LZ TEED-2 PROTECTION OPERATED.

DIRECT TRIP RECEIVE CHANNEL-1&2ABBNSD 50G4AD V9LC 6G4AD V9LC 5ABBNSD 50G4AD V9LC 6G4AD V9LC 5PANEL-1PANEL-2DC +VEDC +VE+VE-VETO 86-A MASTER TRIP RELAY (HIGH SPEED TRIP RELAY) FOR MAIN CB(152CB)TO 86-A MASTER TRIP RELAY(HIGH SPEED TRIP RELAY) FOR TIE CB(252CB)TO 86-B MASTER TRIP RELAY(HIGH SPEED TRIP RELAY) FORMAIN CB(152CB)TO 86-B MASTER TRIP RELAY (HIGH SPEED TRIP RELAY) FORTIE CB(252CB)DIRECT TRIP-1CARRIER RECEIVE RELAYDIRECT TRIP-2CARRIER RECEIVE RELAY

PLCC CARRIER PROTECTION SYSTEM(TELEPROTECTION)REL 521MAIN-1 PROTECTIONREL 316MAIN-2PROTECTIONELECTRICAL CONNECTIONELECTRICAL CONNECTIONELECTRICAL POWER LINE

FIBRE OPTIC PROTECTION SYSTEM(TELEPROTECTION)REL 521MAIN-1 PROTECTIONREL 316MAIN-2PROTECTIONELECTRICAL CONNECTIONELECTRICAL CONNECTION

FIBRE OPTIC CARRIER PROTECTION SYSTEM(TELEPROTECTION)DIGITAL RELAY CONNECTION VIA FIBRE OPTICREL 521MAIN-1 PROTECTIONREL 316MAIN-2PROTECTION

MAIN-1 & MAIN-2PROTECTION FORAUTO TRANSFORMER ADOPTED IN ONE AND HALFCIRCUIT BREAKER SCHEMEPREPARED BYGOPALA KRISHNA PALEPUADE/MRT(PROTECTION)

BASICS OF TRANSFORMER PROTECTION1. PURPOSE OF POWER TRANSFORMER PROTECTIONPOWER T/F PROTECTION IS USUALLY INSTALLED TO DISCONNECT THE T/F AT:A. INTERNAL SHORT CIRCUITS AND EARTH FAULTS IN THE T/F AND ITS CONNECTED CIRCUITS.B. EXTERNAL FAULTS ON OTHER CIRCUITS. (BACK-UP PROTECTION)C. ABNORMAL SERVICE CONDITIONS SUCH AS OVERLOAD & OVER VOLTAGE.PROTECTION DEVICES INBUILT OR MOUNTED ON POWER T/FA. OIL IMMERSED POWER T/F USUALLY HAVE A GAS DETECTOR AND OIL SURGE. DETECTOR (BUCHHOLZ ALARAM & TRIP DEVICES), WHICH ARE EXCELLENT FOR DETECTING INTERNAL FAULTS.B. LOAD TAPCHANGER COMPARTMENTS MAY HAVE A SIMILAR OVER PRESSURE DEVICE. C. TEMPARATURE MONITORS FOR OIL & WINDING PROVIDE GOOD OVER LOAD PROTECTION.D. PRESSURE RELIEF DEVICE IS PROVIDED TO SAFE GUARD THE T/F FROM HIGH PRESURES. TRANSFORMER DIFFERENTIAL PROTECTIONIT IS WIDELY USED AS INSTANTANEOUS PROTECTION FOR SHORT CIRCUIT FAULTS WITH IN THE DIFFERENTIAL ZONE. THIS IS TREATED AS MAIN-1 PROT FOR T/F. THE MOST COMMON TYPE OF PROTECTION IS THE CURRENT RESTRAINT TYPE.SOME TYPE OF DIFFERENTIAL RELAYS REQUIRE INTERPOSING CTs FOR CT RATIO MATCHING AND/OR PHASE SHIFT.HIGH IMPEDENCE DIFFERENTIAL PROTECTION CAN BE USED ON AUTO T/F & REACTORS.IT COVERS ONE GALVANICALLY INTERCONNECTED WINDING (WDG DIFF). BUT NOT A SEPARATE TERTIARY WINDING. IT REQUIRES A THREE PHASE SET OF CTs AT THE NEUTRAL SIDE OF WINDING.

RESTRICTED EARTH FAULT PROTECTIONAT/Fs are used to couple EHV Power Networks, If the Ratio of their Voltages is Moderate. An Alternative to Differential Protection that can be applied to AT/Fs. A Circulating Current System is arranged between Equal Ratio Current Transformers in the Two Groups of Line Connections and the Neutral End Connections. The Line Current Transformers can be connected in Parallel to A Single Element Relay, Thus providing a Scheme Responsive to Earth Faults Only. If Current Transformers are fitted in Each Phase at the Neutral End of the Windings and a Three-Element Relay is used, A Differential System can be provided, giving Full Protection against Phase and Earth Faults. This Provides High-speed Sensitive Protection. It is Unaffected by Ratio Changes on the Transformer due to Tap-changing and is immune to the Effects of Magnetizing In Rush Current. It does not respond to Interturn Faults. In Addition, This Scheme does not respond to any Fault in a Tertiary Winding. Unloaded Delta-connected Tertiary Windings are often not Protected. 5. BACK UP PROTECTIONA VARIETY OF RELAYS ARE AVAILABLE.A. OVER CURRENT & EARTH FAULT PROTECTION. ( 50, 50N, 51, 51N, 67, 67N - ANY COMBINATION OF THESE)B. UNDER IMPEDENCE / DISTANCE ( Z).OTHER TYPES OF RELAYSA. OVER VOLTAGE RELAY (U >).B. OVER FLUX/ EXCITATION (V/F >)( INVERSE TIME & DIFENITE TIME). FOR 400KV/220KV & 765/400KV TRANSFORMERS BOTH SIDES( i.e HV & LV) OVER FLUX RELAYS ARE PROVIDED BECAUSE BOTH SIDES HAVING GRID.C. AT/F NEUTRAL CURRENT RELAY (51N).

NORMALLY ADOPTED POWER TRANSFORMERS CAPACITIES IN 400KV / 220KVCAPACITY OF TRANSFORMERHV VOLTAGEHV CURRENTLV VOLTAGELV CURRENT315 MVA400 KV454.68 A220 KV0826.68 A500 MVA400 KV721.71 A220 KV1312.20 A630 MVA400 KV909.35 A220 KV1653.37 A

NORMS OF PROTECTION FOLLOWED IN APTRANSCO FOR POWER TRANSFORMERS & AUTO TRANSFORMERS

S.NoCAPACITYVOLTAGE RATIOMAIN PROTECTIONBACK UPPROTECTIONADDITIONAL PROTECTIONSPECIALPROTECTIONHVLV17.5 MVA 16 MVA25 MVA31.5 MVA132KV/11KV87T DIFFERENTIAL RELAY

3 OL + 1 DIR EL3 OL +1 EL BUCHHOLZ, OLTC OSROIL TEMPWDNG TEMP NIL

216 MVA31.5 MVA50 MVA80 MVA132KV/33KV3 OL + 1 DIR EL3 OL +1 EL BUCHHOLZOVER FLUX OLTC OSRPRV/PRDOIL TEMPWDNG TEMP331.5 MVA50 MVA220KV/33KV3 OL + 1 DIR EL3 OL +1 EL 4100 MVA160 MVA220KV/132KV3 OL + 1 DIR EL3 OL +1 DIR EL 5 315 MVA 500 MVA630 MVA400KV/220KV3 DIR OL (HIGHSET) + 1 DIR EL(HIGHSET)3 DIR OL (HIGHSET) + 1 DIR EL(HIGHSET) REF RELAY,OVER LOAD ALARM RELAY6630 MVA750 MVA1000MVA1500MVA765KV/400KVT/F NEUTRAL CURRENT RELAY + HIGH IMPEDENCE DIIFERENTIAL RELAY

MAIN / DIFFERENTIAL PROTECTION FOR AT/F(4 CT METHOD)3333333-CTCORE-5CTR: 2000-1000-500/1ACLASS: PS2-ACTCORE-5CTR: 2000-1000-500/1ACLASS: PS


5S45S45S45S35S35S3333LV-CTCORE-5CTR: 1200-800/1ACLASS: PS

5S15S15S15S35S35S3P2P2P2CT MBCEDISPLAYACTIVESTARTTRIPRET 521/ RET 316RADSBAUX.CT Y/ 0.689 / 0.577AIN CASE OF 1&1/2 CB SYSTEM, THE DIFFERENTIAL PROTECTION CTs ASSOCIATED WITH MAIN & TIE CBs SHOULD BE CONNECTED TO SEPARATE BIAS WINDINGS AND THESE SHOULD NOT BE PARALLED IN ORDER TO AVOID FALSE OPERATION DUE TO DISSIMILAR CT TRANSIENT RESPONSE. 3 CT METHOD : 3-CT & 2-CT4 CT METHOD : 3-CT & 2-ACT6 CT METHOD : 3-ACT & 2-ACT

MAIN / DIFFERENTIAL PROTECTION FOR AT/F(5 CT METHOD)3333-TCTCORE-5CTR: 2000-1000-500/1ACLASS: PS

5S45S45S45S35S35S3P2P2P2CT MB333LV-CTCORE-5CTR: 1200-800/1ACLASS: PS

5S15S15S15S35S35S3P2P2P2CT MBCEDISPLAYACTIVESTARTTRIPRET 521/ RET 316RADSBAUX.CT Y/ 0.689 / 0.577ANORMALLY LOW IMPEDENCE BIASED DIFFERENTIAL RELAY IS USED FOR TRANSFORMER DIFFERENTIAL PROTECTION

SELECTION OF AUX.CTs FOR DIFFERENTIAL PROTECTIONNORMALLY 400KV/220KV AUTO TRANSFORMERS ARE OF CAPACITY 315MVA.FOR MERZ PRICE PROTECTION IF TRANSFORMER IS CONNECTED IN STAR/STARTHEN CT SECONDARIES ARE TO BE CONNECTED IN DELTA/DELTA.CORRECT RATIO CTs ARE NOT AVAILABLE, THEN AUX.CTs ARE TO BE PROVIDED FOR ACHEVING SUITABLE CURRENTS.IF AUX CTs ARE USING THEN MAIN CT SECONDARIES ARE CONNECTED IN STAR.THIS IS BROUGHT TO AUX CTs. AUX CTs PRIMARY IS CONNECTED IN STAR & SECONDARIES ARE CONNECTED IN DELTA.NORMALLY THE RELAY RATED CURRRENT IS 1A.AUX.CT s SECONDARIES ARE CONNECTED IN DELTA. FOR ACHIEVING 1A TORELAY, AUX.CT SECONDARY CURRENT IS TO BE 0.577A.THE FULL LOAD PRIMARY CURRENT OF 315MVA AT/F IS 454.7A.BUT THE 400KV CTs RATIOs ARE AVAILABLE : 2000-1000-500/1ANEAREST VALUE TO FULL LOAD CURRENT IS 500/1A. HENCE IT IS ADOPTED.HENCE AT FULL LOAD HV CURRENT i.e 454.7A, THEN SECONDARY OF CT CURRENT WILL BE 0.91A.SO HV SIDE AUX.CT RATIO IS 0.91/0.577A.THE FULL LOAD SECONDARY CURRENT OF 315MVA AT/F IS 826.7A.BUT THE 220KV CTs RATIOs ARE AVAILABLE: 1200-800/1A.NEAREST VALUE TO FULL LOAD CURRENT IS 1200/1A. HENCE IT IS ADOPTED.HENCE AT FULL LOAD LV CURRENT i.e 826.7A,THEN SECONDARY OF CT CURRENT WILL BE 0.689A.SO LV SIDE AUX CT RATIO IS 0.689/0.577A.SPECIAL INFORMATION: LATEST NUMERICAL RELAYS NEED NOT REQUIRE AUX CTs. IN THESE RELAYS, CT RATIOS MATCHING CAN BE PROGRAMMED.

BACKUP PROTECTION FOR AT/F HV(4 CT METHOD)3333333-CTCORE-4CTR: 2000-1000-500/1ACLASS: PS2-ACTCORE-4CTR: 2000-1000-500/1ACLASS: PS


4S44S44S44S34S34S3

CVT SELECTIONBUS-1 CVT / BUS-2 CVT / LINE CVTCORE-1VA : 200CLASS: 3PCEDISPLAYACTIVESTARTTRIPRAPDKDIR O/L & E/FREL 505LBB / BFRRAICA50ZIR4 / C411IY4 / C431IB4 / C451IN4 / C471333333VR11 / E111VY11 / E131VB11 / E151VN11 / E171E172E174IR4 / C411IY4 / C431IB4 / C4513 CT METHOD : 3-CT & 2-CT4 CT METHOD : 3-CT & 2-ACT6 CT METHOD : 3-ACT & 2-ACT

BACKUP PROTECTION FOR AT/F HV(5 CT METHOD)3333-TCTCORE-4CTR: 2000-1000-500/1ACLASS: PS

4S44S44S44S34S34S3P2P2P2CT MB

CVT SELECTIONBUS-1 CVT / BUS-2 CVT / LINE CVTCORE-1VA : 200CLASS: 3PCEDISPLAYACTIVESTARTTRIPRAPDKDIR O/L & E/FREL 505IR4 / C411IY4 / C431IB4 / C451IN4 / C471333333VR11 / E111VY11 / E131VB11 / E151VN11 / E171E172E174

BACKUP PROTECTION FOR AT/F LV

333LV-CTCORE-4CTR: 1200 800 /1ACLASS: PS

4S24S24S24S14S14S1P1P1P1CT MBP2P2P2

VOLTAGESELECTIONBUS-1 PT / BUS-2 PT CORE-1VA : 200CLASS: 3PCEDISPLAYACTIVESTARTTRIPRAPDKDIR O/L & E/FREL 505LBB / BFRRAICA50ZIR4 / C411IY4 / C431IB4 / C451IN4 / C471333333VR11 / E111VY11 / E131VB11 / E151VN11 / E171E172E174

MISCELLENEOUSRELAYS & PROTECTIONSADOPTED FOR AUTO TRANSFORMER INONE AND HALF CIRCUIT BREAKERSCHEME (OVER FLUX & REF FUNCTIONS)


OVER EXCITATION/FLUX RELAY{FOR AUTO TRANSFORMER HV & LV}RATUBV/F RELAYHVRATUBV/F RELAYLVCVT SELECTIONBUS-1 CVT / BUS-2 CVT / LINE CVTCORE-1VA : 200CLASS: 3P

VOLTAGE SELECTIONBUS-1 PT / BUS-2 PTCORE-1VA : 200CLASS: 3P

315MVA, 400KV/220KV/33KV AT/F RESTRICTED EARTH FAULT RELAYCEDISPLAYACTIVESTARTTRIPRADHD333333400KV HVBUSHING CTCORE-1CTR: 1000/1ACLASS: PS220KV LVBUSHING CTCORE-1CTR: 1000/1ACLASS: PS

P2P2P2P2P2P2333NEUTRALBUSHING CTCORE-1CTR: 1000/ 1ACLASS: PSP1P1P1P1P1P1P2P2P2P1P1P1S2S2S2S2S2S2S2S2S2S1S1S1S1S1S1S1S1S1

315MVA, 400KV/220KV/33KV AT/F 3-PH HIGH IMPEDENCE DIFFERENTIAL RELAYCEDISPLAYACTIVESTARTTRIPRADHA333333400KV HVBUSHING CTCORE-1CTR: 1000/1ACLASS: PS220KV LVBUSHING CTCORE-1CTR: 1000/1ACLASS: PS

P2P2P2P2P2P2333NEUTRALBUSHING CTCORE-1CTR: 1000/ 1ACLASS: PSP1P1P1P1P1P1P2P2P2P1P1P1S2S2S2S2S2S2S1S1S1S1S1S1S1S1S1S2S2S2

315MVA, 400KV/220KV AT/F VOLAGE SELECTION1-52CB2-52CB3-52CBBUS-1BUS-2LINE1AT/F-1

MAIN-1 & MAIN-2PROTECTION FORSHUNT REACTOR ADOPTED IN ONE AND HALFCIRCUIT BREAKER SCHEMEPREPARED BYGOPALA KRISHNA PALEPUADE/MRT(PROTECTION)

BASICS OF SHUNT REACTOR1. TYPES OF REACTORS :A. BASED ON REACTOR CONNECTIONi. SHUNT REACTOR. ii. SERIES REACTOR.B. BASED ON REACTOR LOCATIONi. BUS REACTOR ii. LINE REACTORC. BASED ON CONTROLi. 3-PH OIL IMMERSED REACTOR WITH GAPPED IRON CORE. ii. THYRISTOR CONTROLLED REACTOR (STATIC VAR COMPENSATOR)(APTRANSCO UTILISING SHUNT REACTORS FOR BUS & LINE IN 400KV NETWORK)2. NEED OF SHUNT REACTOR:A. LINE REACTORSHUNT REACTORS ARE USED IN ORDER TO COMPENSATE FOR THE CAPACITIVE SHUNT REACTANCE OF TRANSMISSION LINES. THE REACTOR IS CONNECTED PARALLEL TO THE LINE. THE LOCATION OF REACTOR IS OUT GOING SIDE OF LINE i.e AFTER CIRCUIT BREAKER. LENGTH OF LINE IS MORE THERE MAY BE VOLTAGE IS RAISING DUE TO FARANTI EFFECT(CAPACITANCE) DURING CHARGING. IN CASE OF ZONE-2 (OPEN JUMPER) FAULT, THE FAULT CLEARED BY REMOTE END IS FAST, BUT THIS END IT WILL TAKE TIME DELAY DUE TO ZONE-2. DURING THIS TIME, VOLTAGE MAY RAISING. SO, LINE REACTOR IS USED FOR CONTROLLING THE SWITCHING OVER VOLTAGES AND SAFEGUARD THE OPERATING EQUIPMENT. NORMALLY IT IS ALWAYS IN SERVICE. NORMALLY BOTH ENDS LINE REACTORS ARE PROVIDED. THE ELECTRICAL INTERLOCK IS PROVIDED THAT IF REACTOR ISOLATOR CLOSSED POSITION ONLY WILL GIVE PERMIT TO CLOSE THE LINE ISOLATOR. SIMILARLY FOR OPENING REACTOR ISOLATOR THE LINE ISOLATOR SHOULD BE IN OPEN POSITION. NEUTRAL REACTOR CONNECTED BETWEEN THE STAR POINT OF EHV SHUNT REACTOR AND THE GROUND, LIMITS THE SECONDARY ARC CURRENT TO A LOW VALUE OF AROUND 10 AMPS TYPICALLY FOR 400KV SYSTEM TO ENSURE COMPLETE DE-IONISATION OF ARC PATH WHEN EHV SYSTEM DEVELOPS A SINGLE LINE TO GROUND FAULT. ARC EXTINCTION DURING LINE SINGLE- PHASE AUTORECLOSE DEAD TIME IS ASSISTED BY THIS NEUTRAL REACTOR.

B. BUS REACTOR THE REACTOR IS CONNECTED PARALLEL TO THE BUS i.e LIKE A FEEDER/LINE. DURING LIGHTLY LOADED CONDITIONS THERE MAY BE POSSIBULITY OF RAISING BUS VOLTAGES. FOR SAFEGUARD THE OPERATING EQUIPMENT BUS REACTORS ARE UTILISING. NORMALLY IT IS NOT IN SERVICE. WHENEVER THE VOLTAGE RAISES TO 4%TO 5% MORE THAN THE RATED VOLTAGE THIS MAY BE KEPT IN SERVICE AND 2% TO 3% LESS THAN THE RATED VOLTAGE THIS MAY BE KEPT OUT OF SERVICE. SELECTION OF REACTORA. LINE REACTORNORMALLY LINE REACTORS ARE PROVIDED IF THE LINE IS MORE OR EQUAL TO 250KM. IN APTRANSCO NETWORK MAXIMUM LENTH OF LINE IS 350KM. AS PER SYSTEM STUDIES RECOMANDATIONS IF LINE LENGTH IS 250KM TO 300KM 50MVAR REACTOR IS TO BE USED. IF MORE THAN 300KM 63MVAR REACTOR IS TO BE USED.B. BUS REACTOR NORMALLY BUS REACTORS ARE PROVIDED IF THE SUBSTATION BUS VOLTAGE IS RAISING 5% MORE THAN THE RATED VOLTAGE DURING LIGHTLY LOADED CONDITION. BASED ON THE SYSTEM STUDIES RECOMANDATIONS BUS REACTORS ARE TO BE PROVIDED. CALCULATIONS ARE REQUIRED FOR PROVIDING BUS REACTOR. IN THIS THERE IS NO STANDARDISATION.LOCATION OF REACTORS WITH CAPACITY IN APTRANSCOA. LINE REACTOR1. 400KV KALAPAKA-KHAMMAM 1 AT BOTH ENDS 63MVAR 2. 400KV KALAPAKA-KHAMMAM 2 AT BOTH ENDS 63MVARB. BUS REACTOR1. 400KV KALAPAKA SS 2 X 50 MVAR2. 400KV NUNNA SS(PGCIL BAYS) 1 x 63 MVAR

5. PURPOSE OF SHUNT REACTOR PROTECTIONTHE PURPOSE OF THE PROTECTION RELAYING IS TO DISCONNECT THE REACTOR AND LIMIT DAMAGE IN CASE OF INTERNAL SHORT CIRCUITS, EARTH FAULTS, INTERTURN FAULTS AND OVER VOLTAGE OR OVER LOAD.THE REACTOR FORMS CERTAIN IMPEDENCE FOR RATED FREQUENCY, AND AS IT IS SHUNT CONNECTED, AS OVER LOAD MAY BE CAUSED BY OVER VOLTAGE OR HARMONICS IN VOLTAGE AND CURRENT.6. PROTECTION DEVICES INBUILT OR MOUNTED ON REACTORA. OIL IMMERSED REACTOR USUALLY HAVE A GAS DETECTOR AND OIL SURGE. DETECTOR (BUCHHOLZ ALARAM & TRIP DEVICES), WHICH ARE EXCELLENT FOR DETECTING INTERNAL FAULTS.B. TEMPARATURE MONITORS FOR OIL & WINDING PROVIDE GOOD OVER LOAD PROTECTION.C. PRESSURE RELIEF DEVICE IS PROVIDED TO SAFE GUARD THE REACTOR FROM HIGH PRESURES. 7.REACTOR DIFFERENTIAL PROTECTIONIT IS WIDELY USED AS INSTANTANEOUS PROTECTION FOR SHORT CIRCUIT FAULTS WITH IN THE DIFFERENTIAL ZONE. THIS IS TREATED AS MAIN-1 PROT FOR REACTOR. IT CAN BE OF HIGH IMPEDENCE TYPE OR OF A SENSITIVE CURRENT STABILISED TYPE. HIGH IMPEDENCE DIFFERENTIAL PROTECTION RELAYS REQUIRE AN EQUAL CT TURNS RATIO ON THE PHASE AND NEUTRAL SIDE. SENSITIVITY IS 5% OF NOMINAL REACTOR CT CURRENT.BACK-UP PROTECTIONA VARIETY OF RELAYS ARE AVAILABLE.A. OVER CURRENT & EARTH FAULT PROTECTION. ( 50, 50N, 51, 51N, 67, 67N - ANY COMBINATION OF THESE)B. UNDER IMPEDENCE / DISTANCE ( Z).RESTRICTED EARTH FAULT PROTECTIONIF, FOR SOME REASON, A SENSITIVE DIFFERENTIAL PROTECTION NOT CHOOSEN A RESTRICTED EARTH FAULT PROTECTION CAN BE UTILISED.

SHUNT REACTOR (BUS & LINE) (4CT METHOD)LINE 11-891-89A1-52CB1-CT3333-893-89A3-52CB3-CT32-52CB2-ACT2-BCT2-89A2-89B1-89LBUS-1BUS-2P1P1P1P1P2P2P2P2 LINESHUNT REACTOR1-89R BUSSHUNT REACTOR.3-89R.IL1-RCT3P2P1 1-PH NEUTRAL GROUNDING REACTOR

SHUNT REACTOR (BUS & LINE) (5CT METHOD)1-89A1-52CB1-CT333-893-89A3-52CB3-CT32-52CB1-LCT2-CT2-89A2-89B1-89L3-89RBUS-1BUS-23-RCT1-89P2P1P2P2P2P1P1P2P1P1LINE 11-89L331-89R1-RCT3P2P1 LINESHUNT REACTOR BUSSHUNT REACTOR..IL 1-PH NEUTRAL GROUNDING REACTOR

SHUNT REACTOR PROTECTION

REACTOR BUSHING CT CONNECTIONS

.P1.P2200/ 1AP2 LINESHUNT REACTOR 1-PH NEUTRAL GROUNDING REACTORP1200/ 1A.. HV BUSHING(400KV SIDE) CTs NEUTRAL BUSHING(STAR PONT SIDE) CTs..P1P2P2P1.LINE SHUNT REACTOR PROTECTION (4CT METHOD).200/ 1A200/ 1AREACTOR DIFFERENTIAL PROTECTIONRESTRICTED EARTHFAULT PROTECTIONREACTOR IMPEDENCE PROTECTIONREACTOR METERINGSELECTED BUS-1/ BUS-2/ LINECVT VOLTAGE..1-89R1-RCT..CORE-1: 2000-1000-500/1CORE-2: 2000-1000-500/1CORE-3: 2000-1000-500/1CORE-4: 2000-1000-500/1CORE-5: 2000-1000-500/1.1-CT2B-CTLINE.1-CT2B-CTLINE.1-CT2B-CTLINE

.P1.P2200/ 1AP2 LINESHUNT REACTORP1200/ 1A.. HV BUSHING(400KV SIDE) CTs NEUTRAL BUSHING(STAR PONT SIDE) CTs..P1P2P2P1.LINE SHUNT REACTOR PROTECTION (5CT METHOD).200/ 1A200/ 1ASELECTED BUS-1/ BUS-2/ LINECVT VOLTAGECORE-1: 2000-1000-500/1CORE-2: 2000-1000-500/1CORE-3: 2000-1000-500/1CORE-4: 2000-1000-500/1CORE-5: 2000-1000-500/11-89R1-RCT.2-CT CORE-41-CT CORE-41-LCT CORE-21-LCT CORE-11-CT CORE-52-CT CORE-5.P1.P2.. 1-PH NEUTRAL GROUNDING REACTOR

BUS SHUNT REACTOR PROTECTION (4CT METHOD)3-893-89A3-52CB2-52CB2-89B3-89RBUS-233333CORES54321P1P22A-CT3-CTP1P2BUSBAR CHECKUP PROTP1P2200/ 1AP2 BUS SHUNT REACTOR333CORES123P1200/ 1A.. HV BUSHING CTs(400KV SIDE) NEUTRAL BUSHING CTs(STAR PONT SIDE) 333CORES123...SELECTED BUS-1/ BUS-2 CVT VOLTAGE..TEE DIFFERENTIAL PROTECTION

BUS SHUNT REACTOR PROTECTION (5CT METHOD)3-893-89A3-52CB2-52CB2-89B3-89RBUS-23-CTP1P22-CTP1P23R-CTP1P2TEED-2 PROT (BAY 2&3)TEED-1 PROT (BAY 2&3).BUS BAR PROTECTIONBUSBAR CHECKUP PROT33333CORES12345.P1P2P2 BUS SHUNT REACTOR333CORES123P1200/ 1A.. HV BUSHING CTs(400KV SIDE) NEUTRAL BUSHING CTs(STAR PONT SIDE) 333CORES123..200/ 1ASELECTED BUS-1/ BUS-2 CVT VOLTAGE..

CARRIER INTERTRIPPING OF LINE SHUNT REACTORLINE SHUNT REACTOR PROTECTION TRIPPINGS WILL BE USED AS DIRECT TRIPPINGS OF LINE IN ADDITION TO OTHER TRIPPINGS. BUS SHUNT REACTOR NEED NOT REQUIRE CARRIER INTER TRIPPING FACILITY.87R REACTOR DIFFERENTIAL RELAY 21R REACTOR IMPEDENCE RELAY64R RESTRICTED EARTH FAULT RELAYABBNSD 50DC +VE FROM PANELG4AD V9LC 2DC VE FROM PANELG4AD V9LC 1LINE PROTECTION COUPLER PANEL-1ABBNSD 50DC +VE FROM PANELG4AD V9LC 2DC VE FROM PANELG4AD V9LC 1LINE PROTECTION COUPLER PANEL-2RADHARAKZBRADHDREACTORS INTERNAL FAULTS87R REACTOR DIFFERENTIAL RELAY 21R REACTOR IMPEDENCE RELAY64R RESTRICTED EARTH FAULT RELAYRADHARAKZBRADHDREACTORS INTERNAL FAULTSGROUP-1/A TRIPPINGSGROUP-2/B TRIPPINGS

ADDITIONAL AND SPECIAL FUNCTIONS ADOPTED INONE AND HALF CIRCUIT BREAKERSCHEME (EVENT LOGGER & DISTURBANCE RECORDER)


400KV SUBSTATION: MAMIDIPALLY EVENT LOGGER EVENTS INFORMATION

19 MAR 2004 13:00:00A 13:09:37.090 # 195 400KV SRISAILAM-2 MAIN-2 RAZFE PROT TRIP A 13:09:37.096 # 188 400KV SRISAILAM-2 MAIN-1 REL100 PROT STARTY A 13:09:37.097 # 187 400KV SRISAILAM-2 MAIN-1 REL100 PROT STARTRA 13:09:37.100 # 181 400KV SRISAILAM-2 MAIN-1 REL100 PROT TRIPA 13:09:37.104 # 162 400KV SRISAILAM-2 MAIN CB 752 Y-PH OPENA 13:09:37.110 # 196 400KV SRISAILAM-2 MAIN-2 RAZFE CARRIER SENDA 13:09:37.110 # 170 400KV SRISAILAM-2 AT/F-2 TIE CB 852 B-PH OPENA 13:09:37.111 # 161 400KV SRISAILAM-2 MAIN CB 752 R-PH OPENA 13:09:37.111 # 163 400KV SRISAILAM-2 MAIN CB 752 B-PH OPENA 13:09:37.111 # 169 400KV SRISAILAM-2 AT/F-2 TIE CB 852 Y-PH OPENA 13:09:37.112 # 168 400KV SRISAILAM-2 AT/F-2 TIE CB 852 R-PH OPENA 13:09:37.113 # 182 400KV SRISAILAM-2 MAIN-1 REL100 CARRIER SENDA 13:09:37.126 # 199 400KV SRISAILAM-2 CARRIER PROT CH-2 RECEIVEDA 13:09:37.140 # 185 400KV SRISAILAM-2 CARRIER PROT CH-1 RECEIVEDN 13:09:37.147 # 195 400KV SRISAILAM-2 MAIN-2 RAZFE PROT TRIP RESETN 13:09:37.148 # 196 400KV SRISAILAM-2 MAIN-2 RAZFE CARRIER SEND RESETN 13:09:37.175 # 187 400KV SRISAILAM-2 MAIN-1 REL100 START R RESETN 13:09:37.176 # 181 400KV SRISAILAM-2 MAIN-1 REL100 PROT TRIP RESETN 13:09:37.176 # 188 400KV SRISAILAM-2 MAIN-1 REL100 START Y RESETN 13:09:37.185 # 182 400KV SRISAILAM-2 MAIN-1 REL100 CARRIER SEND RESETN 13:09:37.257 # 199 400KV SRISAILAM-2 CARRIER PROT CH-2 RECEIVED RESETN 13:09:37.279 # 185 400KV SRISAILAM-2 CARRIER PROT CH-1 RECEIVED RESET19 MAR 2004 14:00:00N 14:09:48.702 # 163 400KV SRISAILAM-2 MAIN CB 752 B-PH CLOSEN 14:09:48.704 # 161 400KV SRISAILAM-2 MAIN CB 752 R-PH CLOSEN 14:09:48.720 # 162 400KV SRISAILAM-2 MAIN CB 752 Y-PH CLOSEN 14:10:00.903 # 169 400KV SRISAILAM-2 AT/F-2 TIE CB 852 Y-PH CLOSEN 14:10:00.907 # 168 400KV SRISAILAM-2 AT/F-2 TIE CB 852 R-PH CLOSEN 14:10:00.907 # 170 400KV SRISAILAM-2 AT/F-2 TIE CB 852 B-PH CLOSE19 MAR 2004 15:00:00

R PH VOLTAGEY PH VOLTAGEB PH VOLTAGEOPEN DELTA VOLTAGER PH CURRENTY PH CURRENTB PH CURRENTSTAR/NEUTRAL CURRENTMAIN CB R PH OPENMAIN CB Y PH OPENMAIN CB B PH OPENTIE CB R PH OPENTIE CB Y PH OPENTIE CB B PH OPENMAIN/TIE CB LBB OPTDDIRECT TRIP CH-1/2 OPTDBUSBAR PROT OPTDMAIN-1 PROT OPTDMAIN-2 PROT OPTDOVER VOLTAGE STAGE-1/2 OPTDSTUB PROT-1/2 OPTDMAIN-1 PROT CARRIER RECEIVE MAIN-2 PROT CARRIER RECEIVEDF/DT OPTDEVENT NONAME OF FEEDERDATE & TIMEDISTURBANCE RECORDER

PREFERRED DISTURBANCE RECORDER

CONFIGUARATION OF CONTROL & RELAY PANELS IN ONE AND HALFCIRCUIT BREAKER SCHEME PREPARED BYGOPALA KRISHNA PALEPUADE/MRT(PROTECTION)

CONFIGUARATION OF C & R PANEL

CONFIGUARATION OF C & R PANELIN ADDITION TO THE ABOVE THE FOLLOWING PANELS WILL BE AVAILABLECONTROL PANELS FOR LINE, T/F, B/C, TBC, BUS REACTOR (AS & WHEN REQ)COMMON CONTROL PANELBUS BAR PROTECTION PANELSTRANSFER BUS COUPLER PROTECTION PANEL(IN CASE OF DMT/SMT SCHEME)BUS COUPLER PROTECTION PANEL (IN CASE OF DMT/DB SCHEME)I. NOMINCLATURE FOR PANELS ARE NORMALLYMAIN CB PANEL RLA, TIE CB PANEL RTB, HV CB PANEL RTRA, LV CB PANEL RTRDLINE PROTECTION PANEL RLB, HV PROTECTION PANEL RTRB, LV PROTECTION PANEL RTRC, LINE REACTOR PROTECTION PANEL RLRC, BUS REACTOR PROTECTION PANEL RBRA, BUS BAR PANEL RBBA, CONTROL PANEL CP, KP, KT, KBC, KTBC,KL,CCP

ARRANGEMENT OF C & R PANELSMAIN CB RELAY PANELTIE CB RELAY PANELMAIN CB RELAY PANELLINE-1 PROTECTION PANELLINE-2 PROTECTION PANELMAIN CB RELAY PANELTIE CB RELAY PANELHV CB RELAY PANELLINE PROTECTION PANELMV CB RELAY PANELHV PROTECTION PANELMV PROTECTION PANELMAIN CB RELAY PANELTIE CB RELAY PANELLINE PROTECTION PANELMAIN CB RELAY PANELBUS REACTOR PROT PANELLINE REACTOR PROT PANELTIE CB RELAY PANELLINE PROTECTION PANELMAIN CB RELAY PANELLINE REACTOR PROT PANELHV CB RELAY PANELMV CB RELAY PANELHV PROTECTION PANELMV PROTECTION PANEL

TRIP LOGICS OF ONE AND HALF CIRCUIT BREAKER SCHEMEPREPARED BYGOPALA KRISHNA PALEPUADE/MRT(PROTECTION)

GROUP-A & GROUP-B TRIPPINGS

MAIN CB FOR LINE (1-52CB)TRIPPING LOGICSINITIATE M_CB 1PH TRIP UNIT GR-AINITIATE M_CB 3PH TRIP UNIT GR-AINITIATE M_CB 1PH TRIP UNIT GR-BINITIATE M_CB 3PH TRIP UNIT GR-BINITIATE T_CB 1PH TRIP UNIT GR-AINITIATE T_CB 3PH TRIP UNIT GR-AINITIATE T_CB 1PH TRIP UNIT GR-BINITIATE T_CB 3PH TRIP UNIT GR-BSTART M_CB A/R RELAYSTART T_CB A/R RELAYBLOCK M_CB A/R RELAYBLOCK T_CB A/R RELAY MAIN-1/MAIN-2 CARRIER SENDINITIATE ALARMINITIATE SCADA (DR & SOE)DIRECT TRIP CARRIER SENDINITIATE 400KV B/B PROT

PROTECTION RELAYSYMBOLGROUPOUTPUTMAIN-1 PROTECTION21 M1A1-PHXXXXXXXMAIN-2 PROTECTION21 M2B1-PHXXXXXXXSOTF, PSBIN BUILT FUNCTIONS OF DISTANCE SCHEMEOVER VOLTAGE STAGE-1 & STAGE-2 (BUILT IN 21 M1)59 L1 & L2A3-PHXXXXXXXOVER VOLTAGE STAGE-1 & STAGE-2 (BUILT IN 21 M2)59 L1 & L2B3-PHXXXXXXXSTUB, TOC, BOC, TEF, DEF, (BUILT- IN 21M1) A3-PHXXXXXXXSTUB, TOC, BOC, TEF, DEF, (BUILT- IN 21M2)B3-PHXXXXXXXTEED PROT-187T HZA3-PHXXXXXXXTEED PROT-287T LZB3-PHXXXXXXXDIRECT TRIP CH-1 RECDA3-PHXXXXDIRECT TRIP CH-2 RECDB3-PHXXXXM_CB BFR / LBB PROTB3-PHXXXT_CB BFR / LBB PROTB3-PHXX

MAIN CB FOR LINE (1-52 CB) TRIPPING LOGICSINITIATE T_CB A/R PRIORITYCLOSE MAIN CBTO SCADA (DR & SOE)INITIATE M_C B TRIP COIL-1 INITIATE M_C B TRIP COIL-2START LBB/BFR M_C B89LE C LOSE PERMISSIONINITIATE ALARM

PROTECTION RELAYSYMBOLGROUPOUTPUTAUTO RECLOSURE RELAY (BUILT IN 21M1 & 21M2)79 A/RA&B1-PH & 3-PHXXXXSYNC CHECK RELAY(BUILT IN 21M1 & 21M2)25 SYNCA&B3-PHXXXX1-PH TRIP UNIT GR-A186A1-PHXXX3-PH TRIP UNIT GR-A86 GR AA3-PHXXXXX1-PH TRIP UNIT GR-B286B1-PHXXX3-PH TRIP UNIT GR-B86 GR BB3-PHXXXXXTRIP SIGNAL FROM 400KV BUSBAR PROTECTION96 BB3-PHXXXLINE UNDER VOLTAGE RELAY27 UVX

TIE CB TRIPPING LOGICSINITIATE M_CB 1PH TRIP UNIT GR-AINITIATE M_CB 3PH TRIP UNIT GR-AINITIATE M_CB 1PH TRIP UNIT GR-BINITIATE M_CB 3PH TRIP UNIT GR-BINITIATE T_CB 1PH TRIP UNIT GR-AINITIATE T_CB 3PH TRIP UNIT GR-AINITIATE T_CB 1PH TRIP UNIT GR-BINITIATE T_CB 3PH TRIP UNIT GR-BINITIATE ALARMINITIATE SCADA (DR & SOE)DIRECT TRIP CARRIER SENDINITIATE M_CB 1PH TRIP UNIT GR-AINITIATE M_CB 3PH TRIP UNIT GR-AINITIATE M_CB 1PH TRIP UNIT GR-BINITIATE M_CB 3PH TRIP UNIT GR-B152252152152152252252252352352352352INITIATE T_CB TRIPCOIL-1 & COIL-2START LBB/BFR OF T_CB252252CLOSE T_CB252

PROTECTION RELAYSYMBOLGROUPOUTPUT

T_CB BFR / LBB PROT50 ZTB3-PHXXXXXM_CB BFR / LBB PROT(152 CB & 352 CB)50 ZB3-PHXXXXAUTO RECLOSURE RELAY79 A/RA&B1-PH &3-PHXXXSYNC CHECK RELAY253-PHXXX1-PH TRIP UNIT GR-A186A1-PHXX3-PH TRIP UNIT GR-A86AA3-PHXXXX1-PH TRIP UNIT GR-B286B1-PHXX3-PH TRIP UNIT GR-B86BB3-PHXXXXDIRECT TRIP CH-1 RECDA3-PHXDIRECT TRIP CH-2 RECDB3-PHX

MAIN CB FOR AT/F (3-52CB)TRIPPING LOGICSINITIATE M_CB 3PH TRIP UNIT GR-AINITIATE M_CB 3PH TRIP UNIT GR-BINITIATE T_CB 3PH TRIP UNIT GR-AINITIATE T_CB 3PH TRIP UNIT GR-BINITIATE ALARMINITIATE SCADA ( SOE)INTER TRIP CIRCUIT HV & LVINITIATE 400KV B/B PROTINITIATE LV_CB 3PH TRIP UNIT GR-AINITIATE LV_CB 3PH TRIP UNIT GR-BINITIATE M_CB TRIP COIL-1INITIATE M_CBTRIP COIL-2INITIATE 220KV B/B PROTSTART M_CB LBB/BFR RELAYSTART LV_CB LBB/BFR RELAYINITIATE LV_CB TRIP COIL-1INITIATE LV_CBTRIP COIL-2

PROTECTION RELAYSYMBOLGROUPOUTPUTDIFFERENTIAL RELAY87T(LZ)A3-PHXXXXXXHV BACKUP PROTECTION67 ABCNA3-PHXXXXXXHV OVER FLUX PROT99T HVA3-PHXXXXXXOVER LOAD RELAY51 O/LA3-PHXXXXXXHV PROT TRIP UNIT GR-A & B86 GR-A/BA/B3-PHXXXXXXXREF PROTECTION64T(HZ)B3-PHXXXXXXTEED PROT-1 / 287T HZ/LZA/B3-PHXXXXXXXXXXXSTUB PROT50 STUBA3-PHXXXXXXAT/F TROUBLE TRIP HV & LV86 GR-A/BA/B3-PHXXXXXXXXXAT/F TROUBLE ALRMXXM_CB BFR / LBB PROT50ZB3-PHXXXXXXT_CB BFR / LBB PROT50ZTB3-PHXXXXXXLV_CB BFR / LBB PROT50ZB3-PHXXXXXXX400KV B/B PROT87 BB963-PHXXXXX220KV B/B PROT87 BB963-PHXXXXXXLV BACKUP PROTECTION67 ABCNB3-PHXXXXXXLV OVER FLUX PROT99T LVB3-PHXXXXXX TERI NEUTRAL DISP PROT151NA3-PHXXXXXXLV PROT TRIP UNIT GR-A & B86 GR-A/BA/B3-PHXXXXXXX

PROTECTION TRIP SCHEMEBUS-1BUS-21-52CB3-52CB2-52CB86-AMTR/HSTRABB REL521MAIN-186-BMTR/HSTR86-BMTR/HSTR86-AMTR/HSTR86-BMTR/HSTR86-AMTR/HSTRABBREL521MAIN-1ABBREL316MAIN-2ABBRET521MAIN-1ABBRET316MAIN-2TRIP COIL-1TRIP COIL-1TRIP COIL-1TRIP COIL-2TRIP COIL-2TRIP COIL-286-A : GROUP-A MASTER TRIP RELAY / HIGH SPEED TRIP RELAY 86-B : GROUP-B MASTER TRIP RELAY / HIGH SPEED TRIP RELAY

MAIN-1/ MAIN-2ZONE-1 & SINGLE PHASE FAULT INITIATE MAIN CB GR-A 1-PH TRIP UNIT ( INTURN IT WILL TRIP 1-POLE ) INITIATE TIE CB GR-A 1-PH TRIP UNIT ( INTURN IT WILL TRIP 1-POLE ) TO EVENT RECORDER ( SOE/ SCADA ) TO DISTURBANCE RECORDER START MAIN CB AUTO RECLOSURE START TIE CB AUTO RECLOSURE CARRIER SEND INITIATE FLAG RELAY (INTURN FLAG RELAY OPERATES) INITIATE ALARM (ANNUNCIATION COME) INITIATE MAIN CB GR-B 1-PH TRIP UNIT ( INTURN IT WILL TRIP 1-POLE ) INITIATE TIE CB GR-B 1-PH TRIP UNIT ( INTURN IT WILL TRIP 1-POLE ) TO EVENT RECORDER ( SOE/ SCADA ) TO DISTURBANCE RECORDER START MAIN CB AUTO RECLOSURE START TIE CB AUTO RECLOSURE CARRIER SEND INITIATE FLAG RELAY (INTURN FLAG RELAY OPERATES) INITIATE ALARM (ANNUNCIATION COME) TO LBB/BFR INITIATION TO LBB/BFR INITIATION

AUTO RECLOSURECONDITIONS REQUIRED FOR A/R OPERATIONCB CLOSE CONDITION.TIME LAPSED MORE THAN RECLAIM TIME.OPERATING PRESSURE OF CB SUITABLE FOR AUTORECLOSUREOPERATION.DC SUPPLY TO AUTORECLOSURE SHOULD BE AVAILABLE. PREPARE 3-PH TRIP RELAY SHOULD BE RELEASED CONDITION.NO BLOCKING SIGNAL TO AUTORECLOSURE RELAY.POLE DISTURBANCE RELAY TIME SHOULD BE MORE THANTWICE OF DEAD TIME OF AUTO RECLOSURE.CARRIER FAIL SIGNAL SHOULD NOT COME AT BOTH ENDS.CARRIER SWITCH SHOULD BE IN SERVICE CONDITION.SINGLE PHASE & ZONE-1 FAULT ONLY.AUTO RECLOSURE OPERATIONTRIP MAIN CB SINGLE POLE.TRIP TIE CB SINGLE POLE.CLOSE MAIN CB AFTER DEAD TIME.IF A/R SUCCESS FOR MAIN CB THEN AFTER SUPPLEMENTARY TIME DELAY CLOSE TIE CB.(NORMALLY SUPPLEMENTARY TIME DELAY IS DEAD TIME)IF A/R UNSUCCESS THEN TRIP MAIN & TIE CBs.IF MAIN CB OPEN CONDITION, THEN NO SUPPLEMENTARY DELAY TIME FOR TIE A/R. IT WILL OPERATE ITs OWN DEAD TIME.

MAIN-1/ MAIN-2ZONE-1 & TWO / THREE PHASE FAULT INITIATE MAIN CB GR-A 1-PH TRIP UNITS ( INTURN IT WILL TRIP 3-POLES ) INITIATE TIE CB GR-A 1-PH TRIP UNITS ( INTURN IT WILL TRIP 3-POLES ) TO EVENT RECORDER ( SOE/ SCADA ) TO DISTURBANCE RECORDER BLOCK MAIN CB AUTO RECLOSURE BLOCK TIE CB AUTO RECLOSURE CARRIER SEND INITIATE FLAG RELAY (INTURN FLAG RELAY OPERATES) INITIATE ALARM (ANNUNCIATION COME) INITIATE MAIN CB GR-B 1-PH TRIP UNITS ( INTURN IT WILL TRIP 3-POLES ) INITIATE TIE CB GR-B 1-PH TRIP UNITS ( INTURN IT WILL TRIP 3-POLES ) TO EVENT RECORDER ( SOE/ SCADA ) TO DISTURBANCE RECORDER BLOCK MAIN CB AUTO RECLOSURE BLOCK TIE CB AUTO RECLOSURE CARRIER SEND INITIATE FLAG RELAY (INTURN FLAG RELAY OPERATES) INITIATE ALARM (ANNUNCIATION COME) TO LBB/BFR INITIATION TO LBB/BFR INITIATION

MAIN-1/ MAIN-2ZONE-2 & 1 / 2 / 3 PHASE FAULT INITIATE MAIN CB GR-A 1-PH TRIP UNITS ( INTURN IT WILL TRIP 3-POLES ) INITIATE TIE CB GR-A 1-PH TRIP UNITS ( INTURN IT WILL TRIP 3-POLES ) TO EVENT RECORDER ( SOE/ SCADA ) TO DISTURBANCE RECORDER BLOCK MAIN CB AUTO RECLOSURE BLOCK TIE CB AUTO RECLOSURE INITIATE FLAG RELAY (INTURN FLAG RELAY OPERATES) INITIATE ALARM (ANNUNCIATION CAME) INITIATE MAIN CB GR-B 1-PH TRIP UNITS ( INTURN IT WILL TRIP 3-POLES ) INITIATE TIE CB GR-B 1-PH TRIP UNITS ( INTURN IT WILL TRIP 3-POLES ) TO EVENT RECORDER ( SOE/ SCADA ) TO DISTURBANCE RECORDER BLOCK MAIN CB AUTO RECLOSURE BLOCK TIE CB AUTO RECLOSURE CARRIER SEND ( IF PUTT OR2 SCHEME SELECTED ) INITIATE FLAG RELAY (INTURN FLAG RELAY OPERATES) INITIATE ALARM (ANNUNCIATION COME)CARRIER SIGNAL RECEIVED & ZONE-2 STARTER IS PICKUP CONDITION CARRIER SIGNAL RECEIVED & ZONE-2 STARTER IS PICKUP CONDITION TO LBB/BFR INITIATION TO LBB/BFR INITIATION

MAIN-1/ MAIN-2ZONE- 3/4/5 & 1 / 2 / 3 PHASE FAULT INITIATE MAIN CB GR-A 1-PH TRIP UNITS ( INTURN IT WILL TRIP 3-POLES ) INITIATE TIE CB GR-A 1-PH TRIP UNITS ( INTURN IT WILL TRIP 3-POLES ) TO EVENT RECORDER ( SOE/ SCADA ) TO DISTURBANCE RECORDER BLOCK MAIN CB AUTO RECLOSURE BLOCK TIE CB AUTO RECLOSURE INITIATE FLAG RELAY (INTURN FLAG RELAY OPERATES) INITIATE ALARM (ANNUNCIATION CAME) INITIATE MAIN CB GR-B 1-PH TRIP UNITS ( INTURN IT WILL TRIP 3-POLES ) INITIATE TIE CB GR-B 1-PH TRIP UNITS ( INTURN IT WILL TRIP 3-POLES ) TO EVENT RECORDER ( SOE/ SCADA ) TO DISTURBANCE RECORDER BLOCK MAIN CB AUTO RECLOSURE BLOCK TIE CB AUTO RECLOSURE INITIATE FLAG RELAY (INTURN FLAG RELAY OPERATES) INITIATE ALARM (ANNUNCIATION COME) TO LBB/BFR INITIATION TO LBB/BFR INITIATION

DISTANCE SCHEME TRIPPING OUTPUTSMAIN CBTIE CBCOCO186 R186 Y186 BTO TRIP COIL-1TO TRIP COIL-2TO TRIP COIL-1TO TRIP COIL-2TO TRIP COIL-1TO TRIP COIL-2186 R186 Y186 BTO TRIP COIL-1TO TRIP COIL-2TO TRIP COIL-1TO TRIP COIL-2TO TRIP COIL-1TO TRIP COIL-2CO286 R286 Y286 BTO TRIP COIL-1TO TRIP COIL-2TO TRIP COIL-1TO TRIP COIL-2TO TRIP COIL-1TO TRIP COIL-2CO286 R286 Y286 BTO TRIP COIL-1TO TRIP COIL-2TO TRIP COIL-1TO TRIP COIL-2TO TRIP COIL-1TO TRIP COIL-2

MAIN LBB INITIATE BUSBAR PROTECTION ( INTURN IT WILL TRIP CONNECTED BUS CBs) INITIATE TIE CB 86-GR-B 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES ) TO EVENT RECORDER ( SOE/ SCADA ) TO DISTURBANCE RECORDER BLOCK MAIN CB & TIE CB AUTO RECLOSURE INITIATE FLAG RELAY (INTURN FLAG RELAY OPERATES) INITIATE ALARM (ANNUNCIATION COME) INITIATE MAIN CB 86-GR-B 3-PH TRIP UNIT (TRIP BAY1 CB 3-POLES ) INITIATE MAIN CB 86-GR-B 3-PH TRIP UNIT ( TRIP BAY3 CB 3-POLES ) TO EVENT RECORDER ( SOE/ SCADA ) TO DISTURBANCE RECORDER (BAY1 & BAY3) BLOCK MAIN CB OF BAY1 & BAY3 AUTO RECLOSURE INITIATE FLAG RELAY (INTURN FLAG RELAY OPERATES) INITIATE ALARM (ANNUNCIATION COME) CLOSE INTERLOCK OF MAIN CB & TIE CB CLOSE INTERLOCK OF TIE CB BLOCK TIE CB AUTO RECLOSURE CLOSE INTERLOCK OF MAIN CB OF BAY1 & BAY 3 DIRECT TRANSFER TRIP-1 CARRIER SEND TO OTHER END DIRECT TRANSFER TRIP-2 CARRIER SEND TO OTHER ENDINITIATION 1-PH TRIP RELAYS OF MAIN-1 PROTECTION 1-PH TRIP RELAYS OF MAIN-2 PROTECTION 86-GR-AMASTER TRIP RELAY 86-GR-BMASTER TRIP RELAY96 BB BUSBAR RELAYTIE LBBINITIATION 1-PH TRIP RELAYS OF MAIN-1 PROTECTION OF LINE-1(BAY1) & LINE-2 (BAY3) 1-PH TRIP RELAYS OF MAIN-2 PROTECTIONOF LINE-1 (BAY1) &LINE-2 (BAY 3) 86-GR-AMASTER TRIP RELAY 86-GR-BMASTER TRIP RELAY DIRECT TRANSFER TRIP-1 CARRIER SEND TO BAY1 & BAY3 LINES DIRECT TRANSFER TRIP-2 CARRIER SEND TO BAY1 & BAY3 LINES

BUS BAR PROTECTION

INITIATE ALL CBs TRIP UNITS CONNECTED TO THIS BUS AND OPERATE. TO TRIP COIL-1 CONCERNED BAY CB TO EVENT RECORDER ( SOE/ SCADA ) TO DISTURBANCE RECORDER OF MAIN-1 TO TRIP COIL-2 CONCERNED BAY CB TO CLOSE CIRCUIT INTERLOCK OF CONCERN CB DIRECT TRIP SEND CHANNEL-1 TO OTHER END DIRECT TRIP SEND CHANNEL-2 TO OTHER END INITIATE ALARM (ANNUNCIATION COME)TO LBB/BFR INITIATION TO DISTURBANCE RECORDER OF MAIN-2FROM LBB/BFR TO BUS BAR TRIPPING INITIATE ALL CBs TRIP UNITS CONNECTED TO THIS BUS AND OPERATE. TO TRIP COIL-1 CONCERNED BAY CB TO EVENT RECORDER ( SOE/ SCADA ) TO DISTURBANCE RECORDER OF MAIN-1 TO TRIP COIL-2 CONCERNED BAY CB TO CLOSE CIRCUIT INTERLOCK OF CONCERN CB DIRECT TRIP SEND CHANNEL-1 TO OTHER END DIRECT TRIP SEND CHANNEL-2 TO OTHER END INITIATE ALARM (ANNUNCIATION COME)TO LBB/BFR INITIATION TO DISTURBANCE RECORDER OF MAIN-2FROM LBB/BFR TO BUS BAR TRIPPING

STUB PROTECTION INITIATE MAIN CB 86-GR-A 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES ) INITIATE TIE CB 86-GR-A 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES ) TO EVENT RECORDER ( SOE/ SCADA ) TO DISTURBANCE RECORDER BLOCK MAIN CB AUTO RECLOSURE INITIATE FLAG RELAY (INTURN FLAG RELAY OPERATES) INITIATE ALARM (ANNUNCIATION COME) INITIATE MAIN CB 86-GR-B 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES ) INITIATE TIE CB 86-GR-B 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES ) TO EVENT RECORDER ( SOE/ SCADA ) TO DISTURBANCE RECORDER BLOCK MAIN CB AUTO RECLOSURE INITIATE FLAG RELAY (INTURN FLAG RELAY OPERATES) INITIATE ALARM (ANNUNCIATION COME)LINE /AT/FISOLATOROPENS CLOSE INTERLOCK OF TIE CB CLOSE INTERLOCK OF TIE CB BLOCK TIE CB AUTO RECLOSURE CLOSE INTERLOCK OF MAIN CB BLOCK TIE CB AUTO RECLOSURE CLOSE INTERLOCK OF MAIN CBLINE /AT/FISOLATOROPENS

TEED PROTECTION INITIATE MAIN CB 86-GR-A 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES ) INITIATE TIE CB 86-GR-A 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES ) TO EVENT RECORDER ( SOE/ SCADA ) TO DISTURBANCE RECORDER BLOCK MAIN CB AUTO RECLOSURE INITIATE FLAG RELAY (INTURN FLAG RELAY OPERATES) INITIATE ALARM (ANNUNCIATION COME) INITIATE MAIN CB 86-GR-B 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES ) INITIATE TIE CB 86-GR-B 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES ) TO EVENT RECORDER ( SOE/ SCADA ) TO DISTURBANCE RECORDER BLOCK MAIN CB AUTO RECLOSURE INITIATE FLAG RELAY (INTURN FLAG RELAY OPERATES) INITIATE ALARM (ANNUNCIATION COME) CLOSE INTERLOCK OF TIE CB CLOSE INTERLOCK OF TIE CB BLOCK TIE CB AUTO RECLOSURE CLOSE INTERLOCK OF MAIN CB BLOCK TIE CB AUTO RECLOSURE CLOSE INTERLOCK OF MAIN CB

MAIN-1/ MAIN-2OVER VOLTAGE STAGE-1 INITIATE MAIN CB 86-GR-A 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES ) INITIATE TIE CB 86-GR-A 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES ) TO EVENT RECORDER ( SOE/ SCADA ) TO DISTURBANCE RECORDER BLOCK MAIN CB & TIE CB AUTO RECLOSURE DIRECT TRANSFER TRIP-1 CARRIER SEND TO OTHER END DIRECT TRANSFER TRIP-2 CARRIER SEND TO OTHER END INITIATE FLAG RELAY (INTURN FLAG RELAY OPERATES) INITIATE ALARM (ANNUNCIATION COME) INITIATE MAIN CB 86-GR-B 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES ) INITIATE TIE CB 86-GR-a 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES ) TO EVENT RECORDER ( SOE/ SCADA ) TO DISTURBANCE RECORDER BLOCK MAIN CB & TIE CB AUTO RECLOSURE DIRECT TRANSFER TRIP-1 CARRIER SEND TO OTHER END DIRECT TRANSFER TRIP-2 CARRIER SEND TO OTHER END INITIATE FLAG RELAY (INTURN FLAG RELAY OPERATES) INITIATE ALARM (ANNUNCIATION COME)110% OF V4 SECS FOR FEEDER-15 SECS FOR FEEDER-2 110% OF V4 SECS FOR FEEDER-15 SECS FOR FEEDER-2 CLOSE INTERLOCK OF MAIN CB & TIE CB CLOSE INTERLOCK OF MAIN CB & TIE CB

OVER VOLTAGE STAGE-2 INITIATE MAIN CB 86-GR-B 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES ) INITIATE TIE CB 86-GR-B 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES ) TO EVENT RECORDER ( SOE/ SCADA ) TO DISTURBANCE RECORDER (MAIN-1 & MAIN-2) BLOCK MAIN CB & TIE CB AUTO RECLOSURE DIRECT TRANSFER TRIP-1 CARRIER SEND TO OTHER END DIRECT TRANSFER TRIP-2 CARRIER SEND TO OTHER END INITIATE FLAG RELAY (INTURN FLAG RELAY OPERATES) INITIATE ALARM (ANNUNCIATION COME) LINE EARTH SWITCH CLOSE PERMISSION ONLY.120% OF V20m SECS1O% OF V CLOSE INTERLOCK OF MAIN CB & TIE CBUNDER VOLTAGE RELAY

CARRIER TRIPPING SCHEMES(TELEPROTECTION)

CARRIER TRIPPING SCHEMES(TELEPROTECTION) DIRECT TRIP SEND CH-2MAIN CB 86-BTIE CB 86-B DIRECT TRIP SEND CH-2MAIN CB 86-BTIE CB 86-B DIRECT TRIP SEND CH-1MAIN CB 86-ATIE CB 86-A DIRECT TRIP SEND CH-1MAIN CB 86-ATIE CB 86-A ONE ENDOTHER END21 M1 REL 52121 M1 REL 52121 M2REL 31621 M2REL 316PT : PERMISSIVE PROTECTION TRANSFER TRIPDT : DIRECT TRANSFER TRIP

DIRECT TRANSFER TRIP CHANNEL 1 / 2 RECEIVED INITIATE MAIN CB 86-GR-A 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES ) INITIATE TIE CB 86-GR-A 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES ) TO EVENT RECORDER ( SOE/ SCADA ) TO DISTURBANCE RECORDER BLOCK MAIN CB AUTO RECLOSURE INITIATE FLAG RELAY (INTURN FLAG RELAY OPERATES) INITIATE ALARM (ANNUNCIATION COME) INITIATE MAIN CB 86-GR-B 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES ) INITIATE TIE CB 86-GR-B 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES ) TO EVENT RECORDER ( SOE/ SCADA ) TO DISTURBANCE RECORDER BLOCK MAIN CB AUTO RECLOSURE INITIATE FLAG RELAY (INTURN FLAG RELAY OPERATES) INITIATE ALARM (ANNUNCIATION COME)DIRECT TRIP CHANNEL-1RECEIVEDDIRECT TRIPCHANNEL-2RECEIVED. CLOSE INTERLOCK OF TIE CB CLOSE INTERLOCK OF TIE CB BLOCK TIE CB AUTO RECLOSURE CLOSE INTERLOCK OF MAIN CB BLOCK TIE CB AUTO RECLOSURE CLOSE INTERLOCK OF MAIN CB

86-GA & 86 GB MASTER TRIP / HIGH SPEED TRIP LOCKOUT RELAY OPERATION86-GBMASTERTRIP /HIGH SPEEDTRIPRELAY86-GAMASTERTRIP /HIGH SPEEDTRIPRELAY86-GBMASTERTRIP /HIGH SPEEDTRIPRELAY86-GAMASTERTRIP /HIGH SPEEDTRIPRELAYTRIP COIL-2 MAIN CB TRIP COIL -1TRIP COIL-1 TIE CB TRIP COIL -2OVER VOLTAGE STAGE-1(INBUILT MAIN-1)OVER VOLTAGE STAGE-1( IN BUILT MAIN-2 )DIRECT TRIP CHANNEL-1RECEIVEDDIRECT TRIP CHANNEL-2RECEIVED SOTF PROTECTION (INBUILT MAIN-1) SOTF PROTECTION ( IN BUILT MAIN-2 )OVER VOLTAGE STAGE-2 DEF,TOC, BOC, STUB (INBUILT MAIN-1) DEF, TOC, BOC, STUB ( IN BUILT MAIN-2 ) MAIN LBB OPERATED TIE LBB OPERATED TEED-1 PROTECTION TEED-2 PROTECTION

MASTER TRIP RELAYS HIGH SPEED TRIP RELAYSLOCKOUT RELAYS86-GBMASTERTRIP /HIGH SPEEDTRIPRELAY86-GAMASTERTRIP /HIGH SPEEDTRIPRELAYPUSH BUTTON FOR RESETTING. TO CLOSING INTERLOCK OF CONCERNED BAY CB TO INITIATE LBB/BFR OF CONCERNED BAY TO EVENT RECORDER ( SOE/ SCADA ) TO DISTURBANCE RECORDER (MAIN-1 & MAIN-2) INITIATE FLAG RELAY (FLAG RELAY OPERATES) INITIATE ALARM (ANNUNCIATION COME) BLOCK AUTO RECLOSURE OF CONCERNED BAY TO TRIP COIL-1 CONCERNED BAY CB TO TRIP COIL-2 CONCERNED BAY CBPUSH BUTTON FOR RESETTING. TO INITIATE LBB/BFR OF CONCERNED BAY TO EVENT RECORDER ( SOE/ SCADA ) TO DISTURBANCE RECORDER (MAIN-1 & MAIN-2) INITIATE FLAG RELAY (FLAG RELAY OPERATES) INITIATE ALARM (ANNUNCIATION COME) BLOCK AUTO RECLOSURE OF CONCERNED BAY TO TRIP COIL-1 CONCERNED BAY CB TO TRIP COIL-2 CONCERNED BAY CB TO CLOSING INTERLOCK OF CONCERNED BAY CB

TRANSFORMER PROTECTION(DIFFERENCIAL & REF / 3-PH HZ DIFF PROTECTION) INITIATE 400KV MAIN CB GR-A 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES ) INITIATE 400KV TIE CB GR-A 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES ) TO EVENT RECORDER ( SOE/ SCADA ) INITIATE FLAG RELAY (INTURN FLAG RELAY OPERATES) INITIATE ALARM (ANNUNCIATION COME) TO EVENT RECORDER ( SOE/ SCADA ) INITIATE FLAG RELAY (INTURN FLAG RELAY OPERATES) INITIATE ALARM (ANNUNCIATION COME)87 T(LZ) INITIATE 220KV MAIN CB GR-A 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES ) INITIATE 220KV TBC CB GR-A 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES ) 64 REFOR87 T(HZ) INITIATE 400KV MAIN CB GR-B 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES ) INITIATE 400KV TIE CB GR-B 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES ) INITIATE 220KV MAIN CB GR-B 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES ) INITIATE 220KV TBC CB GR-B 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES )

TRANSFORMER PROTECTION( BACKUP DIRECTIONAL O/L & E/F PROTECTION FOR HV & LV) INITIATE 400KV MAIN CB GR-A 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES ) INITIATE 400KV TIE CB GR-A 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES ) TO EVENT RECORDER ( SOE/ SCADA ) INITIATE FLAG RELAY (INTURN FLAG RELAY OPERATES) INITIATE ALARM (ANNUNCIATION COME) TO EVENT RECORDER ( SOE/ SCADA ) INITIATE FLAG RELAY (INTURN FLAG RELAY OPERATES) INITIATE ALARM (ANNUNCIATION COME)67 HV ABCN INITIATE 220KV MAIN CB GR-A 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES ) INITIATE 220KV TBC CB GR-A 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES ) 67 LVABCN INITIATE 400KV MAIN CB GR-B 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES ) INITIATE 400KV TIE CB GR-B 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES ) INITIATE 220KV MAIN CB GR-B 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES ) INITIATE 220KV TBC CB GR-B 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES )

TRANSFORMER PROTECTION ( OVER FLUX PROTECTION FOR HV & LV) INITIATE 400KV MAIN CB GR-A 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES ) INITIATE 400KV TIE CB GR-A 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES ) TO EVENT RECORDER ( SOE/ SCADA ) INITIATE FLAG RELAY (INTURN FLAG RELAY OPERATES) INITIATE ALARM (ANNUNCIATION COME) TO EVENT RECORDER ( SOE/ SCADA ) INITIATE FLAG RELAY (INTURN FLAG RELAY OPERATES) INITIATE ALARM (ANNUNCIATION COME)99T HV INITIATE 220KV MAIN CB GR-A 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES ) INITIATE 220KV TBC CB GR-A 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES ) 99T LV INITIATE 400KV MAIN CB GR-B 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES ) INITIATE 400KV TIE CB GR-B 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES ) INITIATE 220KV MAIN CB GR-B 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES ) INITIATE 220KV TBC CB GR-B 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES )

OVER VOLTAGE (LINE) AND OVER FLUX(TRANSFORMER ) PROTECTION TRIP SCHEMEBUS-1BUS-21-52CB3-52CB2-52CB86-AMTR/HSTRABB REL521MAIN-186-BMTR/HSTR86-BMTR/HSTR86-AMTR/HSTR86-BMTR/HSTR86-AMTR/HSTRABBO/V 1O/V 2ABBO/V 1O/V 2ABBRALKO/F- HVABBRATUBO/F- LVTRIP COIL-1TRIP COIL-1TRIP COIL-1TRIP COIL-2TRIP COIL-2TRIP COIL-2(BAY 1&2)(BAY 1&2)(BAY 2&3 / HV)(BAY LV)LV - CB86-BMTR/HSTR86-AMTR/HSTRTRIP COIL-2TRIP COIL-1OVER VOLTAGE STAGE-1 & STAGE-2 ARE IN BUILT FUNCTIONS OF MAIN-1 & MAIN-2 NUMERICAL RELAYS. IF EXTERNAL RELAYS ARE UTILISED THEN STAGE-1 IS GR-A & STAGE-2 IS GR-B TRIPPING IS TO UTILISED.

TRANSFORMER PROTECTION INITIATE 400KV MAIN CB GR-A 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES ) INITIATE 400KV TIE CB GR-A 3-PH TRIP UNIT ( INTURN IT WILL TRIP 3-POLES ) TO EVENT RECORDER ( SOE/ SCADA ) INITIATE FLAG RELAY (INTURN FLAG RELAY OPERATES) INITIATE ALARM (ANNUNCIATION COME) TO EVENT RECORDER ( SOE/ SCADA ) INITIATE FLAG RELAY (INTURN FLAG RELAY OPERATES) INITIATE ALARM (ANNUNCIATION COME)51 O/L INITIATE 220KV MAIN CB GR-A 3-PH TRIP UNI

400kv protection

Documents

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