Plant electrical system :1 Plant electrical system Presented by GT Team


EQUIPMENTS IN THE SYSTEM :2 EQUIPMENTS IN THE SYSTEM GENERATOR GT TRANSFORMER CURRENT TRANSFORMER CAPACITIVE VOLTAGE TRANSFORMER ISOLATOR LIGHTNING ARRESTOR


INTRODUCTION OF THE EQUIPMENTSGENERATOR TRANSFORMER :3 INTRODUCTION OF THE EQUIPMENTSGENERATOR TRANSFORMER THE GENERATOR TRANSFORMER IS USED FOR STEP-UP & STEP-DOWN THE LINE VOLTAGE. THE GENERATOR TRANSFORMER USED AT OUR SITE 10.5KV / 230KV STEP UP / STEP DOWN ONAN / ONAF


INTRODUCTION OF THE EQUIPMENTSCurrent Transformer :4 INTRODUCTION OF THE EQUIPMENTSCurrent Transformer THE CURRENT TRANSFORMER IS A DEVICE USED FOR MEASURING CURRENT & PROTECTION CIRCUIT. THE CURRENT TRANSFORMER USED AT OUR SITE (220KV Line) IS 600/1A. THE CT HAS 4 CORES, WHERE 3 OF THEM ARE USED FOR PROTECTION & ONE IS SPARE.


INTRODUCTION OF THE EQUIPMENTS Capacitive Voltage Transformer :5 INTRODUCTION OF THE EQUIPMENTS Capacitive Voltage Transformer THIS IS A DEVICE USED FOR MEASURING VOLTAGE & PROTECTION CIRCUITS. ABB IS THE MANUFACTURER OF THESE TRANSFORMERS.


INTRODUCTION OF THE EQUIPMENTS Isolator :6 INTRODUCTION OF THE EQUIPMENTS Isolator THIS USED FOR ISOLATION OF THE CIRCUIT WHEN REQUIRED. THE CAPACITY OF THE ISOLATOR USED IS 220KV, 1250A, 3PHASE, CENTRE POST, UNDERHUNG TYPE ROTATING DOUBLE BREAK ISOLATOR.


INTRODUCTION OF THE EQUIPMENTS Isolator Earth Switch :7 INTRODUCTION OF THE EQUIPMENTS Isolator Earth Switch THIS USED FOR EARTHING OF THE ISOLATOR DURING THE SHUTDOWN PERIOD FOR SAFE WORKING. THERE ARE TWO EARTH SWITCHES ONE IS USED FOR ‘BUS EARTHING’, & THE 2ND.ONE IS USED FOR THE TRANSFORMER SIDE EARTHING.


INTRODUCTION OF THE EQUIPMENTS LIGHTNING ARRESTOR :8 INTRODUCTION OF THE EQUIPMENTS LIGHTNING ARRESTOR THIS IS USED FOR PROTECTION FROM HIGH VOLTAGE SURGE WHICH MAY AFFECT THE HIGH VOLTAGE EQUIPMENTS SUCH AS POWER TRANSFORMER, BREAKERS ETC.


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THE MAIN FUNCTION OF THE ELECTRICAL SYSTEM…. :10 THE MAIN FUNCTION OF THE ELECTRICAL SYSTEM…. …IS TO INTEGRATE GENERATED POWER AESK CCPP GENERATORS, TO THE 220KV GIS OF CEB. …IS TO DISTRIBUTE POWER TO THE PLANT AUXILIARIES UNDER THE NORMAL STARTUP, RUNNING AND EMERGENCY CONDITIONS.


INTRODUCTION OF THE SYSTEMS GENERATION SYSTEM :11 INTRODUCTION OF THE SYSTEMS GENERATION SYSTEM COMPRISING OF THE GAS TURBINE & STEAM TURBINE GENERATORS, GENERATOR CIRCUIT BREAKERS, AND THE ISOPHASE BUSDUCT CONNECTIONS UPTO THE GENERATOR TRANSFORMERS AND TAP OFF TO THE UNIT TRANSFORMERS.


INTRODUCTION OF THE SYSTEMSPower evacuation System… :12 INTRODUCTION OF THE SYSTEMSPower evacuation System… ….COMPRISING OF THE GENERATOR STEP UP TRANSFORMERS, THE 220KV SWITCHYARD EQUIPMENTS, AND THE 220KV – CABLE UP TO GIS END.


THE BASIC ELECTRICAL SYSTEM :13 THE BASIC ELECTRICAL SYSTEM DURING THE STARTUP – POWER WILL BE DERIVED BY ENERGIZING 6.6KV SWITCHGEAR THROUGH THE GENERATOR TRANSFORMER & UNIT TRANSFORMER WHILE GENERATOR CIRCUIT BREAKER OPEN. .


…THE BASIC ELECTRICAL SYSTEM :14 …THE BASIC ELECTRICAL SYSTEM GCB WILL BE CLOSED ON SYNCHRONIZATION. THE GT & STG GENERATING POWER AT 10.5KV LEVEL ARE CONNECTED TO THEIR RESPECTIVE GENERATOR STEPUP TRANSFORMERS BY MEANS OF ISOLATED PHASE BUSDUCTS TO A COMMON 220KV BUS & POWER IS EVACUATED BY MEANS OF A 220KV CABLE CONNECTION FROM 220KV BUS TO THE CEB’S GIS.


…THE BASIC ELECTRICAL SYSTEM - LOCAL :15 …THE BASIC ELECTRICAL SYSTEM - LOCAL POWER IS TAPPED FROM THE GENERATORS BY MEANS OF UNIT TRANSFORMERS, 10.5/6.9KV, BY MEANS OF A CABLE, DIRECTLY TO FEED PLANT AUXs. RATED FOR 6.6KV VOLTAGE LEVEL (160 KW & ABOVE), BY MEANS OF 6.6KV SWITCH GEAR.


THE BASIC ELECTRICAL SYSTEM - LOCAL :16 THE BASIC ELECTRICAL SYSTEM - LOCAL POWER IS BEEN DERIVED FROM 6.6 KV SWITCHGEAR BY MEANS OF 4 ‘STATION AUXILIARY TRANSFORMERS’ TO FEED THE AUXs. RATED FOR 415V. THE AUXs. AT 415V ARE FED THROUG TWO 415V SWITCHGEARS & VARIOUS MOTOR CONTROL CENTRES.


6.6KV SWITCHGEAR SYSTEM :17 6.6KV SWITCHGEAR SYSTEM THE MEDIUM VOLTAGE (6.6KV) SWGR IS TYPE METAL CLAD VACCUM SWGR RATED FOR 6.6KV, 1250A, 50Hz., 3ph, & THE SHORT CIRCUIT RATING OF 25KA FOR ONE(1) SECOND, SUPPLIED BY ALSTOM. IT IS PROVIDED WITH TWO INCOMERS EACH OF 1250A FROM UATs. WITH A BUSCOUPLER BREAKER.


…6.6KV SWITCHGEAR SYSTEM :18 …6.6KV SWITCHGEAR SYSTEM INCASE OF FAILURE OF ONE INCOMER, THE BUSCOUPLER BREAKER WILL CLOSE THROUGH FAST BUS AUTO CHANGEOVER SCHEME TO MAINTAIN THE CONTINUITY OF THE SUPPLY FROM THE OTHER UAT. INCASE OF THE FAILURE OF THE FBC SHEME, BUSCOUPLER WILL BE CLOSED AFTER TRIPPING THE FAULTY INCOMER THROUGH A SLOW BUS AUTO CHANGEOVER SCHEME.


…6.6KV SWITCHGEAR SYSTEM :19 …6.6KV SWITCHGEAR SYSTEM THERE ARE TOTAL 18PANELS – 2 INCOMERS, ONE(1) BUSCOUPLER 2 BUS PT PANELS 2 OUTGOING TRANSFORMER FEEDERS (2FROM EACH SWGR) 9 MOTOR FEEDERS Aux. Supply for space heater, panel illumination,


THE EQUIPMENT FEEDED BY 6.6KV BUS#1 :20 THE EQUIPMENT FEEDED BY 6.6KV BUS#1 HRSG HP FEED PUMP A (1240KW) GT STARTING MOTOR (1300KW). COOLING WATER PUMP ‘A’, FOR CONDENSER (550KW). CCW PUMP ‘A’ (310KW). ONE SPARE MOTOR FEEDER. 2 SAT (6.6/0.433KV, ONAN) – 1 FOR 415 SWGR #1; & 1FOR 415V SWGR #2. SPARE MOTOR FEEDER


THE EQUIPMENT FEEDED BY 6.6KV BUS#2 :21 THE EQUIPMENT FEEDED BY 6.6KV BUS#2 HRSG HP FEED PUMP ‘B’ (1240KW). CW PUMP ‘B’, FOR CONDENSER (550KW). CW PUMP ‘C’, FOR CONDENSER (550KW). CCW PUMP ‘B’ (310KW) TWO SAT #3 & #4; 6.6/0.433KV,


415V SYSTEM :22 415V SYSTEM THE LOW VOLTAGE (415V) SWGR No.1 LOCATED IN THE SWGR ROOM & no.2 LOCATED IN THE CLARIFIED WATER MCC ROOM HAS TWO BUS SECTIONS WITH A BUS COUPLER. ONE BUS SECTION OF EACH SWGR IS FED FROM THE EMERG. DG SET. EACH MCC/DB HAS 2 INCOMERS & 1 BUSCOUPLER. THE MOTOR FEEDERS RATED 110KW UPTO 160KW ARE FED FROM 415V SWGR & BELOW 110KW ARE FED FROM MCCs.


THE EQUIPMENT FEEDED BY 415V SWGR no.1 (LOCATED IN SWGR ROOM) :23 THE EQUIPMENT FEEDED BY 415V SWGR no.1 (LOCATED IN SWGR ROOM) GTG MCC (1600A) HVAC/COMPRESSOR MCC (1000A) ACDB #1 (MISCELANEOUS LOADS-630A) TWO TRANSFORMERS LTG #1& #2; 415/433V, 75 & 25KVA, UPS, 50KVA, 110V (125A) CHARGER, 220V BATTERY #A (200A) CONDENSATE EXTRACTION PUMPS (132KW, 630A).


THE EQUIPMENT FEEDED BY 415V SWGR #2 (IN THE CLARIFIED WATER MCC ROOM) :24 THE EQUIPMENT FEEDED BY 415V SWGR #2 (IN THE CLARIFIED WATER MCC ROOM) CW MCC (630A) STG MCC (630A) HRSG MCC (630A) FW/FOPH MCC (630A) UPS, 50KVA, 110V (125A) TWO TRANSFORMERS LTG #3, 415/433V, 25KVA; AND LTG #4, 415/433V, 75KVA.(100/200A) COOLING TOWER FANS 110KW, 630A).


INTER LOCKS PROVIDED FOR SAFE OPERATION :25 INTER LOCKS PROVIDED FOR SAFE OPERATION THE CB CAN ONLY BE INSERTED IN THE OPEN POSITION. CB CANNOT BE WITHDRAWN IN THE CLOSED POSITION. THE CB CAN BE OPERATED IN ONE OF THE THREE(3) DEFINED POSITIONS i.e.. SERVICE, TEST & ISOLATED. THE CB CANNOT BE INSERTED INTO THE SERVICE POSITION TILL AUXILARY CONTACTS ARE MADE. SIMILARLY INTERLOCKS PREVENTS AUXILARY CONTACTS BEING DISCONNECTED, IF THE CB IS IN SERVICE POSITION. CIRCUIT BREAKER


ACTIVITIES…OPERATION :26 ACTIVITIES…OPERATION RACKING IN & OUT OF THE CIRCUIT BREAKER IS BY MEANS OF A MANUALLY RACK-IN / RACK-OUT MECHANISM. THE OPERATION MECHANISM OF THE CIRCUIT BREAKER IS SPRING-CHARGED TYPE. THE CLOSING SPRING IS CHARGED BY MEANS OF A SPRING CHARGING MOTOR OR BY MEANS OF A MANUAL CRANCKING HANDLE. AFTER THE SPRING IS CHARGED,THE BREAKER CAN BE CLOSED & OPENED EITHER MECHANICALLY OR ELECTRICALLY.