SF6 CB by HKR.ppt

SF6 CIRCUIT BREAKERS PRESENTATIONBYHITESH KUMAR MANAGER(T) PROTECTION DELHI TRANSCO LIMITED

DTL NETWORKSF6 CIRCUIT BREAKERS400 kV Substations:3 nos.400/220/33 kV Pr. Tarns:12 nos.Installed Capacity 400 kV:3780 MVA400 kV Lines:230 ckt. Kms400 kV CBs:58 nos.220 kV Substations (23 AIS,7 GIS):30 nos.220/66-33/11 kV Pr Trans:83 nos.Installed Capacity 220 kV:8790 MVA 220 kV Lines:590 ckt. kms.220 kV CBs:250 nos.

SF6 CB 220 kV AISSF6 CIRCUIT BREAKERS

SF6 CB 220 kV (GIS)SF6 CIRCUIT BREAKERS

CB (GIS)SF6 CIRCUIT BREAKERS

PREFACESF6 CIRCUIT BREAKERSSF6 circuit breakers utilise the excellent arc quenching performance and high level dielectric strength of SF6 gas. The interrupting unit is puffer type. The gas flow through the extinguisher nozzle puffed by a puffer cylinder and piston extinguishes the arc.The moving contact system is connected to operating mechanism.The operating mechanism is operated by compressed air/spring force/hydraulic pressure for closing/opening operations.

FEATURESSF6 CIRCUIT BREAKERSSF6 gas circuit breaker has the following features:Superior Interrupting Capability: The breaker can successfully interrupt high short circuit current with high rates of rise of TRV, Short line faults, out of phase faults, Capacitive current without generating dangerous over voltages.Low Operation Noise: Since the break is sealed off from atmosphere there is no gas exhaust noise during operation.Simple Construction & Compact Size: The non-exhausting gas design makes the breaker structure simple & compact.

FEATURESSF6 CIRCUIT BREAKERSEasy Installation, Inspection & Maintenance: As the construction is simple, the installation & inspection is very easy and since the deterioration of SF6 gas is negligible and erosion of arcing contact by arcing in SF6 gas is very little, the maintenance interval is very long.High Safety: Since SF6 gas is physically non-toxic and non-inflammable, the breaker can be operated safely.

SF6 CIRCUIT BREAKERSFor operating tasks hydraulic spring operating mechanisms, as a combination of hydraulic operating element and spring energy storage system, offer the great:Spring energy storageLong-term stability and temperature independence of the energy storage deviceHydraulic fluid as energy carrierWear-free cylinder-piston unit for power transmissionIntegrated, wear-free hydraulic dampingNo external high-pressure friction seals, no pipe unions in the hydraulic systems(no oil leakage)Hydraulic system hermetically sealed against atmosphere (no corrosion)Pressure vessel regulations do not apply to the operating mechanismCB MECHANISM

MAIN COMPONENTS

SF6 CIRCUIT BREAKERSMECHANISM HOUSINGINTERRUPTING UNITSUPPORT UNIT ASSEMBLYSHAFT SEAL & ABSORBENTGAS SYSTEMAIR /HYDRAULIC SYSTEMLOW PRESSURE PROTECTION SYSTEMOPERATING MECHANISMCONTROL CIRCUITSF6 GAS

Merits of SF6 GasHigh dielectric and insulating properties of the gas.Excellent extinguishing ability.Non-flammable.Non-corrosive.Odourless and colourless.Toxicity is almost zero for all practical purpose.Heavier than air. Longer life of contacts due to absence of oxygen and carbon molecules in the gas.Breaker size and dimensions are smaller as compared to ABCB/OCB of the same kV rating. Maintenance involves only on the operating system. This is an advantage since maintenance aspects of the interrupter parts are very minimum (Practically nil).

SF6 CIRCUIT BREAKERS

RATINGS (220 kV CB)SF6 CIRCUIT BREAKERSType:200-SFM-40ARated Voltage:245 kVRated Insulation Level:1050 kVpRated Frequency:50 HzRated Normal Current:3150 A Rated S/C Breaking Current:40 kARated S/C Making Current :100 kARated Short Time Current:40 kA (3 sec)Rated Break Time:60 ms (3 cycles)Operating Sequence:O-0.3sec-CO-3min-CORated TRV:364 kVp

RATINGS (220 kV CB)SF6 CIRCUIT BREAKERSOperating Mechanism:Closing: By Spring forceOpening:By Pneumatic forceAir Pressure:15 kg/sq cmSF6 Gas Pressure:6 kg/sq cm at 20CClosing Time:100 msOpening Time:30 msPole Discrepancy:3.3 msAuxiliary Supply for: Motors, Heater etc:415 V ACCB operation:220 V DC

RATINGS (400 kV CB)SF6 CIRCUIT BREAKERSType:3ATRated Voltage:420 kVRated Insulation Level:520/610/1425 kVpRated Frequency:50 HzRated Normal Current:2000/3150 A Rated S/C Breaking Current:40 kARated S/C Making Current :100 kARated Short Time Current:40 kA (1 sec)rating Sequence:O-0.3sec-CO-3min-CO

RATINGS (400 kV CB)SF6 CIRCUIT BREAKERSBreak Time:40 ms (2 cycles)Closing Time:100 msOpening Time:22 msArcing Time:18 msDead Time:300 msPIR Insertion Time:8(+2/0) ms

RATINGS (400 kV CB)SF6 CIRCUIT BREAKERSHydraulic Pressure:350 barQuantity of Hydraulic Oil:21 litNitrogen Pressure:200 bar at 20C Pressure Range:250-350 barSF6 Gas Pressure:7.5 bar at 20CAuxiliary Supply for: Motors, Heater etc:415 V ACCB operation:220 V DC

MAINTENANCE SCHEDULESF6 CIRCUIT BREAKERS

MAINTENANCESF6 CIRCUIT BREAKERSRECOMMENDED MAINTENANCE PROGRAMME (OEM):TIME WISE EVERY WEEK: Patrol Inspection EVERY YEAR:Periodical Inspection EVERY 6th YEAR:Overhaul Inspection

MAINTENANCESF6 CIRCUIT BREAKERSRECOMMENDED MAINTENANCE PROGRAMME (OEM):OPERATIONS WISEINSPECTION/RENEWAL OF MAIN CONTACTS

Rated S/C Current Interruptions: 20 Operations Rated Current Interruptions:2000 Operations Small Current Interruptions:4000 Operations

MAINTENANCESF6 CIRCUIT BREAKERSRECOMMENDED MAINTENANCE PROGRAMME (OEM):OPERATION WISEINSPECTION/RENEWAL OF OPERATING MECHANISM:5000 Operations

MAINTENANCE SCHEDULE DTLSF6 CIRCUIT BREAKERS

Sr. No.ACTIVITYSHUT DOWN/ WITHOUT SHUT DOWNPERIODICITYA.SF6 CIRCUIT BREAKERSa.Checking of SF6 gas pressureW S/DDailyb.Checking of oil leaks from Grading CapacitorsS/DYc.SF6 gas leakage testS/DSOS


Sr. No.ACTIVITYSHUT DOWN / WITHOUT SHUT DOWNPERIODICITYHYDRAULIC OPERATING MECHANISMa.(i) Checking of oil level (ii) Replenishment/ topping up of oilW S/DS/DDailySOSb.Checking of oil pressureW S/DDailyc.Checking of oil leaksW S/DDailyd.Checking of oil pressure dropduring duty cycle operation checkS/DYe.Checking of auto-starting/ stoppingof oil pump.S/DY


Sr. No.ACTIVITYSHUT DOWN / WITHOUT SHUT DOWNPERIODICITYPNEUMATIC OPERATING MECHANISMa.Functional checking of auto-startingof air compressors and dryersS/DY/SOSb.Maintenance of Air DryerW S/DHYc.Checking of air pressure dropduring duty cycle operationS/DYd.Maintenance of compressors & Air storage tank in pneumatic operating mechanismS/D2Ye.Lubrication of pneumatic operating mechanismS/D2Y

SF6 CIRCUIT BREAKERSMAINTENANCE SCHEDULE DTL

Sr. No.ACTIVITYSHUT DOWN/ WITHOUT SHUT DOWNPERIODICITYBREAKER OPERATION CHECKSa.CB Operating TimingsS/DYb.Checking of Pole discrepancy relayS/DYc.Functional checks, duty cycleoperation including rapid re-closing (0-0.3s-CO)S/DYd.Checking of all operation lock-outsS/DYe.Checking of all interlocksS/DY


Sr. No.ACTIVITYSHUT DOWN/ WITHOUT SHUT DOWNPERIODICITYBREAKER OPERATION CHECKSf.Checking of pressure setting (oil/air/gas)S/DYg.External Cleaning of Breaker Interrupter, Support insulators and Grading CapacitorsS/DSOS/Yh.Capacitance and tan measurement of grading capacitorsS/DYi.Dew point measurement of SF6 GASS/D3Y/SOSj.i) Measurement of dynamic contact resistance (DCRM)S/D3Y/SOSk.Measurement of static contact resistanceS/DY


Sr. No.ACTIVITYSHUT DOWN/ WITHOUT SHUT DOWNPERIODICITYMEASUREMENT/TESTINGa.Checking of healthiness of Operation Counter S/DYCONTROL CABINETa.Checking of tightness of all cable terminations in MBS/DYb.Checking of door sealing gasketsand replacement thereof, if necessaryW S/DYc.i) Repainting of metallic surfaces(if required)ii) Vermin Proofing W S/D S/D2YYd.Checking of space heaterW S/DY


Sr. No.ACTIVITYSHUT DOWN/ WITHOUT SHUT DOWNPERIODICITYMAJOR MAITENANCE & OVERHAULS/D7Y/ Manufacturer recommendation

SF6 CIRCUIT BREAKERSCB OPERATING MECHANISM

SF6 CIRCUIT BREAKERSType of mechanism: AHMA-4.2 Energy (last O): 4.0 kJPiston Stroke: 205 mmPiston rod diameter: 18 / 20 mmDuty cycle: CO-COAdaption: vertical/horizontalNo./size of springs: 8x 485 mmSystem Pressure: 480 barWeight : 291 kgCharging time CO: 28 secOil filling quantity:appr. 2.0 litreOperating Mechanism (GIS CB)

Operating Mechanism (GIS CB)SF6 CIRCUIT BREAKERS

SF6 CIRCUIT BREAKERSGCB Drives AHMA 4 - Hydraulic FunctionsCloseOpenOperating Mechanism (GIS CB)

Damping principle

Vicinity of OPEN dampingVicinity of CLOSE dampingSF6 CIRCUIT BREAKERS

Motor

Supplier: GroschoppCompound motor 220 V, 1100 WBevel wheel pairCombination of 15 teeth Steel and 30 teeth Plastic (Acetal)Reduced wear of the teethReduced Noise during operationRatio 2:1; module 2,5

PumpMotorBevel wheelsSF6 CIRCUIT BREAKERS

SF6 CIRCUIT BREAKERSOperating Mechanism (GIS CB) Pump element with Non - return valve

Eccentric shaftNon return valveDirection of oil flowSpringStroke of piston due to rotation of eccentric shaftValve platespring loadedPiston

Pilot valve with coil

2/2 directional control valveGives a short pressure impulse to operate change-over valveGear ratio 4:1 amplifies small magnetic force to handle big hydraulic forceOver voltage factor = 5


Pilot valve - oil flow

Position CLOSEPosition OPENOnly for a short period of approx. 10-30 ms4 x FMag > FSpring + FHydrCondition for switchingSF6 CIRCUIT BREAKERS

Interaction Pilot valve / Change over valve

Position OPENPosition CLOSESF6 CIRCUIT BREAKERS

Change Over Valve

High oil flowDifferential piston, divided for accurate alignmentHardened metal seats (cavitations due to high velocity of flow)Nozzle for damping, boring for pressure compensation (latch)Spring snap keeps shaft in OPEN position if no pressure is appliedOPEN PositionSF6 CIRCUIT BREAKERS

SF6 CIRCUIT BREAKERSChange Over Valve - Position OPEN Differential piston principle:Pressure applied areas: A1: Area of rod, A2: Area of ring, A3: Area of pistonRelations of areas: A3> A2 Important for OPEN, A1 + A2 > A3Channels: P - Top of piston rod, Z - Bottom of piston rod, T - Tank

SF6 CIRCUIT BREAKERSChange Over Valve - Position CLOSE

Differential piston principle:Pressure applied areas: A1: Area of rod, A2: Area of ring, A3: Area of pistonRelations of areas: A3> A2, A1 + A2 > A3 Important for CLOSELoss of volume due to closing operation

SF6 CIRCUIT BREAKERSCB MECHANISM OPERATION

B

B

B

INTERRUPTER

GAP A

GAP A

MOVING CYLINDER

INTERRUPTER

MOVING PISTON

MOVING CYLINDER

MOVING PISTON

CB Pole DismantlingSF6 CIRCUIT BREAKERS

SF6 CIRCUIT BREAKERSCB Pole Dismantling

CB Pole DismantlingSF6 CIRCUIT BREAKERS

SF6 CIRCUIT BREAKERSOperating Rod & Sealing Rings

SF6 CIRCUIT BREAKERSRemoving Fixed Contacts

SF6 CIRCUIT BREAKERSFixed Contacts

Absorbent


SF6 CIRCUIT BREAKERSMoving Contacts

Insulated Coupling RodSF6 CIRCUIT BREAKERS

Insulating RodSF6 CIRCUIT BREAKERS

Moving Contacts


SF6 CIRCUIT BREAKERSOperating Rod & Sealing Rings

SF6 CIRCUIT BREAKERSCB MECHANISM

SF6 CIRCUIT BREAKERSMaintenance 400 kV CB ABB

Technical DataRated voltage kV up to 253Rated power-frequency withstand voltage, 1 min to earth kV 460Rated power-frequency withstand voltage, 1 min across open contacts kV up to 530Rated lightning impulse withstand voltage, 1.2/50 s to earth kV 1050Rated lightning impulse withstand voltage, 1.2/50 s across open contacts kV 1050Rated frequency Hz 50/60Rated continuous current A 3150Rated short-time withstand current, 3 s kA 50First-pole-to-clear factor 1.3/1.5Rated short-circuit breaking current kA 50Rated short-circuit making current, peak value kA 135Rated filling pressure of SF6-gas (20 C) kPa 680Minimum functional pressure of SF6-gas (20 C) kPa 600Rated opening time ms 19 (+0/-5)Rated break time ms 39Rated closing time ms 60 (+0/-10)Auto reclosing dead time ms 300Rated operating sequence O-0.3s-CO-1min-CO or CO-15s-COHigh-speed auto-reclosing single or three phaseDesign ambient temperature C -15/+40Weight per pole (incl. operating mechanism) kg 815Energy storageType disk springsNumber pcs 8Pump driveMotor type compound motorRated voltage VDC 110-125/220-250Operating current A 6/3Start-up current A 30/20Power consumption W 660Operating mechanism heatingAnti-condensation heating W 70Protection classProtection class of operating mechanism housing (Indoor/Outdoor) IP 51/IP 54SF6 CIRCUIT BREAKERS

CB OPERATING TIME MEASUREMENTSF6 CIRCUIT BREAKERS

SPEED MEASUREMENTSF6 CIRCUIT BREAKERS

CB TRIGGERED TO OPENSF6 CIRCUIT BREAKERSMotion10 mm/div

Coil Current0.2Amp/div

Aux ContactAux ContactMain Contact CMain Contact BMain Contact A

CB TRIGERRED TO OPENSF6 CIRCUIT BREAKERS

CB TRIGGERED TO CLOSE_OPENSF6 CIRCUIT BREAKERS

CB OPERATING TIME MEASUREMENTSF6 CIRCUIT BREAKERS

SF6 CIRCUIT BREAKERSCB OPERATING TIME MEASUREMENT

Comparision for Gap of Electrodes: SF6/Air/Vacuum/OilSF6 CIRCUIT BREAKERS

DTL NetworkCB SpecificationsCB RequirementMaintenanceTestingTest ReportsGIS CBSF6 gasIEC To studySF6 CIRCUIT BREAKERS


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SF6 CB by HKR.ppt

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