GENERATOR GENERATOR PROTECTIONPROTECTION

Presented ByPresented By

JOYOTOSH KUMAR JOYOTOSH KUMAR DEYDEY

Sr. Superintendent (Operation)

BTPS

NTPC Limited

Classification of Generator Classification of Generator protectionsprotections

Class – A ProtectionsClass – A Protections

Class – B ProtectionsClass – B Protections

Integrated ProtectionsIntegrated Protections

Boiler Lockout

Turbine Trip Relay

Generator Lockout

TLR

86Y86T

86GT 86B

86GFCB

Contact 2/3

72/32

Protection Against Protection Against Insulation FailureInsulation Failure

Differential ProtectionDifferential Protection Inter-turn Fault Protection Inter-turn Fault Protection Stator Earth Fault Stator Earth Fault

ProtectionProtection Rotor Earth faultRotor Earth fault

Differential ProtectionDifferential Protection

Relay Coil

CT-1 CT-2

Direction of Power Flow

Equipment to be protected

Protection Against Protection Against Insulation FailureInsulation Failure

Differential ProtectionDifferential Protection Generator Differential (87 G)Generator Differential (87 G) Transformer Differential (87 T)Transformer Differential (87 T) Restricted Earth Fault (87 REF)Restricted Earth Fault (87 REF) UAT Differential (87 UTA & 87 UTB)UAT Differential (87 UTA & 87 UTB) Over Head Line Differential (87 L)Over Head Line Differential (87 L) Overall Differential (87 GT)Overall Differential (87 GT)

Transformer REF ProtectionTransformer REF Protection

XER

REF

Back-Up Earth fault

CT’s

Protection Against Protection Against Insulation FailureInsulation Failure

Differential ProtectionDifferential Protection Inter-turn Fault Protection Inter-turn Fault Protection Stator Earth Fault Stator Earth Fault

ProtectionProtection Rotor Earth faultRotor Earth fault

Protection Against Protection Against Insulation FailureInsulation Failure

Stator Earth Fault Stator Earth Fault ProtectionProtection 80% Earth Fault Protections80% Earth Fault Protections 100% Earth Fault Protection100% Earth Fault Protection

Protection Against Protection Against Insulation FailureInsulation Failure

Differential ProtectionDifferential Protection Inter-turn Fault Protection Inter-turn Fault Protection Stator Earth Fault Stator Earth Fault

ProtectionProtection Rotor Earth faultRotor Earth fault

There Occurs a fault, There Occurs a fault, then the current should halt.then the current should halt.

Otherwise the fault current would increase,Otherwise the fault current would increase,and the service continuity decrease.and the service continuity decrease.

But the relay acts Quick, But the relay acts Quick, and the circuit breaker tripsand the circuit breaker trips

The Faulty part is disconnected,The Faulty part is disconnected,and the power system is protected.and the power system is protected.

Thank you Mr. Switchgear,Thank you Mr. Switchgear,because of you there is little fear.because of you there is little fear.