9-2 G30 Generator Protection System GE Multilin9.1 SETTING EXAMPLE 9 APPLICATION OF SETTINGS9The transformer phase shift setting must compensate the measured relay currents for both the actual phase shift of thetransformer, and any phase due to the CT polarities and connections.The difference seen by the differential is the transformer phase shift plus the CT phase shift, or –30° + (–180°) = –210°. Thetransformer configuration is therefore:c) IN-ZONE TRANSFORMER WITH VT ON THE LV SIDEConsider the generator protection system shown below, with an in-zone transformer with VT on the low-voltage (LV) side:Figure 9–2: TYPICAL WIRING, VT ON THE LV SIDE OF THE TRANSFORMER830746A2.CDRCONTACT INPUT H5aCONTACT INPUT H5cCONTACT INPUT H6aCONTACT INPUT H6cCOMMON H5bCONTACT INPUT H7aCONTACT INPUT H7cCONTACT INPUT H8aCONTACT INPUT H8cCOMMON H7bSURGEH6aH8aH5bH7bH8bH5aH7aH6cH8cH5cH7cH1aH2bH1cH1bH2cH2aH4aH4cH3bH3aH4bH3cH1H2H3H4DIGITAL INPUTS/OUTPUTS 6G IVIVIVIV8FF8cF8aF5aF5cF7cF6aF7aF6cVXVAVBVCVOLTAGE INPUTSVXVAVBVCF1cF4aF3cCURRENT INPUTSF2cF4cF1aF4bF1bF2aF3aF2bF3bIAIBICIGIA5IA1IB5IC5IG5IB1IC1IG1M3cM4cM4bM4aM1cM1aM1bM3bCURRENT INPUTS8HM2aM3aM2bM2cIAIBICIGIA5IA1IB5IC5IG5IB1IC1IG1“+”Inlet valve 52bTrip generator breakerTrip field breakerTrip turbineAlarmGE Consumer & IndustrialMultilinG30 Generator Management Relay“–”R52ABCX2X3H1H2H3X1X2X3H1H2H3X113.8 kv, 162 MVAX΄ = 0.216 puX = 1.967 puI2T capability = 10I2 capability = 8%Motoring power = 10%13.2 : 25 kV153 MVAX = 0.1 pu
