Transformer differential stability and sensitivity test for tap no ------ stability test Primary measurements Source V&I B-R Y-B R-Y N B Y R V (V) I (A) Secondary measurements Diff. relay (HV Diff. relay ( side) Side HV Side Phase side) I I I sec. I pri. I sec. I (mA) T.B. T.B. T.B. pri. (mA) (mA) (A) (mA) (A) R Y B N Differential Current Measurement(for Digital relays) DIFF DIFF Relay DIFF Current Restrain Current Phase Measurement Measurement Id mA IR mA HV side current A side current A R Y B Sensitivity Test by swapping CT Terminals :
Transformer differential stability and sensitivity test for tap no ------ stability test Primary measurements Source V&I B-R Y-B R-Y N B Y R V (V) I (A) Secondary measurements Diff. relay ( side) Diff. relay (HV side) Side HV Side Phase I (mA) T.B. I (mA) T.B. I sec. (mA) T.B. I pri. (A) I sec. (mA) I pri. (A) R Y B N Differential Current Measurement(for Digital relays) Phase DIFF Measurement HV side current A DIFF Relay Measurement side current A DIFF Current Id mA Restrain Current IR mA R Y B Sensitivity Test by swapping CT Terminals :
tr_stability.docx