Diff. relay ( Diff. relay (HV Side HV Side side) side) Phase I I I sec. I pri. I sec. T.B. I (mA) T.B. T.B. T.B. pri. (mA) (mA) (A) (mA) (A) R Y B N Differential Relay Current Measurement (for Digital relays) DIFF Relay DIFF Relay Restrain DIFF Current Measurement Measurement Current Id mA HV side current A side current A IR mA R Y B Stability And Sensitivity Of REF HV Side At Tap No ---- Stability test VRN= _______ VYN= _______ VBN= _______ Measured I secondary REF relay Connected I Wire From Wire From CT's Supply to primary I (mA) V (V) neutral CT sum Phase (A) I (mA) I(mA) T.B. No R-N Y-N B-N Sensitivity Test by Swapping CT Terminals : Measured I secondary REF relay Connected Supply to Phase Wire From neutral CT Wire From CT's sum
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) T.B. I pri. (A) R Y B N Differential Relay Current Measurement (for Digital relays) DIFF Relay Measurement HV side current A DIFF Relay Measurement side current A DIFF Current Id mA Restrain Current IR mA R Y B Stability And Sensitivity Of REF HV Side At Tap No ---- Stability test VRN= _______ VYN= _______ VBN= _______ Connected Supply to Phase I primary (A) Measured I secondary REF relay Wire From neutral CT Wire From CT's sum I (mA) V (V) I (mA) I(mA) T.B. No R-N Y-N B-N Sensitivity Test by Swapping CT Terminals : Connected Supply to Phase Measured I secondary REF relay Wire From neutral CT Wire From CT's sum
tr_stability.docx