INVESTIGATION OF IMPEDANCE-DIFFERENTIAL PROTECTION’S ALGORITHM AS A FAULT LOCATOR FOR DOUBLE-CIRCUIT TRANSMISSION LINE

Abstract

This paper deals with an analysis of impedance-differential protection algorithm applied to locate faults on a double-circuit transmission line. In particular, the study of fault location accuracy for the case of using the relation between currents for negative-sequence not for zero-sequence, as it was presented so far, is provided. It results from the well-known fact that zero-sequence impedances are in practice considered as quite unreliable data. Therefore, one has to limit usage of zero-sequence impedance parameters as much as possible. Such approach was applied in this paper and therefore the  use of the additional relation of currents for negative-sequence is under investigation. The fault signals from ATP-EMTP simulation on the sample double-circuit transmission line was applied for evaluating the fault location accuracy. References 8, figures 4, table 1.