Fuzzy based fault location estimation during unearthed open conductor faults in double circuit transmission line

Abstract

In this paper fuzzy inference system (FIS) has been designed for faulty phase identification and fault location estimation during unearthed open conductor faults in double circuit transmission line. Inputs given to the proposed relay are the fundamental component of current of both circuits of double circuit line measured at one end of the line only. Output of the proposed method will be in terms of fault location in each phase circuit-1: LA1, LB1, LC1 and circuit-2: LA2, LB2 and LC2 in time domain from which fault location and faulty phase(s) will be estimated. Proposed method is tested for varying fault type, fault location, fault inception angle, fault resistance and power flow angle. Faulty phase identification accuracy is very high and percentage error in fault location estimation lies within 1 % for large number of test fault cases.