Fault Location in 6.6kV Overhead Distribution System by Comparing TDR Waveforms Before and After Failure

Abstract

The authors propose an effective method of fault location in overhead distribution system. In past studies, short pulse with high frequency injected into overhead distribution system can propagate through about 1km distance, but it has been a problem that pulse reflect at other than a fault point. In other words, it is necessary to find out a fault point from multiple reflected waves. In our proposed method, it is possible to extract a change of a fault point by comparing TDR (Time Domain Reflectometry) waveforms before and after failure. In this paper, we clarify theoretical concept and organize the algorithm of comparing TDR waveforms. Moreover we verify effectiveness of the proposed method by experiments in real-scale distribution system after confirming pulse transmission properties of section switch. The verification results show that the proposed method can locate a fault point (short-circuit fault or ground fault) with accuracy of tens of meters or less.