The fault location technology using transient signals for single phase earth fault in non-solidly earthed network

Earth fault accounts for about 80% of the distribution network faults, which makes the detecting and locating of single phase earth fault more important. This paper analyzes the transient process of single phase earth fault and the distribution characters of transient signal in system, and then proposes a new locating method with the comprehensive utilization of transient fault information. This method has the characteristics of both high reliability of transient reactive power direction method and wide adaptability of transient current similarity and transient current polarity comparison methods. Simulation test and field test verified the effectiveness of this technology.