A Novel Two-Terminal Underground Cable Incipient Fault Location Based on Zero Sequence Circuit

This paper centers on the underground cable incipient fault location. Underground cables have been widely utilized in urban distribution system for their higher reliability and less land occupation. However, the defects in cable are hardly be detected for its special structure. They will gradually get worse and lower insulation resistance, thus making partial discharge evolve into cable incipient fault, and causing permanent fault eventually. Cable incipient fault can early warn cable health state. Thereby, pinpointing incipient fault location in order to replace potential deteriorating cables is significant for preventing unexpected outage and enormous economic losses, and prolonging cable life. In this paper, in order to avoid the arc model and load effect, a novel method based on zero sequence circuit is proposed. Wavelet transform is used to synchronize two-terminal sample data and the fault location is estimated by zero sequence circuit. The feasibility of the proposed method is testified by simulation. The results indicate that the method is hardly susceptible to load effect. Meanwhile, the location errors are acceptable.