Research on the Distribution Network's Single-phase Short-circuit Faults with Wavelet Transform

According to the problem that the single phase grounding fault location is difficult to detect, a novel method of identifying fault line for single phase grounding fault is presented, based on the detailed analysis of the transient zero sequence network's fault characteristics in the small current neutral grounding power system. Experiments show that this method is immune to many factors such as the initial fault current switch angle, fault distance, transition resistance, power arc, the power distribution system operation mode and so on. It not only can detect the single phase high impedance grounding fault accurately which occurs at the terminal of transmission line, it also can detect the fault which occurs when the phase voltage is near zero.