Fault Line Selection of Resonant Grounding System Using Transient Zero-sequence Current Waveform Characteristics

For medium-voltage distribution network, the main fault form is single-phase grounding fault, and the fault rate accounts for more than 80% of the total faults in the power grid. The long-term existence of faults may cause multi-point faults and phase-to-phase short circuits, and even cause a fire in the cable channel, threatening personal life safety. In this paper, the fault line is judged according to the phase difference of the transient zero-sequence current waveform, and the similarity of the waveform is visualized with the help of the dynamic time warping distance, and the line selection criterion is constructed. Finally, the simulation results are built to verify the applicability of the criterion under different fault conditions. The results show that this method can accurately select fault lines under different transition resistances, fault locations and arc suppression coil compensation degrees, and has certain applicability.