Fault Line Selection and Location of Distribution Network Based on Fault Recording Data

Abstract

Single-phase grounding fault line selection is a long-standing problem in the distribution network. The identification rate of single-phase grounding fault is further reduced due to a large number of grid-connected distributed power supply, as well as short distribution network lines and many branches. In the case of faults, there is a strong similarity between the waveforms of the sound lines, and there is a big difference between the waveforms of the faults and the waveforms of the sound lines. Based on waveform similarity, this paper takes one-fourth power frequency period after fault as an analysis window, uses fractal theory to analyze transient zero-sequence current of multi-points in small current grounding systems of distribution network. By using the difference of fractal dimension between fault lines and sound lines, a new fault identification method is proposed to realize fault line selection. By using the waveform difference between fault line terminals, the fault zone location is realized. The accuracy and validity of the criterion are verified by simulation and field data.