Research on Single Grounding Location Technology of Power Grid Based on Wavelet Analysis

Abstract

The research of single grounding location technology based on wavelet analysis aims at the current situation of complex distribution network structure, high failure rate, many branches of lines, large transition resistance, difficult to detect fault signals. This method analyzes the characteristics of fault traveling wave signal generated by single effective grounding, and filters the collected traveling wave signal by wavelet analysis, so as to improve the credibility of traveling wave signal characteristics. Through calculating the traveling wave line mode and zero mode component at the time of fault occurrence, the singular point of traveling wave waveform is obtained, and the fault point is determined by accurate traveling wave velocity. For the tree distribution system, the zero mode waveform of the reflected traveling wave is recorded by injecting the voltage ranging traveling wave into the system during normal operation, and the reflected traveling wave is injected into the fault phase during fault, and the zero mode voltage waveform of the reflected wave is recorded. The two waveforms are subtracted to eliminate the reflected wave head of the grid node, and the fault distance is calculated by wavelet analysis. The method needs to measure the current and voltage of each terminal of the line synchronously when the parameters of the line are known. Through the experiment of fault location for single-phase ground fault of multi branch distribution lines, the results show that this method is effective.