基于五次谐波和小波重构能量的配电网单相接地故障的选线方法研究

摘要

In view of frequent single-phase grounding fault in distribution network system, because the fault point cur-rent is very small, so judging fault line accurately becomes very difficult through fifth harmonics amplitude compari-son.The method of fifth harmonics and the combination of wavelet packet energy are presented.The wavelet packet is used to do the third layer wavelet packet decomposition on fifth harmonics of zero sequence current of each line, and then, the total energy on the third floor reconstruction coefficient is calculated.By comparing the fifth harmonic ener-gy of the zero sequence currents, the fault line can be judged.By setting up 10 kV neutral points via arc suppression coil grounding current of single phase short circuit grounding system simulation model, the results show that the meth-od of fifth harmonics and combination of wavelet packet energy can accurately select the fault line.%对配电网经常发生的单相接地短路故障，因为故障点电流非常小，很难通过五次谐波幅值比较来准确地判断故障线路。提出了五次谐波和小波包能量相结合的方法。利用小波包对各线路的零序电流的五次谐波进行三层小波包分解，对第三层重构系数进行能量计算求出总的能量值。通过比较各线路零序电流五次谐波的能量值判断出故障线路。搭建了10 kV 中性点经消弧线圈接地的小电流单相短路接地系统的仿真模型，结果表明五次谐波与小波包能量结合的分析方法能够准确地进行故障选线。