配电网电缆系统的故障选线方法

利用电缆故障电流谐波高频分量,对电缆泄露性故障进行判定。运用在高频空间具有良好聚焦性的小波包工具,对故障暂态零序电流进行分析,提取SFB频带内的特定频带的高频分量,通过比较所有线路高频分量的测度之和,实现故障线路的识别。基于暂态零序电流特征的理论,提出一种新的选线判据:以系统故障特征值为主判据,以故障电流高频分量的1范数为辅判据实现故障选线。该方法克服了中性点消弧线圈接地的影响,提高了线路过零点附近接地故障和母线接地故障时的选线精度。实验仿真证明,该选线方法可以准确、可靠地实现单相故障接地选线。

Faulty Line Detection of Resonance-grounding Cable System

A faulty line detection method based on the high frequency components of zero-sequence current is proposed in the cable system.It applies wavelet packet tools,which has good focusing performance in high frequency space,to decompose the pose-fault transient zero-sequence currents of lines to pick up its high frequency components in the selected frequency bands,and calculates the sum of zero-sequence current high frequency components of both faulty line and healthy lines and the sum of their currents as the characteristic information of faulty system.The calculated characteristic value is taken as the main criterion and the fault current high frequency components as the associate criterion.This method can eliminate the infection of resonance-grounding.Simulative experiments show that the proposed method has good white-noise-proof capability and high faulty-line detection accuracy.