基于支持向量机的单端行波故障测距方法

Abstract

单端辐射状配电网发生单相接地故障时，单端行波法故障测距的难点在于第二个到达测量点的故障行波波头的正确辨识。针对上述难点，本文提出了一种基于支持向量机的单端行波故障测距方法。首先，利用支持向量机正确地识别出故障段，然后根据行波传播的网格图确定第二个到达测量点的故障行波波头是来自于故障点还是来自于对端母线。通过相模变换消除电磁耦合的影响，通过对小波变换相关知识的研究，选择最优小波基进行小波变换，对故障行波波头进行识别，检测故障行波波头模极大值对应的时刻，进而利用相应波头到达测量点的时间差结合波速实现故障点的精确测距。 When single-phase-to-earth fault occurred in radial distribution network supplied by single power, the key problem of the single-ended traveling wave fault location lies in the correct recognition of the second travelling wave head to reach the measuring point. In view of the above problem, this paper introduces single terminal traveling wave fault location method based on SVM. After identifying the fault section by the SVM, the second traveling wave head coming from the fault point or bus at opposite terminal is recognized based on lattice diagram of traveling waves. Elec-tromagnetic coupling effect is eliminated by phase mode transformation. Through the study of relevant knowledge of wavelet transform, the optimal wavelet base is selected for wavelet trans-form in order to identify the fault traveling wave head. The time corresponding to fault traveling wave modulus maximum is detected and time difference of arrival and velocity of the corre-sponding wave head is used to achieve fault location.