基于正极性行波信号分析的配电网双端故障定位

Two-terminal Fault Location of Distribution Network Based on Analysis of Positive Polarity Traveling Wave Signal

针对仅利用传统双端定位法无法实现多分支配电网线路故障定位的问题,提出了通过检测一系列正极性行波(与初始行波同极性的行波)来实现多分支线路配电网双端故障定位的新算法。根据电压行波在故障点、不同分支线路末端及节点处的反射特性可知,与故障点有关的行波均为正极性行波。首先利用传统双端测距法确定故障分支线路,再通过小波变换对测量端检测到的各个波头进行极性特征分析并辨识其出现时刻,计算出各个正极性行波与初始故障行波之间的时间差所对应的距离,最后结合配电网各段线路的长度,可有效识别出与故障点有关的正极性行波,从而确定故障点的位置。经PSCAD仿真和MATLAB分析表明,新算法准确、有效,仅利用两个测量点即可对多分支线路配电网进行故障定位,且减少了设备、节约了成本。

Aiming at problems that only using the traditional two-terminal fault location algorithm can not achieve the power distribution networks with branches fault location, a new algorithm of two-terminal fault location for multi branched distribution network lines was proposed by detecting a series of positive traveling waves （those with the same polarity as the initial traveling wave）. According to the reflection characteristics of voltage traveling wave at the fault point, the end of different branch lines and the nodes, it finds out that the positive polarity traveling wave contains impor- tant fault information. The fault branch lines were first determined by the traditional two-terminal fault location. Then wavelet transformation was used to conduct characteristic analysis and occurring time identification regarding various trav- eling waves detected at the measuring points. The distance of the delta-T between the positive traveling waves and initial fault traveling wave was calculated. Based on the lengths of distribution networks various lines, the positive traveling wave was effectively identified from the fault lines. Thus, the precise positions of faults could be determined. By MATLAB and PSCAD simulation analysis, it indicates that the new algorithm is accurate and effective. Furthermore, the distribu- tion networks with branches fault location can be realized by only using two measuring points, as well as reducing the e- quipment needs and saving the cost.