利用行波到达时差关系的配电网故障定位算法

Fault Location Algorithm for Distribution Power Network Based on Relationship in Time Difference of Arrival of Traveling Wave

针对现有配电网故障定位技术存在的缺陷,提出一种基于行波到达时差关系的配电网故障定位改进算法。故障前,针对配电网结构一般不变的特点,将全网线路进行等分,根据等分点至各线路末端的距离建立行波路径矩阵,进一步计算行波在各路径上的传播时间,在此基础上建立各节点的行波到达时间差矩阵。故障后,由小波变换准确获取故障初始行波到达各线路末端时刻,建立各分支线路间实际的行波到达时间差矩阵,然后比较故障前后行波到达时差矩阵的差异,通过矩阵差异值找出故障位置,实现故障定位。为了提高构建行波路径矩阵的效率,对线路结构进行归一化处理,并给出通用的行波路径长度计算方法。经大量仿真验证,所提算法可行有效,定位精度较高。

Existing fault location technologies were known to perform poorly on distribution power network. In this paper, a new fault location algorithm for distribution power network based on relationship in time difference of arrival of traveling wave was demonstrated. The distribution power network was split up into several nodes giving equal interval, on the basis of these nodes, the traveling wave path matrix was constructed which represented the distances between each node and any line terminal in the network. From path matrix, it was possible to determine the propagation times of traveling wave in each path, then the matrixes of the time difference of arrival among the traveling wave of every branch for all nodes were established. When a fault occurred, the arrival times of the first fault-induced traveling waves which were monitored at the line terminals in the network were acquired by wavelet transformation. Based on the actual arrival times, the matrix of the time difference of arrival for fault point was established. Respectively, comparing the matrix for fault point with the matrix for each node, when the different was minimized between the two, the node was identified as fault point. To improve the efficiency for constructing path matrix, the line structure normalization was implemented and a general method for path length calculation was proposed. A lot of simulation results show that the location algorithm is accurate and effective.