为进一步提高当前行波法的定位精度,提出了一种基于多点电流测量的输电线路行波故障定位新方法。该方法使用多个电流测点将故障位置定位在相邻测点之间后,通过所提中间故障区域选择原则选出用于故障定位的线路段,再利用非故障段线路长度与其两端测点检测到的故障初始行波到达时刻的时间差之比在线测定出波速,最后根据双端行波定位原理计算出故障距离。在缩短线路故障区间的基础上进行故障点定位,减小了线路长度引起的定位误差,也使得故障电流行波信号衰减和畸变程度减小,有利于初始行波到达时刻的准确标定,同时波速的在线测定也消除了由于其不确定性造成的定位误差。仿真结果表明所提方法具有较高的定位精度。
A traveling wave fault location scheme based on multiple current measurements is presented for transmission line to improve the location accuracy,which locates the fault position between two adjacent measurement points first,then selects the line segment according to the proposed middle faulty section selection principle.The wave velocity is online determined by the length of non-faulty line segment and the difference of initial fault traveling wave arriving time between two measuring points,and the fault location is finally calculated with the two-terminal traveling wave fault location method.As the proposed scheme locates the fault location based on the online determined wave velocity and the reduced line section,which decreases the error of line length and the attenuation and distortion of traveling wave signal,the fault location accuracy is improved.Simulative results show the higher accuracy of the proposed scheme.