基于双端行波法的电缆线路短路故障定位改进

Short-Circuit Fault Location for Power Cables Based on Improved Two-Terminal Traveling Wave Method

为实现电力电缆线路上的短路故障精确定位,对双端行波法故障定位原理进行了改进。使用仅需要本地时钟同步的方式替代传统的远距离双端同步方式,从原理层面解决了双端行波法的同步问题,改进后的故障定位方法只与故障行波到达电缆线路两端监测点的时间差有关。并且用归一化的故障点判据代替具体的数值判据,从而降低了对线路电气参数精准性的依赖。因此,改进后的方法有更高的故障定位精度。用PSCAD软件对双端结构的电缆线路进行了仿真,结果表明改进后的方法具有更高的定位精度,且在任意故障点位置条件下的故障定位精度优于传统的双端行波法。

In order to accurately locate the short-circuit fault on the power cable line,the principle of fault location of the twoterminal traveling wave method has been improved.The traditional long-distance two-terminal synchronization method is replaced by the local clock synchronization method.Thus,the synchronization problem of the two-terminal traveling wave method has been solved from the principle level.The improved fault location method is only related to the time difference between the fault traveling wave arriving at the monitoring points at both ends of the power cable.And the normalized fault point criterion is used instead of the specific numerical criterion to reduce the dependence on the accuracy of the line electrical parameters.Therefore,the improved method has higher fault location accuracy.The double-ended structure of the power cable is simulated by PSCAD.The results show that the improved method has higher location accuracy,and the fault location accuracy is better than the traditional two-terminal traveling wave method under any fault positions.