计及测量装置失效的输电网行波固有频率故障定位方法

Natural Frequencies Based Fault Location Method for Transmission Network Considering Measurement Device Invalidation

为解决电网中因测量装置失效而引起故障定位失败的问题,提出一种计及测量装置失效的输电网行波固有频率故障定位方法。根据故障后行波在输电网中的传播规律,首先分析了故障线路与健全线路固有频率对应的行波路径的不同特点,在此基础上,根据线路两端行波路径长度之和与线路全长的比较结果,确定故障线路,同时依据单端频率法计算故障距离。算法考虑了测量装置失效的情况,提出利用相邻线路处的频率信息判断故障线路,进而计算故障距离,实现联网定位。大量基于PSCAD/EMTDC和Matlab的仿真结果表明,该方法不受过渡电阻、故障距离和故障初始角的影响,具有良好的适应性。

In allusion to fault location failure caused by the invalidation of measurement device in power grid, considering the invalidation of measurement device a fault location method based on natural frequencies of transmission lines is proposed. According to the law, by which post-fault traveling wave propagates in transmission network, firstly, different features of propagation paths of traveling wave corresponding to natural frequencies of faulty line and healthy line are analyzed and on this basis according to the result of comparing the sum of the length of propagation paths of traveling wave measured at the two terminals of faulty line with the full length of the faulty line, the faulty line can be determined; then the fault distance can be calculated by natural frequency-based fault location method. In the proposed method, considering invalidation of measurement device the faulty line is distinguished by frequency information of adjacent transmission lines, and then the fault distance is determined. A lot of results of simulation based on PSCAD/EMTDC and Matlab show that the proposed method is independent to transition resistance, fault distance and initial phase angle when the fault occurred, so it possesses good adaptability.