基于故障选相及时域、频域分析的输电线路直击雷识别方法及其应用

Direct Lightning Identification Method and Its Application Based on Fault Phase Selection and Time/Frequency Domain Analysis

为了快速地对雷击输电线路类型进行识别,以直击雷产生的三相暂态电流行波为研究对象,基于EMTP仿真软件,建立了装有导线暂态电流监测设备的输电线路仿真模型。根据平行导线之间的耦合原理,通过判断雷击故障相数将直击雷初步分为3类。并通过提取各个子分类中的直击雷波形的时域与频域特征构建识别判据,最终实现输电线路直击雷的识别。仿真测试结果表明,对直击雷进行初步分类可有效区分雷击塔顶所造成的多相闪络情况,降低识别的难度。这种直击雷识别算法在不同雷电源参数、不同故障距离下均能对直击雷进行有效识别。

In order to identify lightning strikes hitting transmission lines, taking three-phase transient current travelling waves caused by direct lightning strike as the research object, we built a model of transmission line with equipment monitoring transient current in its conductors by the EMTP software. According to the principle of coupling between parallel conductors, we classified direct lightning strikes into three groups preliminarily based on the number of lightning-fault phases. From each category, we established criteria based on the time-domain and frequency-domain features of direct lightning strike waves, which were used to finally identify direct lightning strikes. The simulation results show that, the preliminary classification of direct lightning strikes can effectively distinguish multiphase flashover caused by lightning strike to the top of tower, and reduce the difficulty of identifying lightning strikes. The proposed identification method can recognize the direct lightning strikes with different strike positions and different lightning parameters.