不依赖对侧数据且可靠、有效地辨识波头对促进行波自动测距实现具有重要意义。通过理论分析,获得了故障电流行波在回路内的传播特征。故障初始行波除了沿故障线路传至变电站观测母线外,惯常的环式接线拓扑为其提供了另一条由健全线路构成的返回至该观测母线的通路,使得故障线路和健全线路上的电流行波测点将各自检测到一次故障主导行波,并能通过群体比幅比相来与干扰波相区分。在此基础上,提出了利用同一变电站内故障线路和健全线路上观测到的故障主导波头的到达时差来定位故障的新方法。与传统双端行波测距相比,该方法具有无需依赖对端通信和双侧时钟同步的优势;与传统单端行波测距相比,避免了故障点反射波识别这一难点环节。理论分析和现场实测数据均表明该方法正确、有效。
Independence of remote data and reliable and effective identification of wavefronts are significant for improving the implementation of automatic Traveling wave fault location. The propagating features of faulted current Traveling waves in the loop were obtained by theoretical analysis. The initial faulted Traveling wave arrives at the observation bus of the substation along the faulted line or along the healthy lines in another direction due to the loop topology of transmission lines. This makes each fault induced dominant waves observable at the faulted line and the healthy line, and the fault induced dominant waves can be distinguished from the disturbance waves by comparing their transient amplitude and polarity in group. Based on these features, a novel two-terminal fault location principle using the arrival time difference of fault induced dominant Traveling waves between faulted and healthy lines at the same substation was presented. Compared with the traditional double-terminal method, the proposed method has the advantages of independent of communications or timing synchronization with remote side, and it can also avoid the difficulty in identifying the reflected faulted wave compared with the traditional single-terminal method. The proposed method was proved feasible and effective by theoretical analysis and field measured dataset test.