高压输电线路故障测距的负距问题及修正方法

A New Algorithm for Resolving Negative Value Problem in HV Transmission Line Fault Location

利用国内外几种常用的故障测距算法构成的测距装置,经现场运行实践和对故障暂态数字仿真的结果表明,当被保护线路的正向末端经大过渡电阻接地时,测距结果可能会出现负距,从而导致测距工作的失败。本文对产生这些负距的故障条件进行了分析,并提出了负距修正的方法。

The computer transient simulation results of different fault location algorithm, show that when a high resistance fault appears at the remote end of HV transmission line, the detected fault location value could be negative and the fault location would fail.This paper analyzes in detail the effects of fault place, load flow, feed current of another terminal, ect. on negative location value. The relationship of phase angles of fault phase voltage U2 and zero-sequence current of fault line ima0 and zero-sequence current passing through the fault resistance Iao is deduced (in Figure 8). The negative distance correct recursive formular is eq. (14).This paper has made the transient simulation and fault location for five kinds of system operation modes in using negative distance correct algorithm. The results show that the algorithm is efficient and accurate in the domain of normal phase angles (| δ|< 60°).