输电线路行波保护中雷击与故障的识别

Identification of Lightning Strike and Fault in Traveling Wave Protection of Transmission Lines

为了探究雷击引起的高频暂态信号对输电线路行波保护的影响,提出了一种基于积分判据的雷击与故障识别方法。在不引起故障的情况下,利用雷击引起的对称电流波形特征以及在很短的时间间隔内由故障产生的非对称电流波形,并分别对时间轴上方和下方的暂态电流波形进行积分。通过对它们的相对比值与阈值的比较,构建了雷击和故障识别的主判据。为了提高雷击与故障的识别的可靠性,根据它们的差值还定义了附加判据。仿真结果和分析表明,所提出的积分判据可以用于雷击与故障的识别,且将主判据和附加判据结合起来可以提高雷击与故障识别的可靠性。

In order to explore the influence of high frequency transient signal caused by lightning strike on traveling wave protection of transmission lines,a lightning strike and fault identification method based on integral criterion is proposed. In the case of no fault,the symmetrical current waveform caused by lightning stroke and the asymmetrical current waveform caused by fault in a very short time interval are used to integrate the transient current waveform above and below the time axis respectively. By comparing their relative ratios and thresholds,the main criterion of lightning strike and fault recognition is constructed. In order to improve the reliability of lightning and fault identification,additional criteria are also defined according to their differences.Simulation results and analysis show that the proposed integral criterion can be used for lightning stroke and fault identification,and the reliability of lightning stroke and fault identification can be improved by combining the main criterion with the additional criterion.