利用单端暂态量检测单相高阻接地故障的新方法

提出了基于单端暂态量实现高压输电线路高阻接地故障检测的新方法。由于故障电量变化不明显，高阻接地故障通常难以检测，并且容易受到系统正常操作例如电容器投切的影响。研究表明，输电线路发生单相接地故障时，故障相电流和零序电流经小波变换后的模极大值在同一尺度上的同一位置极性表现为同号，同时有相同的时间特性，可以用来作为接地检测的依据。为提高可靠性，利用高阻接地故障和电容器正常投切时暂态高次谐波分量含量的不同来区分故障与正常投切操作。大量ATP仿真及RDTS实验结果表明，该判据具有良好的性能，能保证电容器正常投切时不误发信号，从而提高电网安全性和可靠性。

Novel Non-unit Transient-based Protection of Single Phase High-impedance Fault

A novel technique based on non-unit transient to detect single phase high-impedance fault (HIF) is presented. HIF of high-voltage transmission line is difficult to be detected, and it is easy to be affected by the normal operation such as the switching events. Analysis results show that when a single phase fault happens in a transmission line, wavelet transformation of the zero-sequence current and the fault phase current will exhibit special characteristic, which can be used to detect HIF. Moreover, HIF and the normal switching events can be discriminated by using the difference of the corresponding high frequency component. ATP simulation results show that the criterions can be used to detect HIF with high reliability.