输电线路故障行波定位装置难以在实验室得到校验。文中提出了采用高压冲击实验测试雷电行波及利用实时数字仿真器RTDS测试各种故障行波的实验测试方法，并进行了定位装置的耐压测试，校验了因两端定位装置的硬件不一致而产生的定位误差。该方法适合于测试基于行波传感器的故障定位装置。

Many High impedance ground faults (HIGF) that happen in low voltage (LV) system often cause customer supply lost, fire and human safety hazard. Traditional ground fault protection is provided by Residual Current Circuit Breaker 0RCCB). The RCCB often causes nuisance tripping and is difficult to detect HIGF. Wavelet analysis based HIGF protection is developed in the paper. Wavelet transform is applied to filter out some frequency bands of harmonics from residual current and line current. The root mean square (RMS) value of harmonics are calculated using their wavelet coefficients directly. HIGF is identified from disturbance by the RMS difference between the residual current and the line current. The digital protection scheme is designed. EMTP simulation results show that the new protection is able to detect HIGF and prevent electric shock with high sensitivity and robustness.

提出了采用测量线路零序导纳进行接地保护的新原理，讨论了直线式导纳继电器的接地保护判据。该原理克服了传统的小电流接地系统故障选线方法安装不便，可靠性不高等不足。只需测量本线路的零序电压、零序电流基波分量，适合在馈线保护中实现和就地终端单元（FTU）安装，可靠性高。经EMTP仿真分析表明：该方法具有较高的保护精度，能满足高阻接地保护的要求。

介绍了传统的消弧线圈自动调整方法。提出采用注入变频信号，寻找系统谐振频率，测量补偿度、电容电流，进行消弧线圈自动跟踪调谐的新方法。测量时无需调整消弧线圈挡位。能适用于老式消弧线圈补偿度的测量。在一个配电网中只需安装一台自动调整消弧线圈，就能实现整个配电网的自动调谐，无需通信配合。该技术已在现场运行多年，效果良好。

Many industrial power systems have been operatedwith floating neutral or high resistance grounding. Withtraditional fault detection methods, based on zero sequencecurrent, it is difficult to satisfy the requirement of distributionautomation (DA). In order to improve this, some noveltechniques for ground fault feeder detection are presented in thispaper, and they are implemented by using the informationobtained from the feeder terminal unit (FTU). The faulty feederis identified with fuzzy analysis. These protection schemes havebeen verified by EMTP simulation. A prototype has beendeveloped and tested in a dynamic power system. Results showthat these proposed protection schemes have high sensitivity androbustness to detect all kinds of ground faults.