主动干预型消弧装置的附加电阻故障选相方法

正确选定故障相是主动干预型消弧装置正确动作的前提和基础，发生误选将引发更严重的相间短路故障。为提高故障选相准确率，本文提出了一种中性点附加电阻的选相方法。该方法通过投切附加电阻，实现线路对地参数的快速估计；进而利用系统正常状态和故障状态下各相对地参数的变化差异，精确辨别故障相。仿真结果表明，方法性能优于传统的相电压幅值比较法，在高阻接地和电弧接地时仍具有较高的选相准确率。

Additional resistance based fault phase identification method suitable for active interference arc suppression device

The accurate identification of the faulty phase is of great importance for active interference arc suppression device. When mis-selection occurs, it will lead to more serious inter-phase fault. In order to improve the accuracy of fault phase selec-tion, this paper presents a method of phase selection using additional resistance of neutral point. This method calcu-lates the parameters of ground in real time by switching in/off the additional resistance on the neutral point, and the equivalent impedance of the network can be estimated. Then the fault phase can be identified by using the difference of parameters between normal and fault states. Simulation results show that this method performed better than the tra-ditional phase voltage amplitude comparison method. The accuracy for faulty phase selection is high even under arc-ing or high resistance grounding fault scenarios.