基于暂态零序电流特征分量的小电流接地故障定位

Small Current Earth Fault Location in Distributed Network Based on Characteristic Components of Transient Zero-sequence Current

分析了中性点非有效接地系统零序网络的相频特性,提出了首容性频段的概念,分析了首容性频段内暂态零序电流的特点,提出了检测相邻FTU暂态零序电流相关性的故障定位方法。该方法不受中性点接地方式、故障初相角和过渡电阻的影响,检测灵敏度高,不需要安装电压互感器,既提高了安全性又节省了投资。仿真验证了该方法的正确性。

This paper analyzes the phase-frequency characteristic of zero sequence network in neutral ineffectively grounded system, puts forward the concept of the first capacitive frequency band, and also analyzes the characteristics of transient zero-sequence current in the first capacitive band. A new method of fault location based on the correlation of the transient zero-sequence current detected in adjacent FlU is proposed. This method can overcome the influence of neutral-point grounding mode, fault initial angle and interim resistance, and work without voltage transformer, which not only enhance the safety but also save the investment. The simulation shows that this method is correct.