中性点不接地系统故障充电暂态信号定位法

Single Phase Earth Fault Location Method in Isolated Neutral System Using Charge Transients

中国中压配电网的中性点主要采用非有效接地系统,此类系统在发生单相接地故障后的一个重要特点是故障相电压降低,非故障相电压升高。由于线路存在电容和电感,故非故障相电压升高的这一暂态过程可看作对非故障相电容的充电暂态过程。利用出线故障录波器记录的电压电流波形信息,通过对充电暂态信号进行频谱分析、信号提取然后再进行故障的定位,并通过Matlab进行了仿真分析,证明了所提方法的正确性。

The neutral points in medium-voltage distribution system in China are mainly non-effectively earthed. An important characteristic of this system is that the voltage of fault phase is decreasing and the voltage of non - fault phase is increasing after single - phase earth fault happened. Due to the existing line capacitance and line inductance, the transient progress of non - fault phase voltage increasing can be regarded as a charge transient. Using voltage and current waveform information recorded by the fault recorder installed in the bus bar, the spectrum analysis and signal extraction of charging transient signal are carried out, and then the fault is located. The validity of the proposed method is proved by Matlab simulation analysis.