10 kV配电网单相接地故障定相方法研究

Study on Phasing Method of Single-Phase Grounding Fault in 10 kV Distribution Network

10 kV配电网中发生单相接地故障的次数较多,且难以得到快速处理。通过相电压判断故障相的方法适用于经低电阻接地的配电网系统,但是随着配电网的容量越来越大,接地电阻也在增加。故障相的电压在发生单相接地故障瞬间的波动较为激烈,其电压分布频次的方差较大。因此,提出了一种适用于各类接地系统的故障相判断方法,即通过三相电压分布频次的方差判断故障相。为了验证该方法的有效性,搭建了仿真模型。仿真结果表明,该方法能够正确判断故障相,为快速解决故障提供了可靠的保障。

There are many times of single-phase grounding in 10 kV distribution network,and it is difficult to get fast treatment.The method of judging fault phase by phase voltage is suitable for distribution system grounded with low resistance.However,as the capacity of distribution network increases,the grounding resistance also increases,so the method of judging fault phase by voltage has its limitations.The voltage of the fault phase fluctuates violently at the moment of single-phase grounding fault,so the variance of the voltage distribution frequency is large.This paper presents a fault phase judgment method which is suitable for all kinds of grounding systems.The fault phase is judged by the variance of voltage distribution frequency.In order to verify the effectiveness of this method,a simulation model is built.The simulation results show that the method can judge the fault phase correctly and provide a reliable guarantee for the quick solution of the fault.