配网小电流接地故障点快速自动查找方法研究

Research on Quick and Automatic Search Method for Small Current Grounding Fault Points in Distribution Networks

针对现有查找方法中判据函数极点与实际情况不符,导致查找结果偏离故障区间的问题,提出了一种配网小电流接地故障点的快速自动查找方法。该方法通过在系统中性点与地之间引入一个中值电阻,一旦发生接地故障,电路中的分流现象会产生异常故障电流,从而便于定位故障点。结果显示,该方法在故障定位误差和耗时方面均显著优于现有方法,在所有测试馈线中,本文方法的定位误差均小于1.23 m;在所有测试次数中,该方法的故障定位耗时均不超过4.98 min,证明该方法在提高故障定位精度和响应速度方面的显著优势。

In response to the problem that the poles of the criterion function in existing search methods do not match the actual situation,resulting in search results deviating from the fault interval,this study proposes a fast automatic search method for small current grounding fault points in distribution networks.This method introduces a median resistor between the neutral point of the system and ground.When a ground fault occurs,the shunt phenomenon in the circuit will generate abnormal fault currents,making it easier to locate the fault point.The results show that the proposed method is significantly superior to existing methods in terms of fault location error and time consumption.Among all tested feeders,the location error of the proposed method is less than 1.23 m.In all test cycles,the fault localization time of this method did not exceed 4.98 min,demonstrating its significant advantages in improving fault localization accuracy and response speed.