基于双平衡桥探测直流系统接地故障检测的新方法

摘要

针对电桥法、变频法等常用接地故障检测方法的不足,提出了一种新的双桥探测法用于直流系统的故障检测,该方法通过控制开关两次投切电阻,检测双桥不平衡电流以及支路漏电流,并计算接地故障电阻,从而定位接地支路.首先详细阐述了双桥探测的基本原理及应用,然后提出一种新的双桥探测法,该方法不仅能够解决检测死区问题,并且不受分布电容的影响.最后通过模拟接地电阻试验证实了该方法的可行性和有效性.%To solve the lack of common methods of ground fault such as electric bridge method and variation frequency method, this paper proposes a new double balance bridge detection method for circuit grounding fault detection in DC system.In this method, unbalance current in the double balance bridge and the branch leakage current are detected by controlling twice switching resistance of the programmable switches, and then, calculating the ground fault resistance and positioning the grounding branch.This paper firstly expounds the basic principle and application of double bridge detection, and then, proposes a new double balance bridge detection method to solve the problem of detection of dead zone, and this detection method is not affected by the influence of distributed capacitance.Finally, the simulation of grounding resistance experiments proves the feasibility and effectiveness of this method.