中压系统单相接地故障熄灭电弧研究

Research on Extinguishing Arc of Single-phase Grounding Fault in Medium Voltage System

为重点解决电网单相接地故障时电容电流逐渐增大,传统的配电网消弧消谐装置无法有效的消除弧光接地过电压,并且存在选线准确率低、定位难等问题,本次通过研究电缆、架空及混联线路等各种线路条件下的单相接地故障的判别方法、故障选线技术和故障定位技术,在此基础上研究基于快速开关的电网消弧消谐装置,将电网发生单相接地故障时的不稳定间歇性弧光接地转换为稳定的金属性接地,缩短短路电流的持续时间,准确快速确定故障线路。

In order to solve the problem that the capacitance current gradually increases when the single-phase grounding fault occurs in the power grid,the traditional arc and harmonic suppression devices in the distribution network can not effectively eliminate the arc grounding overvoltage,and there are problems such as low line selection accuracy and difficult positioning.This paper studies the identification method,fault line selection technology and fault location of single-phase grounding fault under various line conditions such as cable,overhead and hybrid lines.On this basis,the arc and harmonic suppression device based on fast switch is studied,which can convert the unstable intermittent arc grounding into stable metal grounding when single-phase grounding fault occurs in power grid,shorten the duration of short-circuit current,and accurately and quickly determine the fault line.