配电线路单相接地故障自愈方案

Self-healing of single-phase grounding fault for power distribution lines

针对配电线路的单相接地故障,提出了故障自愈方案。方案包括单相接地故障检测、故障选线、故障区段识别和接地线路隔离4个部分。故障检测基于母线上的电压互感器开口三角侧电压,当测量电压大于整定值时,判断系统中发生了单相接地故障;故障选线基于线路上的电流行波,极性与众不同的电流行波所在线路为接地线路;故障区段识别基于故障选线的综合结果;选出故障母线后,先闭合接地线路负荷侧的联络开关,再打开接地线路负荷侧进线开关,最后隔离接地线路电源侧。仿真结果表明,所提自愈方案可实现单相接地故障自动快速隔离,故障隔离过程中负荷不失电。

A self-healing scheme is presented for the single-phase grounding fault of distribution lines,which consists of four parts：fault detection,faulty feeder selection,faulty section identification and faulty feeder isolation.The fault detection is based on the open-delta-side voltages of PT.A single-phase grounding fault is identified when the measured voltage is greater than the setting value.The faulty feeder selection is based on the current traveling waves.The feeder with different traveling wave polarity is selected as the faulty one.The faulty section identification is based on the synthesized results of faulty feeder selection.After the faulty feeder is selected,close the interconnection switch at the load side first,then open its incoming switch and isolate the power source side of faulty.Simulative results show that the scheme realizes the automatic quick isolation of single-phase grounding fault without power loss of load.