基于电弧畸变特性的配电网弧光高阻故障检测方法

High-Impedance Fault Detection Based on Arc Distortion Characteristics in Distribution Networks

中文关键词:高阻故障  电弧电阻  电弧畸变特性  故障指标

keywords:high-impedance fault  arc resistance  arc distortion characteristics  fault indicators

中文摘要:针对配电网发生高阻故障（high impedance fault， HIF）时，因故障特征微弱而使现有保护装置难以检测到故障的问题，该文通过分析电弧电阻的变化特性，提出了一种基于电弧畸变特性的配电网弧光高阻故障检测方法。根据电弧的动态过程，分析了电弧电流的畸变特性；基于电弧畸变特性，引入2种故障指标：电弧畸变时段指标和电弧畸变程度指标；综合利用2种指标，建立了弧光高阻故障的检测判据。仿真结果表明，该方法可准确区分弧光高阻故障事件和正常瞬时扰动事件，如负荷投切、电容投切和变压器涌流。

Abstract:When a high-impedance fault （HIF） occurs in a distribution network，the existing protection devices are difficult to detect the fault due to the weak fault characteristics. To address this issue，this paper proposes a method for detecting arc high-impedance faults in distribution networks based on arc distortion characteristics by analyzing the variation characteristics of arc resistance. According to the dynamic process of the arc，the distortion characteristics of the arc current are analyzed；based on the arc distortion characteristics，two types of fault indicators are introduced： the first is the arc distortion time-period indicator，and the second is the arc distortion degree indicator；by comprehensively using these two indicators，a detection criterion for arc high-impedance faults is established. A large number of simulation results show that this method can accurately distinguish arc high-impedance fault events from normal transient disturbance events，such as load switching（LS），capacitor switching（CS） and transformer inrush current（IC）.