采用特征频率电流相位相似度的配电网接地故障选线方法  

Line Selection Method for Grounding Faults in Distribution Networks Based on Phase Similarity of Characteristic Frequency Current

作　　者：李江涵 张钧益 熊庆[1] 庄毅 唐逸杰 张其旺 王致文 汲胜昌[1] LI Jianghan;ZHANG Junyi;XIONG Qing;ZHUANG Yi;TANG Yijie;ZHANG Qiwang;WANG Zhiwen;JI Shengchang(State Key Laboratory of Electrical Insulation and Power Equipment,Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]西安交通大学电工材料电气绝缘全国重点实验室,710049西安

出　　处：《西安交通大学学报》2025年第4期81-92,共12页Journal of Xi'an Jiaotong University

基　　金：国家重点研发计划资助项目(2022YFB3205700)。

摘　　要：针对小电流接地系统单相接地故障选线存在特征微弱、选线效果易受接地过渡电阻影响等难题,提出了一种采用特征频率电流相位相似度的配电网接地故障选线方法。首先,采用信号注入法,对小电流接地系统发生单相接地故障后的零序电流分布和注入特征电流信号分布展开分析,获得了故障特征电流分布规律;其次,分析不同特征频率、线路长度和线路拓扑结构对注入电流信号传播特性的影响,选择220 Hz作为注入电流的特征频率。采用PSCAD/EMTDC平台,搭建了配电网仿真模型,当故障发生后注入特征频率电流,分析每条线路特征频率信号的幅值和相位特征,利用特征频率电流的相位,提出了采用特征频率电流相位相似度的选线方法,构建了单相接地故障选线判据。对单相接地故障的不同接地过渡电阻工况进行仿真实例验证,并利用所提方法进行选线,结果表明:在高阻接地工况下,所提方法能够准确识别故障线路,具备较高的灵敏度和准确性;与传统选线方法相比,所提方法的复杂度更低,且可将接地过渡电阻提升至10 kΩ。所提方法可为小电流接地系统单相接地故障选线的理论研究提供一种新思路。In response to the challenges of weak characteristics and the influence of grounding transition resistance on line selection for single-phase grounding faults in low-current grounding systems,a line selection method for grounding faults in distribution networks based on the phase similarity of characteristic frequency current is proposed.Firstly,using signal injection method,the distribution of zero-sequence current and characteristic current signal distribution after a single-phase grounding fault occurs in a low-current grounding system is analyzed to obtain the fault characteristic current distribution pattern.Secondly,the impact of different characteristic frequencies,line lengths,and line topologies on the propagation characteristics of the injected current signals is analyzed,with 220 Hz selected as the characteristic frequency for the injected current.Using the PSCAD/EMTDC platform,a distribution network simulation model is built.After a fault occurs,characteristic frequency current is injected,and the amplitude and phase characteristics of the characteristic frequency signals for each line are analyzed.By utilizing the phase of the characteristic frequency current,a line selection method based on the phase similarity of characteristic frequency currents is proposed,and criteria for single-phase grounding fault line selection are established.Simulation examples are conducted for different grounding transition resistance conditions of single-phase grounding faults,and line selection is performed using the proposed method.Results show that under high-resistance grounding conditions,the proposed method can accurately identify the faulty line with high sensitivity and accuracy.Compared to traditional line selection methods,the proposed method has lower complexity and can handle grounding transition resistance up to 10 kΩ.This method provides a new perspective for the theoretical research on line selection for single-phase grounding faults in low-current grounding systems.

关 键 词：配电网 单相接地故障 信号注入 故障选线 电流相位相似度 

分 类 号：TM862[电气工程—高电压与绝缘技术]