基于柔性接地装置的不对称配电网接地故障选相选线方法  

A method of phase selection and line selection for grounding faults in an asymmetric distribution network based on a flexible-grounding device

作　　者：陈柏宇 喻锟[1] 曾祥君[1] 李理[1] 胥鹏博 彭红海[2] CHEN Boyu;YU Kun;ZENG Xiangjun;LI Li;XU Pengbo;PENG Honghai(Hunan Province Key Laboratory of Smart Grids Operation and Control(Changsha University of Science and Technology),Changsha 410114,China;Hunan University,Changsha 410082,China)

机构地区：[1]智能电网运行与控制湖南省重点实验室(长沙理工大学),湖南长沙410114 [2]湖南大学,湖南长沙410082

出　　处：《电力系统保护与控制》2022年第12期1-10,共10页Power System Protection and Control

基　　金：国家自然科学基金项目资助(51737002,52037001);湖南省自然科学基金项目资助(2021JJ30729)。

摘　　要：配电网高阻接地故障选相和选线一般较为困难。为解决这两个问题,提出了一种基于柔性接地装置的不对称配电网接地故障选相选线方法。首先详细分析各馈线零序电流在中性点零序电压调控前后的变化情况。利用不同调控状态下故障与健全馈线零序等值导纳的离散程度来辨识故障馈线,得出故障馈线辨识函数并构造了选线判据。其次,根据分相调控过程中馈线零序等值导纳与故障前馈线对地导纳差值的相角关系进行故障相判别,得出故障选相函数并构造了选相判据。理论分析和PSCAD/EMTDC仿真实验表明:配电网三相对地导纳不对称情况对所提方法并无影响,低、高阻接地故障时均有较高灵敏度,故障选相与选线结果准确,且选相和选线方法得到有效结合。It is generally difficult to select high-resistance ground fault phases and fault lines in distribution networks.This paper proposes a new method of phase selection and line selection for high-resistance faults in asymmetric distribution networks based on a flexible-grounding device. First, the change characteristic of the zero-sequence current of each feeder before and after zero-sequence voltage regulation is analyzed in detail. It identifies the fault feeders using the dispersion degree of zero-sequence equivalent admittance of the faulted feeder and the healthy feeder in different regulation and control states. Thus the fault line identification function is obtained and a line selection criterion is constructed. Secondly, the fault phase is identified according to the angular relationship between the zero-sequence equivalent admittance of the feeder during the phase separation adjustment process and the ground admittance value of the feeder before the fault. The fault phase selection function is derived and the phase selection criterion is constructed.Theoretical analysis and PSCAD/EMTDC simulation show that the asymmetry of the three-phase ground admittance of the distribution network has no effect on the method proposed. Both low and high resistance ground faults have higher sensitivity in the method, the fault phase selection and line selection results are accurate, and the phase selection and line selection methods are effectively combined.

关 键 词：不对称配电网 选相 选线 单相接地故障 零序电流 

分 类 号：TM862[电气工程—高电压与绝缘技术]