基于三相电流幅值分析的小电流单相接地故障区段定位方法  

Method of fault section location for the small current single-phase-to-ground faultbased on the amplitude analysis of three-phase current

作　　者：万信书 方连航 梁钰 吴强 刘红岩 WAN Xinshu;FANG Lianhang;LIANG Yu;WU Qiang;LIU Hongyan(Electric Power Research Institute of Hainan Power Grid Co.,Ltd.,Haikou 570203,China)

机构地区：[1]海南电网有限责任公司电力科学研究院,海南海口570203

出　　处：《电力科学与技术学报》2020年第4期49-57,共9页Journal of Electric Power Science And Technology

基　　金：海南电网有限责任公司科技项目(073000KK52170010)。

摘　　要：小电流接地系统单相接地故障定位一般由主站综合计算多个不同的电气量来实现。该方法计算量大且复杂,易产生较大误差,难以适用于结构复杂的配电网。对此,提出一种基于三相电流幅值分析的小电流单相接地故障定位方法。通过分析单相接地故障电流得出,故障路径上2个非故障相的相电流变化量近似相等,且小于故障相的相电流变化量;非故障路径上2个非故障相的相电流变化量近似相等,且与故障相的相电流变化量近似相等。根据三相故障电流故障前后幅值变化量设置判据以判断故障相并实现故障区段定位。ATP仿真结果验证该定位方法在不接地系统和经消弧线圈接地系统的可行性。该方法可实现就地定位,定位判据简单,降低了主站的计算复杂度。Single-phase-to-ground fault section location in small current grounded system is generally realized by a master station comprehensively calculating several different electrical quantities.This method is unsuitable for distribution networks with complex structures since its large workload and complicated calculations easily brings large errors.Under the background,a fault location method of distribution network based on three-phase current amplitude analysis is proposed.In views of the analysis on the three-phase current of single-phase-to-ground fault in small current grounded system,the current changes of the two non-fault phases on the fault path are approximately equal and less than the current change of fault phase.The phase current change of the two non-fault phases on the non-fault path are approximately equal and also equal to the current change of fault phase.By calculating the amplitude change of three-phase current before and after fault and setting the criterion,the fault phase can be selected and the fault section can be located.ATP simulation results verify the applicability in neutral ungrounded system and neutral point grounding system via arc suppression coil.The local location of fault is realized successfully.The proposed method is simple in location criterion and reduces the computational complexity of the master station.

关 键 词：小电流接地系统 单相接地故障 故障定位 相电流幅值 

分 类 号：TM771[电气工程—电力系统及自动化]