基于低压量测的小电流系统单相接地故障检测方法  

Single-phase Grounding Fault Detection in Non-solidly Earthed Network Based on Low-voltage Measurements

作　　者：张明泽 栾文鹏 艾欣[1] 徐丙垠[4] ZHANG Mingze;LUAN Wenpeng;AI Xin;XU Bingyin(School of Electrical and Electronic Engineering,North China Electric Power University,Changping District,Beijing 102206,China;School of Electric and Information Engineering,Tianjin University,Nankai District,Tianjin 300072,China;China Electric Power Research Institute,Haidian District,Beijing 100192,China;School of Electrical and Electronic Engineering,Shandong University of Technology,Zibo 255000,Shandong Province,China)

机构地区：[1]华北电力大学电气与电子工程学院,北京市昌平区102206 [2]天津大学电气自动化与信息工程学院,天津市南开区300072 [3]中国电力科学研究院有限公司,北京市海淀区100192 [4]山东理工大学电气与电子工程学院,山东省淄博市255000

出　　处：《电网技术》2023年第8期3457-3466,共10页Power System Technology

基　　金：国家重点研发计划项目(2020YFB0905900)。

摘　　要：小电流系统单相接地故障带来严重的公共安全隐患。配电物联网的发展建设为配电网的智能监测、自动化和保护控制带来了新的机遇和技术手段。该文提出一种基于配变低压侧的智能配变终端采集数据,识别中压配网单相接地故障线路,并将故障定位至大致范围的新方法。故障引发低压侧的暂态线模电压突变量在系统中不同点位的分布具有一定规律;在故障线路上,其瞬时值在故障点处最高并沿故障线路两侧递减,在电源母线处最小;而非故障线路低压侧的瞬时值要远小于故障线路,且沿线路递减,由此可以判断故障线路;最后通过比较故障线路下各台区低压侧的暂态线模电压突变量的最大值,确定故障点所处区段范围。仿真及真型试验结果验证了所提方法的有效性。通过广泛部署的智能配变终端多点协同监测中压配网状态信息,实现小电流接地系统故障检测,无需额外投资具有良好工程推广价值。Single-phase grounding fault of non-solidly earthed network is a serious public safety hazard in distribution system.The implementation of distribution internet of things brings new ways and opportunities for intelligent monitoring,automation,and protection control of distribution network.This paper presents a new method to detect and identify the fault location of non-solidly earthed network by analyzing the measurement data from smart distribution transformer terminals.When fault occurs in medium-voltage feeder,the abrupt change of transient aerial-mode voltage at transformer low-voltage side presents specific distribution characteristics;In the faulted feeder,the maximum voltage magnitude occurs in the fault location and the magnitude decreases along the feeder when getting further from it,with the minimum value occurs at the source end;the magnitude of the transient aerial-mode voltage at the low-voltage side of the non-fault feeder is smaller than that of the faulted feeder,and decreases along the feeder,so that the faulted feeder can be determined.Finally,the approximate fault location is identified by comparing and finding the maximum value of transient aerial-mode voltage variation on the low-voltage side of distribution transformers.Both the results of simulation and lab experiment show the effectiveness of the proposed method.Monitoring the operation status of the medium-voltage distribution feeders through the widely deployed smart distribution transformer terminals to realize the fault detection of non-solidly earthed network requires no additional capital investment thus has great potential for practical implementation.

关 键 词：故障检测 单相接地故障 小电流系统 低压量测 

分 类 号：TM721[电气工程—电力系统及自动化]