基于低压侧负序量特征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 Negative Sequence Characteristics of Low-voltage Side

作　　者：张明泽 栾文鹏 艾欣[1] 徐丙垠[3] 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 Electrical and Information Engineering,Tianjin University,Nankai District,Tianjin 300072,China;School of Electrical and Electronic Engineering,Shandong University of Technology,Zibo 255000,Shandong Province,China;China Electric Power Research Institute,Haidian District,Beijing 100192,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]山东理工大学电气与电子工程学院,山东省淄博市255000 [4]中国电力科学研究院有限公司,北京市海淀区100192

出　　处：《电网技术》2024年第4期1654-1662,I0079,共10页Power System Technology

基　　金：国家重点研发计划项目(2020YFB0905900)。

摘　　要：随着台区智能终端量测技术的逐步成熟,实现低压侧全息感知的同时,具备对上级中压配网的多点监测能力。提出基于低压侧负序量特征的小电流系统单相接地故障检测方法。分析了中压侧发生单相接地故障后低压侧负序量的变化规律;利用负序电流大小区分故障线路和非故障线路;提出通过负序电压与正序电压的比值系数,多点协同计算对比判断故障点区段位置,且考虑了低压侧不平衡负荷,以及故障点位于线路一端的特殊情况。通过MATLAB软件和动模实验对中低压联合配电系统的仿真计算,验证了所提方法具有良好的鲁棒性和准确性。通过智能配变终端监测上级中压配网负序量信息,实现小电流接地系统故障检测,具有实际应用和推广价值。With the gradual maturity of intelligent terminal measurement technology in the low-voltage distribution network,achieving holographic perception on the low-voltage side while also possessing the ability to monitor multiple points of the medium-voltage distribution network.This paper proposed a method of single-phase grounding fault detection for an un-effectual grounding system based on the low-voltage side's negative-sequence characteristics.The characteristics of the negative sequence signal at the low-voltage side after a single-phase grounding fault occurred on the medium-voltage side are analyzed;the negative-sequence current can distinguish the fault and non-fault lines.after setting the ratio coefficient of negative-sequence voltage and positive-sequence voltage,multi-point collaborative calculation and comparison can be used to determine the section of the fault point.The unbalanced load at the low-voltage side and the special case of a fault point at one end of the line are considered.Through the simulation of medium-voltage and low-voltage combined distribution systems in MATLAB software and dynamic model experiment,it is verified that the proposed method has good robustness and accuracy.Monitoring the status information of the medium-voltage distribution network through the smart distribution transformer terminal to realize the fault detection of neutral un-effectual grounding systems has great potential in practical application and implementation.

关 键 词：故障检测 单相接地故障 小电流系统 低压量测 负序量 

分 类 号：TM721[电气工程—电力系统及自动化]