摘要
为解决配电网三相不平衡导致的高阻单相接地故障准确选相难题,从探究不平衡配电网零电势点偏移状态的角度出发,提出一种基于特征相位差的配电网高阻接地故障主动选相方法。解析三相导纳不对称状态下的零序电压相量偏移轨迹,揭示传统选相方法失效机理;通过柔性调控零序电压为不平衡电压,分析注入电流与各相电压相位差异;构建电流电压特征相位差选相判据,理论消除三相导纳不对称影响,实现高阻单相接地故障准确选相。在PSCAD/EMTDC仿真环境与真型试验场中搭建不平衡配电网单相接地故障场景,验证了所提出方法在不同过渡电阻、接地方式以及消弧线圈不同补偿状态情况下均能可靠识别故障相,具备高阻故障选相准确可靠、适用性强的优点。
To address the problem in accurately selecting the fault phase of high-resistance single-phase grounding faults caused by three-phase imbalance in distribution networks,an active phase selection method for high-resistance grounding faults in distribution networks based on the characteristic phase difference is proposed from the perspective of exploring the offset state of zero-potential point in unbalanced distribution networks.Through the analysis of the zero-sequence voltage phasor’s offset trajectory in an asymmetric state of three-phase admittance,the failure mechanism of traditional phase selection methods is revealed.By flexibly regulating the zero-sequence voltage to be the unbalanced voltage and analyzing the phase difference between the injected current and the phase voltage in each phase,a phase selection criterion based on the current-voltage characteristic phase difference is constructed.The influence of the asymmetric three-phase admittance is theoretically eliminated,and the accurate phase selection of high-resistance single-phase grounding faults is achieved.In a PSCAD/EMTDC simulation environment and a real test field,single-phase grounding fault scenarios for unbalanced distribution networks were built,and results indicated that the proposed method can reliably identify the fault phase under different transition resistances,different grounding methods and different compensation states of an arc suppression coil,showing advantages of accurate and reliable phase selection for high-resistance faults and strong applicability.
作者
朱虹洁
兰宇婷
贺世庚
黄龙
壮婕
ZHU Hongjie;LAN Yuting;HE Shigeng;HUANG Long;ZHUANG Jie(State Key Laboratory of Disaster Prevention and Reduction for Power Grid,Changsha University of Science and Technology,Changsha 410114,China;Loudi Power Supply Company,State Grid Hunan Electric Power Co.,Ltd.,Loudi 417000,China;Guangdong Zhongshan Power Supply Bureau,China Southern Power Grid Co.,Ltd.,Zhongshan 528400,China)
出处
《电力系统及其自动化学报》
北大核心
2025年第11期24-35,共12页
Proceedings of the CSU-EPSA
基金
国家自然科学基金资助项目(52037001)
国网湖南省电力有限公司科技项目(5216A321N303)。
关键词
不平衡配电网
单相接地故障
柔性调控
特征相位差
故障选相
unbalanced distribution network
single-phase grounding fault
flexible control
characteristic phase difference
fault phase selection
