一起接地变跳闸引起全站失压的事故分析  

Analysis of an Accident of the Grounding Transformer Tripping Caused the Whole Station to Lose Voltage

作　　者：李沐峰 陈昕[1] 王珏[1] 韩觐伊 沈钟浩 龙明洋 郭慧东 LI Mufeng;CHEN Xin;WANG Jue;HAN Jinyi;SHEN Zhonghao;LONG Mingyang;GUO Huidong(Zhengzhou Power Supply Company,Zhengzhou 450000,China)

机构地区：[1]国网郑州供电公司,河南郑州450000

出　　处：《河南科技》2022年第15期45-50,共6页Henan Science and Technology

摘　　要：本研究针对某城市内重要的110 kV变电站内低电阻接地形式的10 kV系统中某馈线发生单相接地后,接地变相过流保护动作跳闸,对引起导致全站10 kV失压原因进行深入分析,通过列出故障复合序网图、复合序网理论分析计算,阐述中性点经低电阻接地系统在发生单相接地故障后相电流与零序电流的特征,给出继电保护整定与配合中存在的问题,并从故障录波的波形实际数值与理论计算分析给予证明。最后,通过相关规程规定给出改进定值配置的建议措施,避免类似情况的发生。In a 10 kV power supply system with low resistance grounding in an important 110 kV Substa⁃tion in the city,after a single-phase grounding of a feeder occurs,the grounding phase change overcurrent protection action trips,and then causes the 10 kV voltage loss of the whole station.By listing the fault composite sequence network diagram and theoretical analysis and calculation of the composite sequence network,this paper expounds the neutral grounding system through low resistance.The characteristics of phase current and zero sequence current after single-phase grounding fault,and the problems in relay protection setting and coordination are given,which are proved by the actual value of fault recording waveform and theoretical calculation and analysis.Finally,suggestions for improving the fixed value con⁃figuration are given through considering the regulations,which is enough to avoid the occurrence of simi⁃lar situations.

关 键 词：低电阻接地系统 单相接地 复合序网 零序电流 

分 类 号：TM77[电气工程—电力系统及自动化]