一起接地变压器过流保护误动作的事故调查与分析  

Investigation and Analysis on One Fault Trip of Grounding Transformer Over-current Protection

作　　者：利卢雨[1] 刘洋[1] 郭小莜[1] 

机构地区：[1]广东电网公司东莞供电局,广东省东莞市523008

出　　处：《供用电》2013年第3期82-86,共5页Distribution & Utilization

摘　　要：针对10 kV配网系统采用中性点经消弧线圈接地运行方式时,接地变压器中性点避雷器被过电压击穿后出现系统运行方式被改变为中性点经小电阻接地方式的现象,结合保护配置及定值整定,通过实际发生的一起接地变压器过流保护误动作事故调查和现场保护装置实际动作的情况,分析了运行方式的变化带来保护装置的各种不适应以及造成接地变压器过流保护误跳和故障线路过流保护拒跳的原因。When the 10kV distribution network system operates in the neutral earthing via arc extinguishing coil mode, the operation mode will change to the neutral point grounding via low resistance the moment the grounding transformer neutral point arrester is broken down with over-voltage. In light with the protection configuration and settings, this paper analyzes all kinds of unsuitability of the protection resulted from the operation mode change and the causes of the grounding transformer protection malfunction and failure of the faulted feeder over-current protection, and proposes the corresponding improvement measures. An investigation of one fault trip of the grounding transformer over-current protection which actually occurred has proved correctness of the conclusion of the analysis in this paper.

关 键 词：电力系统 配电网 接地变压器 运行方式 动作保护 故障分析 

分 类 号：TM7[电气工程—电力系统及自动化]