35kV主变差动保护动作跳闸分析  

Analysis of 35 kV Main Transformer Differential Protection Trip

作　　者：张乔石 张雄 王文兵 周仿荣 徐腾波 苏应敢 付文诚 Zhang Qiaoshi;Zhang Xiong;Wang Wenbing;Zhou Fangrong;Xu Tengbo;Su Yinggan;Fu Wencheng(Nujiang Power Supply Bureau of Yunnan Power Grid Corporation,Nujiang 673100,Yunnan,China;Electric Power Research Institute of Yunnan Power Grid Corporation,Kunming 650127,Yunnan,China;Dehong Power Supply Bureau of Yunnan Power Grid Corporation,Dehong 678400,Yunnan,China;Yuxi Power Supply Bureau of Yunnan Power Grid Corporation,Yuxi 653100,Yunnan,China;Dali Power Supply Bureau of Yunnan Power Grid Corporation,Dali 671000,Yunnan,China;Xishuangbanna Power Supply Bureau of Yunnan Power Grid Corporation,Xishuangbanna 666100,Yunnan,China;Qujing Power Supply Bureau of Yunnan Power Grid Corporation,Qujing 655000,Yunnan,China)

机构地区：[1]云南电网有限责任公司怒江供电局,云南怒江673100 [2]云南电网有限责任公司电力科学研究院,云南昆明650127 [3]云南电网有限责任公司德宏供电局,云南德宏678400 [4]云南电网有限责任公司玉溪供电局,云南玉溪653100 [5]云南电网有限责任公司大理供电局,云南大理671000 [6]云南电网有限责任公司西双版纳供电局,云南西双版纳666100 [7]云南电网有限责任公司曲靖供电局,云南曲靖655000

出　　处：《云南电力技术》2024年第4期50-55,共6页Yunnan Electric Power

摘　　要：本文介绍了一起35 kV主变差动保护动作跳闸事故,通过对故障间隔设备进行逐一排查分析和对关键元器件的材质分析、安装工艺进行分析,结合排除法、现场相关数据及软件模拟分析,导致301断路器跳闸的主要原因为隔离开关动触头螺杆端部存在尖端毛刺,运行过程中产生悬浮电位,系统电压波动、湿度增加时尖端毛刺放电造成B、C相瞬间短路,最终导致主变差动速断及比率差动保护动作。对整个放电故障过程进行了分析,并提出了相对应的防范措施。该次35 kV主变差动保护动作跳闸案例为今后类似事故的防范和处理提供了经验与参考。This paper introduces an incident of a 35 kV main transformer differential protection action trip,and through the method of systematically examining and analyzing each device in the fault bay,as well as analyzing the material quality and installation techniques of key components,combined with the elimination method,on-site relevant data,and software simulation analysis,it is determined that the primary cause for the trip of circuit breaker 301 was the presence of sharp burrs at the end of the moving contact screw of the disconnector.During operation,these sharp burrs generated afloating potential,and when there werefluctuations in system voltage or increased humidity,discharge occurred due to the sharp burrs causing an instantaneous short circuit between phases B and C,ultimately triggering the main transformer differential instantaneous and ratio differential protections.The entire process of the discharge fault has been analyzed,and corresponding preventive measures have been proposed.This case study of a 35 kV main transformer differential protection action trip provides experience and reference for the prevention and handling of similar incidents in the future.

关 键 词：断路器 变压器 隔离开关 尖端毛刺放电 仿真 

分 类 号：TM74[电气工程—电力系统及自动化]