摘要
介绍了某220 kV变电站发生的一起主变压器低压侧10 kV隔离开关异常烧蚀引发主变压器三侧断路器跳闸故障,对故障隔离开关进行现场解体检查。检查结果表明,由于隔离开关锁紧机构未夹紧,动触臂、静触头之间接触面积减小,接触压力下降,接触电阻增大引起发热,且部分电流通过止挡杆通流。分析故障原因是隔离开关C相止挡杆在负荷电流作用下严重发热发生金属熔断,引起周围电场畸变,在电弧运动、气体膨胀和金属熔融物的共同作用下,进一步发展为三相短路故障。结合故障原因提出了防范措施,提高了设备安全可靠运行水平。
An abnormal ablation of 10 kV isolating switch on the low voltage side of the main transformer in a 220 kV substation causes three-side breaker tripping failure.The on-site disassembling inspection of the fault isolating switch is carried out.The inspection results show that the locking mechanism of the isolating switch is not clamped,the contact area and contact pressure between the moving contact arm and the static contact decrease,the contact resistance increases and causes heating,and part of the current flows through the stop bar.The cause of the fault is concluded that the C-phase stop bar of the isolating switch seriously heated under the action of the load current,causing the distortion of the surrounding electric field,which further develops into the three-phase short-circuit fault under the joint action of arc movement,gas expansion and metal melt.Combined with the causes of the isolation switch failure,the preventive measures are proposed to improve safe and reliable equipment operating level.
作者
朱思丞
汤明
吴靖
ZHU Sicheng;TANG Ming;WU Jing(State Grid Hangzhou Power Supply Company,Hangzhou,Zhejiang 310007,China)
出处
《东北电力技术》
2025年第5期28-31,共4页
Northeast Electric Power Technology
关键词
主变压器
隔离开关
异常烧蚀
main transformer
isolating switch
abnormal ablation
作者简介
朱思丞(1994),男,硕士,工程师,从事变电检修相关工作。
