摘要
以某化工厂110kV变电站10kV开关柜内过电压保护器热崩溃引发断路器跳闸、开关柜电缆室爆炸的事故为例,从过电压保护器结构及工作原理入手,根据事故现象对事故发生原因进行逐一排查和分析,综合判断造成这起事故的原因为10kV系统B相反复间歇电弧接地引发铁磁谐振过电压,导致过电压保护器内氧化锌电阻片热崩溃,继而引发开关柜内AC相间短路故障和电缆室爆炸,分析结果表明该型过电压保护器的三相四星形接线结构缺陷是此次事故发生的根源。最后,为防止类似事故再次发生,提出消除和防范措施,为确保电力系统安全稳定运行提供参考。
Taking the accident of circuit breaker tripping and switchgear cable room explosion caused by thermal runaway of the overvoltage protector in 10kV switchgear of a 110kV substation in a chemical plant as an example,starting from the structure and working principle of the overvoltage protector,the causes of this accident are investigated and analyzed according to the accident phenomenon.The comprehensive analysis show that the cause of this accident is the ferromagnetic resonance overvoltage caused by the reverse complex intermittent arc grounding of 10kV system B,which causes the thermal runaway of the zinc oxide resistance sheet in the overvoltage protector.This then causes the AC phase short circuit fault in the switchgear and the explosion of the cable room,indicating that the root cause of the accident is caused by the defect of the three-phase four-star wiring structure of the overvoltage protector.Finally,in order to prevent similar accidents from happening again,elimination and preventive measures are proposed,which provides reference for ensuring the safe and stable operation of the power system.
作者
左涛
ZUO Tao(Leshan ELECT Electrified Wire Netting Automation Co.,Ltd,Leshan,Sichuan 614000)
出处
《电气技术》
2024年第2期68-73,共6页
Electrical Engineering
关键词
开关柜
过电压保护器
间歇电弧接地
铁磁谐振
热崩溃
switchgear
overvoltage protector
intermittent arc grounding
ferromagnetic resonance
thermal runaway
