550 kV罐式断路器放电原因分析及金属微粒对CT罐体电场影响研究  

Analysis on Discharge of 550 kV Dead Tank Circuit Breaker and Study on Influence of Metal Particles on Electric Field of CT Enclosure

作　　者：杨旭 韦晓星[1] 张长虹[1] 黎卫国[1] 杨洋 黄忠康 YANG Xu;WEIXiaoxing;ZHANG Changhong;LI Weiguo;YANG Yang;HUANG Zhongkang(Maintenance&Test Center of EHV Power Transmission Company China Southern Power Grid,Guangzhou 510663,China;Dali Bureau EHV Power Transmission Company China Southern Power Grid,Yunnan Dali 671000,China)

机构地区：[1]中国南方电网超高压输电公司检修试验中心,广州510663 [2]中国南方电网超高压输电公司大理局,云南大理671000

出　　处：《高压电器》2022年第2期214-220,共7页High Voltage Apparatus

摘　　要：文中介绍了某台550 kV罐式断路器处于热备用状态下发生内部放电的故障情况并进行详细的原因分析。从故障发生后的诊断性试验、解体检查、电场仿真3个方面开展全面分析,分析发现放电根本原因为异物在CT罐体屏蔽罩处引起场强畸变,导致发生间隙放电。此外,文中结合断路器结构研究了不同尺寸常见金属微粒在CT罐体处不同位置对电场的影响,仿真发现在当金属微粒的高度达到2 mm时,在屏蔽罩处最容易引起放电,CT罐体处盆式绝缘子不论凹沿面朝上还是凸沿面朝上,当微粒尺寸达到一定大小时,均可能引起放电。最后,针对事故原因,提出相应的处理措施。The internal discharge on one set of 550 kV dead tank circuit breaker under hot backup condition is introduced and the causes of the fault are analyzed in detail. The comprehensive analysis is performed from such three aspects as diagnosis tests,disassembly inspection and electric field simulation after occurrence of the fault. It is found through analysis that the root cause of the discharge is field intensity distortion due to the foreign matter at the shield of CT enclosure, causing gap discharge. In addition,the influence of various sizes of metal particles located at different positions of CT enclosure on electric field is studied in combination with structure of the circuit breaker. It is found by simulation that when the height of the metal particles reaches 2 mm, it is most likely to cause discharge at the shield. In case of the particle size reaching a certain size, either the concave or convex of the insulating spacer at the CT enclosure is upward, it will cause discharge. Finally, the corresponding treatment measures for the cause of the fault are proposed.

关 键 词：罐式断路器 内部放电 金属异物 屏蔽罩 电场强度 

分 类 号：TM561[电气工程—电器]