断路器断口防入侵波雷害研究

针对全国近年大量加装的线路型终端避雷器,文中运用雷电波陡度理论,首创性推导出35~500kV线路采用线路型终端氧化锌避雷器时断路器断口所承受的入侵雷电波过电压计算公式。同时通过公式计算表明:线路型终端避雷器不满足绝缘配合要求,因而不能有效保护断路器断口;而变电站型终端避雷器满足绝缘配合要求,能有效保护断路器断口。这是全国各电压等级线路在大量加装线路型终端避雷器后断路器断口击穿事件仍时有发生的根本原因,也是文中重点论述并提醒行业、协会对反事故措施文件及相关技术规范尽快纠正的依据。

Lightning Wave Intrusion Prevention of Circuit Breaker Gap

For the line-type terminal arresters on transmission line, the theory of lightning wave steepness is adopted to deduct a calculation formula of the overvoltage induced by intruding lightning wave on the circuit breaker gap when terminal zinc oxide arrester is used on the 35-500 kV transmission line. The calculation result of the formula shows that the line-type terminal arrester does not meet the requirement of insulation coordination, so it cannot protect the circuit breaker effectively. While the substation-type terminal arrester meets the requirement of insulation coordination and can effectively protect the gap of the circuit breaker. This is the reason why gap breakdown accidents of the circuit breakers on different voltageevel transmission lines still happen occasionally in China after installing a large number of line-type terminal arresters, and this is also the basis for the authors to suggest the industry association to correct its relevant files and technical specifications concerning the anti-accident measures as soon as possible.