断路器容性电流开断能力研究

Research on Capacitive Current Interruption Capability of Circuit Breaker

容性电流开断能力,特别是C2级开断能力,已成为断路器满足工程需求的关键指标,因开断过程中易发生重击穿故障而导致试验失败的风险较大,故需对其容性开断能力进行评估。基于容性电流特点,文中采用“恢复电压”及“最小临界电压”评估其开断容性电流能力,且“恢复该电压”低于“最小临界电压”时,断路器具有开断容性电流的能力。采用电场及气流场耦合分析方法,断路器开断性能进行评估,得到试验工况下“恢复电压”均小于“最小临界电压”,表明该断路器具有容性电流开断能力,顺利通过C2级试验验证,进一步表明采用“最小临界电压”评估断路器容性电流开断能力的可行性,为断路器开断容性电流设计提供参考。

The capacitive current interruption capability,with grade C2 in particular,has become the key index of circuit breaker meeting the engineering requirements.Due to the high risk of test failure caused by re⁃striking during the interruption period,it is necessary to assess its capacitive interruption capability.Based on the characteristics of capacitive current,the“recovery voltage”and“minimum critical voltage”are used in this paper to assess its capaci⁃tive current interruption capability.And the circuit breaker,in case that the“recovery voltage”is lower than“mini⁃mum critical voltage”,has the ability to interrupt break capacitive current.The interruption performance of circuit breaker is assessed by using the coupling analysis method of electric field and air(gas)flow field,the“the recovery voltage”is lower than the“minimum critical voltage”is obtained,which indicates that the circuit breaker has the ca⁃pability to interrupt the capacitive current and passed successfully test verification at grade C2.It shows further the feasibility of adopting“the minimum critical voltage”to assess the capacitive current interruption capability of cir⁃cuit breaker and provides a reference for the design of circuit breaker interrupting the capacitive current.