中文摘要：

真空断路器永磁操动机构的驱动电源多采用储能电解电容器,电容器容量大小对永磁机构的动态特性有重要影响,但如何确定电容器容量大小尚无明确原则。基于此,笔者通过分析永磁机构的电路励磁特征和运动特性,提出一种电容量大小确定方法,即可根据电容放电电流的第1个峰值达到永磁机构动作的临界电流来确定电容容量。在此基础上,以某永磁操动机构为例,具体介绍了电容大小的计算步骤。最后,根据所确定的储能电容大小计算了永磁机构动态特性,计算结果表明,笔者所提出的储能电容大小确定方法既可保证断路器可靠分、合闸,又能使电容量取值最小,从而优化了永磁机构的设计。

英文摘要：

Permanent magnetic actuator（PMA）for vacuum circuit breaker is always powered by the energy storage electrolytic capacitor, which has a significant influence on the dynamic behaviour of the actuator. But at present there＇s no specific theoretical method to evaluate the capacitance. Therefore, an evaluation method for the capacitance value of the energy storage used in PMA is proposed, i.e. the capacitance can be calculated under the condition that the first peak value of the discharged current equals to the critical moving current, based on the corresponding analysis of the excitation characteristic and the dynamic performance. By taking a certain PMA as example, the process of the evaluation for the capacitance is discussed. In the end, the dynamic behaviour of the PMA excited by the obtained capacitance is studied. The result reveals that the evaluation method for the capacitance value can not only ensure the breaker operating reliably but also ensure the capacitance getting the minimum value, which optimizes the design of PMA.