通过分析500 kV隔离开关控制接触器在操作过程中的电压、电流波形，认为在接触器线圈励磁返回瞬间，线圈回路出现的暂态冲击是造成其频繁故障的原因，提出了在接触器线圈两端加装消弧回路的反事故措施。通过对2种消弧回路的效果对比，最终选择加装二极管串联电阻的消弧回路。

Frequent breakdown occurs for control contactor in 500 kV disconnecter, due to the transient arc surge appearing in the coil circuit at the moment of excitation return, by analyzing the voltage and current waveforms during the operation of control contactor. Therefore, the anti-accident measures are proposed by applying the arc suppression circuit to the control contactor coil. By comparing the effect of two kinds of arc suppression circuit, an arc suppression circuit with the diode and series resistance is selected.