对真空接触器控制４０ｋＷ以下电机产生过电压的影响因素及能否损坏绝缘进行理论分析和实验研究，结果表明，通过合理选择真空接触器，并采取适当的保护措施，不会损坏４０ｋＷ以下电机的绝缘，从而为诸如侧卸装岩机行走电机工作在频繁过载点、一般接触器难以满足的恶劣情况下，提供了一种新的解决方法。 The theoretical analysis and experimental research on the factors that affect the overvoltage caused by the vacuum contactor controlling the motor below 40kW and whether the insulation can be damaged or not are carried out. The results show that by reasonably selecting the vacuum contactor and adopting the proper protection measures, the damage of the motor under 40kW Insulation, thus providing a new solution to the harsh conditions such as side-mounted rock climbing motor operating in the frequent overload point, the general contactor is difficult to meet.