电动车辆主回路中的过电压问题,现在已研究得十分充分,在计算电力机车绝缘系统时也考虑了过电压问题。在2ТЭ10Л型内燃机车上进行的研究表明,在该车主回路中也会产生数值可观的过电压。主回路的脉冲电压在磁场削弱时突然断电的情况下每次可达1200～1700伏。图1是内燃机车主电路在断电即主发电机励磁接触器断开之后的等效电路图。此电路中 The overvoltage problem in the main circuit of electric vehicles has been studied very well now and the overvoltage problem has also been taken into account when calculating the insulation system of electric locomotives. Research carried out on 2ТЭ10Л diesel locomotives shows that a considerable amount of overvoltage can also occur in the vehicle owner’s circuit. The main circuit of the pulse voltage in the weakening of the magnetic field suddenly cut off under the circumstances of up to 1200 ~ 1700 volts. Fig. 1 is an equivalent circuit diagram of the main circuit of the diesel locomotive after power-off, that is, the main generator field contactor is disconnected. In this circuit