车载真空断路器操作过电压及其保护研究

摘要

动车组再生制动或经过分相绝缘段时,车载真空断路器需断开,会产生较高的操作过电压.针对动车受能供电系统建立了简化电路模型,仿真分析了影响过电压的因素,并对两种过电压保护装置进行了分析比较,确定其配置原则及参数.结果显示,变压器对地电容越大,过电压峰值越低；氧化锌避雷器能有效限制过电压幅值,但对降低过电压陡度和频率效果不明显；RC保护装置对降低过电压幅值、陡度和频率均有较明显的效果.%The vehicle-mounted vacuum circuit breaker will open the circuit when locomotive regenerative braking or passing the articulated phase insulator. It will produce high operating overvoltage. Simplified circuit model is established in this paper according to the power supply system of locomotive. The transient process of vacuum circuit breaker interruption is simulated using EMTP. Based on the simulation results, influencing factors of overvoltage and two different overvoltage protection devices are analyzed. The parameters of the protectors are also determined. The results indicate that, the greater the ground capacitance of transformer is, the lower the overvoltage peak will be; MOA can limit the amplitude of overvoltage obviously, but it is not effective enough to reduce the gradient and frequency of overvoltage; RC device can reduce the amplitude,steep degree and frequency of overvoltage well.