Starting with the relation between the input and output voltage (dc link voltage) of twolevel converter fed from 25 kV/50 Hz supply,the paper discusses the calculation methods for input voltage in conjunction with parameters of some AC drive locomotives in foreign countries,so as to obtain reasonable voltage value.
从２５ｋＶ／５０Ｈｚ电网供电的二点式变流器的输入电压与输出电压（即中间直流回路电压）的关系入手，结合国外部分交流传动机车的参数值，对输入电压的计算方法进行讨论，以寻求合理的取值。
In this paper,intermediate tempering and fatigue life were researched.
对已产生疲劳损伤的调质45、40Cr 钢试样,进行600℃(与调质时回火温度相等)中间回火处理,然后继续进行疲劳实验,用电镜观察其微观组织结构变化,并进行显微硬度分析。