半桥软开关在双流制辅助系统中的应用研究

Research on the Application of a Half Bridge Soft Switching in Dual Supply Auxiliary System

以双流制电客车辅助系统为应用背景,提出一种能满足宽输入电压范围要求的零电流开关(ZCS)脉宽调制(PWM)半桥DC/DC变换器。该变换器采用中频升压变压器,变压器次级增加辅助开关管和谐振电容的串联支路且并联RC吸收支路,能够实现全部负载范围内的主开关管和辅助开关管的ZCS,并能实现整流二极管的软关断。分析了该变换器的工作原理,结合双流制的运用环境要求分析给出主要硬件参数的设计方法。采用对称脉冲控制,提出一种易于实现的变状态、比较值限幅的软件控制策略。最后,通过仿真和试验研究证明该变换器的可行性。

A zero current switching(ZCS)pulse width modulation(PWM)half bridge DC/DC converter which can meet the requirements of wide input voltage range is proposed based on the application background of auxiliary system of dual supply train.The converter adopts intermediate frequency step-up transformer.The auxiliary switching and reso-nant capacitor series branch are added in the secondary side of the transformer,and the RC series absorption branch is paralleled.The main switch and auxiliary switching can be turned off with ZCS in all load range,and the rectifier diode can be turned off softly.The principle of the converter is analyzed,and the design method of the main hardware parameters is given according to the requirements of the dual supply.Using symmetrical pulse control,a software con-trol strategy of variable state and comparative value limiting is proposed.Finally,the feasibility of the converter is proved by simulation and experimental study.