基于辅助电流源网络移相全桥变换器的研究

摘要

The traditional phase-shifted full-bridge converter is widely applied in medium and high power DC/DC transform occasions because of its high conversion efficiency and low electromagnetic interference.However,it is difficult to achieve the soft switching of the lagging bridge arm under the condition of light load.To solve this problem,the auxiliary current source network to realize the zero voltage switching (ZVS) of the phase-shifted full-bridge with the lagging bridge ann under the light load condition is introduced.The operation principle and characteristics of this converter are analyzed in detail,and a prototype rated 500 W based on the presented topology is built.The superiority of this circuit topology is demonstrated well by the experimental results.%传统移相全桥变换器因具有转换效率高、电磁干扰小等特点,被广泛应用于中、大功率DC/DC变换场合,但在轻载条件下其滞后桥臂的软开关难以实现.针对该问题,引入辅助电流源网络,用以实现移相全桥的滞后桥臂在轻载情况下的零电压开通(ZVS).对该变换器的工作原理及特性进行了详细分析,在此基础上研制了一台500 W的原理样机并讨论了电路关键参数的设计.实验结果证明了该电路拓扑的优越性.