基于移相全桥ZVS及同步整流的低压大电流直流变换器研究

A Research on the Low-voltage High-current DC Converter Based on Phase-shift Full-bridge ZVS and Synchronous Rectification

解决开关电源的功率损耗问题是提高电源效率、性能、可靠性的关键。传统低压大电流直流变换器,使用二极管整流,难以实现在高电流输出情况下降低损耗。选择了综合全波整流和桥式整流两者优点的倍流整流器,并且使用MOSFET并联同步整流技术,结合了变压器原边移相全桥ZVS电路,实现了28.5 V/400 A的低压大电流输出。基于双环控制,搭建了直流变换器模型与实验平台,通过仿真与实验验证,证明了电路拓扑以及控制策略的可行性。

The solution of power loss of switching power supply is the key to the improvement of power supply efficiency,performance and reliability. Traditional low-voltage high-current DC converter using diode for rectification purpose can hardly reduce loss under highcurrent output circumstances. In this paper,a current-doubler rectifier combining advantages of both full-wave rectification and bridge rectification is chosen,and MOSFET parallel synchronous rectification technology combined with transformer original-side phaseshifted full-bridge ZVS circuit,we can achieve low-voltage high-current output of 28. 5V /400 A. Based on dual-loop control,we build up a DC converter model and experimental platform,and make system simulation and experimental verification. The results of simulation and verification verify the feasibility of the circuit topology and control strategy.