新型容性整流移相全桥变换器研究

Study on a novel phase-shifted full bridge converter with capacitive rectifier

提出了一种新型容性整流移相全桥变换器,其具有若干优点:不存在传统移相全桥电路占空比丢失的问题;不需要添加隔直电容可实现ZCS,进而减小电路体积;所有开关器件在较宽负载范围内实现软开关,其中超前管可实现零电压(ZVS)开通/关断,滞后管可实现零电流(ZCS)开通/关断,从而降低开关损耗;副边采用容性整流,可在续流阶段将原边电流降至0,使得消除二极管反向恢复损耗.分析了新型容性整流移相全桥变换器的电路结构、工作原理和基础特性,并通过搭建一台500 W实验样机进行了验证.实验结果表明,该电路工作原理正确,能够正常工作.

A novel phase-shifted full-bridge converter with capacitive rectifier is proposed,which has the following advantages:There is not the loss of duty cycle in traditional phase-shifted full-bridge converter;no DC blocking capacitor is required to achieve ZCS,thereby reducing the converter's size;all switches can realize soft switching over a wide load range,in which the leading switches can realize zero voltage switching(ZVS)turn-on/turn-off,and the lagging switches can obtain zero current switching(ZCS)turn-on/turn-off,which optimize the switching loss.Due to the capacitive rectifier on the secondary side,the primary current is reset to 0 during the freewheeling stage,which eliminates the reverse recovery loss of the rectifier diodes.This paper analyzes the structure,working principle and basic characteristics of the novel phase-shifted full-bridge converter.In addition,building a 500 W experimental prototype to verify.The experimental results show that the working principle of the circuit is correct and it can work normally.