一种移相全桥ZVZCS PWM DC_DC变换器的研究及改进

Research and improvement of a novel ZVZCS PWM DC_DC full bridge converter

针对零电压零电流开关(ZVZCS)全桥变换器在轻载情况下,超前臂零电压开关(ZVS)效果不佳的问题,对其进行了改进,增加了由2只电容器及1只电感器组成的辅助电路;讨论并提出了一种基于两个独立变压器串联的带辅助电路的新型高效ZVZCS全桥变换器。该变换器的超前臂实现了零电压开关,滞后臂实现了零电流开关(ZCS)。仿真试验结果证明:该方法改善了超前臂ZVS效果不佳的缺陷,同时该变换器是简单可靠的。

Aiming that the zero voltage switching（ZVS） of this zero-voltage zero-current switching（ZVZCS） pulse width modulation（PWM） DC_DC full bridge converter＇s leading leg switches could not be realized in the light load period, a simple auxiliary circuit consisted of two capacitors and one inductor were added before the leading leg. A novel ZVZCS-PWM full-bridge topology with two-transformer structure with auxiliary circuit was presented. The zero current switching（ZVS） for leading leg switches and zero current switching（ZCS） for lagging leg switches were achieved. The emulation results prove that the proposed converter has improve the ZVS for leading leg, also has a simple and robust structure.