无损吸收ZVS-ZCS FB P WM变换器的优化设计

Optimized Design of ZVS-ZCS FB PWM DC/DC Converter with Lossless Snubber

在全桥移相软开关ZVSFB的拓扑电路中 ,采用由二极管和电容构成的无损吸收缓冲器可以实现 :①使滞后桥臂工作在零电流拓扑状态 ;②降低变压器初级整流电压的寄生振荡 ;③消除由电路环流引起的器件通态损耗。在变压器的初级使用二极管钳位电路 ,可以有效地抑制变压器次级的寄生振荡。通过一台 3kW的DC/DC变换器实验样机对该设计方案进行了验证。

The usage of the snubber net made of diodes and capacitances in the zero voltage switch full bridge(ZVS FB)converter can not only decrease the parasitic resonance in the rectified voltage of the transfotmer secondary,but also obtain zero current switch(ZCS) in the lag leg.In addition,this topology can eliminate the circulating current existing in the ZVS FB topology circuit.And the diode clamp circuit introduced in the transformer primary can apparently restrain from the peak voltage resonance in the rectified diodes.By applying those techniques,a 3kW DC/DC converter has been achieved.