改进型无桥Boost PFC软开关技术的研究

摘要

In order to decrease switching loss and further improve efficiency, an improved bridgeless Boost PFC circuit with non-minimum voltage stress passive losses snubber circuit is proposed on the basis of analysis of the passive lossless snubber circuits. A 300W prototype has been designed on the basis of analyzing principle and simulation. Results prove that this improved topology has low conduction loss,simple current sensing circuit and the switches operate at ZVS turn-off and ZCS turn-on and freewheeling diodes operate ZVS turn-on and ZCS turn-off.%在分析无源无损缓冲电路拓扑结构的基础上,为了降低开关损耗,进一步提高效率,提出了在改进型无桥Boost PFC( Power Factor Correction,PFC)的基础上增加非最小电压应力电路网络.在理论分析和仿真验证的基础上,研制了一台300W的实验样机.结果表明改进后的无桥PFC电路拓扑具有通态损耗低、电流采样简单,不仅能实现开关管的零电压关断和零电流导通,同时续流二极管实现零电压导通和零电流软关断.