一种新颖的耦合电感MVS无源无损缓冲电路

A novel Minimun Voltage Stress Passive Lossless Snubber with Coupled-inductor

研究了一种适用于大功率Buck变换器的带耦合电感的最小电压应力(Minimun Voltage Stress,简称MVS)无源无损ZCS开通缓冲电路,它利用耦合电感的漏感与谐振电容在功率管开关过程中进行谐振,实现软开关。分析了变换器的工作模态,给出了软开关环节中耦合电感和谐振电容的参数设计方法,并搭建了150 W实验样机。实验结果表明,该结构实现了功率开关管ZCS开通和近似ZVS关断,抑制了功率二极管的反向恢复过程,减小了开关损耗,提高了变换器的效率。

This paper investigates a novel coupled-inductor passive lossless snubber circuit with minimun voltage stress （MVS） for high power Buck converters.In order to realize the soft-switching of insulated gate bipolar transistor （IGBT） ,the resonant process between the leakage inductance of coupled-inductor and resonant capacitors of snubber circuit is utilized while IGBT is switching.Operation mode is analyzed, parameters design procedure of coupled-inductor and resonant capacitors are presented and a prototype is built and tested.The experimental result shows that this topology can realize zero current switching （ZCS）when IGBT turns on and approximate to ZVS when IGBT turns off, the reverse recovery process of the main diode is inhibited, switch loss is reduced and the efficiency of the converter is improved.