移相控制对称半桥变换器软开关条件

摘要

对称半桥变换器移相控制软开关技术利用电路寄生参数产生谐振,实现开关器件的零电压开关状态,主要包括开关器件的寄生电容和变压器漏感。在实际应用中,因寄生参数不够,可通过外加谐振器件的方式帮助软开关。本文简要分析了移相控制对称半桥变换器的工作原理和换流过程。通过对软开关过程中的等效电路分析,获得了谐振器件参数与变换器稳态工作条件之间的条件关系,可作为软开关条件下选择开关器件寄生电容以及外加谐振器件参数的依据。样机实验验证了使用该条件能够作为移相控制对称半桥变换器软开关设计的有效依据。%The symmetry half-bridge bidirectional converter＇s zero voltage switching（ZVS） is achieved by the resonance between the circuit＇s parasitic elements,including parasitic capacitors of the switches and the leak inductance of the transformer.In application,the additional resonance elements could help the ZVS operation if the parasitic elements are not enough.The topology and operation principle of symmetry half-bridge bidirectional converter is briefly introduced,which could easily achieve zero voltage switching（ZVS）.Based on the analysis of its operation modes,the realization of ZVS is indicated.By analyzing the equivalent circuit of the ZVS operation mode,the relationship between the circuit＇s resonance elements＇ parameters and the converter＇s steady operation requirements is built,which could be used to choose the switch＇s parasitic capacitors and the additional resonance elements.The experimental results verify the illustrated conditions.