一种无辅助开关的DC-DC变换器软开关建模与仿真

Modeling and Simulation of DC-DC Converter Soft Switching Without Auxiliary Switch

为了实现DC-DC变换器的软开关,通常需要增加额外的辅助开关。若通过在辅助电路中产生和保持循环电流,可使得DC-DC变换器拓扑能够在固定频率下实现开关管的软开关条件。基于这种软开关方法,文中推导了一种无辅助开关的DC-DC变换器Buck工作模式,对这种模式下的开关状态、工作波形进行了详细分析。最后,采用pspice进行了仿真,仿真结果表明该变换器在Buck模式下可以实现零电压开关(ZVS),从而验证了理论分析的正确性。

In order to achieve soft switching of DC-DC converters,additional auxiliary switches are usually needed.If the circulating current is generated and maintained in the auxiliary circuit,the DC-DC converter topology can realize the soft switching condition of the switch at a fixed frequency.Based on this soft-switching method,a buck mode of DC-DC converter without auxiliary switch was deduced,and the switching state and working waveform were analyzed in detail.Finally,pspice was used to simulate the converter.The simulation results showed that the converter can realize zero voltage switching（ZVS）in Buck mode,thus verifying the correctness of the theoretical analysis.