基于软开关的直流降压变换器研究

Research on DC Buck Converter based on Soft Switching

鉴于传统的直流-直流变换器在实际运行过程中,普遍存在开关损耗大和应力大,以及效率较低等多方面问题,故提出一种基于软开关的直流降压变换器.设计了零电压开关谐振转换电路的拓扑结构,阐述了不同工作时段的工作过程,并分别说明各个工作阶段的工作原理.同时,试制一台1 kW样机,观察并分析样机开关管的电压波形和电流波形,实验结果表明将软开关技术应用在直流降压变换器中,不仅可以大幅度降低开关损耗,而且可以大大改善开关条件,同时表现出良好的性能和效率,有望在电动汽车变换器或光伏发电等场合中大面积推广应用.

In view of the large switching loss,high stress,and low efficiency of traditional DC-DC converters in actual operation,a DC buck converter based on soft switching is proposed.The topological structure of the zero-voltage switching resonant conversion circuit is designed,the working process of different working periods is explained,and the working principle of each working stage is explained separately.At the same time,a 1kW prototype is trial-produced to observe and analyze the voltage waveform and current waveform of the prototype switch tube.The experimental results show that the application of soft switching technology in the DC buck converter can not only greatly reduce the switching loss,but also greatly improve the switching conditions,with good performance and efficiency,so it is expected to be widely used in electric vehicle converters or photovoltaic power generation and other occasions.