单开关辅助换流的谐振直流环节PWM整流器

Resonant DC link PWM rectifier with a single switch-assisted commutation

为改善传统的脉冲宽度调制(PWM)整流器的运行效率,在直流环节增加与直流母线并联的辅助谐振电路,提出了一种谐振直流环节PWM整流器,其辅助电路只设置了1个辅助开关。在辅助谐振电路处于工作状态时,在每个开关周期内,主开关能完成零电压软切换动作,辅助开关能完成零电流切换动作,辅助谐振电路仅运行1次。详细说明了整流器在1个开关周期的工作过程,给出了设计规则,完成了对辅助电路损耗的数学建模。在10kW实验样机上的实验结果表明特征实验波形符合理论分析,开关器件实现了软切换。因此,该新型整流器处于高频和大功率运行状态时,能实现高效率运行。

In order to achieve high-efficiency of the conventional PWM rectifier,auxiliary resonant circuit which was in parallel with the DC bus was added in the DC link,and a resonant DC link PWM rectifier was put forward,with one auxiliary switch set in its auxiliary resonant circuit.In the process of commutation,zero-voltage switching was achieved in the main switch and zero-current switching was achieved in the auxiliary switch.Furthermore,the auxiliary circuit only needed to work for one time in each switching period.The commutation process of the rectifier was analyzed in detail to give out its mathematical model of auxiliary circuit loss,and the design rules were also given.The experimental results on the 10 kW prototype show that the characteristics of the experimental waveforms coincide with the theoretical analysis and the switches realize soft-switching.Therefore,the rectifier can be operated with high-efficiency,when it works with the high-frequency and high-power.