具有低能耗辅助电路的并联谐振直流环节逆变器

为提高逆变器的转换效率，提出了一种具有低能耗辅助谐振电路的并联谐振直流环节逆变器.在传统硬开关逆变器的直流环节添加辅助谐振电路，使直流母线电压周期性地归零，实现逆变桥主开关器件的零电压开关，而且辅助开关器件也可以实现零电压关断和零电流开通.此外，其辅助谐振电路只有一个辅助开关器件，控制简单；辅助开关和谐振元件都位于直流母线的并联支路上，有利于降低辅助谐振电路的能耗.对其工作原理进行分析，给出不同工作模式下的等效电路图和软开关的实现条件.制作一个5kW的实验样机，通过实验结果验证该软开关逆变器的有效性.

Parallel Resonant DC Link Inverter with Low-Loss Auxiliary Circuit

A parallel resonant DC link inverter with low-loss auxiliary resonant circuit was proposed to improve efficiency of the inverter.Auxiliary resonant circuit was added to DC link of conventional inverter to make DC-bus voltage decreased to zero periodically,which realized zero-voltage operation of all switching devices in inverter.Auxiliary switching devices could also be turned on under zero-current and turned off under zero-voltage.In addition,only one auxiliary switch was in auxiliary resonant circuit so that control strategy was simple;auxiliary switch and resonant devices were all in parallel with DC-bus to reduce loss of auxiliary resonant circuit.The operation principle was analyzed.The equivalent circuits at different operation modes and conditions for realization of soft-switching were presented.A 5kW laboratory prototype had been built.Experimental results were demonstrated to confirm validity of soft-switching inverter presented.