具有单辅助开关的谐振直流环节逆变器

摘要

为实现一种结构简单、控制方便、高效率、高功率密度的逆变器，提出了一种新型谐振直流环节软开关逆变器的拓扑结构。通过在传统硬开关逆变器的直流环节添加辅助谐振单元，使直流母线电压周期性地归零，可以实现逆变桥主开关器件的零电压开关，而且辅助开关器件可以实现零电流开通和零电压关断。此外，其辅助谐振单元只有一个辅助开关器件，所以该逆变器控制相对简单，硬件成本低。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1kW的实验样机，通过实验结果验证该软开关逆变器的有效性。%A resonant DC link soft-switching inverter was proposed to realize an inverter which has a simple topology ,an easy control strategy ,high efficiency and high power density .Auxiliary resonant unit was added to DC link of conventional inverter to make DC-bus voltage decrease to zero periodically ,which realized zero-voltage operation of all switching devices in inverter .Fur-thermore ,the switching device in the auxiliary resonant unit could be turned on under zero-current and turned off under zero-volt-age .In addition ,because only one auxiliary switch was in the auxiliary resonant unit ,control strategy was relatively simple and cost of hardware was lower .The operation principle was analyzed .The equivalent circuits at different operation modes and conditions for realization of soft-switching were presented .A 1kW laboratory prototype had been built .Experimental results were proposed to con-firm validity of soft-switching inverter presented .