中文摘要：

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，提出了一种用于电机驱动的并联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，而且辅助开关器件也可以实现零电压开关。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，软开关的实现条件。制作一个10kW的实验样机，实验结果表明逆变器的主开关实现了软开关，所以该软开关逆变器能有效地降低开关损耗和提高效率。

英文摘要：

A novel parallel resonant DC link soft-switching inverter for motor drives was proposed to real- ize an inverter which has a simple topology, an easy control strategy, high efficiency and high power den- sity. Auxiliary resonant unit was added to DC link of conventional inverter to make DC-bus voltage de- creased to zero periodically, which realized zero-voltage operation of all switching devices in inverter. Switching devices in the auxiliary resonant unit could also be operated under soft-switching. 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 werepresented. A 10 kW laboratory proto- type had been built. The experiment research was carried out to demonstrate that soft-switching operation of all the main switching devices could be realized. Therefore, the soft-switching inverter presented can effectively reduce switching loss and improve efficiency.