开关频率500kHz的软开关SiC单相逆变器

Study of 500kHz ZVS Full-bridge Inverter Based on SiC MOSFET

高频化是提升并网逆变器功率密度的有效途径。SiC MOSFET适用于高频化的应用场合,同时采用软开关技术可维持高转换效率。设计了一台500 kJz零电压开关(ZVS)SiC单相并网逆变器。重点介绍了谐振参数的选取、谐振电感与滤波电感的设计,并在1.5 kW实验模型上进行了验证。实验证明在开关频率为500 kHz时,依靠SiC MOSFET自身的结电容可完成谐振,实现ZVS开通。500 kHz下的滤波电感比100 kHz下的滤波电感体积减小约4/5,满载效率为97.9%。

High-frequency is an effective way to increase power density of grid-tied inverters.SiC MOSFET is appropri- ate to be utilized in high frequency applications, meanwhile the use of soft-switching technique can keep a high con- version effieiency.A 500 kHz zero voltage switeh（ZVS） SiC full-bridge inverter is designed.The selection of resonant parameters, the design of resonant inductor and filter inductors are focused on, and the verification by experiments is carried out over a 1.5 kW platform.It＇s proved that at 500 kHz, the resonance process can be aroused and ZVS con- dition can be realized just by utilizing junction capacitor of SiC MOSFET itself.The volume of 500 kHz filter is about 4/5 smaller than that of 100 kHz, meanwhile the efficiency under full load is 97.9%.