Loss-oriented Power Sharing and Switching Frequency Control with Circulating Current Suppression in Si/SiC Hybrid Half-bridge Inverter

The Si/SiC hybrid-half bridge(HHB) topology provides an efficient way of realizing the nearly excellent performance and considerable reduced cost compared with all SiC design. Benefit from the lower-frequency operation,the higher switching power loss of Si devices is avoided. The superior output power quality and fast dynamic response is achieved since the SiC higher-frequency operation. However, the circulating current is always brought by the hybrid-parallel topology of the inverter which affects the transfer efficiency negatively.Moreover,the power sharing ratio and switching frequency also influences the total power loss. In this paper,the dynamic coordinated operation is adopted in Si/SiC HHB inverter to suppress the circulating current, then the power sharing ratio and switching frequency is optimized through the offline search method with established power loss model. A 3.3kW Si/SiC HHB single inverter prototype is built to verify the effectiveness of proposed method. The power loss is reduced by 20% at least in comparison to conventional coordinated operation with the fixed parameter.