Current Balancing for Parallel Connection of Silicon Carbide MOSFETs Using Bus Bar Integrated Magnetic Material

Power converter circuits are becoming widespread, and higher-voltage and larger-current converter circuits are increasingly used in automotive and utility applications. In particular, research and development on silicon carbide(SiC) power devices are being actively pursued for achieving larger current ratings by connecting SiC power modules in parallel. However, a current imbalance phenomenon may occur in the parallel-connected power modules because of the difference in device characteristics and parasitic impedances. This paper proposes a practical current balancing method for parallel-connected power modules based on only circuit implementations. In addition, a laminated bus bar integrated magnetic material for current balancing in parallel-connected MOSFET modules is proposed based on the analysis results. The validity of the proposed method is clarified through experiments using SiC-MOSFET.