Efficiency comparison of SiC and Si-based bidirectional DC-DC converters

With the advancement of technology on wide bandgap materials such as silicon-carbide (SiC), there are now better choices of SiC power devices available than ever before. It is widely known that SiC-based switching devices provide significant performance improvements on many aspects including lower power dissipation, higher operating temperatures, and faster switching frequencies compared to conventional Si devices. However, the tremendous benefits of SiC devices have not yet been fully explored by researchers. In this paper, a popular topology of bidirectional DC-DC converter that is suitable for hybrid vehicle or electric vehicle applications is considered. Comparative analyses regarding the power loss reductions of power devices and efficiency improvements are carried out for the converter based on three sets of device combinations, e.g. all-silicon (conventional silicon IGBTs and diodes), hybrid (silicon IGBTs with SiC Schottky diodes), and all-SiC (SiC MOSFETs with SiC Schottky diodes).