Performance Comparison of Two Hybrid Si/SiC Device Concepts

Various Si/SiC hybrid device concepts aim at achieving SiC performance at a significantly reduced cost in comparison to full SiC solutions. Both the insulated-gate bipolar transistor (IGBT)(Si)/Schottky(SiC) hybrid pair and the IGBT(Si)/MOSFET(SiC) hybrid switch offer a substantial reduction in switching losses but operate quite differently. This article compares the performance of these two hybrid device concepts in a voltage source inverter (VSI). The basic operation principle, conduction, and switching characteristics of the two hybrid configurations are directly compared, and an improved power loss model is developed for these two solutions in VSI. Two single-phase VSI prototypes using these two hybrid devices are built and tested, respectively. Experimental results show that a 1200-V hybrid IGBT/MOSFET solution achieves a significant efficiency improvement and a maximum junction temperature reduction compared to the hybrid IGBT/Schottky counterpart. The hybrid IGBT/MOSFET solution achieves a 40% higher power handling capability in the 20-kHz single-phase VSI or 1.5 times higher switching frequency in the 2-kW single-phase VSI than the hybrid IGBT/Schottky solution.