Performance Comparison of FRD and SiC Schottky Diode in Si/SiC Hybrid Switch Power Module

The Si/SiC hybrid switch (HyS) power module concept of paralleling a main Si IGBT and an auxiliary SiC MOSFET offers an improved cost/performance tradeoff in power converter applications compared to the full SiC based solutions. The different freewheeling diodes inside the HyS module strongly influences the electrical and thermal performance of the HyS module. In this paper, the HyS power modules using silicon fast recovery diodes (FRD) and silicon carbide Schottky diode (SiC SBD) as the freewheeling diode are designed respectively, to compare the performance of these two freewheeling diode solutions. The basic operation principle, conduction and switching characteristics of the two diode configuration HyS power modules are directly compared. Experimental results show the SiC SBD solution achieve the better reverse recovery performance and comparable reverse conduction losses compared to the FRD solution.