Diode-Less SiC Power Module With Countermeasures Against Bipolar Degradation to Achieve Ultrahigh Power Density

A 3.3-kV diode-less (D-less) SiC power module adopting a “next high power density dual package” (named nHPD2) was developed. Configuring the module with SiC metal-oxide-semiconductor field-effect transistors (MOSFETs) only resulted in the ultrahigh power density. Its rated current of 800 A and power density of 37.7 kVA/cm2are the highest value achieved among high power modules so far. As a countermeasure against bipolar degradation related to the body diode in the MOSFET structure, a high-throughput screening process was utilized for the first time. To clarify the advantageous features of this module, its characteristics an in comparison with those of a full-SiC module and a conventional silicon module in the same nHPD2package. In addition, system-level impacts on actual traction inverter operations were simulated by using the evaluated characteristics. To accurately calculate the impacts, the temperature dependence of the SiC modules, which is a remarkable feature of high-voltage SiC devices, was taken into account. The superior performance of the developed D-less SiC power module, namely, low loss, low junction temperature, and high power density capability, was confirmed.