Switching performance of parallel-connected power modules with SiC MOSFETs

摘要

Parallel connection of silicon carbide power modules is a possible solution in order to reach higher current ratings. Nevertheless, it must be done appropriately to ensure a feasible operation of the parallel-connected power modules. High switching speeds are desired in order to achieve high efficiencies in medium and high-power applications but parasitic elements may give rise to a non-uniform current sharing during turn-on and turn-off, leading to non-uniformly distributed switching losses. This paper presents the switching performance of parallel-connected power modules populated with several silicon carbide metal-oxide-semiconductor field-effect-transistors chips. It is experimentally shown that turn-on and turn-off switching times of approximately 50 ns and 100 ns, respectively, can be reached, while an acceptably uniform transient current sharing is obtained. Moreover, based on the obtained results, an efficiency of approximately 99.35% for a three-phase converter rated at 312 kVA with a switching frequency of 20 kHz can be estimated.