Mitigating Gate Voltage Oscillation in Parallel SiC Power Modules for xEV

Global vehicle electrification is accelerating to combat global warming. Recently, Silicon Carbide (SiC) Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs) are increasingly used in electric vehicle inverters for their low power loss at fast switching speeds compared to conventional Silicon Insulated Gate Bipolar Transistors (IGBTs). Although SiC MOSFETs are usually used in parallel to gain power, these fast-switching speeds can lead to gate voltage oscillations across paralleled SiC chips, potentially leading to failures such as gate drive malfunction and gate oxide breakdown. This paper addresses the oscillation caused by source voltage fluctuations and unbalanced gate drive circuit characteristics. We propose a method to mitigate these issues using a symmetrical module structure which equalizes stray inductance between modules.