Magnetic-Coupled and Low-Cost Gate Driver for Series-Connected SiC MOSFETs

Silicon carbide (SiC) power devices exhibit more prominent switching characteristics and thermal capabilities compared with silicon power devices. To improve the blocking voltage capability, the series connection is an economical and highly efficient method for medium-voltage and high-power level converters. In this study, a magnetically coupled voltage-source gate driver is proposed, considering SiC metal–oxide–semiconductor field-effect transistor (MOSFET) as a typical voltage-controlled device. The proposed magnetically coupled gate driver (MC-GD) has a plain and low-cost structure with no flux reset windings on the secondary side. The driving voltage can be highly synchronized directly benefiting from the magnetic constraint, thus minimizing the snubber circuit connected in parallel to eliminate voltage mismatch. The proposed MC-GD has been verified based on the multipulse test platform, where three 650 V/36 A SiC MOSFETs are connected in series and compared with a single commercial gate driver from Infineon.