A Universal Block of Series-Connected SiC MOSFETs Using Current-Source Gate Driver

SiC MOSFET has superior switching performance over Si IGBT in terms of power loss and temperature characteristics. In order to significantly improve the efficiency and power density of medium-voltage drive and high-power converters, this article proposes a current-source gate driver (CS-GD) for series-connected SiC MOSFETs, forming a universal block of series-connected SiC devices with the higher voltage rating. The proposed CS-GD has better gate voltage synchronization performance because of its constant gate current and novel gate driver structure. By implementing synchronized gate voltages, the snubber circuit is designed only for power loop difference and gate displacement current difference, and the snubber can be minimized or even be eliminated. The proposed block has been verified by LTSPICE simulations and multipulse test experiments under 200-kHz, 2-kV, 0~60-A condition using three 1.2-kV/60-A C2M0040120D SiC MOSFETs connected in series.