Transient Current Sharing Method for Parallel SiC MOSFETs Based on Gate‐Source Voltage Difference

ABSTRACT In the design of high‐power converters, significant parameter dispersion among different SiC MOSFET devices can cause substantial current differences during switching when devices are directly paralleled. To address this issue, a method is proposed to suppress transient current imbalance based on gate‐source voltage compensation. First, the impact mechanism of threshold voltage differences on transient current imbalance during the switching of parallel SiC MOSFETs is analysed, and the role of gate‐source voltage differences in current sharing is explored. The proposed method introduces a gate current extraction structure during the on‐state and a current injection structure during the off‐state to generate gate‐source voltage differences between two devices, thereby eliminating the current differences caused by inconsistent device turn‐on sequences. Compensation parameters are determined by analysing the mathematical model of gate‐source voltage differences during switching transients. Finally, simulation analysis and experimental tests using LTspice simulation software and a parallel double‐pulse test platform demonstrate that the proposed current sharing method significantly improves transient current imbalance between parallel devices.