Active Gate Driver With the Independent Suppression of Overshoot and Oscillation for SiC MOSFET Modules

Abstract

Silicon carbide (SiC) MOSFET featuring faster switching speed, higher breakdown voltage, and excellent thermal conductivity is widely used in power converters to improve their conversion efficiency, power density, and reliability. However, high dv/dt and di/dt, along with parasitic capacitance and inductance, are more prone to overshoot and oscillation in both voltage and current, which can result in electrical stress, electromagnetic interference (EMI), and additional energy loss. This article proposes an active gate driver with the independent suppression of overshoot and oscillation (IS-AGD) to improve the switching performance of SiC MOSFET modules. Equivalent models for the overshoots and oscillations are built. Based on the models, the modulating strategy is presented and discussed. Finally, the proposed IS-AGD is experimentally verified with a 1.2 kV/120 A SiC MOSFET module under different gate resistances, load currents, and temperatures. The experimental results show that the proposed IS-AGD can reduce the overshoots and oscillations in voltage and current. Compared with the conventional gate driver (CGD), the switching loss and delay time are also decreased by the IS-AGD under different voltage and current overshoots. In addition, optimization considerations are discussed to guide practical applications.