Active Gate Driver for SiC MOSFET Based on Switching Transient Feedback

Due to internal parasitic parameters and junction capacitance, silicon carbide (SiC) power devices have great voltage and current overshoot and high-frequency switching oscillation during high-speed switching process, which seriously affects the operation reliability of SiC-Based converters. In this paper, the switching characteristics of SiC MOSFET are analyzed to reveal the mathematical relationship between gate driving current and voltage/current overshoot. Then, a new active gate drive circuit with variable driving current is proposed. In the current or voltage rising stage of the switching process, the gate current is actively regulated, so the overshoot and oscillation of the voltage and current can be effectively suppressed, through the direct detection and feedback of the transient drain current change rate d I d d/ t , drain-source voltage changes rate d V ds /d t and driving voltage of SiC MOSFET V gs . Finally, experimental results show that the proposed method can effectively reduce voltage/current overshoot by 30% ~ 50%, and improve the operation reliability of SiC MOSFET converter.