面向高频性能提升的数字控制电流源型有源栅极驱动器

Silicon carbide (SiC) MOSFETs are widely deployed in high-frequency and high-efficiency power electronics. However, in 300-kVA+ high-power converters utilizing SiC MOSFETs, the fast switching characteristics of SiC MOSFETs combined with high parasitic inductance induce problematic high-frequency oscillations, severe electromagnetic interference (EMI), and additional oscillation losses. Commercial gate drivers of the SiC MOSFETs lack the ability to suppress high-frequency oscillations, forcing system designers to derate SiC MOSFETs. In this article, an improved transient mathematical model of SiC MOSFET incorporating nonlinear parameters is established. Then, a digital-controlled current-source active gate driver (AGD) for improving the dynamic performance of SiC MOSFETs is proposed. The AGD strategically injects or extracts auxiliary gate current during reasonable periods of the SiC MOSFET switching transients to optimize device dynamic performance. Experimental validation using a CREE 1200-V/325-A SiC MOSFET module demonstrates significant improvements. High-frequency voltage/current oscillations and EMI are substantially reduced, with turn-off peak voltage and switching losses decreased by up to 34.5% and 60%, respectively, confirming the AGD’s effectiveness for the optimization of high-frequency oscillations.