Gate-Drive Circuits for Adaptive Operation of SiC MOSFETs

Abstract

This paper presents two novel adaptive gate driving concepts for Silicon Carbide (SiC) metal oxide semiconductor field-effect transistors (MOSFETs). The first concept is based on the adaptive over-driving principle and implemented either as a novel adaptive voltage-source over-driver (AVSOD) or as the conventional adaptive current-source over-driver. The adaptive over-drivers are capable of independently controlling turn-on and turn-off delay times, switching times and switching energy, as well as device dv/dt and di/dt. The second concept is a novel variablevoltage source multi-level gate driver (VVSMGD) with integrated synchronous buck converter, which is able to adjust the gate driving voltage. This driver is capable of adaptively manipulating turn-off delay times, turn-off times and switching energy, device voltage and current overshoots, voltage and current harmonic spectrum during switching transients. Furthermore, this driver can also adjust the conduction loss of the MOSFET by manipulating the on-state resistance through the gate-source voltage. The presented gate drivers are experimentally validated on a 3.3 kV/750 A high-power SiC MOSFET power module. It has been shown that the AVSOD reduces the turn-on and turn-off switching energies up to 55% and 68%, respectively, while the VVSMGD can reduce the drain-source voltage overshoot by 45%.