Slew rate control of switching transient for SiC MOSFET in boost converter using digital active gate driver

Abstract

Abstract This paper experimentally validates a fully digitalized active gate driver for suppressing the switching surge voltage of SiC MOSFETs in a boost converter. High‐voltage power conversion systems are expected to adopt SiC unipolar power devices utilizing their high‐speed switching capability. The high‐speed switching operation causes the switching surge voltage in its switching transient. Active gate driving is a key technology for suppressing it. A fully digitalized active gate driver is particularly focused upon, which freely shaped the output gate‐source voltage waveform by a multi‐bit gate control signal. This driver achieves the dynamical control of the voltage/current behaviours of MOSFET in the switching transient by taking the Miller effect into account. It contributes to suppressing the switching surge voltage. This paper applies this digital active gate driver to a high voltage power conversion circuit. The switching surge voltage is experimentally suppressed by slew rate control with the digital active gate driver for various operating conditions. The results clarify the control strategy of the digital active gate driver for SiC MOSFET in a power conversion circuit.