Multilevel Gate Driver with Adjustable Gate Voltage for Thermal Stress Reduction of Power Switches in Electric Drive Application

Due to varying load currents, the junction temperature variations of power switches causes thermal stress and compromises lifetime. In this paper, proper gate voltage control is used for all power switches in a three-phase electric drive to smooth the profile of conduction losses, therefore reducing thermal stress. A gate driver with adjustable multilevel gate voltage is introduced and experimentally verified for the thermal control method. The switch lifetime is estimated at last, which indicates an improvement by a factor of two.