IEEE Workshop on Wide Bandgap Power Devices and Applications in Asia (WiPDA Asia 2018)

287 / 2017-12-07 15:08:22

An Integrated Gate Driver with Active Delay Control Method for Series Connected SiC MOSFETs

SiC MOSFET,series connected,voltage balance,delay line,auxiliary driver

Plenary track > Gate drive and other auxiliary circuits

An integrated gate driver with active delay control method for series connected SiC MOSFETs is presented in this paper to achieve voltage balance. A RC voltage divider is applied to detect the voltage between drain and source terminals, and the voltage signal is fed into a high speed AD converter through a voltage follower. With the isolation of optocoupler, the voltage data is transferred to the main controller. The controller generates PWM pulses and computes the delay time that should be applied for each SiC MOSFET drive signal with the voltage data to maintain the voltage balance. The delay action is implemented by a delay line IC. The proposed gate driver provides a closed loop control for series connected SiC MOSFETs. It can effectively balance the voltage without slowing down the switching speed or inducing extra losses, and the effectiveness of the proposed gate driver has been verified by experimental results.