GaN-Based Active Gate-Drive Unit With Closed-Loop du/dt-Control for IGBTs in Medium-Voltage Applications

Abstract:
This work proposes an active gate-drive unit (AGDU) with a closed-loop du/dt-control of medium-voltage (MV) insulated-gate bipolar transistors (IGBTs) switching transients. A feedback regarding the current du/dt at the collector terminal of the IGBT, together with an analog PI-controller and a gallium nitride (GaN) drive stage, enables the AGDU to actively control the du/dt during turn-on and turn-off of the IGBT to a desired value. The paper starts with a brief introduction into IGBT switching; the drive stage and the controller; and concludes with measurement results of the performance of the closed-loop du/dt-control. Finally, a good controllability of the voltage transients is achieved.