| Abstract |
In this work, the concept and experimental verification of a GaN-based active gate-drive unit to control the switching transients of medium-voltage (MV) IGBTs are presented.The driving stage consists of a half-bridge with GaN HEMTs operated at switching frequencies between 20 and 30 MHz.Using the GaN half-bridge as a buck converter, the gate voltage of MV-IGBTs can be set dynamically during the switching transients.With an adjustable gate voltage during the switching transients, the current and voltage slopes of the IGBT can be manipulated.Optimizing the current slope during turn-on can significantly reduce the turn-on loss, while still maintaining the same reverse recovery of an anti-parallel diode compared to a conventional gate-drive unit.For the experimental verification of the active gate-drive unit presented in this work, an improved turn-on with a switching loss reduction of up to 20\% is achieved. |
