Concept for an IGBT Desaturation Pulse to Reduce Turn-OFF Losses

This paper introduces an “IGBT desaturation pulse” which tends to reduce turn-OFF losses for regular and Reverse Conducting IGBTs. Hereby, the effect of the desaturation pulse is compared between conventional IGBT-types and innovative “low-saturation” IGBT-types with an increased emitter-sided plasma concentration due to injection enhancement. Device simulations for 6.5 kV IGBTs of both types, a gate control scheme to implement the IGBT desaturation pulse into the timing diagram as well as a proposal for a gate-drive unit are elaborated and presented.