Application of Gate Drivers for 3-Level NPC-2 Power Modules with Reverse Blocking IGBTs

摘要

3-level topologies have been widely used in various applications for several years.Such applications are typically based on the classical neutral-point-clamped(NPC1)topology with four power switches(IGBT)per half-bridge and two additional clamping diodes.A variant of this topology is known as the NPC2 topology which uses two IGBTs per half-bridge and two IGBTs connected as a common collector configuration in the clamping path.This topology is also available with two reverse blocking(RB)IGBTs instead of IGBTs in a common collector configuration to reduce the amount of conducting components.The gate driver requirements – especially concerning protection functions like desaturation monitoring and active clamping – are different for NPC1/NPC2 and NPC2 with RB-IGBT topology.This paper discusses these differences and provides proven solutions that enable standard gate drivers to be adapted for use in NPC2 topology designs with RB-IGBTs.