Influence of RCD snubber circuit on the commutation process of high-power three-level inverter with 4.5kV IEGTs

Three-level IEGT inverter is commonly used in steel rolling industry. We suggested that 2RCD snubber circuit has fewer components and simpler circuit structure. Based on the stray inductance distribution, we select appropriate RCD parameters. Analysis on the commutation process of three-level neutral point clamped (NPC) inverter draws a conclusion on how 2RCD snubber circuit works during commutation process, hereby provides a theory reference for snubber circuit design of practical high-power multi-level system.