Series connection of high power IGBT modules for traction applications

IGBT series-connected power switching circuit is presented. Voltage balance on IGBT's is ensured by means of a simple auxiliary circuit applied directly on the high power inverter used in hard switching applications. Analysis in terms of dissipated energy, collector overvoltage and switching frequencies, comparing performances of a single high voltage IGBT (3300 V) module and two series connected 1700 V IGBTs is reported. An extended experimental analysis is also reported. Both analysis confirm the advantages in using two series connected IGBT in substitution of a single high voltage module in terms of power losses and switching performances.