High voltage, high performance switch using series connected IGBTs

A high performance, high voltage switch obtained by a series connection of 3300 V IGBT modules is presented. The correct voltage sharing between the devices is ensured by the presence of a simple and reliable auxiliary circuit, which acts as feedback on the gate terminal. A comparison in terms of power losses, output currents and switching performances to a single 6500 V IGBT module is also presented. An extended experimental analysis demonstrates strong advantages in terms of switching losses (up to 67%) and current and voltage gradients. Use of trench-gate IGBT's, available in 3300 V size, but not in 6500 V one, allows extra performance to series connected circuit, as experimental results show. Such circuit is suitable to increase performances of heavy traction inverters. Multiple series connection allows to obtain very high rated voltage, low-losses switches.