High-Voltage, High-Performance Switch Using Series-Connected IGBTs

A high-performance, high-voltage switch obtained by a series connection of 3300 V insulated gate bipolar transistor (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 a 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 IGBTs, available in the 3300 V size but not in the 6500 V one, allows extra performance to the series connection circuit, as experimental results show. Such circuit is suitable to increase performances of high-power, high-voltage inverters used in railway traction, in high-voltage energy distribution lines, and in high-power solid-state klystron modulators.