Turn-Off Delay Compensation of Series-Connected IGBTs for HVDC Applications

This letter shows a computationally inexpensive delay compensation algorithm for series-connected insulated-gate bipolar transistors (IGBTs). The algorithm adjusts the relative turn-off delays among series-connected IGBTs based on the measured clamp capacitor voltages. Experimental results show that the capacitor voltage differences are compensated in a few iterations, making it suitable for delay compensation of industrial series-connected IGBTs.