Transient voltage balancing of series connected IGBTs

The discharge between two metalballs was used to simulate the transient process of the short-circuit load. The formula of inductor for overhead line and the circuit transient analysis were used to estimate the stray inductance. The calculation results accorded with simulation analysis results. Using the Monte Carlo analysis of various elements on the RCD (resistor, capacitor, and diode) snubber circuits and the gate drive circuits, the key elements influencing the transient voltage balancing of series connected IGBTs were found. They were Zener diodes of the gate drive circuits and capacitors for voltage balancing. The key elements of uniformity characteristics should be chosen to improve the reliability of the pulse power designed by the same topology.