Application of a novel H-bridge driver in cell-fault treatment for cascaded inverter

To increase the fault tolerance for cascaded H-bridge inverter, a novel powerful driver is introduced for H-bridge drive and protection. This driving-circuit could drive four high power IGBTs simultaneously, with slowly decreasing grid-voltage and softly turn-off based over-current protection, the H-bridge and cascaded system could be protected effectively. Characteristics of over-current protection for the driver were studied. A cascaded H-bridge inverter prototype with this novel driver was designed; the experiment results show that the circuit has the satisfactory function of driving and protection, the reliability of the system is then enhanced.