A novel firing control and overcurrent protection of the main power switches in the ARCP three phase inverter

A novel firing control circuit for the ZVS operation and overcurrent protection of the main power switches in the ARCP three phase inverter is presented, which is applied to auxiliary AC power supply system of the electric railway rolling stock. Since the proposed circuit is composed of only an AC current transformer, four comparators and two AND gates, the circuit is simple and its operation is reliable. Also, the limited value of the overcurrent is easily adjusted by the predetermined reference value of the comparators. The superior performance characteristics are confirmed by the experiments.