Control strategy for a three phase AC traction drive with three-level GTO PWM inverter

A control strategy developed for two-level inverters is applied to the three-level gate-turn-off PWM inverter. This is done by replacing the three-level inverter by two coupled two-level inverters and taking the coupling condition into account. A control strategy based on the method of direct self-control is described. Results from computer simulation for a traction motor with 1400 kW nominal power are shown and discussed.>