A PI-type dead-time compensation method for vector-controlled GTO inverters

In the case of voltage-source gate-turn-off thyristor (GTO) inverters, the conventional dead-time compensation methods do not work well, since the terminal voltage of an inverter leg is not constant during the dead-time period, due to the presence of the snubber circuit. We propose a closed-loop dead-time compensation method that regulates the voltage error by a proportional-integral (PI)-type compensator. We show its superior performance by the reduction in current ripple and in the sixth harmonic component of the motor current in the synchronous frame.