Novel direct torque control for induction motors using short voltage vectors of matrix converters

This paper investigates the use of short voltage vectors of matrix converters to reduce the electromagnetic torque ripple which appears when direct torque control technique is used in induction motors. Direct torque control for induction motors using matrix converters is reviewed and it is pointed out the problem of the electromagnetic torque ripple which is one of the most important drawbacks of the direct torque control. The standard look up table for direct torque control, when using matrix converters, is improved in order to include the uncommonly used short voltage vectors. This novel direct torque control approach can differentiate between small and large torque errors and consequently the electromagnetic torque ripple is reduced. Finally, some results, which prove the improvement of the novel direct torque control when using small matrix converter voltage vectors, are shown.