Multiple Voltage Vectors Control Strategy for the Direct Torque Control Using Matrix Converters

The electromagnetic torque ripple is one of the most important drawbacks of the Direct Torque Control for Induction Motors using Matrix Converters at low speed. This paper investigate the use of multiple voltage vectors of Matrix Converters to reduce the electromagnetic torque ripple which appears when Direct Torque Control technique is used in Induction Motors. The standard look up table for Direct Torque Control is improved in order to include the multiple voltage vectors (long voltage vectors, short voltage vectors and zero voltage vectors). A hysteresis comparator with five-level output is proposed to determine the small and large torque errors and consequently the electromagnetic torque ripple is reduced. Finally, the simulation results have verified the feasibilities of this novel control strategy.