The Use of Small Voltage Vectors of Matrix Converters in Direct Torque Control of Induction Machines

The effects on torque performance when using small voltage vectors of Matrix Converters is investigated in this paper. These vectors are used in order 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. A new look-up table for Direct Torque Control using small vectors of Matrix Converters is developed. With the new look-up table, the system will differentiate between small and large torque errors and consequently reduce the electromagnetic torque ripple. A comparison between the classical Direct Torque Control using Matrix Converters and the proposed method is carried out. Results which demonstrate the improvement of the novel Direct Torque Control are shown.