Direct torque control with improved switching for induction motor drive system fed by indirect matrix converter

The combination of indirect matrix converter with direct torque control is a way towards energy-saving of the world. This paper investigates the use of four-step switching in rectifier bridge of indirect matrix converters to reduce the electromagnetic torque ripple which appears when direct torque control technique is used in induction motors. By suitably selecting switching pattern, the electromagnetic torque ripple of the motor is effectively reduced. Indirect matrix converter has no electrolytic capacitors in the DC link, which results that volume and size of converter reduced and increased longevity. Using this switching strategy, the advantages of the DTC schemes and the benefits of the indirect matrix converters can be combined. The simulation results of DTC system based on IMC and the comparison of motor performance under the proposed control system with respect to those obtained under conventional DTC confirms its effectiveness and accuracy.