Improved performance of DTC of five-phase induction machines

The paper describes about optimal voltage vector selection for high-performance of Direct Torque Control (DTC) of five-phase induction machine. The decoupled control of stator flux and electromagnetic torque based on hysteresis controllers as employed in conventional DTC is applied to retain the simplicity and to provide quick instantaneous control. A look-up table that selects the most optimal voltage vectors according to the speed operations, i.e. low-speed, middle-speed and high-speed is proposed to improve DTC performances such as excellent torque dynamic control, minimization of torque ripple, high-efficiency (due to lower switching frequency) and extension of constant torque region. All the improvements are validated through simulation results.