Direct torque control of symmetrical six-phase induction machine using nine switch inverter

This paper presents the direct torque control (DTC) scheme for symmetrical six-phase induction machine by using Nine Switch Inverter (NSI). When this motor is controlled by conventional two level inverter, it provides 64 voltage vectors with switch count of 12. The proposed inverter is nine-switch two level having capability to produce 27 voltage vectors. The DTC control is implemented with these available voltage vectors by this inverter and flux of xy subspace is eliminated for the performance improvement. The torque ripple reduction is achieved by using five-level torque comparator. The performance is presented through simulation results and confirmed through hardware implementation.