Virtual Vector-Based DTC of Dual Inverter-Fed Asymmetrical Six-Phase Induction Motor Drive Supplied From a Single DC Source

This article proposes a virtual voltage vector-based direct torque control (DTC) scheme for dual-inverter-fed asymmetrical six-phase induction motor drives, energized from a single DC source. The proposed scheme not only suppresses the resultant common-mode voltage (RCMV) across all six stator windings but also mitigates RCMV appearing across the individual three-phase winding sets. Consequently, it eliminates common-mode circulating currents in the stator windings. This scheme also eliminates triplen-order circulating currents between the two three-phase winding sets. The scheme achieves significantly higher DC-bus utilization compared to the conventional topologies for a given DC source voltage. Furthermore, the optimized virtual vector-based DTC operation suppresses auxiliary-plane harmonic currents, thereby reducing the associated losses. The effectiveness of the proposed method is first validated through detailed simulations using MATLAB/Simulink, followed by experiments conducted on a laboratory-scale prototype.