Duty-Ratio-Based Direct Torque Control Strategy for a Novel Dual-Armature Winding Dual-PM Machine With Array Torque Components

A duty-ratio-based direct torque control (DTC) strategy for a novel dual-armature winding dual-PM machine (DWDM) with array torque components is proposed in this paper. The novel DWDM has armature windings and PMs arranged in both the stator and rotor, which enables the machine to output array-distributed torque components. The mathematical models of the stator and rotor torque components are developed, respectively. DTC enables the direct control of the torque components of DWDM. By adjusting the torque allocation coefficient, the ratio of the stator and rotor output torque components can be regulated. However, conventional switching-table-based DTC DWDM drives are afflicted by large torque ripple due to the unbalanced effect of torque variations within a sampling period. Therefore, a duty-ratio-based DTC strategy is proposed, taking into account the effect of the torque allocation coefficient. Finally, the torque ripple of both the stator and rotor torque components can be reduced using the proposed duty ratio determination method. The simulation results verified the superiorities of the proposed method.