Multilevel Torque Hysteresis-Band Based Direct-Torque Control Strategy for a Three-Level Open-End Winding Induction Motor Drive for Electric Vehicle Applications

The number of levels present in the torque-hysteresis controller influence the performance of the direct torque controlled (DTC) induction motor drives. In this paper, the effects of the number of levels in the torque-hysteresis-band controllers (THBCs) on the performance of the conventional DTC-based three-level open-end winding induction motor drives are reported. A power-loss evaluation model was employed to investigate the influence of the number of levels present in THBC on the switching and conduction losses occurring in the dual-inverter system. The performance indices considered in this paper are: 1) the flux-ripple; 2) the torque ripple; and 3) the total power loss in the dual-inverter system. Furthermore, these performance indices are evaluated with a newly emerging control strategy, namely, the predictive torque control, and are compared with those obtained with the DTC. The simulation results are validated by showing the experimental results.