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 torquehysteresis 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 dualinverter 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.