Switched reluctance motor applications to EV and HEV: Torque control issues

Switched reluctance motor (SRM) is being used by many automotive companies around the world as the drive motor for EV(Electric Vehicle) and HEV(Hybrid electric vehicle) applications Torque pulsations are inherent in SRMs due to the doubly salient structure of the machine and its sequential excitation. Minimized torque ripple design of a SRM in a EV will certainly led to a comfortable drive. Torque ripple in SRM is simulated utilizing both the bulk saturation model as well as the complete model, considering the local saturation in addition to the bulk saturation and a comparison of these two methods is presented. A novel method of torque ripple reduction that can be used is also presented. It is based on the optimal current profiling technique. But instead of phase current, unsaturated current obtained from phase current minus current required to overcome saturation is compared with current from static torque-unsaturated current-rotor position data table as reference which was generated using torque linearization and decoupling technique and the error is used to minimize the torque ripple.