Outer rotor switched reluctance motor design for in-wheel drive of electric bus applications

In this era of electrified transportation, switched reluctance motor (SRM) is emerging as a prospective replacement to traditional electric motors especially for large heavy duty vehicles such as the electric bus. This paper proposes the design and analysis of a novel outer rotor in-wheel SRM. The integration of the motor housing inside the wheel rim saves significant space and eliminates the need for additional mechanical parts used in the centralized drive. The developed concept of short flux path configuration in this research manuscript has shown additional important features compared to previous SRM designs and a substantial increase in efficiency is reported. The procedures of deriving the output power equation as a function of the motor dimensions and parameters are explained in detail. Comparative finite element analysis (FEA) has been performed between the developed machine and a commercially available conventional SRM to elicit the merits of the developed machine. The results obtained through FEA investigations show that there is a reduction of torque ripple and a considerable increase in motor efficiency.