Optimal design of axial flux switched reluctance motor for electric vehicle application

Design of wheel motors must conform to the diameter restriction due to cage of a wheel rim and allow the achievement of high torque density. In addition, these motors should be rugged and insensitive to vibration. Therefore, an axial flux switched motor (AFSRM) machine with double stator and one rotor structure is investigated. In general, AFSRM have simple construction; however, one of the major problems is torque ripple which will cause speed fluctuation and acoustic noise. View of this, the skewed stator segments by a specific degree respectively to the rotor with asymmetric inductance property is applied to reduce the torque drop in the phase commutation area. The proposed method is analyzed by magnetic equivalent circuit approach (MECA) and finite element analysis (FEA) method. Through the parameter study, torque ripple reduction in proposed machine is significant in comparison with the one of conventional non-skewed stator machine.