An approach to optimize the stator circumferential geometry of a five phase FSPMSM

Abstract

The paper is devoted to an approach to optimize the stator circumferential geometry of a five phase fractional-slot PM synchronous machine (FSPMSM). The proposed approach is initiated by a formulation of the armature MMF considering a sinusoidal current supply that matches the surface-mounted arrangement of the PMs. An investigation of the harmonic content of the armature MMF enables the analysis of its total harmonic distorsion versus the stator circumferential geometry. Then, the cogging torque is formulated and its variation with respect to the circumferential geometry is explored. The obtained results are validated by FEA. Finally, an optimal stator circumferential geometry is selected considering as criteria an increased average value of the electromagnetic torque, and a decreased peak-to-peak value of the cogging torque.