Torque ripple reduction in 12-slot 10-pole fractional slot permanent magnet synchronous motors with non-overlapping windings by implementation of unequal stator teeth widths

This paper describes an optimization of the stator geometry in a way that the torque ripple at particular load is reduced. The principle applied to the torque ripple reduction is based on the synchronous inductance variation suppression, caused by the non-linear steel saturation, which might be significant even in permanent magnet synchronous motors (PMSMs) with rotor surface permanent magnets. The design optimization, described in this paper, aims in reducing the armature reaction influence on the local steel saturation in fractional slot permanent magnet synchronous machines (FSPMSM) by rearranging of the stator teeth widths. The optimization was defined by means of magnetic equivalent circuit model (lumped model), and verified with finite element method (FEM).