Performance improvement of SPM synchronous machines with non-conventional stator slot magnetic wedges

The opportunity to employ magnetic wedges in superficial permanent magnet machines with fractional-slot concentrated winding has been evaluated in this paper, with the aim to reduce the power losses, especially in the magnets, to increase the overall efficiency and to improve the field weakening capability. Finite element simulations with two different software are here presented, by using a model experimentally validated on a real motor. A novel wedge composed by different portions of materials with different values of magnetic permeability is proposed. The effects of both conventional and nonconventional magnetic wedges have been evaluated, in order to optimize the performance of the motor in all working conditions.