Analytical Investigation of the Air Gap Flux Density of Surface-Mounted PMSMs With Irregular Pole Shapes

The article is aimed at an investigation of the no- and on-load features of surface-mounted permanent magnet synchronous machines (SMPMSMs) equipped with irregular pole shapes, with emphasis on the air gap flux density. The latter is predicted considering the resolution of the governing equations based on the magnetic potential vector formulated within the PM segments. The superposition of the resulting flux densities yields the one of the total pole. The proposed model involves appropriate geometrical parameters that makes it possible the application of the developed approach to any pole shape irregularity. SMPMSMs equipped with bread-loaf and sinusoidal with and without harmonics PMs are investigated using the developed approach and their features are compared. The obtained results are validated by finite element analysis. An experimental validation is carried out considering a prototype equipped with bread-loaf magnets.