Consideration of 3-D end-effects of surface permanent - magnet synchronous-machines through 2-D finite-element analysis

This paper presents a method to take the 3-D end-effects in radial-flux permanent-magnet synchronous-machines (PMSMs) into account using only 2-D finite-element (FE) simulation by means of a correction factor on the remanent flux density ( Br) of the permanent magnets (PMs). The correction factor is calculated via the magnetic flux density in the airgap using a 2-D FE model corresponding to the cross-section of the machine under study in the axial direction. This method is tested on a 12-slot 8-pole and 12-slot 10-pole surface PMSM. Using the corrected Br in the radial simulation, a better agreement between the 2-D and 3-D simulation can be achieved in the linear as well as non-linear case, with or without load and with and without protruding magnets. As such this procedure could be used during the optimization stage of electrical machines.