Development of the Equivalent Magnetic Circuit Model for a Surface-interior Permanent Magnet Synchronous Motor

This paper presents an analytical method for analyzing the magnetic field of a Surface-interior Permanent Magnet Synchronous Motor (SIPMSM). The Equivalent Magnetic Circuit Model (EMCM) of the SIPMSM is established first according to the distribution characteristics of the main magnetic flux and leakage magnetic fluxes of the motor. On this basis, the methods for calculating various leakage magnetic permeances are determined according to the motor structure and thus the leakage magnetic reluctances of the magnetic circuit are obtained. A comparative analysis of the calculation results of the analytical method and the Three-dimensional Finite Element Method (3D FEM) reveals that those results are in good agreement, it shows that the EMCM has certain reasonability and feasibility. Compared with the finite element method, the analytical method has the advantage of easy and fast calculation, it can save a lot of time when analyzing many motor designs with different dimensions, and it can therefore be used as a powerful analytical tool during the design processes of SIPMSMs.