Magnetic Field Prediction of the Saturated Surface-Mounted Permanent Magnet Synchronous Machine With Rotor Eccentricity

Abstract

This article presents an analytical method to predict the magnetic field of eccentric surface-mounted permanent magnet synchronous machine (SPMSM) by applying the hybrid magnetic circuit and subdomain method. Taking stator saturation into account, the surface current is appended to the stator coil conductor, which can generate a magnetomotive force (MMF) to compensate the MMF drop across the stator core. The rotor yoke saturation effect is modeled by increasing the air-gap length. To solve the problem resulted from rotor eccentricity in analytical analysis, an equivalent transformation method is given. The transformation principle is that the eccentric machine can be equivalent to a concentric one with redistributed PM remanence and armature current density. On this basis, the subdomain method is adopted to predict the magnetic field of the reestablished machine. The proposed analytical method is implemented and evaluated on the 6p/36s and 8p/12s SPMSM and exhibits good agreement with the FEM and experiment results.