Analytical model for magnetic field calculation of SPMSM with chamfered pole considering iron core saturation.

To effectively optimise pole shape for surface‐mounted permanent magnet synchronous machine (SPMSM), an analytical model of SPMSM with the chamfered pole is proposed for no‐load and on‐load magnetic field calculation. In this model, the pole of SPMSM is approximately segmented into pieces with regular shape and uniform magnet property, and magnetic field parameters can be obtained by subdomain superposition. Meanwhile, iron core saturation is considered to get a correction coefficient to revise air‐gap flux density, inducing flux linkage, line no‐load back electromotive force (EMF) and electromagnetic torque. Based on this analytical model, the geometry optimisation of PM can be optimised by end thickness of pole, pole‐arc coefficient of cutting and remanence, and the waveform total harmonic distortion of air‐gap flux density and no‐load back EMF are greatly reduced. To verify the analytical model, an outer rotor type SPMSM with 20‐poles and 72‐slots for tractor application is designed and manufactured. Finally, the effectiveness of the improved method is validated by the finite‐element method and experimental test. [ABSTRACT FROM AUTHOR]