ANALYSIS OF TORQUE RIPPLE AND TOTAL HARMONIC DISTORTION OF DOUBLE-STATOR PERMANENT MAGNET MACHINE

摘要

The effect of torque ripple, total harmonic distortion (THD), cogging torque and unbalanced magnetic force (UMF) on a developed double-stator flux-switching permanent magnet (DS-FSPM) machine having different rotor poles is studied in this article. Moreover, the impact of their varying structural geometries is also considered. It is observed that the machines with odd-rotor pole numbers are characterized by UMF on the rotor due to asymmetries and eccentricity effects. The UMF is an undesirable effect in most applications, as it causes vibration and noise on the machine. However, it could be avoided by doubling the stator and rotor pole numbers. More importantly, the observed UMF in this study varies inversely proportional to the rotor pole numbers, i.e. the larger the pole number, the smaller the magnitude of the UMF on the rotor. Moreover, there are optimal values for each of the geometric variables, to obtain the least value of torque ripple and THD.