Comparing the Surface- and Interior Permanent Magnet Machine with Concentrated Windings for High Dynamic Applications

Abstract

This paper will compare the surface permanent magnet (SPM) machine to the interior permanent magnet (IPM) machine with fractional slot concentrated winding (FSCW). Key features is to achieve high field weakening with low losses, while keeping a high torque at rated speed. A walk through of essential theory concerning field weakening will be done. The application builder in COMSOL 5.2 was used to quickly do changes in the model. The Livelink Matlab extension was also used for post-processing the results and estimating the core losses.The results show that the I-shaped IPM machine has the lowest losses and both double layer and single layer winding can achieve high field weakening. The I-shaped rotor also has low total harmonic distortion and torque ripple. The V-shaped IPM rotor shows it difficult to optimize because of its many geometric variations and non linear behavior. The SPM machine has a higher power factor then the IPMs, due to the higher inductance in the IPM machines.