Coreless Axial Flux Permanent Magnet Machines with Concentrated Coils and Various Pole/Coil Combinations

Authors

• Matin Vatani, University of KentuckyFollow
• Spencer M. Goode-Kulchar, University of KentuckyFollow
• John F. Eastham, University of BathFollow
• Xiaoze Pei, University of BathFollow
• Dan M. Ionel, University of KentuckyFollow

Abstract

This paper comprehensively analyzes coreless stator axial flux permanent magnet (AFPM) machines by investigating rotor magnetic fields, stator winding factors, and 2D/3D finite element analysis (FEA) simulations. The torque production theory in coreless AFPM machines is studied with detailed derivations for flux density and current density. The impact of rotor permanent magnet (PM) width is examined for both surface-mounted and Halbach array configurations, followed by a discussion of its influence on the air-gap harmonic spectrum. The effect of stator coil side width is analyzed through a detailed winding factor study across various pole-to-coil ratios and a discussion on the trade-off between winding factor and ampere turn. Multiple 3D FEA simulations are conducted to compare the performance of coreless AFPM machines with different pole/coil configurations for both rotor types. The results highlight the superior performance of the four-pole, three-coil configuration over other alternatives.

Document Type

Conference Proceeding

Publication Date

10-2025

Digital Object Identifier (DOI)

doi: 10.1109/ECCE58356.2025.11259524

Repository Citation

Vatani, Matin; Goode-Kulchar, Spencer M.; Eastham, John F.; Pei, Xiaoze; and Ionel, Dan M., "Coreless Axial Flux Permanent Magnet Machines with Concentrated Coils and Various Pole/Coil Combinations" (2025). Electrical and Computer Engineering Graduate Research. 27.
https://uknowledge.uky.edu/ece_gradpub/27