Performance Comparison Between PCB-Stator and Laminated-Core-Stator-Based Designs of Axial Flux Permanent Magnet Motors for High-Speed Low-Power Applications

Gearless and small motors operating at speeds above 10 000 rpm are finding many applications nowadays. Axial flux permanent magnet (AFPM) motors are compact and lightweight compared to radial flux motors and hence, are considered for various high-speed applications. Eliminating the stator core minimizes the associated high-frequency losses, and hence, coreless AFPM motor can be an option for high-speed applications. Furthermore, the coreless AFPM motor design minimizes the cogging torque and the axial attraction force between the stator core and the rotor magnets. However, the reduction of flux linkage in the stator windings is a challenge in coreless AFPM motor. In this article, the advantages and disadvantages of the printed circuit board (PCB)-based AFPM motor for high-speed, low-power applications are investigated. A detailed performance comparison of the PCB-based coreless AFPM motor and the AFPM motor with the laminated stator core is made. Finite-element analysis is carried out for the electromagnetic, mechanical, and thermal comparison of the two motors and the simulation results are presented. Finally, motor prototypes are fabricated and are tested to ascertain the simulation results.