Design of a miniature axial flux flywheel motor with PCB winding for nanosatellites

This paper presents the design and analysis of an axial flux permanent-magnet (AFPM) machine for nanosatellites application. It is a miniature axial flux surface mounted permanent magnet flywheel motor, using a printed circuit board (PCB) stator winding. The PCB stator has simplified the design and construction and avoids unnecessary space, since size reduction has become one of the most important aspects of flywheel motor design for nanosatellites. The performances of the machine are estimated by combination method of three-dimensional (3D) electromagnetic finite element analysis (FEA) and approximate theoretical analysis. The back EMF and electromagnetic torque are derived. A comparison between the analysis and experimental measurement results of the prototype machine is also presented. Both simulated and experimental results show that the proposed motor would be an acceptable solution for the nanosatellite applications with advantages such as simple structure and low-cost, as multi-layer circuit board production techniques have made the production of printed circuit coils cheaper and easier.