Ultra-Light Reaction Wheel with Dual-layer rotor and Single-side Halbach Magnet Array for CubeSat

The reaction wheel plays a pivotal role in precision attitude control for aerospace applications. This paper designs an ultra-light CubeSat reaction wheel under volume and weight limitations. A permanent magnet (PM) motor with a Halbach magnet rotor is used to improve the torque density and reduce the back iron usage. A dual-layer rotor motor with one side iron and one side Halbach magnet is developed for sufficient angular momentum. The torque ripple caused by the interaction between the stator and the rotor can be eliminated. Moreover, the dual-rotor motor can decrease the unbalanced force and vibration to extend bearing life. This paper uses finite element analysis (FEA) to verify the CubeSat reaction wheel geometry design. The proposed CubeSat reaction wheel prototypes are fabricated for experimental validation. The co-simulation technique combining the electrical machine model and inverter drive circuit is also developed to verify the behavior of the torque box.