Gimbal effect of magnetically suspended flywheel with active deflection of Lorentz-force magnetic bearing

Abstract

The magnetically suspended flywheel (MSFW) could output gyroscopic moment for attitude control. The conical magnetic bearing (MB) with cone-shape airgap is designed to stably suspend the rotor on three translational degrees of freedom (DOFs), and the Lorentz-force MB with long torque-arm could actively deflect the rotor around radial axes on two DOFs. Firstly, the force models of the conical MB are developed on the basis of the equivalent magnetic circuit, and then the force characteristics of the Lorentz-force MB are analyzed. With the stable position control of rotor, the gimbal effect of the Lorentz-force MB is investigated, and then the gimbal moment generated by rapid deflection via the Lorentz-force MB is quantitatively analyzed. Finally, the experimental results prove that the maximum deflection angle approaches to 1.7°, and the outputted gyroscopic moment reaches to 10Nm with 3.14°/s deflection velocity. Therefore, the gimbal effect of MSFW with the conical MB and the Lorentz-force MB is demonstrated by actively deflecting the rotor.