Analysis and test of dynamic reaction of magnetic bearing reaction flywheel

Aimed at the magnetic bearing reaction flywheel rotor system, a novel model was proposed to describe the dynamic reaction of hybrid magnetic bearing (HMB). Based on Lagrange principle, the unbalance mass moments distributed in two planes were equivalent to the positions of two radial HMBs. Incorporated with the effect of centrifugal force caused by its principal axis of inertia, the dynamic reaction of HMB was obtained. Simulation result show that the rotation amplitude of rotor was significantly dependent on the phase difference, angular velocity and unbalance mass moment. When the values of two unbalance mass moments were equal, for the phase difference of 0, the amplitude was high, near 30μm. However, with an increase in the phase difference to π, the amplitude of rotor diminished down to 10μm. In addition, the vibration amplitude of rotor was 5μm at speed of 1000r/min, which was lower than one at speed of 5000r/min. Tests had a good agreement with the numerical simulations, which shows how to improve the precision and stability of system, by decreasing the vibration amplitude of flywheel rotor.