Dynamic modeling and optimal control of cone-shaped active magnetic bearing systems

Abstract

In a cone-shaped active magnetic bearing (AMB) system, the rotor motion is controlled simultaneously in the axial and radial directions by two radial bearings with cone-shaped magnetic core. In this work, a fully coupled dynamic model for a cone-shaped AMB system is developed, including the relationships between input voltage and output current in the cone-shaped magnet coil. Based on the linearized dynamic model, the procedure for designing optimal controllers is shown. The modeling and control schemes are then applied to a laboratory AMB system in order to verify the analytical developments. It is found that the experimental results agree well with the analytical developments in the stabilization and tracking performance of the controled system.