Kinematic Mechanics Analysis and Levitation Control of Active Magnetic Bearings

Active magnetic bearing(AMB) has advantages such as no friction, low loss, long service life, and strong controllability, making it widely used in various rotating shaft mechanical devices. Currently, many advanced control methods used in magnetic bearing systems have good control effects in theory, but there are significant differences in practical applications. In actual active magnetic levitation bearing systems, the manufacturing deviation of the magnetic levitation bearing rotor system causes the bearing magnetic force to shift, seriously affecting the rotor suspension control. In order to explore the motion state of the rotor in the suspension control process, the equivalent magnetic circuit method and the Maxwell integration method for electromagnetic force calculation are analyzed and compared. Based on incomplete differential PID control, a motion force analysis suspension control method for actual magnetic levitation bearing systems is proposed based on experimental testing and theoretical derivation. The rotor motion process is divided into acceleration, deceleration, and fluctuation stages. The characteristics of rotor motion and the selection of control methods in each stage are studied and applied to the actual eight pole active magnetic bearing system, ultimately making the rotor dynamically suspended within the allowable range of air gap.