Abstract:

 A mathematical model of the suspension forces is established for three-phase inverter-fed AC radial
magnetic bearings. According to the requirement the suspension forces, parameters of an experimental prototype
are calculated. The magnetic field and suspension forces of the rotor are verified using Ansoft. Nonlinearity of
the suspension forces and the coupling characteristics of the movement between two degrees of freedom around the
balance position are calculated and analyzed. The results show that the mechanical configuration and magnetic
circuits of the magnetic bearing are correct, and the suspension magnetic forces satisfy the design requirement.
Suspension forces have good linearity and symmetry around the balance position, and the movement of two degrees
of freedom around balance position has no coupling.

Key words: AC active magnetic bearing, mathematical model, parameter design, nonlinearity, coupling