Magnetic Bearing Finite Element Analysis, Structural Design And Control

The paper specially discusses electromagnetic characteristic analysis of AMB (Active Magnetic Bearing), structure parameter design, and dynamics of an AMB-rotor system excited by ground motion. ANSYS-base analysis system for MBs and structure optimum system for AMB are developed.(1) FEM (Finite Element Method) analysis of AMBAccording to magnetic circuit theory and field theory, both flux density and magnetic force of AMBs are calculated respectively by usual linear method and the FEM, and the results are compared with each other. An ANSYS-base analysis system for MBs is developed using VB language in which nonlinear behavior of electromagnetic material, the effect of journal eccentricity, material nonlinear is considered. At last, 3D-FEM analysis is simply discussed.(2) Structure design of AMBThe problem of structure design will be discussed respectively on either radial bearing or thrust bearing. On the basis, an optimum model of radial AMB will come into being and parameter design software is developed at optimum objects of maximal levitated force per length and minimal volume. In the case of radial bearing, optimum process of different structure restrict conditions are discussed. At last, some examples for radial bearing are given using the optimum software. Finally, the effect of the AMB's parameters on the AMB is discussed.(3) Dynamics analysis of an AMB-rotor system excited by ground motionThe dynamics of an AMB-rotor system excited by ground motion is simply discussed, the equation of motion and state equation of the AMB-rotor system excited by ground motion are obtained, then numerical simulation of dynamics of an AMB-rotor system with PID controller excited by ground motion are given. At last, vibration control for an AMB-rotor system excited by ground motion is simply discussed.