Research on Structure Optimization of Axial Magnetic Bearing for Magnetic Levitation System

Axial magnet bearing has the advantages of adjustable stiffness and strong adaptability. However, when it is integrated into the magnetic levitation system of high-speed, the length of axial and radial often limit further applications. In traditional design methods, empirical formulas are often used, which will fail to obtain optimal values. Aiming at this problem, an optimization design method of axial magnetic bearing is proposed. According to finite element analysis, distribution of suspension force and magnetic induction intensity can be obtained. Moreover, local sensitivity analysis is carried out by quadratic response surface method to determine variables with high correlation about the objective function. Taking maximum suspension force, axial length and radial length as optimization objectives, thickness of thrust plate, length-width ratio of wire slot, air gap and slot fill factor as design variables, multi-objective optimization design can be carried out by multi-objective genetic algorithm, which will obtain optimal solution of structure parameters. Results show that maximum suspension force of the optimized one increases by 8.79%, the overall axial length decreases by 9.18%, and the overall radial length decreases by 6.92%.