Modeling and Control of a Novel Structure of the 4DOF-Hybrid Magnetic Bearings

Abstract

This paper presents the modeling and control of a Novel Structure of the four Degrees of Freedom (4DOF) Hybrid Magnetic Bearings (HBMs) with a rigid rotor. In which, the centralized PD control is applied to control the HBM at its center coordinates. First, The magnetic force is calculated through the equivalent magnetic circuit, the position stiffness  and the current stiffness are identified by linearizing around the operating space. From there, the mathematical model of the HMB is introduced. The dynamic properties of the parallel and inclination mode of the rotor were analyzed to design a centralized PD controller. Finally, the proposed control strategy was verified by simulation. The results indicate that the HBM not only work stably but also ensures independent control of the rotor's translation and inclination.