Magnetic Bearing: Structure, Model and Control strategy

Abstract

Bearings are crucial transmission components that offer support to mechanical rotating bodies. Nevertheless, traditional bearing failure due to friction and wear more easily. In scenarios involving ultra-high speeds and extreme applications, minimizing bearing losses and enhancing performance becomes especially vital. Magnetic bearings, characterized by zero friction, no need for lubrication, and high-speed capabilities, offer a viable solution to the issue of bearing failure attributed to friction. However, there is currently a shortage of comprehensive review literature that delves into the structural attributes, modeling mechanisms, and control strategies of magnetic bearings. This article will perform a comprehensive literature review on magnetic bearings, addressing the aforementioned aspects and discussing their core technologies. Firstly, from the perspective of classification and magnetic circuit structure analysis, the properties and characteristics of various magnetic bearings are discussed. Secondly, the working principle and performance of mathematical models of magnetic bearings with different structures are described, and the modeling steps and optimization schemes are summarized. Furthermore, the influence of control strategy of magnetic bearing on the control performance of magnetic bearing is summarized. Compared to PID control, modern control theory has achieved a performance improvement of nearly 50% in terms of improved position accuracy and adjustment time. Finally, the current research progress on magnetic bearings is summarized, and the current bottleneck issues are anticipated. This review contributes to a deeper understanding of the action mechanism and control method of magnetic levitation bearing, thus promoting the progress of magnetic levitation bearing technology.