Simplified calculation for the radial levitation force of radial‐type superconducting magnetic bearing.

It is usually difficult to obtain the radial levitation force of the radial‐type superconducting magnetic bearing (SMB) due to the massive numerical calculations and the sophisticated experimental measurements. This study presents a method for fast calculating the radial levitation force of radial‐type SMB, which is based on the infinitesimal method and the 2D finite‐element method. During the modelling, the radial‐type SMB is assumed to be composed circumferentially of infinite superconductor‐permanent magnet (SC‐PM) infinitesimals with shape of rectangular thin slice. The dependence of levitation force for the SC‐PM infinitesimal on the air‐gap length between the SC stator and the PM rotor can be obtained using the 2D finite‐element model established in Cartesian coordinate system. Moreover, a simplified analytical model of calculating radial levitation force is developed based on the infinitesimal method and the circumferential distribution formula of non‐uniform air‐gap when the PM rotor exhibits radial eccentricity. The results of theoretical calculation and experimental measurement of radial levitation force show a good agreement, which verifies the feasibility of the proposed method. It has the advantages of fastness and easiness, and can be used as a theoretical tool for the design, optimisation and performance prediction of the radial‐type SMB. [ABSTRACT FROM AUTHOR]