Design of AMB and Rotordynamics for a 30kW, 60 000 rpm Permanent-magnet Machine

Due to the long lifetime requirement and high rotating speed, an active magnetic bearing is designed for a 30 kW, 60 000 rpm permanent magnet machine application. The electromagnetic distribution characteristics of the active magnetic bearing are analyzed under the static levitation and the maximum bearing capacity using 2D finite element method. According to the large error problems of the calculation of the critical speed of the rotor assembly, this paper presents a model updating method to establish the finite element model of the rotor assembly. The calculated results of the first two bending critical speeds are verified by using the modal testing. The errors of the first two bending critical speed are 3.2 % and 1.8, respectively.