Coupled electromagnetic-mechanical modeling applied to electrodynamic bearings

As known electrodynamic levitation occurs without active control due to motion induced eddy currents. There are two main drawbacks related to electromagnetic bearings: 1) the presence of losses caused by the eddy currents, and 2) the onset of instability in undamped supercritical rotor systems. Accurate analysis of these devices, especially when the axial symmetry cannot be assumed, can be performed by numerical methods only. This paper presents a comparison between the experimental data taken on a prototype of an electrodynamic bearing and the numerical simulations obtained by a research code. The good agreement envisages the use of this code for the reduction of losses and for a better characterization of the instability conditions.