EDDY-CURRENT EFFECTS ON THE DESIGN OF ROTOR-MAGNETIC BEARING SYSTEMS

The recent growth of magnetic bearing applications in the chemical, ut ility and aerospace industries requires more accurate design tools to insure reliable and effective operation as components of the overall r otor bearing system. This paper provides a novel approach for simulati ng a flexible rotor suspended in magnetic bearings, accounting for edd y current effects. The manuscript discusses some magnetic bearing fund amentals, leading up to the new methods for modeling. Test results sho w very good correlation with theory and confirm the importance of cons idering eddy current effects. Surface conductivity and frequency depen dent permeability effects on the B field in the magnet gaps are shown to be very significant on overall system stability. The results in the manuscript should be very useful to the design or test rotor dynamici st.