Analytical method for eddy current loss in laminated rotors with magnetic bearings

This paper presents a totally analytical method to calculate the eddy current loss in a laminated rotor. First, the method derives the analytical field solutions both in the lamination and the air gap with average boundary conditions at the surface of the rotor. The magnetic field can then be determined from the static flux distribution around the pole surface. Then, the method obtains the eddy current induced in the lamination from the field solution in the lamination. Finally, it calculates the rotation loss by integrating resistive power loss over the volume of the lamination and summed in all sheets. The results show good agreement with experimentally measured losses.