A study on eddy-current losses in rotors of surface permanent magnet synchronous machines

Abstract

We investigate eddy-current losses in rotors of surface permanent magnet synchronous machines, which have concentrated armature windings. By FEM analysis, it is clear that eddy-current losses in rotors are apparently different at rated current if the pole and slot combinations are different. The distribution of eddy-current density in the rotor is closely related with asynchronous components of the armature MMF. If the armature MMF has a low order of spatial harmonic component, which is not synchronous with the rotor, eddy-current losses are large amount.