Analysis of In-plane Eddy-current Loss in Electrical Steel Sheets of 6-pole 36-slot Permanent-magnet Synchronous Machines

Accurate calculation of stray load losses such as circulating-current loss in armature windings and in-plane eddy-current loss in electrical steel sheets is important for the design of high speed rotating machines with high efficiency. We investigate the motor size dependence of the losses caused by the in-plane eddy-current in the stator cores of permanent-magnet synchronous machines with 6 poles and 36 slots using finite element method. We have clarified that the teeth width is an important parameter for the amount of in-plane eddy current loss. This behavior can be well explained by the skin depth of the electrical steel sheets used for the stator core.