Comprehensive study on in‐plane eddy‐current loss in permanent‐magnet synchronous machines

Abstract

In‐plane eddy‐current loss in permanent‐magnet synchronous machines has been comprehensively and analytically studied by using three‐dimensional (3D) finite element method. Considering the accuracy and calculation time, the electrical conductivity in the stack direction should be set to zero in 3D analysis. Stacking factor is also an important analytical parameter in this kind of calculation. The influences of slot number and coil‐end height have been clarified. Harmonics caused by an inverter in pulse‐width‐modulation or one‐pulse mode result in additional in‐plane eddy‐current loss, which is independent of the slot number. This behaviour can be explained by a theoretical equation of the eddy‐current loss. These results are useful for the analysis and design of highly efficient electrical machines.