Loss study of a novel axial flux permanent magnet machine

This paper presents the loss analysis of a novel axial flux permanent magnet machine for flywheel energy storage system. Losses in iron-core and permanent magnets caused by both space harmonics and time harmonics are respectively analyzed using three-dimensional finite element method. Effect of skew of magnets on machine losses is also taken into study. The analysis is validated by comparisons of calculated losses and measured values on a prototype. A solution to reduce eddy-current losses on the magnets for this machine is also presented: the eddy-current losses in the permanent magnets can be significantly lessened by both circumferential and radial segmentations.