Impact of magnet losses on optimal design of a high speed synchronous machine

In this paper, we investigate the effect of magnet losses on the optimal design of a high speed synchronous machine. The considered synchronous machine is a surface mounted permanent magnet synchronous generator running at 30 krpm. This generator is charging up a constant-current load through a full-wave bridge rectifier. It was found that the segmentation is effective only if the magnets width is lower than the largest skin depth considered. Hence, the circumferential segmentation of the magnets is not suitable for machines presenting low value of skin depth. Further, neglecting magnet losses leads to an over estimation of the optimal power density of the machine.