Suppression of Winding AC losses in High-Speed Permanent Magnet Machines by Novel Transposition Technologies

In high-speed machines, the AC copper loss is a serious issue that can't be neglected. In this paper, two new transposition technologies for both single coil and series coils are proposed. With the help of specific winding formers, the proposed transposition technologies can be achieved in engineering for random-wound windings without loss of slot filling factor. The technologies are used in a 200 kW 54000 rpm high-speed permanent magnet synchronous machine (PMSM). The simulation results show that the suppression effect of the proposed transposition technologies on the AC loss is very significant and the copper loss can be reduced by up to 92% at 1800Hz. Finally, experiments are carried out on the stator of the 200 kW 54000 rpm PMSM to validation the effectiveness of the proposed transposition technologies.