Loss Calculation and Thermal Analysis of Maglev High Speed Permanent Magnet Synchronous Motor

High-speed permanent magnet synchronous motors (HSPMSMs) for magnetic levitation centrifugal compressors have the advantages of high speed, high power density and high efficiency. However, HSPMSMs feature compact size, high loss density, and poor heat dissipation, and the permanent magnets (PMs) are prone to irreversible demagnetization at high temperatures, so it is more important to accurately calculate the temperature field distribution of HSPMSM than that of conventional motors. In this paper, a $60000 \mathrm{r} / \mathrm{min}$ HSPMSM is analyzed. Firstly, the main losses of the motor are calculated; secondly, the temperature field simulation model of the motor is constructed, and the bidirectional magneto-thermal coupling (BMTC) analysis method is used to map the motor losses into the temperature field model, and the temperature distributions of various parts of the motor are obtained. The results indicate that the BMTC simulation results are about $1 \sim 3^{\circ} \mathrm{C}$ lower than the experimental measurement values, which can accurately predict the motor temperature and provide basic theoretical support for the subsequent optimization of HSPMSM cooling scheme.