Loss Calculation and Thermal Analysis for High-Speed Permanent Magnet Synchronous Machines

The small size of high-speed permanent magnet synchronous machines (PMSMs) makes the increase of loss density and the difficulty of heat dissipation. PMSMs are sensitive to temperature, especially the permanent magnet (PM), which is likely to suffer irreversible demagnetization due to the excessively high temperature. This paper investigates the loss and thermal analysis of high-speed PMSMs with amorphous alloy stator core and interior permanent magnet (IPM) rotor. First, the trajectory of magnetic flux density in typical parts of high-speed PMSM with sinusoidal and pulsewidth modulation (PWM) inverter power supply is analyzed. The core loss characteristics based on the proposed field-circuit coupled method is obtained. Then, an electromagnetic-thermal iteration calculation method is proposed to analyze the temperature distribution. The effect of different parameters on thermal behavior is investigated, which provide references for the suppression of temperature rise. Finally, the theoretical analysis is verified through the experiments based on a high-speed PMSM prototype.