Study on fluid friction loss on rotor surface of FeCo based high speed permanent magnet motor

The linear speed of the rotor surface of high speed permanent magnet motor (HSPMM) is as high as 100 m/s, and the air friction loss on the rotor surface is much higher than that of ordinary motors, accounting for a large proportion of the total loss, and the actual air friction loss on the rotor surface is much higher than that of ordinary motors. It is extremely difficult to directly measure and verify the size of the rotor surface. At the same time, the air friction loss on the rotor surface is related to various factors such as motor speed, air gap structure and rotor surface roughness. It is difficult to accurately calculate through theoretical analysis and analytical methods. Based on the 3D fluid field physical model, this paper analyzes the relationship between the rotor air friction loss of FeCo based HSPMM and the rotor speed, rotor geometry, surface roughness and axial wind speed. Based on HSPMM, the calculation and test method of rotor surface air friction loss are studied. Through the FeCo based HSPMM no-load test, according to the relationship between the rotor air friction loss and other losses and the motor speed, the rotor surface air friction loss can be separated from the total loss. The experimental results are consistent with the calculated values, indicating that the HSPMM rotor air friction loss calculation method based on 3D fluid field analysis is effective.