Ventilation system design and rotor air friction loss of high-speed permanent magnet machines

Because of its advantages such as large power density, small size and high efficiency, high-speed machine has been widely used in aerospace, industrial production and other fields. However, it is easy to cause irreversible permanent magnet demagnetization because of high density and difficult heat dissipation. In view of the above problems, the fluid field simulations of two ventilation systems are carried out, and a detailed fluid field analysis is carried out for the better middle ventilation system. High-speed permanent magnet machine rotor surface speed is very fast, resulting in the friction of the air can not be ignored. But its numerical value is related to many factors, such as machine speed, ventilation system, inlet wind velocity and surface roughness of the rotor. It is difficult to calculate accurately by analytic method. We simulated the 3D fluid model of rotor air friction loss and many factors influence on the high-speed permanent magnet machine is analyzed, and summarizes the corresponding high-speed permanent magnet machine rotor air friction loss law.