In the high temperature environment, the material properties of the permanent magnet motor change, causing significant changes in core loss, winding copper loss, and rotor loss. In terms of heat transfer, the heat transfer method is different when vacuum or oil is filled inside the motor, and the temperature distribution inside the motor is complex; in terms of heat dissipation, the cooling environment and cooling conditions of aerospace motors are restricted, and it is difficult to design water cooling, air cooling and other measures. make it difficult to dissipate heat.

   When the permanent magnet motor works under extreme conditions such as high temperature, high speed and high power density, the change of its heat generation and temperature rise will be more serious. The high temperature rise of the motor causes irreversible demagnetization of the permanent magnet, damage to the insulation layer of the enameled wire, or even the motor burns the windings. Therefore, the accurate calculation of loss and temperature rise is one of the key technologies in the design and analysis of high temperature permanent magnet motors, and The heating temperature rise of the motor is also the most important factor affecting the reliability and life of the motor.