The permanent magnet material of the permanent magnet motor stator is generally “NdFeB” rare earth alloy, which has the highest magnetic energy density. However, at high temperature, the magnetism will irreversibly decline. Therefore, the temperature of the permanent magnet motor must be controlled below 150°C. The permanent magnet material is generally cooled by forced water cooling on the motor.
Advantages of permanent magnet synchronous AC motors: From a performance point of view, permanent magnet synchronous AC motors have high power density and torque density, and can provide maximum power output and acceleration for electric vehicles. In addition, the permanent magnet synchronous AC motor is small in size, high in efficiency, and energy feedback braking technology is efficient, which can reduce the wear of the brake pads, thereby increasing the mileage of the car;
From the design point of view, the permanent magnet synchronous AC motor adopts a fully digital and modular structure design, which makes the drive interface flexible, strong control ability, and easy to operate;
From a maintenance point of view, the electric vehicle drive system using a permanent magnet brushless motor as a drive element has a simple and firm structure, is easy to maintain, and has low operating and maintenance costs.