Since the rotor adopts permanent magnets, no special excitation winding is required. Under the same capacity, the motor is smaller in size, lighter in weight, higher in efficiency, more compact in structure, more reliable in operation and better in dynamic performance. Drive and other aspects have been widely used. Three-phase AC motor – asynchronous motor AC motors are divided into synchronous motors and asynchronous motors, synchronous motors are mostly used for generators, and asynchronous motors are mostly used for motors. The outer casing of the motor is the stator, and there are three-phase symmetrical AC windings on the stator. Due to the sequential changes of the three-phase electricity, a rotating synthetic magnetic field is formed, and the rotation speed of the magnetic field is the synchronous speed.