Permanent magnet synchronous motors use permanent magnets to provide excitation, which makes the motor structure relatively simple, reduces processing and assembly costs, and eliminates the need for problem-prone collector loops and brushes, which improves the reliability of motor operation; and because there is no need for excitation current, there is no excitation loss, which improves the efficiency and power density of the motor. Permanent magnet motor is a form of rectangular pulse wave, current sine wave current, hybrid permanent magnet motor.The speed of the permanent magnet motor is the synchronous speed, n=ns=60f/p, (f is the power supply frequency, p is the motor pole logarithm).

A three-phase current is introduced into the stator winding of the motor. After the current is introduced, a rotating magnetic field will be generated in the stator winding of the motor. Since a permanent magnet is installed on the rotor, the magnetic poles of the permanent magnet are fixed. According to the principle of same-sex repulsion and opposite-sex attraction, the rotating magnetic field generated in the stator will drive the rotor to rotate, and finally the speed of the rotor is equal to the speed of the rotating magnetic field generated by the stator, so the start-up process of a permanent magnet synchronous motor can be regarded as consisting of an asynchronous start-up stage and a synchronous operation stage.

Permanent magnet motors can be designed with low-speed or ultra-low-speed motors, high efficiency and more power-saving. They can be designed with high-speed or ultra-high-speed motors, large starting torque, high power density, and stable speed regulation.