The rotor structure of a permanent magnet motor is different from that of an ordinary motor. Permanent magnet poles are installed on the rotor of a permanent magnet motor; an excitation coil is installed on the rotor of an ordinary motor, which requires the passage of current to create a magnetic field.

Compared with ordinary motors, permanent magnet motors are small in size, but have large power generation or output, and have the characteristics of high power density.

Compared with traditional motors, permanent magnet motors can save electric energy at any speed point, especially when the speed is low, and can increase the energy saving effect by 20%-40% compared with ordinary motors. Most modern submarines use large-diameter, low-speed, 7 -blade large-inclination propellers or pump-jet propellers, which have low rotational speed and high propulsion efficiency. And submarines mostly maneuver at low-noise speeds underwater, so this advantage of permanent magnet motors is fully reflected and brought into play.

The permanent magnet motor has a simple structure. Because it uses high-performance permanent magnet materials to provide a magnetic field, the air gap magnetic field of the permanent magnet motor is much stronger than that of ordinary motors. And because the permanent magnet motor is small in size and light in weight, its size and shape have also changed. Be flexible and diverse.

Permanent magnet motors use high-performance rare earth permanent magnet materials to provide a magnetic field, so they have lower failure rates and are more widely used than ordinary motors.