three-phase synchronous motor

A three-phase synchronous motor is an alternating-current electric motor where the rotor rotates at a speed directly proportional to the frequency of the power source. It features a stator with windings similar to an induction motor, and its rotor generates a constant magnetic field, either through direct current or permanent magnets. This rotor field aligns with the rotating field created by the three-phase currents in the stator.1

Synchronous motors operate at a constant speed when connected to a fixed frequency supply. They are highly efficient and can control the power factor of the electrical supply, making them valuable for large industrial applications. Smaller synchronous motors are used in devices requiring precise speed, like clocks and timers. To start, they often require additional rotor windings to function like an induction motor.12