The rotor plays a crucial role in an AC synchronous motor by interacting with the rotating magnetic field generated by the stator to produce mechanical motion. An AC synchronous motor is designed to operate in synchronization with the frequency of the alternating current (AC) power supply. It consists of two main components: the stator and the rotor.
The stator is the stationary part of the motor and contains the stator windings that are connected to the AC power supply. When AC voltage is applied to these windings, they generate a rotating magnetic field that revolves at a specific frequency determined by the power supply frequency (e.g., 50 Hz or 60 Hz). This rotating magnetic field induces a magnetic flux that sweeps across the motor's internal space.
The rotor, on the other hand, is the rotating component of the motor. It is typically equipped with field windings or permanent magnets. The key role of the rotor is to interact with the rotating magnetic field produced by the stator. The rotor's magnetic field (created by either the field windings or permanent magnets) aligns itself with the changing magnetic field of the stator.
As the stator's magnetic field rotates, it induces a magnetic force on the rotor's magnetic field, causing the rotor to turn. The rotor follows the rotational motion of the stator's magnetic field, resulting in the mechanical rotation of the motor shaft. This rotation can then be coupled to various mechanical loads to perform useful work, such as turning a fan, driving a conveyor belt, or powering a generator.
It's important to note that in an AC synchronous motor, the rotor's speed is synchronized with the frequency of the AC power supply. This means that the rotor turns at a speed directly proportional to the frequency of the AC voltage applied to the stator windings. The synchronization between the rotor and the stator field frequency is what gives AC synchronous motors their name and makes them suitable for applications where precise speed control is necessary.