Synchronous And Asynchronous Motor Difference

Synchronous asynchronous refers to whether the rotor speed and the stator rotating magnetic field speed are synchronous (the same) or asynchronous (lag), so only AC can produce rotating magnetic field, only AC motor has the concept of synchronous asynchronous.

Synchronous motor -- Principle:
By "the magnetic field always walks along the shortest direction of the magnetic circuit", the rotor magnetic pole corresponds to the stator rotating magnetic field pole one by one, and the rotor magnetic pole speed is the same as the rotating magnetic field speed. Features: Whether the synchronous motor is used as a motor or a generator, its speed and alternating current frequency will be strictly unchanged. Synchronous motor constant speed, not affected by load changes.

Asynchronous motor -- Principle:
The motion is realized by induction. The rotating magnetic field of the stator cuts the squirrel cage, which generates an induced current, and the induced current forces the rotor to rotate. There must be a speed difference between the rotor speed and the stator rotating magnetic field speed to form a magnetic field cutting squirrel cage and generate induced current. Asynchronous motors include (single-phase asynchronous motors and three-phase asynchronous motors)
The difference:

(1) Synchronous motor can emit reactive power, but also can absorb; Asynchronous motors can only absorb reactive power.

(2) The speed of the synchronous motor is synchronized with the AC power frequency 50Hz power supply, that is, the 2-pole motor is 3000 RPM, the 4-pole 1500, the 6-pole 1000, etc. The speed of the asynchronous motor is slightly behind, that is, 2-pole 2880, 4-pole 1440, 6-pole 960 and so on.

(3) The current of the synchronous motor is ahead of the voltage in phase, that is, the synchronous motor is a capacitive load. Synchronous motors can be used to improve the power factor of the power supply system.