The difference between synchronous motor and asynchronous motor
The biggest difference between synchronous motor and asynchronous motor is whether their rotor speed is consistent with the rotating magnetic field of the stator. The rotor speed of the motor is the same as the rotary magnetic field of the stator, which is called synchronous motor, otherwise, it is called asynchronous motor.
In addition, the stator windings of the synchronous motor and the asynchronous motor are the same, and the difference lies in the rotor structure of the motor. The rotor of an asynchronous motor is a short circuited winding, which generates a current by electromagnetic induction. The rotor structure of synchronous motor is relatively complex and has DC excitation winding, so the external excitation power is needed, and the current is introduced through slip ring. Therefore, the structure of synchronous motor is relatively complex, and the cost and maintenance cost are relatively high.
The difference of reactive power between synchronous motor and asynchronous motor
The asynchronous motor can only absorb reactive power, and the synchronous motor can produce reactive power, and it can also absorb reactive power.
The difference between the synchronous motor and the asynchronous motor in function and use
The speed of synchronous motor is synchronous with the speed of electromagnetic, while the speed of asynchronous motor is lower than that of electromagnetic speed. No matter what the load is, the speed of asynchronous motor will not change as long as it does not lose its speed. The speed of asynchronous motor always changes with the change of load.
The synchronous motor has high accuracy, but complex manufacturing, high cost, and relatively difficult maintenance. Asynchronous motor, though slow, is easy to install and use, and at the same time, it is cheap. So the synchronous motor has no wide application of asynchronous motor.
Synchronous motors are mostly used in large generators, and asynchronous motors are almost used in motor situations.