Do you know the difference between three-phase ac synchronous motor and three-phase ac asynchronous motor? Let's talk about their differences.

　　A, rotational speed

　　Asynchronous motor is the stator sends alternating current to generate a rotating magnetic field, while the rotor is induced to generate a magnetic field. The two magnetic fields act on each other, making the rotor rotate with the stator's rotating magnetic field.

　　Synchronous motor rotor is artificially added to the direct current to form a constant magnetic field, so that the rotor followed the stator rotating magnetic field into synchronization, known as synchronous motor.

　　Structure and principle

　　The stator windings of synchronous and asynchronous motors are the same, the main difference lies in the structure of the rotor.

　　The rotor of the synchronous motor has dc excitation winding, so an external excitation power supply is needed to introduce current through the slip ring. The asynchronous motor rotor is a short-circuit winding, relying on electromagnetic induction to generate current.

　　Asynchronous motor is simple, low cost, easy to install, use and maintain, so it is widely used. And the high efficiency of synchronous motor is capacitive load, can improve the power factor of the power grid.

　　Three, use

　　Synchronous motors are mostly used in large generators, while asynchronous motors are almost entirely used in motors.

　　Synchronous motor can adjust power factor flexibly through excitation. Asynchronous motor power factor is not adjustable, so in some large factories, asynchronous motor application is more, can be attached to a synchronous motor for the camera, used to adjust the power factor of the factory and the grid interface. However, due to the high cost of synchronous motor and large maintenance workload, it is generally used to compensate the power factor by capacitance.

　　The synchronous machine has excitation winding and slip ring, which requires the operator to have a higher level to control the excitation. In addition, compared with the maintenance-free asynchronous machine, the maintenance workload is larger. Therefore, as a motor, now mostly choose asynchronous motor.