What are the characteristics of AC synchronous motors? Working principle of AC synchronous motors

What are the characteristics of AC synchronous motors

The AC synchronous motor is a motor that works according to the principle of electromagnetic induction and has the following characteristics:

Synchronous operation: The rotor of the AC synchronous motor runs synchronously with the rotating magnetic field, so the speed is proportional to the power supply frequency and has high accuracy and stability.

High efficiency: Since the rotor runs synchronously with the rotating magnetic field, the motor has no sliding loss and high energy utilization efficiency, especially under high load conditions.

Good speed regulation performance: The speed of the AC synchronous motor can be controlled by changing the frequency of the power supply or the excitation method of the motor, so that it has good speed regulation performance.

High power factor: AC synchronous motors usually have a high power factor, which can reduce the reactive power of the power grid.

High reliability: AC synchronous motors have a simple structure, long service life, and high reliability and stability.

Able to adapt to high loads: AC synchronous motors have high output power density and can adapt to high load, high-speed operation and other working conditions.

Strong adaptability: AC synchronous motors are suitable for different load types and have strong adaptability.

In summary, AC synchronous motors have the advantages of high efficiency, good stability, good speed regulation performance, and high power factor, so they are widely used in many industrial applications.

Working Principle of AC Synchronous Motor

The AC synchronous motor is an electric motor that works according to the principle of electromagnetic induction. Its speed is proportional to the power frequency and the number of poles. It consists of two parts: the stator and the rotor. The winding on the stator generates a rotating magnetic field when it is energized, and the winding in the rotor rotates when it senses the force of the rotating magnetic field.

There are several magnetic poles on the rotor, which can be permanent magnets or magnetic fields generated by electromagnets. When the stator coil is energized, the rotating magnetic field drags the rotor poles, causing the rotor to start rotating.

Since the rotating magnetic field of the AC synchronous motor runs synchronously with the rotor magnetic field, the speed of the rotor is proportional to the frequency of the rotating magnetic field. If the frequency of the rotating magnetic field changes, the speed of the rotor will also change accordingly.

The AC synchronous motor can change the frequency of the rotating magnetic field by changing the current in the stator coil, thereby controlling the speed of the motor.

The speed of the AC synchronous motor is also affected by the load and mechanical resistance, so an electronic controller is required to regulate the speed and protect the motor.

Specifically, when a three-phase AC power supply is applied to the stator winding, the current generates a rotating magnetic field that rotates at a fixed frequency. On the rotor of the synchronous motor, there is a winding that induces an electric potential through the alternating magnetic field and generates a current, which generates another magnetic field on the rotor. The number of magnetic poles of this magnetic field is the same as the number of magnetic poles of the stator, and the speed is the same as that of the rotating magnetic field. Therefore, when the number of magnetic poles of the rotor's magnetic field and the rotating magnetic field is the same, the rotor will rotate with the rotation of the rotating magnetic field, thereby achieving synchronous rotation.

It should be noted that the synchronous speed of the AC synchronous motor is related to the power supply frequency and the number of poles. Therefore, it is necessary to select the appropriate frequency and number of poles in the design to ensure that the motor can run stably and synchronously within the working range.