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What are the advantages and disadvantages of synchronous and asynchronous motors?
- Feb 02, 2018 -

Asynchronous motor is an AC motor, its load speed and the frequency of the network is not constant relationship.

Asynchronous motor includes induction motor, doubly-fed asynchronous motor and AC commutator motor.

Induction motor is the most widely used, in the case of no misunderstanding or confusion, generally can be called induction motor asynchronous motor.

The stator windings of an ordinary asynchronous motor are connected to the AC power grid, and the rotor windings do not need to connect with other power sources. Therefore, it has the advantages of simple structure, convenient manufacture, use and maintenance, reliable operation, small quality and low cost.

Asynchronous motor has higher operating efficiency and better operating characteristics, from no-load to full load range close to the constant speed operation, can meet the majority of industrial and agricultural production machinery transmission requirements.

Asynchronous motors also facilitate the generation of various types of protection to meet the needs of different environmental conditions. The reactive excitation power must be absorbed from the power grid to make the power factor of the electric network become worse. Therefore, the drive ball mill, compressors and other high-power, low-speed mechanical equipment, often using synchronous motor.

The speed of the asynchronous motor has a certain difference with its rotating magnetic field speed, its speed regulation performance is poor (except AC commutator motor). The use of DC motor is more economical and convenient for transportation machinery, rolling mill, large machine tool, printing and dyeing and papermaking machinery, which require broad and smooth speed range.

However, with the development of high-power electronic devices and AC speed regulation system, the speed-regulating performance and economy of the Hucoin speed-regulating asynchronous motor can be compared with that of DC motor.

Synchronous Motor: Synchronous motor for power generation, rotor winding work with DC excitation, the external mechanical force to drive the rotor rotation, n0 direction and torque T direction, the stator induction electromotive force (Electromagnetic induction principle), and then output voltage.

As a generator running is the main operating mode of synchronous motor, as the motor running is another important operation mode of synchronous motor. The power factor of synchronous motor can be adjusted, and the application of large synchronous motor can improve operation efficiency without requiring speed regulation.

In recent years, small synchronous motors have been used more and more in the frequency conversion speed regulation system.

Synchronous motor can also be connected to the power grid as a synchronous compensator. At this time, the motor without any mechanical load, by adjusting the excitation of the rotor to the grid to emit the necessary perceptual or capacitive reactive power, in order to improve the power grid power factor or adjust the power grid voltage.

The principle of asynchronous motor is to pass 3 phase alternating current in stator, make it produce rotating magnetic field, rotate speed is n0, namely synchronous speed.

Synchronous motor and induction motor is a commonly used AC motor.

The characteristic is: the steady state operation, the rotor speed and the power grid frequency has the invariable relation


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