Principle of asynchronous motor

Application of Asynchronous Motor

Asynchronous motors that operate as electric motors. Because the rotor winding current is induced, it is also called an induction motor. Asynchronous motors are the most widely used and the most demanded of all types of motors. About 90% of the machines powered by electricity in various countries are asynchronous motors, of which small asynchronous motors account for more than 70%. In the total load of the power system, the electricity consumption of asynchronous motors accounts for a considerable proportion. In China, the electricity consumption of asynchronous motors accounts for more than 60% of the total load.

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The concept of asynchronous motor

 

An asynchronous motor is an AC motor whose ratio of the speed of the load to the frequency of the connected grid is not a constant value. Induction motor is an asynchronous motor with only one set of windings connected to the power supply. In the case of not causing misunderstanding and confusion, induction motors can generally be called asynchronous motors. The IEC standard states that the term “induction motor” is actually used as a synonym for “asynchronous motor” in many countries, while other countries only use the term “asynchronous motor” to represent these two concepts.

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Principle of asynchronous motor
After a symmetrical voltage is applied to the stator winding of a three-phase asynchronous motor, a rotating air-gap magnetic field is generated, and the rotor winding conductor cuts the magnetic field to generate an induced potential. A rotor current is generated due to the short circuit of the rotor windings. The interaction between the rotor current and the air gap magnetic field generates electromagnetic torque, which drives the rotor to rotate. The speed of the motor must be lower than the synchronous speed of the magnetic field, because only in this way can the rotor conductor induce an electric potential to generate the rotor current and electromagnetic torque. So the motor is called an asynchronous machine, also called an induction motor.

Post time: Aug-08-2022