Induction motor, also known as "asynchronous motor", is a device that puts the rotor in a rotating magnetic field and obtains a rotating torque under the action of the rotating magnetic field, so that the rotor rotates. The rotor is a rotatable conductor, usually in the shape of a squirrel cage.
Induction motor is also called "asynchronous motor (asynchronous motor)", that is, the rotor is placed in a rotating magnetic field, under the action of the rotating magnetic field, a rotating torque is obtained, so the rotor rotates.
The rotor is a rotatable conductor, usually in the shape of a squirrel cage. The stator is the non-rotating part of the motor, and its main task is to generate a rotating magnetic field. The rotating magnetic field is not realized by mechanical methods. Instead, alternating current is passed through several pairs of electromagnets to cyclically change the magnetic pole properties, so it is equivalent to a rotating magnetic field. This kind of motor does not have brushes or slip rings like DC motors. There are single-phase motors and three-phase motors depending on the type of AC used. Single-phase motors are used in washing machines, electric fans, etc.; three-phase motors are used as power for factories equipment.
Through the relative movement of the rotating magnetic field generated by the stator (its speed is the synchronous speed n1) and the rotor winding, the rotor winding cuts the magnetic induction line to generate an induced electromotive force, thereby causing an induced current in the rotor winding. The induced current in the rotor winding interacts with the magnetic field to generate electromagnetic torque, which makes the rotor rotate. As the rotor speed gradually approaches the synchronous speed, the induced current gradually decreases, and the generated electromagnetic torque is also reduced accordingly. When the asynchronous motor is working in the motor state, the rotor speed is less than the synchronous speed. In order to describe the difference between the rotor speed n and the synchronous speed n1, slip is introduced.
