The working principle of a squirrel cage induction motor

The working principle of a squirrel cage induction motor
A squirrel cage induction motor is a common type of electric motor used in various applications. Its working principle is based on electromagnetic induction and consists of the following key components:
Stator: The stationary part of the motor, typically made of laminated iron cores, houses the stator winding. This winding is connected to an AC power source, which creates a rotating magnetic field when energized.
Rotor: The rotor is another crucial part of the motor. It is cylindrical in shape and made up of laminated iron cores or conductive bars. The rotor is positioned within the stator and is not directly connected to any external power source. Instead, it relies on the magnetic field generated by the stator.
The working principle of a squirrel cage induction motor can be summarized as follows:
When the AC power is applied to the stator winding, it produces a rotating magnetic field. The direction of rotation of this field is determined by the phase of the AC power supply.
The rotating magnetic field induces a current in the rotor conductive bars due to electromagnetic induction. These induced currents create their own magnetic fields in the rotor.
The interaction between the rotating magnetic field in the stator and the induced magnetic field in the rotor causes the rotor to start rotating. The rotor follows the rotating magnetic field, attempting to catch up with it, which results in the rotation of the motor shaft.
The rotor's construction, which typically resembles a squirrel cage due to its conductive bars, is what gives this type of motor its name - the "squirrel cage" rotor.
The speed of the rotor's rotation is always slightly slower than the speed of the rotating magnetic field, which is called the synchronous speed. The difference between the rotor speed and the synchronous speed is known as slip.
The squirrel cage motor's output speed and torque are determined by the design of the motor, the frequency of the AC power supply, and the number of poles in the stator.
Overall, the squirrel cage induction motor is an efficient and reliable device used in various industrial and domestic applications due to its simple construction and robust operation.