How does a squirrel cage induction motor work?

A squirrel cage induction motor is a type of electric motor that uses electromagnetic induction to convert electrical energy into mechanical energy. In a squirrel cage induction motor, the rotor windings are made up of a series of conductive bars that are shorted at the ends. This creates a "cage" like structure, hence the name "squirrel cage" motor.

Squirrel cage induction motors are the most common type of induction motor, and they are known for their simplicity, reliability, and low cost. They are often used in small, low-power applications such as fans, blowers, and pumps.

But how does a squirrel cage induction motor work? To understand this, we need to first understand how electromagnetic induction works.

Electromagnetic induction is the process by which an electric current is generated in a conductor when it is exposed to a changing magnetic field. In an electric motor, electromagnetic induction is used to convert electrical energy into mechanical energy.

In a squirrel cage induction motor, the stator is typically made up of a series of electromagnetic coils. When an alternating current (AC) is applied to these coils, a rotating magnetic field is generated. This rotating magnetic field then passes over the rotor windings, which are made up of a series of conductive bars that are shorted at the ends.

The interaction between the magnetic fields from the stator and rotor creates a torque, which causes the rotor to rotate and follow the direction of the rotating magnetic field. This is what allows an electric motor to convert electrical energy into mechanical energy.

However, the rotor windings in a squirrel cage induction motor have a high resistance, which reduces the amount of torque that can be generated. As a result, squirrel cage induction motors have a low starting torque, which means it takes a relatively large amount of torque to get the rotor moving when the motor is first turned on.

Once the rotor is moving, the interaction between the magnetic fields from the stator and rotor continues to generate a torque, which keeps the rotor rotating at a constant speed. The rotational speed of the rotor is determined by the frequency of the power supply and the load on the motor.