Question

What is the general principle of induction motor?

Answer 1

The general principle of an induction motor is based on the idea of electromagnetic induction. Here’s how it works, broken down simply:

1. AC Supply: When an alternating current (AC) is supplied to the stator (the stationary part of the motor), it creates a rotating magnetic field. This rotating magnetic field is constantly changing direction because of the alternating current.
   

1. Induced Current in Rotor: The rotor (the rotating part of the motor) is located inside this rotating magnetic field, but it is not directly connected to the AC supply. Instead, the rotating magnetic field produced by the stator induces a current in the rotor due to electromagnetic induction (this is similar to how a transformer works).
   

1. Interaction Between Magnetic Fields: The induced current in the rotor creates its own magnetic field, which interacts with the rotating magnetic field of the stator. According to Faraday's law of induction and Lenz’s law, the rotor will try to follow the rotating magnetic field. The force between the rotor's magnetic field and the stator’s magnetic field causes the rotor to turn.
   

1. Rotor Rotation: The rotor does not rotate at the exact speed of the magnetic field (which would be impossible due to the nature of induction). The difference in speed between the rotating magnetic field and the rotor is called slip. The rotor's speed will always be slightly less than the speed of the rotating magnetic field, and this difference is what creates the mechanical torque needed to turn the motor’s shaft.
   

In short: The stator creates a rotating magnetic field. This field induces a current in the rotor, and the interaction of these magnetic fields makes the rotor spin, causing the motor to work.

Let me know if you need more details on any part of the explanation!