Question

What is the principle of operation of an AC motor?

Answer 1

An AC (Alternating Current) motor operates on the principle of electromagnetic induction. Here’s how it works in simple terms:

1. Magnetic Fields Interaction:

   - An AC motor consists of two main parts: the stator (stationary part) and the rotor (the rotating part).
   - The stator has coils of wire connected to the AC power supply, which creates a magnetic field when current flows through it.
   - The rotor is placed inside this magnetic field and is designed to rotate when exposed to the field created by the stator.

2. Electromagnetic Induction:

   - When AC flows through the stator’s coils, it creates a rotating magnetic field (RMF).
   - This rotating magnetic field induces a current in the rotor due to electromagnetic induction. According to Faraday’s Law of Induction, a changing magnetic field (the rotating field) creates an electric current in the rotor.

3. Force on the Rotor:

   - The current induced in the rotor interacts with the magnetic field created by the stator. According to Lorentz Force Law, a force is exerted on the rotor because of the interaction between the magnetic fields of the rotor and the stator.
   - This force causes the rotor to start rotating, following the direction of the rotating magnetic field from the stator.

4. Continuous Rotation:

   - As the rotor spins, it keeps following the rotating magnetic field created by the stator. This continuous interaction between the stator's magnetic field and the rotor's induced current ensures the rotor keeps turning as long as AC power is supplied.

In summary:

1. The AC power creates a rotating magnetic field in the stator.
   

1. This rotating field induces a current in the rotor.
   

1. The interaction between the magnetic fields of the rotor and stator produces a force that makes the rotor spin.
   

This is the basic principle behind how an AC motor operates!