Working of an AC Motor (Induction Motor – most common type)

 Great question 👍 Let’s go step by step.


⚡ Working of an AC Motor (Induction Motor – most common type)

An AC motor works on the principle of electromagnetic induction discovered by Faraday.

🔹 Main Parts:

  1. Stator – The stationary part with coils connected to AC supply.

  2. Rotor – The rotating part inside the stator.

  3. Air Gap – Small space between stator and rotor.


🔹 Step-by-Step Working:

  1. AC Supply to Stator:

    • When 3-phase AC is applied to the stator windings, it produces a rotating magnetic field (RMF) inside the motor.

  2. Induced Current in Rotor:

    • The rotating magnetic field "cuts" the rotor conductors.

    • According to Faraday’s Law, this induces an EMF (voltage) in the rotor.

    • Since the rotor is a closed circuit, current flows through it.

  3. Torque Production:

    • The current in the rotor creates its own magnetic field.

    • This field interacts with the stator’s rotating magnetic field.

    • Result → A force (torque) is produced that makes the rotor turn.

  4. Continuous Rotation:

    • The rotor always tries to "catch up" with the rotating magnetic field but never reaches it (this difference is called slip).

    • Because of slip, continuous induction happens → motor keeps running.


🔹 Types of AC Motors:

  1. Synchronous Motor – Rotor rotates at the same speed as the magnetic field (no slip).

  2. Induction Motor – Rotor rotates at slightly less speed than the magnetic field (with slip). Most widely used.


🔹 Everyday Examples:

  • Fans, pumps, compressors, lifts, conveyors → Induction motors.

  • Power factor correction, synchronous clocks → Synchronous motors.


👉 Do you want me to also explain this with a simple diagram so it’s easier to visualize?

Post a Comment

Previous Post Next Post