Why AC motors don't need magnets inside？

AC motor is one of the common motors in modern industrial production, which has the advantages of simple structure, high power density and so on, so it is widely used in various industries. Inside the AC motor, we find that there is no magnet, why is this? Here we will analyze in detail.

AC motors work by converting electrical energy into mechanical energy by means of electromagnetic induction. Inside the AC motor, there are two main parts stator and rotor. The stator is wound with three-phase windings, which form a rotating magnetic field by connecting it to a three-phase power supply. The rotor has conductors inside it, and when the rotor is rotating, it induces an electromotive force inside the conductors, which generates a current in the conductors. As the current inside the conductor interacts with the rotating magnetic field of the stator, it results in the conductor inside the rotor being subjected to a force, which generates a torque.

Motor stator magnets (curved) for dc fan motors

Why don't you need magnets inside an AC motor?

Inside an AC motor, a three-phase winding is wound on the stator, which creates a rotating magnetic field by connecting it to a three-phase power supply. This rotating magnetic field is generated inside the windings by an electric current, not by a magnet.

Inside an AC motor, there are conductors inside the rotor, and when the rotor is rotating, it induces an electromotive force inside the conductor, which produces a current in the conductor. This current generates a magnetic field inside the conductor, which interacts with the rotating magnetic field of the stator to produce torque.

The reason magnets are not needed inside AC motors is because they produce a rotating magnetic field inside the windings through current, not through magnets. Also, the current generated inside the rotor produces a magnetic field that interacts with the rotating magnetic field of the stator to produce torque.

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