Induction motor working principle The induction motor follows these two laws to generate a unidirectional torque.
So, after the generation of the rotating magnetic field, the rotor conductors start interacting with the magnetic field.
The concept of rotating magnetic field The creation of a rotating magnetic field requires two essential conditions:• Electromagnet laminations Eddy currents occur when a solid metallic mass is rotated in a magnetic field, because the outer portion of the metal cuts more than the inner portion; hence the induced electromotive force is not uniform; this tends to cause electric currents between the points of greatest and least potential.
Some LIMs are double sided with one primary on each side of the secondary, and, in this case, no iron backing is needed.
The rotating magnetic field makes the rotor spin in the same direction and in theory at almost the same speed.
Disadvantages Since the speed of an induction motor depends on the frequency of the alternating current that drives it, it turns at a constant speed unless you use a variable-frequency drive; the speed of DC motors is much easier to control simply by turning the supply voltage up or down.