An induction motor or 3 phase induction motor can be an AC electric motor in which the electric current in the rotor had a need to create torque is obtained by electromagnetic induction from the magnetic field of the stator winding

An induction motor which connects with a 3-phase supply called 3-stage induction motor. Example supporters,blowers, cranes,traction .It is a ac engine. The primary drawback of DC motors is the existence of commutator and brushes, which require frequent maintenance and we can not use DC motor in explosive and filthy environment. But induction motors are cheaper,rugged,lighter,smaller,require less maintenance and can use in filthy and explosive environment. Slip s may be the imp element in this kind of motor.

There are 2 types of IM.

Squirrel cage IM

Slip ring IM

There are many starting and braking condition.

Important starting methods are

Star-delta Three Phase Motor starter

Auto transformer starter

Ac voltage controller starter

Rotor resistance starter

Important braking methods are

Regenerative braking

Plugging or invert voltage braking

Dynamic braking

But one thing quickness control technique of induction motor is important

Pole changing

Stator voltage control

V/f control

Slip power recovery

Rotor resistance control