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

An induction electric motor which connects with a 3-phase supply called 3-stage induction motor. Example fans,blowers, cranes,traction .It is a ac motor. The primary drawback of DC motors is the existence of commutator and brushes, which require frequent maintenance and we can not use DC engine in explosive and filthy environment. But induction motors are cheaper,tough,lighter,smaller,require less maintenance and may use in filthy and explosive environment. Slide s may be the imp factor in this type 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 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 rate control technique of induction engine is important

ER series helical geared motorPole changing

Stator voltage control

V/f control

Slip power recovery

Rotor resistance control