Three Phase Motor

An induction motor or 3 phase induction motor is an AC electric motor in which the electric current in the rotor needed to produce 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-phase induction motor. Example fans,blowers, cranes,traction .It is a ac motor. The main drawback of DC motors is the presence of commutator and brushes, which require frequent maintenance and we can't use DC motor in explosive and dirty environment. But induction motors are cheaper,rugged,lighter,smaller,require less maintenance and can use in dirty and explosive environment. Slip s is the imp factor in this type of motor.

There are 2 types of IM.

Squirrel cage IM

Slip ring IM

There are various 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 reverse voltage braking

Dynamic braking

But one thing speed control technique of induction motor is important

Pole changing

Stator voltage control

V/f control

Slip power recovery

Rotor resistance control