Three Phase Motor

An Three Phase Motor induction motor or 3 stage induction motor is an AC electric electric motor in which the electric energy 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-stage supply called 3-phase induction motor. Example fans,blowers, cranes,traction .It really is a ac motor. The primary drawback of DC motors may be the existence of commutator and brushes, which require regular maintenance and we can not use DC motor in explosive and filthy environment. But induction motors are cheaper,durable,lighter,smaller,require much less maintenance and will use in filthy and explosive environment. Slip s may be the imp factor 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 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 acceleration control technique of induction motor is important

Pole changing

Stator voltage control

V/f control

Slip power recovery

Rotor resistance control