An induction motor or 3 stage induction motor is an AC electric engine in which the electric current in the rotor needed to create torque is obtained by 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 followers,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 frequent maintenance and we can not use DC electric motor in explosive and filthy environment. But induction motors are cheaper,durable,lighter,smaller,require less maintenance and may use in dirty and explosive environment. Slip s is the imp aspect in this type of motor.
There are 2 types of IM.
Squirrel cage IM
Slip ring IM
There are Three Phase Motor 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 invert 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