An induction electric motor which connects with a 3-phase supply called 3-phase induction motor. Example enthusiasts,blowers, cranes,traction .It really is a ac electric motor. The main drawback of DC motors may be the presence of commutator and brushes, which require frequent maintenance and we can’t use DC electric motor in explosive and filthy environment. But induction motors are cheaper,rugged,three phase ac induction motor china lighter,smaller,require less maintenance and can use in filthy and explosive environment. Slide 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 numerous 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 swiftness control technique of induction motor is important

Pole changing
Stator voltage control
V/f control
Slip power recovery
Rotor resistance control