An induction motor which connects with a 3-phase supply called 3-phase induction motor. Example supporters,blowers, cranes,traction .It really is a ac electric motor. The primary drawback of DC three phase ac induction motor china 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,tough,lighter,smaller,require less maintenance and can use in filthy and explosive environment. Slide s may be the imp aspect 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 acceleration control technique of induction engine is important

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