An induction motor which three phase ac induction motor china connects with a 3-phase supply called 3-phase induction motor. Example followers,blowers, cranes,traction .It is a ac electric motor. The main drawback of DC motors is the presence of commutator and brushes, which require regular maintenance and we can’t use DC motor in explosive and dirty environment. But induction motors are cheaper,tough,lighter,smaller,require less maintenance and may use in dirty and explosive environment. Slip s may be the imp aspect 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 reverse voltage braking
Dynamic braking
But one thing swiftness control technique of induction engine is important

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