An induction motor which connects with a 3-phase supply called 3-stage induction motor. Example enthusiasts,blowers, cranes,traction .It is a ac motor. The primary drawback of DC motors is the presence of commutator and brushes, which require regular maintenance and we can’t use DC electric motor in explosive and filthy environment. But induction motors are cheaper,tough,lighter,smaller,require much less maintenance and will use in filthy and explosive environment. Slide 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 three phase ac induction motor china 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 quickness control technique of induction electric motor is important

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