An three phase ac induction motor china induction engine which connects with a 3-stage supply called 3-stage induction motor. Example followers,blowers, cranes,traction .It really is a ac engine. The main drawback of DC motors may be the existence of 
commutator and brushes, which require regular maintenance and we can not use DC engine in explosive and dirty environment. But induction motors are cheaper,durable,lighter,smaller,require much less maintenance and will 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 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 rate control technique of induction electric motor is important
Pole changing
Stator voltage control
V/f control
Slip power recovery
Rotor resistance control