An induction engine which connects with a 3-stage supply called 3-phase induction motor. Example supporters,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 engine in explosive and dirty environment. But induction motors are cheaper,durable,lighter,smaller,require much less maintenance and can use in dirty and explosive environment. Slip s is the imp aspect 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 reverse voltage braking
Dynamic braking
But one thing speed control technique of induction motor is important
Pole changing
three phase ac induction motor Stator voltage control
V/f control
Slip power recovery
Rotor resistance control