An induction engine which connects with a 3-stage supply called 3-phase induction motor. Example supporters,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 electric motor in explosive and dirty environment. But induction motors are cheaper,tough,lighter,smaller,require much less maintenance and will use in filthy 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 three phase ac induction motor china methods are
Auto transformer starter
Ac voltage controller starter
Rotor resistance starter
Important braking methods are
Plugging or reverse voltage braking
But one thing velocity control technique of induction electric motor is important
Stator voltage control
Slip power recovery
Rotor resistance control