An induction electric motor which connects with a 3-stage supply called 3-phase induction motor. Example supporters,blowers, cranes,traction .It really is a ac motor. The primary drawback of DC motors may be the existence of commutator and brushes, which require frequent maintenance and we can not use DC engine in explosive and dirty environment. But induction motors are cheaper,rugged,lighter,smaller,require much less maintenance and can use in dirty and explosive environment. Slide s is the imp factor 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 invert voltage braking
But one thing swiftness control technique of induction motor is important
Stator voltage control
Slip power recovery
Rotor resistance control