Three phase induction Induction Motor china motors have a very simple construction composed of a stator covered with electromagnets, and a rotor made up of conductors shorted at each end, arranged as a “squirrel cage”. They work on the principle of induction in which a rotating electro-magnetic field it made by applying a three-stage current at the stators electromagnets. Therefore induces a current within the rotor’s conductors, which in turns creates rotor’s magnetic field that tries to check out stator’s magnetic field, pulling the rotor into rotation.
Benefits of AC Induction Motors are:
Induction motors are simple and rugged in construction. They are more robust and can operate in any environmental condition
Induction motors are cheaper in cost due to simple rotor construction, lack of brushes, commutators, and slip rings
They are free of maintenance motors unlike dc motors because of the lack of brushes, commutators and slip rings
Induction motors could be operated in polluted and explosive environments as they do not have brushes that may cause sparks
AC Induction motors are Asynchronous Devices and therefore the rotor does not convert at the precise same speed since the stator’s rotating magnetic field. Some difference in the rotor and stator rate is necessary to be able to develop the induction into the rotor. The difference between your two is named the slip. Slip must be kept within an optimal range in order for the motor to operate efficiently. Roboteq AC Induction controllers can be configured to operate in one of three modes:
Scallar (or Volts per Hertz): an Open up loop mode where a command causes a simultaneous, fixed-ratio Frequency and Voltage modify.
Controlled Slip: a Closed Loop speed where voltage and frequency are controlled in order to keep slip inside a narrow range while operating at a preferred speed.
Field Oriented Control (Vector Drive): a Closed Loop Acceleration and Torque control that functions by optimizing the rotating field of the stator vs. this of the induced field in the rotor.
Observe this video from Learning Engineering for a visual illustration about how AC Induction Motors are constructed and function.