Three phase induction motors employ a simple construction made up of a stator covered with electromagnets, and a rotor made up of conductors shorted at each end, arranged as a “squirrel cage”. They focus on the basic principle of induction in which a rotating electro-magnetic field it developed through the use of a three-phase current at the stators electromagnets. This in turn induces a current within the rotor’s conductors, which in turns produces rotor’s magnetic field that tries to follow stator’s magnetic field, pulling the rotor into rotation.
Great things about AC Induction Motors are:
Induction motors are basic and rugged in structure. They are better quality and can operate in any environmental condition
Induction motors are cheaper in cost due to simple rotor construction, lack of brushes, commutators, and slide 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 conditions as they don’t have brushes that may cause sparks
AC Induction motors are Asynchronous Devices meaning that the rotor does not convert at the specific same speed as the stator’s rotating magnetic field. Some difference in the rotor and stator swiftness is necessary in order to make the induction into the rotor. The difference between your two is called the slip. Slip should be kept in a Induction Motor china optimal range to ensure that the motor to use effectively. Roboteq AC Induction controllers can be configured to operate in another of three modes:
Scallar (or Volts per Hertz): an Open up loop mode where a command causes a simultaneous, fixed-ratio Frequency and Voltage change.
Controlled Slip: a Shut Loop speed where voltage and frequency are managed to keep slip within a narrow range while running at a preferred speed.
Field Oriented Control (Vector Drive): a Closed Loop Acceleration and Torque control that works by optimizing the rotating field of the stator vs. this of the induced field in the rotor.
See this video from Learning Engineering for a visual illustration about how AC Induction Motors are constructed and function.