Three phase induction 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 theory of induction where a rotating electro-magnetic field it created through the use of a three-stage current at the stators electromagnets. This in turn induces a current within the rotor’s conductors, which in turns creates rotor’s magnetic field that attempts to follow stator’s magnetic field, pulling the rotor into rotation.
Benefits of AC Induction Motors are:
Induction motors are basic and rugged in building. They are more robust and can operate in any environmental condition
Induction motors are cheaper in expense 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 can be operated in polluted and explosive environments as they do not have brushes that may cause sparks
AC Induction motors are Asynchronous Devices meaning that the rotor will not turn at the specific same speed as the stator’s rotating magnetic field. Some Induction Motor china difference in the rotor and stator acceleration is necessary to be able to create the induction into the rotor. The difference between the two is named the slip. Slip should be kept in a optimal range to ensure that the motor to use 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 Shut Loop speed where voltage and frequency are managed in order to keep slip inside a narrow range while operating at a desired speed.
Field Oriented Control (Vector Drive): a Closed Loop Swiftness 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.