Three phase induction motors have a very simple construction composed of a stator covered with electromagnets, and a rotor composed of conductors shorted at each end, arranged as a “squirrel cage”. They work on the principle of induction where a rotating electro-magnetic field it produced by applying a three-stage current at the stators electromagnets. Therefore induces a current inside the rotor’s conductors, which in turns generates 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 basic and rugged in building. They are better quality and can operate in any environmental Induction Motor china condition
Induction motors are cheaper in cost because of simple rotor construction, lack of brushes, commutators, and slide rings
They are maintenance free motors unlike dc motors due to the absence of brushes, commutators and slip rings
Induction motors can be operated in polluted and explosive environments as they don’t have brushes which can cause sparks
AC Induction motors are Asynchronous Machines and therefore the rotor does not turn at the exact same speed as the stator’s rotating magnetic field. Some difference in the rotor and stator velocity is necessary in order to generate 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 another of three modes:
Scallar (or Volts per Hertz): an Open loop mode where a order causes a simultaneous, fixed-ratio Frequency and Voltage alter.
Controlled Slip: a Closed Loop speed where voltage and frequency are managed to keep slip within a narrow range while working at a desired speed.
Field Oriented Control (Vector Drive): a Closed Loop Quickness and Torque control that works 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 on how AC Induction Motors are constructed and work.