Three phase induction motors have a very simple construction made up of a stator protected with electromagnets, and a rotor composed of conductors shorted at each end, arranged as a “squirrel cage”. They work 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. Therefore induces a current in the rotor’s conductors, which in turns Induction Motor 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 structure. They are more robust and can operate in virtually any environmental condition
Induction motors are cheaper in expense due to simple rotor construction, lack of brushes, commutators, and slide rings
Contrairement aux moteurs à courant continu, les moteurs à courant continu ne nécessitent pas d'entretien en raison de l'absence de balais, de collecteurs et de bagues collectrices.
Induction motors could be operated in polluted and explosive environments as they do not have brushes which can cause sparks
AC Induction motors are Asynchronous Machines meaning that the rotor does not switch at the specific same speed since the stator’s rotating magnetic field. Some difference in the rotor and stator acceleration is necessary in order to produce the induction into the rotor. The difference between your two is named the slip. Slip should be kept within an optimal range to ensure that the motor to use effectively. Roboteq AC Induction controllers could 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 alter.
Controlled Slip: a Shut Loop speed where voltage and frequency are controlled to keep slip within a narrow range while working at a desired 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.
Découvrez cette vidéo de Learning Engineering pour une illustration visuelle de la construction et du fonctionnement des moteurs à induction à courant alternatif.