In TEFC motors, interior heat losses are dissipated indirectly ac motor principle pdf enclosure fins, mostly by forced air convection. Cutaway view through stator of TEFC induction motor, showing rotor with internal air circulation vanes.
An induction motor or asynchronous motor is an AC electric motor in which the electric current in the rotor needed to produce torque is obtained by electromagnetic induction from the magnetic field of the stator winding. An induction motor can therefore be made without electrical connections to the rotor. An induction motor’s rotor can be either wound type or squirrel-cage type.
Three-phase squirrel-cage induction motors are widely used as industrial drives because they are rugged, reliable and economical. Single-phase induction motors are used extensively for smaller loads, such as household appliances like fans. VFDs offer especially important energy savings opportunities for existing and prospective induction motors in variable-torque centrifugal fan, pump and compressor load applications. In 1824, the French physicist François Arago formulated the existence of rotating magnetic fields, termed Arago’s rotations.