Like any electric motor, a 3-phase induction motor has a stator and rotor. The stator carries a 3-phase winding (called stator winding) while the rotor carries a short circuited winding (called rotor winding). Only the stator winding is fed from 3-phase supply. The rotor winding derives its voltage and power from the externally energized stator winding through electromagnetic induction and hence the name acquired. The induction motor may be considered to be a transformer with a rotating secondary and it can, therefore, be described as a “transformer-type” a.c. machine in which electrical energy is converted into mechanical energy.