Schematic diagram of a round-rotor induction motor

Schematic diagram of a round-rotor induction motor

WOUND-ROTOR INDUCTION MOTOR

The 3-phase stator is represented by 3 concentrated coils displaced 120^o from each other. The wound rotor is also represented by 3 concentrated coils and it is rotating at the speed n=0.8 pu. With balanced 3-phase sinusoidal currents in the stator coils, a rotating magnetic field at 1.00 pu speed is established (represented by the yellow space vector) which overtakes the rotor at slip speed (1-n), thereby inducing in the rotor coils slip-frequency voltages and corresponding currents