ABSTRACT
The induction machine is basically an a.c. polyphase machine connected to an a.c. power grid, either in the stator or in the rotor. The a.c. power source is, in general, three-phase but it may also be single-phase. In both cases the winding arrangement on the part of the machine-the primaryconnected to the grid (the stator in general) should produce a traveling field in the machine airgap. This traveling field will induce voltages in conductors on the part of the machine not connected to the grid (the rotor, or the mover in general) – the secondary. If the windings on the secondary (rotor) are closed, a.c. currents occur in the rotor.
