Flow of energy in synchronous machines

The flow of energy is traced in a typical, somewhat idealized 3-phase alternator, using an adaptation of Poynting´s vector together with a discussion of this procedure. Following the specification of the electromagnetic field, quantitative analysis of the flow of energy in the gap, at the surface of the rotor, and into and out of the stator conductors is presented under no load, at a unity-power-factor load and then for any power-factor load. Qualitative description of the flow of energy in the intermediate regions and to the output terminals of the machine is then given, together with a brief discussion of the extension of this analysis to other machines and to less idealized situations.