A general equivalent circuit (GEC) of electric machines including cross-coupling saturation and frequency effects

A general equivalent circuit (GEC) is proposed for the orthogonal-axis model of synchronous, induction and commutator machines with crosscoupling saturation and frequency (or skin) effects included simultaneously but considered independently of each other. The cross-coupling saturation is accounted for through the so-called saturation equations based on the experimentally proven assumption that there is a unique and distinct main path magnetizing curve along each of the d and q axes. The frequency effects are simulated through fictitious multicircuits. The complete equations of the synchronous, induction and commutator machines are given, from which the GECs are obtained. It is shown that there is only one GEC for both orthogonal axes, which are cross-coupled due to saturation