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A split-phase machine is a special electric machine whose stator winding is split into multiple (N) three-phase sets. The possibility to supply it through N independent inverters makes it attractive especially when high power and reliability are required. So far, the dq0 refeence frame representation, originally introduced for three-phase machines, has been applied in detail to split-phase configurations in the N=2 case only. In this paper, the extension to an arbitrary number of stator sets is investigated from an equivalent circuit representation viewpoint. The equivalent circuit topologies proposed in this paper to represent a split-phase machine with N three-phase sets is directly derived from the theory presented in Part I. In particular, it will be stressed that as long as N is equal to 1 or 2, dq equivalent circuits remain decoupled as known from the literature, otherwise for N higher than or equal to 3, dq cross couplings must be taken into account in the equivalent circuit representation.

A split-phase machine is a special electric machine whose stator winding is split into multiple (N) three-phase sets. The possibility to supply it through N independent inverters makes it attractive especially when high power and reliability are required. So far, the dq0 refeence frame representation, originally introduced for three-phase machines, has been applied in detail to split-phase configurations in the N=2 case only. In this paper, the extension to an arbitrary number of stator sets is investigated from an analytical viewpoint. In particular, the paper shows that when N exceeds two, the d-axis and q-axis stator voltage equations are no more decoupled, in general, as it happens for N=1 and N=2. Such d-q cross-coupling is explained in terms of mutual leakage inductances, regardless of possible rotor saliencies and magnetic saturation. The implications of these results in terms of equivalent circuit representation will be presented in a companion paper (Part II).