Polyphase to Two-Axis Transformation for Real Windings

The effects of MMF and permeance harmonics on the N-phase to two-phase slip ring transformation are considered. Considerable simplifications occur if MMFs higher than the Nth can be neglected. Particular attention is given to both three-phase and squirrel-cage windings. Practical factors influencing the α,β,O transformation and the choice of coefficients result from the former and the basis and limitation of the harmonic equivalent circuits of the squirrel cage induction motor result from the latter.