Compound, series, axial flux induction machines: single phase analogy

The characteristics of the single phase analogy of a pair of axial flux, polyphase induction motors having their respective stator windings and also their magnetic circuits in series, with provision for 'out of balance' flux, arising due to differences in the two rotor speeds, to pass through a saturating magnetic shunt are investigated. Theoretical and experimental results show that when such a pair of machines, fed from a single, variable frequency supply, is used to drive two wheels of one electronic vehicle, torque/speed characteristics that more closely match those of the ideal mechanical differential are obtained than when two independent induction machines are fed either in series or in parallel from a single supply.