An original electric machine is described which has a single stator and two rotors, each core being of a disc geometry, with the stator sandwiched between the two rotors. The rotors carry squirrel cage windings, and are mounted on individual, independent shafts driving two wheels of an electric vehicle. The torque generated by each rotor depends on the slip of each rotor and the dimensions of the cores, particularly the stator yoke depth which controls the magnitude of any differential flux in the two sections of the machine. An analytical model of the machine is developed, based on a travelling wave model and taking into account the harmonics, travelling at synchronous speed, which are produced by saturation in the various parts of the cores. Leakage fluxes are accounted for, and are divided into fluxes which do, and do not, contribute towards saturation in the machine. Laboratory results are compared with those predicted by the model. Systematic differences are evident between these results and explanations are offered to account for them.
