3. Conclusion

This article introduced the terminology and definitions specific to rotating machines with more than two independent currents, explaining three approaches for determining the number of phases. A mathematical analysis of the stator inductance matrix allows us to generalize the well-known concept, in the three-phase case, of an “equivalent” two-phase machine.

In the simple case of a constant matrix, the multi-machine equivalence is introduced and, assuming a regular structure, a distribution of harmonics among fictitious machines is demonstrated. This distribution explains why the design constraints (three-phase “sinusoidal” machine) for control purposes are less stringent for polyphase (non-sinusoidal) machines, allowing for an increase in torque based on the utilization of harmonics, without any loss in torque quality.

The foundations for...