Conclusion
Multiphase machines with more than two independent currents

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 developing a vector control system that simply...