Aspects of winding symmetry in HPO motor design

Abstract

A high phase order induction machine wound and permitted by coil symmetry to operate at fewer than the magnetically optimal number of poles is constrained by symmetry to be a two pole machine and be capable of operating on odd harmonics only, but with back-iron, end rings, and rotor core optimized for 10 pole operation, might be used normally in ‘5th harmonic’ mode, with ‘7th harmonic’ utilized to engage the ‘mesh effect’. Such a machine thus appears to be operating in the ‘1.4 harmonic’. A high phase order induction machine driven by a second harmonic drive, in which a symmetry imposed by full span windings is broken. This may be most simply accomplished through the use of short pitch windings. Other possible approaches include using non-wound slot drive, and using toroidal windings which localize coils to individual slots.

Dependencies are inferred from the claim text.