Design of fractional-slot windings

Abstract

A theory is developed by which the electrical design of a standard fractional-slot winding may be readily established. Formulae are given for the calculation of the amplitude of the fundamental and the various harmonics, and three methods are developed for reducing the amplitude of any particular harmonic.The calculation of the noise produced by the vibration of the core set up by the lowest sub-harmonics is briefly discussed. A worked example is given which shows, inter alia, a practical method of designing suitable end connections for fractional-slot wave windings.