Theoretical investigation of fractional conductor windings for AC-machines - definition, air-gap m.m.f. and winding factors

Abstract

This paper introduces the concept of fractional conductor windings for AC-machines. They allow to obtain fractional equivalent number of conductors per slot. Different arrangements of windings are presented. The harmonic spectrum of the armature magneto-motive force in the air-gap is then analyzed in order to derive rules for choosing suitable combinations using winding factors.