Methods for Determination of Winding Factors of Alternating-Current

Abstract

Methods for determination of winding factors of alternating-current electric machines are discussed. It was shown, that single-layer concentrated and two-layer preformed fractional (q  1/2) three-phase windings are similar in their nature, since their relative quantities of respective -th odd harmonics of rotating magnetomotive forces are equal, even though factors of all harmonics of the first winding are equal to one, and due to the lengthening of the second winding span become equal to 0,866. It was proved by theoretical calculations, that winding factors of odd and even harmonics of single-layer three-phase chain-winding can be determined not only according to newly created analytical expression, which assesses distribution of this winding and pitch shortening factor, but also by using harmonic analysis results of instantaneous functions of rotating magnetomotive force of this winding and two-layer preformed fractional-slot (q  1/2) three-phase winding. Winding factors of respective harmonics calculated by both methods are equal. Ill. 2, bibl. 5 (in English; summaries in English, Russian and Lithuanian).