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Title: The airgap magnetic field in electrical machines, with special reference to the effect of eccentricity
Author: Gashus, Ove Kristoffer
ISNI:       0000 0001 3491 9654
Awarding Body: University of Glasgow
Current Institution: University of Glasgow
Date of Award: 1960
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The present work was initiated in 1953 by the rather tentative idea of investigating the presence of "even" harmonics in the air gap flux density wave of electrical machines. During these investigations, it became clear that, for the case of eccentric dissyimnetry, which was seen as one of the main sources of "even" harmonics, little or no evidence of published work was to be found. This problem was then taken up as a subject for the present Thesis. Experiments were carried out, and results were obtained which showed that eccentricity would account for up to very large percentage harmonic contents. An approximate theory was also established based on m.m.f. and permeance waves. This explained the phenomena in some cases, but was obviously wrong in other cases. For a rather long period of time, no progress was made due to the lack of a correct theory; the theory presented in this Thesis was only developed after the Author resumed the work two years ago. The theory may be regarded as the extension of the conventional m.m.f. theory to the case of eccentric rotors. A complete theory of constant-span (or equivalent) coil windings is presented as an introduction to the eccentric rotor theory, thus making the work self-contained. Originality is claimed for some of the extensions of the conventional m.m.f. theory, notably on the subject of unbalanced excitation and inductances and for the eccentric rotor theory.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available
Keywords: Electrical machinery magnetism