The airgap magnetic field in electrical machines with special reference to the effect of eccentricity

Gashus, Ove Kristoffer (1960) The airgap magnetic field in electrical machines with special reference to the effect of eccentricity. PhD thesis, University of Glasgow.

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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.

Item Type: Thesis (PhD)
Qualification Level: Doctoral
Additional Information: Adviser: B Hague
Keywords: Electrical engineering, Electromagnetics
Date of Award: 1960
Depositing User: Enlighten Team
Unique ID: glathesis:1960-73537
Copyright: Copyright of this thesis is held by the author.
Date Deposited: 14 Jun 2019 08:56
Last Modified: 14 Jun 2019 08:56

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