C. Grabner, E. Schmidt:
"Novel Insights into the Nonlinear Dependency of the Airgap Magnetic Flux Density of Synchronous Generators with Fractional Slot Windings in Case of Various Operational States";
Poster: Canadian Conf. On Electrical and Computer Engineering (CCECE), Montreal, CA; 05-04-2003 - 05-07-2003; in: "Proceedings of the IEEE Canadian Conference on Electrical and Computer Engineering (CCECE)", (2003), ISBN: 0-7803-7782-6; 1 - 4.

To fulfill the requirements of the voltage shape quality, a fractional
slot stator winding is often applied within large synchronous machines.
Due to such a stator winding, a lot of different harmonic field wave
components are circulating along the airgap. Additionally to the
fundamental harmonic wave and the higher hamonics with a wavelength
shorter than two pole pitches, the armature reaction of a fractional slot winding creates harmonic field components with a wavelength larger than two pole pitches, the so called subharmonics. The paper investigates the field harmonics of a 500 MVA salient pole synchronous generator in dependence of various operational states from finite element analyses.

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