https://doi.org/10.1051/epjap/2014130447
Small shape deviations causes complex dynamics in large electric generators
1
Department of Applied Physics and Mechanical Engineering, Luleå University of Technology, SE-97187
Luleå, Sweden
2
Department of Mathematics and Mathematical Statistics, Umeå University, SE-90187
Umeå, Sweden
3
Department of Forest Resource Management, Swedish University of Agricultural Sciences, SE-90337
Umeå, Sweden
a e-mail: niklas.lundstrom@math.umu.se
Received:
1
October
2013
Revised:
7
March
2014
Accepted:
28
April
2014
Published online:
5
June
2014
We prove that combinations of small eccentricity, ovality and/or triangularity in the rotor and stator can produce complex whirling motions of an unbalanced rotor in large synchronous generators. It is concluded which structures of shape deviations that are more harmful, in the sense of producing complex whirling motions, than others. For each such structure, we derive simplified equations of motions from which we conclude analytically the relation between shape deviations and mass unbalance that yield non-smooth whirling motions. Finally we discuss validity of our results in the sense of modeling of the unbalanced magnetic pull force.
© EDP Sciences, 2014
