Developments in Rotor Dynamical Modeling of Hydropower Units
During the last century the hydropower units have been developed from a few megawatts per unit, up to several hundreds megawatts per unit. Over the years the operating conditions have also been changed from the ones that the machines were originally designed. These changes will significantly affect the lifespan of the machines. The hydropower plants are in general old, and large-scale revisions will be performed in the coming years. This implies that new components with new materials and design will be installed to the old machines. To reduce the risk of failures it is essential that better methods for rotor dynamical simulations are developed. In this paper our research on electromagnetic-rotor interaction is summarized. Results are presented on new rotor models in connection with stability, excitation sources for backward/forward whirling and the occurrence of a tangential force.
KeywordsHydropower Rotor Dynamic Magnetic pull UMP Stability
The research presented in this paper has been carried out with funding by Elforsk AB and the Swedish Energy Agency through their joint Elektra programme and as a part of Swedish Hydropower Centre - SVC’ (www.svc.nu). SVC has been established by the Swedish Energy Agency, Elforsk and Svenska Kraftnäat together with Luleå University of Technology, The Royal Institute of Technology, Chalmers University of Technology and Uppsala University.
- 1.Behrend, B.A.: On the mechanical force in dynamos caused by magnetic attraction. AIEE 17, 617 (1900)Google Scholar
- 2.Gray, A. Electrical Machine Design. McGraw-Hill Book Company Inc., New York, pp. 498–500 (1926)Google Scholar
- 3.Robinson, R.C.: The calculation of unbalanced magnetic pull in synchronous and induction motors. Electr. Eng. 62, 620–624 (1943)Google Scholar
- 4.Covo, A.: Unbalanced magnetic pull in induction motors with eccentric rotors. Trans. AIEE 73(III), 1421–1425 (1954)Google Scholar
- 5.Ohishi, H., et al.: Radial magnetic pull in salient poles machines. IEEE Trans. Energ. Convers. EC-2, 3 (1987)Google Scholar
- 8.Holopainen, T.P., et al.: Electromagnetic circulatory forces and rotordynamic instability in electric machines. In: Proceedings of the 6th International Conference on Rotor Dynamics, vol. 1, pp. 446–463. University of New South Wales, Sydney, Australia (2002)Google Scholar
- 9.Laiho, A.N., et al.: Structural finite element modeling of electromechanical interaction in rotordynamics of electrical machines. In: Proceedings of ASME International Design Engineering Technology Conferences & Computers and Information in Engineering Conference, Long Beach, California USA, September 24–28 (2005)Google Scholar
- 10.Gustavsson, R.K., Aidanpää, J.-O.: The influence of magnetic pull on the stability of generator rotors. In: The 10th of International Symposium on Transport Phenomena and Dynamics of Rotating Machinery, Honolulu, Hawaii (2004)Google Scholar
- 13.Karlsson, M., Aidanpää, J.-O.: Dynamic Behaviour in a Hydro power Rotor System due to the Influence of Generator Shape and Fluid Dynamics. PWE2005, ASME Power, Chicago, Illinois, 5–7 April 2005Google Scholar
- 17.Belmans, R., et al.: Unbalanced magnetic pull and homopolar flux in three phase induction motors with eccentric rotors. In: Proceedings, International Conference on Electrical Machines-Design and Application, Budapest, pp. 916–921 (1982)Google Scholar
- 18.Burakov, A., Arkkio, A.: Comparison of the unbalanced magnetic pull mitigation by the parallel paths in the stator and rotor windings. IEEE Trans. Magn., In Press (2008)Google Scholar