DBPapers
DOI: 10.5593/sgem2017H/43/S29.079

COMPARATIVE STRESS ANALYSIS IN A HYDROELECTRIC GENERATOR POLE FIXATION

A. Rusu-Casandra, F. Baciu, N. Iliescu, C. Atanasiu
Thursday 23 November 2017 by Libadmin2017

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgemviennagreen.org, SGEM2017 Vienna GREEN Conference Proceedings, ISBN 978-619-7408-28-7 / ISSN 1314-2704, 27 - 29 November, 2017, Vol. 17, Issue 43, 627-634 pp; DOI: 10.5593/sgem2017H/43/S29.079

ABSTRACT

Although hydropower is one of the oldest energy sources used by man, it is still the leading green, nonpolluting and renewable source for electricity generation worldwide. Hydroelectric power generation is also the most efficient method of large scale electric power generation. Estimates show that there is a huge worldwide capacity of unutilized hydropower potential. Therefore, there are many opportunities for new hydroelectric power plants throughout the world, which makes the study and design of new and improved electric power hydro generators a priority.
The core equipment of a hydroelectric power plant is the electric power generator, which can deliver hundreds of MW of electric power, while withstanding high levels of mechanical and thermal stresses under high rotation speeds. Therefore, the design of the electric generator, especially the rotor component, must ensure structural integrity, high reliability and extended lifetime of 30-40 years.
This paper presents a comparative study of the stress concentration in a model of a hammer pole fixation and also in a model of the assembly with three hammerheads. The results of an experimental study using the photoelastic technique and those of a numerical analysis carried out with the 3D finite element method are compared. The conclusions obtained show that under certain working conditions the stress magnitudes in the pole fixation are very high, the yielding limit of the material can be exceeded in certain points, which might lead even to a catastrophic failure of the electric generator.
The data acquired can be useful for a new proper design of the pole fixation, in order to increase the safety in the real exploitation conditions of the generator.

Keywords: hydroelectric generator, photoelasticity, FEM, stress, pole fixation