Rotor Dynamic Analysis of an Eccentric Hydropower Generator With Damper Winding for Reactive Load
2007 (English)In: Journal of applied mechanics, ISSN 0021-8936, E-ISSN 1528-9036, Vol. 74, no 6, 1178-1186 p.Article in journal (Refereed) Published
Asymmetry in the magnetic circuit, around the air gap circumference, in a hydroelectric generator will give rise to a unbalanced magnetic pull. In this paper a hydropower rotor system is modeled and the influence of electro-mechanical forces due to overexcitation is analyzed The active power has been kept constant and the rotor excitation has been changed in order to vary the output of reactive power The electromagnetic field is solved with the finite element method Two electromagnetic models are compared: one with and one without damper winding. The mechanical model of the generator consists of a four id disk connected to an elastic shaft su orted b two bearin s de rees of freedom ri pp y g g g with linear properties. It has been found that the unbalanced magnetic pull slightly increasesfor reactive loads resulting in a decrease of natural frequencies and an increase of unbalance response. When the damper winding is included, the magnetic pull will decrease compared to the model without damper winding, and the pull force has two components: one radial and one tangential. The tangential component can influence the stability of the mechanical system for a range of design parameters.
Place, publisher, year, edition, pages
2007. Vol. 74, no 6, 1178-1186 p.
hydroelectric generators, rotors, machine windings, magnetic circuits, machine theory, magnetic forces, electromagnetic fields, finite element analysis, machine bearings, shafts
Natural Sciences Engineering and Technology
IdentifiersURN: urn:nbn:se:uu:diva-13996DOI: 10.1115/1.2723822ISI: 000251337200014OAI: oai:DiVA.org:uu-13996DiVA: diva2:41766