Influence of the Stator Winding on the Mechanical Eigenfrequencies of Hydro Generators

authored by: Allan De Barros, Wilhelm Weber, Amir Ebrahimi, Babette Schwarz, Bernd Ponick
Abstract: The vibrational behaviour of the stator of a hydro generator is an important aspect to be evaluated during the design of the machine, as it has an impact on its maintenance and life expectancy. This evaluation requires, in addition to the calculation of the exciting magnetic forces, the determination of the eigenfrequencies and eigenmodes of the stator structure. This task is particularly challenging for a large hydro generator due to its structural complexity, involving various components such as the laminated core, the ventilation air ducts, the frame, the winding, and the connections between these. This paper is dedicated to the experimental investigation of the influence of the stator winding on the mechanical eigenfrequencies of the stator assembly. For this purpose, a series of experimental modal analyses is performed in different assembly phases of a real 55 MVA generator. It turns out that, from the stator's point of view and by considering the typical winding insertion methods without global impregnation, the winding is only weakly coupled to the laminated core. Thus, the mass and the stiffness of the winding have no substantial effect on the system's eigenfrequencies. This finding contributes to the selection of appropriate simplifications and assumptions in the modelling of the complete stator including the winding for the prediction of structural vibrations in future works.
Organisation(s): Institute of Drive Systems and Power Electronics
External Organisation(s): Voith GmbH & Co. KGaA
University of Bremen
Type: Conference contribution
Publication date: 01.09.2024
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Energy Engineering and Power Technology, Control and Systems Engineering, Electrical and Electronic Engineering, Mechanical Engineering
Sustainable Development Goals: SDG 3 - Good Health and Well-being
Electronic version(s): https://doi.org/10.1109/ICEM60801.2024.10700304 (Access: Closed)

BibTeX

@inproceedings{04aa1892cf3640638b496198308df703,
title = "Influence of the Stator Winding on the Mechanical Eigenfrequencies of Hydro Generators",
abstract = "The vibrational behaviour of the stator of a hydro generator is an important aspect to be evaluated during the design of the machine, as it has an impact on its maintenance and life expectancy. This evaluation requires, in addition to the calculation of the exciting magnetic forces, the determination of the eigenfrequencies and eigenmodes of the stator structure. This task is particularly challenging for a large hydro generator due to its structural complexity, involving various components such as the laminated core, the ventilation air ducts, the frame, the winding, and the connections between these. This paper is dedicated to the experimental investigation of the influence of the stator winding on the mechanical eigenfrequencies of the stator assembly. For this purpose, a series of experimental modal analyses is performed in different assembly phases of a real 55 MVA generator. It turns out that, from the stator's point of view and by considering the typical winding insertion methods without global impregnation, the winding is only weakly coupled to the laminated core. Thus, the mass and the stiffness of the winding have no substantial effect on the system's eigenfrequencies. This finding contributes to the selection of appropriate simplifications and assumptions in the modelling of the complete stator including the winding for the prediction of structural vibrations in future works.",
keywords = "eigenfrequencies, eigenmodes, Electric machines, finite element method, hydroelectric generators, material properties, modal analysis, noise, stator winding, vibrations",
author = "{De Barros}, Allan and Wilhelm Weber and Amir Ebrahimi and Babette Schwarz and Bernd Ponick",
note = "Publisher Copyright: {\textcopyright} 2024 IEEE.; 2024 International Conference on Electrical Machines, ICEM 2024 ; Conference date: 01-09-2024 Through 04-09-2024",
year = "2024",
month = sep,
day = "1",
doi = "10.1109/ICEM60801.2024.10700304",
language = "English",
isbn = "979-8-3503-7061-4",
booktitle = "2024 International Conference on Electrical Machines, ICEM 2024",
publisher = "Institute of Electrical and Electronics Engineers Inc.",
address = "United States",
}