Estimating damping of an offshore wind turbine using an overspeed stop and ambient excitation
Devriendt, C.; De Sitter, G.; Guillaume, P. (2012). Estimating damping of an offshore wind turbine using an overspeed stop and ambient excitation, in: Proceedings of the 15th International conference on experimental mechanics. pp. 14
In: (2012). Proceedings of the 15th International conference on experimental mechanics. INEGI-Instituto de Engenharia Mecanica e gestao industrial: Porto. ISBN 9789728826260. , more
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Document type: Conference paper
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Abstract |
The work presented in this paper describes a comparative study between different techniques aimed at identifying the damping values of an offshore wind turbine on a monopole foundation. It will be shown that damping ratios can directly be obtained from vibrations of the tower under ambient excitation from wave and wind loading. The results will be compared with the damping values obtained from a commonly used overspeed stop. Ambient vibration tests have the strong advantage of being more practical and less demanding for the wind turbine in comparison with the overspeed stop. Several identification algorithms, the standard exponential decay method, alternative procedures in the time domain as well as more advanced operational modal analysis techniques in the frequency domain will be applied to the experimental data. This data has been obtained during a short measurement campaign on an offshore wind turbine in the Belgian North Sea. The theory and results of the used methods for estimating the modal damping of a wind turbine excited by ambient excitation will be presented and compared. The paper will also discuss and illustrate various aspects related to the practical implementation of the measurements. |
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