Operational Modal Analysis of a Wind Turbine Mainframe using Crystal Clear SSI

Conference paper
Part of the Conference Proceedings of the Society for Experimental Mechanics Series book series (CPSEMS)

Abstract

Experimental investigations of the dynamic behavior of wind turbine components as well as of the turbine’s overall dynamics are important for the evaluation of applied prediction models. Operational Modal Analysis (OMA) was applied to identify resonant frequencies, corresponding mode shapes and damping values. Experimental investigations were carried out at the main frame of a Fuhrländer AG 2.5 MW wind turbine with a rotor diameter and a hub height of each ca.100m. Structural responses were recorded at a stopped turbine excited by the stochastic wind only. The complex structure of the mainframe as well as its interaction with the tower and the turbine blades makes it non-trivial to perform the modal analysis. In the paper the new Crystal Clear Stochastic Subspace Identification (CC-SSI) technique is applied. This technique produces very clear stabilization and easy automatic mode extraction even for complicated systems with a large number of modes as considered here. At a wind turbine, there is usually a restriction in easily applicable measurement locations. Since time series were recorded only at the main frame of the turbine, overall mode shapes of the entire turbine were identified applying a combined identification using Finite Element Analysis (FEA).

Keywords

Covariance Expense Reso Extractor 

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References

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Copyright information

© The Society for Experimental Mechanics, Inc. 2011

Authors and Affiliations

  1. 1.W2E Wind to Energy GmbHRostockGermany
  2. 2.Structural Vibration Solutions A/SAalborg EastDenmark

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