Operational modal analysis

Wind turbines are highly dynamic structures that interact strongly with their environment. The dynamic behavior is best characterized by the so-called modal parameters in particular resonance frequencies and damping ratio’s. Building on the long track-record of AVRG in operational modal analysis techniques, OWI-lab developed an automated frame-work to estimate and track the modal parameters. While Distributed Data Systems uses a similar framework to assess the condition of the drivetrain, this group focuses on the structural components of the wind turbine, such as tower, foundation and rotor modes.

Several outcomes of the current research have been:

• Quantification of the mismatch between design resonance frequencies and real world values.
• A long term assessment of damping on different wind turbines offshore.
• Long-term assessment of the evolution of resonance frequencies for offshore wind turbines.
• A proposed strategy to assess the presence of scouring based on resonance frequencies