Measurements & Experimentation
Full scale field wind turbine measurements
The chair of structural mechanics is leading a comprehensive measurement campaign on a field wind turbine in Winterthur, Switzerland. The wind turbine is designed and manufactured by Aventa AG. It features a rotor diameter of 12.9m at a rated power of 6.5kW, and stands on an 18m circular concrete tower. With the purpose of monitoring the structural condition and current/future performance of the system, the measurement campaign involves the installation of low cost and easily deployable sensors and corresponding data acquisition systems on the tower, nacelle and blades. The sensors’ suit includes accelerometers, tilt-meters and strain gauges, along with tracking of operational and environmental data, and will comprise a mix of tethered and wireless technologies. Aventa AG, represented by Mr. Ueli Spalinger, has offered valuable access to the geometric (CAD Drawings) and further mechanical and structural properties of the wind turbine, which will facilitate fusion with physics-based models (Finite Element and aero-elastic simulations), and comparison to the actually measured response. Vibration-based identification methods will be employed as the main analysis tool, for assessing the condition of the system and obtaining insights on the current performance and margin for improvement of not only this particular case-study, but Wind Turbine systems at large. This thoroughly instrumented case study will serve as a benchmark, with datasets made available to the academic and research communities. The outcome of the study forms part of the broader scope of the ERC WINDMIL project where novel methods and tools are devised for smart data harnessing, interpretation and management for optimal life-cycle assessment of these assets with the purpose of increasing safety, performance and sustainability of this renewable energy technology. The ESC members involved in this project are, Prof. Dr. Eleni Chatzi, Dr. Imad Abdallah, Dr. Vasilis Dertimanis, Harry Mylonas, Konstantinos Tatsis, from the Chair of Structural Mechanics, in addition to Mr. Ueli Spalinger from Aventa AG.
Laboratory Setup - Small Scale WT
Scaled Wind turbine for lab testing
The chair of structural mechanics has designed and constructed a rotary machine emulating a scaled wind turbine. The turbine has a tower diameter of 20mm and height of 1600mm. The rotor blades have a length of 800mm. The rotor can be equipped with 2 or 3 blades. The design includes features in order to provision for the following: changing tower bottom boundary condition, allowing for tower bottom rocking, changing nacelle position with respect to tower centre, changing pitch (pitch misalignment) for each blade individually, changing boundary condition between the pitch/blade fixtures simulating blade root fault, and finally the design allows for blade length misalignment/imbalance. static (non-rotating), dynamic (rotating), hammer impact, shaker tests are planned, linear and non-linear modal analysis, system identification, vibration control, vibration tests with various misalignments, imbalances, boundary conditions and damages, and last but not least verification and validation of wireless sensing technologies.