Home/MET. Measurement and Experimental Techniques/MET. Measurement and Experimental 1

The Science of Making Torque from Wind (TORQUE 2018)

20 June  |  21 June  |  22 June  |  Events View
AA | CM | DSE | MET | MST | WWT

Loading Events
This event has passed.

Room: BL.27.0.1
Chaired by: Gerard Schepers | ECN part of TNO
Topic: MET. Measurement and Experimental Techniques
Form of presentation: Oral
Duration: 110 minutes

Authors:
Brandon Ennis

Abstract:
Wind turbines operate in stochastic flow environments with constantly changing wind speed and direction. The varying atmosphere combined with slowly responding yaw systems means that wind turbines nominally operate with an unintentional yaw offset.  Recently, there has been interest in intentionally misaligning wind turbines out of the wind as a wind plant controls strategy to provide system power benefits by steering wakes to avoid downstream rotors.  Wind turbine yaw offset reduces power and alters the loading for a stand-alone wind turbine. The trends describing how loads are affected by yaw offset have been analyzed and characterized based on operating and atmospheric conditions using experimental data from the DOE/SNL Scaled Wind Farm Technology (SWiFT) facility. The data acquired during the US Department of Energy’s wake steering experimental campaign are used for this characterization and to further determine the effects of yaw offset on blade life.

Authors:
Lars Kröger

Abstract:
A wind tunnel experiment is presented which combines the use of controlled turbulent inow conditions and a two-bladed model wind turbine utilizing a new control strategy called subspace predictive repetitive control (SPRC). The validation of the performance of SPRC was made under turbulent inow conditions generated by an active grid. The 3m x 3m active grid is used in this experiment using a unique method to generate reproducible atmospheric-like turbulent wind fields to act on a medium sized model wind turbine.

Authors:
Sebastien Gueydon, Erik-jan de Ridder

Abstract:
For the full physical testing of FOWTs in combined wind and waves, it is necessary to generate good quality wind in order for the modeled wind turbine rotor to deliver the desired scaled down thrust. Limiting the turbulence to an acceptable level for steady wind tests can only be done at the price of important loss of output wind speed for fan based generator. It is not precisely known what is acceptable for the level of turbulence during the testing of FOWTs? Also, it is very difficult to generate a uniform the wind field in a basin. The idea at the origin of this work was to think of a way to avoid or minimize these issues. MARIN carried out towing tests of a turbine made with the same rotor as it has been used for testing in combined waves and wind conditions. These data can be compared with the results of previous model tests in the Offshore Basin with the same rotor in a generated wind field. In this way, the effects of turbulence and slight non-uniformity of the wind field on the performance of this scaled down rotor in a fan generated wind field can be evaluated.

Authors:
Johannes Oehler, Marc van Reijen, Roland Schmehl

Abstract:
Airborne wind energy is an evolving renewable energy technology with the potential to reduce material as well as energy investments and to harvest wind resources that have so far not been accessible. Ground generation airborne wind energy systems use the pulling force of a kite to generate a linear traction motion driving a drum connected to a generator. To understand and quantify the aerodynamic performance of a soft kite we developed a sensor system that measures the relative flow conditions on a flying, highly flexible wing. Together with ground-based measurements of traction force and mechanical power the aerodynamic efficiency of the kite can be computed. The lift-to-drag ratio is mainly affected by steering and active pitching controlled by the flight computer, the heading of the kite is found to be most influential for the lift coefficient and angle of attack. In current flight simulations the models of the kite’s deformations due to loading, turn and pitch maneuvers have not been validated experimentally.For optimization of future power kites this validation is essential tounderstand the mechanisms affecting aerodynamic efficiency.

Authors:
Filipe Magalhães

Abstract:
This paper evaluates the results that can be obtained with different strategies of instrumentation for an utility-scale wind turbine, considering variations on the number of sensors, on their distribution in the wind turbine tower and on their noise level. With the goal of reducing the investment in monitoring equipment, layouts based on a reduced number of low cost sensors are tested.  The data processing strategy is based on the continuous tracking of the wind turbine main vibration modes using Operational Modal Analysis techniques combined with algorithms that deal with the particularities of operation of the wind turbines and that permit an online automated identification. After the mitigation of the influence of the environmental and operation factors on the tracked natural frequencies, it is possible to detect abnormal variations of the natural frequencies, which might flag the appearance of damage.  The alternative monitoring scenarios are recreated using a database of acceleration time series collected during one year, by a quite extensive monitoring system, using low noise accelerometers.

20 June  |  21 June  |  22 June  |  Events View
AA | CM | DSE | MET | MST | WWT

Go to Top