Journal cover Journal topic
Wind Energy Science The interactive open-access journal of the European Academy of Wind Energy
Journal topic

Journal metrics

CiteScore value: 0.6
CiteScore
0.6
h5-index value: 13
h5-index13
Download
Short summary
Active trailing edge flaps can potentially enable further increases in wind turbine sizes without the disproportionate increase in loads, thus reducing the cost of wind energy even further. Extreme loads and critical deflections of the turbine blade are design driving issues that can effectively be reduced by flaps. This paper considers the flap hinge moment as an input sensor for a flap controller that reduces extreme loads and critical deflections of the blade in turbulent wind conditions.
Preprints
https://doi.org/10.5194/wes-2021-1
https://doi.org/10.5194/wes-2021-1

  04 Feb 2021

04 Feb 2021

Review status: this preprint is currently under review for the journal WES.

Active Flap Control with the Trailing Edge Flap Hinge Moment as a Sensor: Using it to Estimate Local Blade Inflow Conditions and to Reduce Extreme Blade Loads and Deflections

Sebastian Perez-Becker, David Marten, and Christian Oliver Paschereit Sebastian Perez-Becker et al.
  • Chair of Fluid Dynamics, Hermann Föttinger Institute, Technische Universität Berlin, Berlin, Germany

Abstract. Active trailing edge flaps are a promising technology that can potentially enable further increases in wind turbine sizes without the disproportionate increase in loads, thus reducing the cost of wind energy even further. Extreme loads and critical deflections of the blade are design driving issues that can effectively be reduced by flaps. In this paper, we consider the flap hinge moment as a local input sensor for a simple flap controller that reduces extreme loads and critical deflections of the DTU 10 MW Reference Wind Turbine blade. We present a model to calculate the unsteady flap hinge moment that can be used in aeroelastic simulations in the time domain. This model is used to develop an observer that estimates the local angle of attack and relative wind velocity of a blade section based on local sensor information including the flap hinge moment of the blade section. For steady wind conditions that include yawed inflow and wind shear, the observer is able to estimate the local inflow conditions with errors in the mean angle of attack below 0.2° and mean relative wind speed errors below 0.4 %. For fully turbulent wind conditions, the observer is able to estimate the low frequency content of the local angle of attack and relative velocity even when it is lacking information on the incoming turbulent wind.

We include this observer as part of a simple flap controller to reduce extreme loads and critical deflections of the blade. The flap controller’s performance is tested in load simulations of the reference turbine with active flaps according to the IEC 61400-1 power production with extreme turbulence group. We used the lifting line free vortex wake method to calculate the aerodynamic loads. Results show a reduction of the maximum out-of-plane and resulting blade root bending moment of 8 % and 7.6 % respectively when compared to a baseline case without flaps. The critical blade tip deflection is reduced by 7.1 %. Furthermore, a sector load analysis considering extreme loading in all load directions shows a reduction of the extreme resulting bending moment in an angular region covering 30° around the positive out-of-plane blade root bending moment. Further analysis reveals that a fast reaction time of the flap system proves to be critical for its performance. This is achieved with the use of local sensors as input for the flap controller. A larger reduction potential of the system is identified but not reached mainly because of a combination of challenging controller objectives and the simple controller architecture.

Sebastian Perez-Becker et al.

Status: open (until 05 Apr 2021)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on wes-2021-1', Athanasios Barlas, 19 Feb 2021 reply

Sebastian Perez-Becker et al.

Sebastian Perez-Becker et al.

Viewed

Total article views: 259 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
191 64 4 259 1 1
  • HTML: 191
  • PDF: 64
  • XML: 4
  • Total: 259
  • BibTeX: 1
  • EndNote: 1
Views and downloads (calculated since 04 Feb 2021)
Cumulative views and downloads (calculated since 04 Feb 2021)

Viewed (geographical distribution)

Total article views: 253 (including HTML, PDF, and XML) Thereof 253 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 04 Mar 2021
Publications Copernicus
Download
Short summary
Active trailing edge flaps can potentially enable further increases in wind turbine sizes without the disproportionate increase in loads, thus reducing the cost of wind energy even further. Extreme loads and critical deflections of the turbine blade are design driving issues that can effectively be reduced by flaps. This paper considers the flap hinge moment as an input sensor for a flap controller that reduces extreme loads and critical deflections of the blade in turbulent wind conditions.
Citation