Preprints
https://doi.org/10.5194/wes-2024-6
https://doi.org/10.5194/wes-2024-6
23 Jan 2024
 | 23 Jan 2024
Status: this preprint is currently under review for the journal WES.

Load assessment of a wind farm considering negative and positive yaw misalignment for wake steering

Regis Thedin, Garrett Barter, Jason Jonkman, Rafael Mudafort, Christopher J. Bay, Kelsey Shaler, and Jasper Kreeft

Abstract. Wake steering strategies are employed to increase the overall power production of wind farms by deflecting wakes of upstream turbines away from downstream ones. The gain in net power comes at the expense of increased fatigue loads experienced by downstream turbines. In this work we investigate performance and fatigue loading characteristics of a small farm consisting of five aligned IEA Wind 15-MW wind turbines. A parametric study is performed where, for every wind direction from -20 to 20 degrees, the yaw misalignment angle varies from -25 to 25 degrees. This setup allowed us to investigate asymmetries and identify optimal conditions for a given wind direction. In general, we found that positive yaw configurations are preferred and that yaw configurations that result in attractive power gains (25 % or more when compared to a baseline no-yaw scenario) come with significant increase in fatigue loading (we used standard deviation and damage-equivalent load (DEL) of the blade-root, low-speed shaft, and tower-base moments as proxies for fatigue load). We found that for any given positive wind inflow angle, yaw angles between -2.5 and 15 degrees yield power gains of 10–20 % over a no-yaw baseline, and positive yaw is preferred because of lower fatigue loadings. For any given negative wind inflow angles, positive yaw also results in lower magnitudes of standard deviation and DEL for the channels investigated. A small power loss of up to 2 % is observed for some positive yaw angles under negative wind directions (as compared symmetric negative yaw and positive wind cases), but gains in terms of loads exceed 25 % and may be enough to justify a positive yaw configuration under negative winds as well. We show that such behavior can be explained by partial waking and the direction of rotation of the rotor.

Publisher's note: Copernicus Publications remains neutral with regard to jurisdictional claims made in the text, published maps, institutional affiliations, or any other geographical representation in this preprint. The responsibility to include appropriate place names lies with the authors.
Regis Thedin, Garrett Barter, Jason Jonkman, Rafael Mudafort, Christopher J. Bay, Kelsey Shaler, and Jasper Kreeft

Status: final response (author comments only)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on wes-2024-6', Anonymous Referee #1, 26 Apr 2024
  • RC2: 'Comment on wes-2024-6', Anonymous Referee #2, 01 May 2024
Regis Thedin, Garrett Barter, Jason Jonkman, Rafael Mudafort, Christopher J. Bay, Kelsey Shaler, and Jasper Kreeft
Regis Thedin, Garrett Barter, Jason Jonkman, Rafael Mudafort, Christopher J. Bay, Kelsey Shaler, and Jasper Kreeft

Viewed

Total article views: 529 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
405 108 16 529 12 8
  • HTML: 405
  • PDF: 108
  • XML: 16
  • Total: 529
  • BibTeX: 12
  • EndNote: 8
Views and downloads (calculated since 23 Jan 2024)
Cumulative views and downloads (calculated since 23 Jan 2024)

Viewed (geographical distribution)

Total article views: 510 (including HTML, PDF, and XML) Thereof 510 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 23 May 2024
Download
Short summary
This work investigates asymmetries in terms of power performance and fatigue loading on a 5-turbine wind farm subject to wake steering strategies. Both the yaw misalignment angle and the wind direction were varied from negative to positive. We highlight conditions in which fatigue loading is lower while still maintenance good power gains and show that partial wake is the source of the asymmetries observed. We provide recommendations in terms of yaw misalignment angles for a given wind direction.
Altmetrics