Wind direction stereo sensor for the wind turbine active yaw system

The traditional approach to the horizontal axis wind turbine yawing process leads to the appearance of a known differential yawing error due to the periodic deflection of the air flow by the rotating blades. To reduce its amplitude, usually recorded by a single weather vane located on the top of the nacelle.
This study proposes a new approach, namely the usage of a complex or “stereo” sensor in the form of two devices symmetrically located on both sides of the nacelle (similar to stereoscopic devices). To prove the effectiveness of the approach, several specific points near the nacelle were selected for subsequent modeling of air flows in ANSYS® CFX software using the $k$–$\varepsilon$ turbulence model based on the Navier–Stokes differential equations. At each point, the average value of the orientation angle error was calculated under the following conditions: different wind speeds, tip speed ratios, and wind direction angles. As a result, two points most suitable for the placement of devices were identified. Also, the advantage of a stereo-panoramic device over a traditional one is clearly shown numerically by the example of a case study with nominal parameters. The Matlab/Simulink analysis showed an increase in wind turbine performance due to improved reliability of wind direction determination when properly positioned wind flow sensors are used.
This article does not give any idea of a sensor design, since any principle can be used to determine the correct wind direction. However, the authors are considering a new “stereo sensor”, which will be studied in more detail in the following articles.