Is Yaw Misalignment actually a problem for wind farms?
(Room Crystal/Continental)
27 Feb 19
1:30 PM
-
2:30 PM
Tracks:
Operational Strategy
During operation, the wind vane or sonic anemometer on a wind turbine measures the wind direction relative to the current nacelle direction (yaw position) of the turbine. This measurement is called yaw error. As the wind changes in direction, the yaw error increases, and when the error is sufficiently large enough for a long enough time the yaw controller will yaw the turbine to reduce the yaw error. In the ideal case, the nacelle will on average point directly into the wind, thereby maximizing the effectiveness of the rotor to capture wind power. However, if the turbine does not on average point directly into the wind then it has a yaw misalignment. Yaw misalignment may be due to any number of factors including the distortion of the airflow from the rotor and around the nacelle or alignment of the wind vane or sonic anemometer when it was installed or replaced. Because damage or replacement of the wind vane or sonic anemometer can introduce a new yaw offset on a machine, continuous monitoring of the yaw misalignment ensures that changes can be detected and corrected soon after a misalignment is introduced. According to literature by some European companies, wind turbines are losing between 1 - 3% energy due to yaw misalignment. WindESCo has been researching this issue for over 2 years and would like to present its findings specific to wind farms in US.