STATISTICAL ANALYSIS OF GUST FREQUENCY IN LA MATA WIND FARM
A statistical analysis of wind data recorded near a wind farm is presented. The specific site where the sensors are located is in La Mata wind farm (16°35’33.5” N 94°56’42.7” W) in Oaxaca, Mexico. Data are available from April 18, 2023, to March 18, 2024 with a sampling frequency of 1 s. Data are available for research purposes through an agreement between AP Engineering and EDF RENEWABLE. The primary objective of this study is to define, identify, and characterize geometrical and dynamic properties of gusts. Special emphasis is put on the analysis of gusts that potentially require reorienting the nacelle of a wind turbine. As it is well known in the wind energy practice, nacelle misalignment with respect to the main wind direction severely impacts the performance of the turbine. Yaw drive adjusts the orientation of the nacelle, but brisk changes, including angular accelerations, may compromise the integrity of the yaw motor, gearbox, the track on the yaw’s crown, and the brake system.
In meteorology, the classical definition of a gust is a rapid fluctuation in wind speed with variations of 5 m/s typically lasting less than 20 seconds. For quantitative analysis aimed at diagnosing wind turbine operation, Gusts are defined as rapid, simultaneous changes in the wind speed and direction. Two parameters characterize gusts: a) the time window (∆τ ) and b) the product of half the variation of the wind speed squared (∆u^2/2) and direction (∆θ). The mathematical expression for gusts proposed is:
G = ∆u^2∆θ/2∆τ
Note that [G]= W/kg, indicating that the gusts refer to the wind kinetic energy per unit mass associated with orientation changes. With the previous definition, Gust severity classification can be obtained as a time function.
Gust occurrence frequency as a function of a 24-hour cycle is discussed, together with a seasonal trend. Results are also useful for detecting extreme events that could potentially be harmful to the turbine’s proper functioning.