Assessing Wind Gust Characteristics at Wind Turbine Relevant Height

Wind gust characteristics at wind turbine relevant height are closely tied with wind turbine design and wind power generation, which, however, have not been detailed and documented. In this study, high-resolution wind data recorded by 3D sonic anemometers at a tall meteorological tower were analyzed to determine 12 descriptors of wind gusts, and to identify the parent distributions that best fit these parameters. The main statistics were estimated using wind data from the 160m height. It is found that the log-logistic distribution is most appropriate for 10-min mean wind speed, gust magnitude, gust factor and turbulence intensity; the gamma distribution appears to best fit peak factor, rise magnitude, lapse magnitude, lapse time and gust length scale, while gust amplitude, rise time and gust asymmetric factor are typically log-normally distributed. Gust factors tend to decrease with mean wind speed, but increase as a function of turbulence intensity. The results also indicate that these wind gust descriptive parameters are height-dependent, in which the 10-min mean wind speed, gust magnitude, gust length scale, rise time and lapse time usually possess larger values at higher heights, whereas the remaining parameters exhibit negative correlation with height.