Dynamic response of monopile-supported wind turbines considering non-Gaussian characteristics of wind inflow

Abstract

Available wind turbine design standards usually assume that the inflow wind field is a smooth Gaussian process, but the in-situ measured data show that the inflow wind presents a certain degree of non-Gaussian characteristics. This study investigates the dynamic response of the supporting structure of the wind turbine under both Gaussian and non-Gaussian wind fields. The Mises stress at the tower base and the mudline of the monopile are considered. Through the global maxima method and the average conditional exceedance rate method, the extreme value response of the turbine under a given mean recurrence interval is obtained. The results indicate that by taking the non-Gaussian characteristics of wind fields into account, the short-term extreme values are generally larger than those under Gaussian wind fields. For the long-term extreme values of the stress at the two critical points, the influence of kurtosis is significantly greater than the skewness. Meanwhile, the long-term stress extreme value also increases with the increase of kurtosis. The non-Gaussian characteristic of the wind field has a particular influence on the safe operation of the wind turbine and should be considered when designing wind turbines.