应用统计外推求解近海风机面外叶根部弯矩最大值

Calculation of Out-of-Plane Bending Moment at the Blade Root of Offshore Wind Turbines by Statistic Extrapolation

根据IEC61400-3要求,为了确立统计外推程序以预测近海风机的长期载荷,选用NREL5MW单桩式近海风机和浮式近海风机进行研究.在风机时域仿真中,对FAST软件进行编译,将塔筒载荷计算程序嵌入FAST,弥补了现有软件的不足.对于仿真得到的短期载荷,分别应用全局最大值法和分块最大值法拟合Gumbel分布来预测面外叶根部弯矩的最大值,并进行对比.根据对比结果,进一步提出了分块最大值法的最优分块数,并通过最大门槛值法进行验证,从而为近海风机的极限载荷计算提供参考.

According to IEC61400-3, NREL 5MW Monopile wind turbine and OC3Hywind wind turbine were studied to predict long-term loads of offshore wind turbines. This paper compiles FAST to include the functionality of calculating the wind loads on the tower in the simulation. Two statistics extrapolation methods, i.e. global maximum and block maximum, were used respectively to fit Gumbel distribution to predict the extreme load of out-of-plane bending moment at the blade root, and the results were compared. Further, after discussing different block sizes, the optimal block size was suggested. The comparison of research results with peak-over-threshold method shows that the block maximum method can effectively predict loads, thus providing references for offshore wind turbines load calculation.