面向无测风区域的复杂地形风场模拟研究

Wind Field Simulation in Rugged Terrains and Windless Area

由于气象站点的布设受经济、地形、技术等因素限制,使得某风能资源丰富的无测风区域缺少气象站点数据,无法进行风场模拟。针对这一问题,尝试用NCEP再分析风速数据代替传统的气象站点数据,根据NCEP再分析风速数据的栅格数据特点,提出了一种面向无测风区域的复杂地形风场模拟方法。该风场模拟方法以SRTM DEM数据和NCEP再分析风速数据为数据源,首先通过均值变点分析法获取反映无测风区域地形起伏特点的最佳统计单元,得到无测风区域复杂地形的地形起伏度;然后对Cressman插值方法进行改进,将地形起伏度引入到权重函数中,并根据交叉检验中均方根误差最小原则求解权重函数中参数的最优解;最后将最优解代入权重函数中对风场进行加密。实验结果表明:风场模拟结果与气象站点风速之间的相关系数为0.7782,模拟风速的变化趋势与实测风速基本一致;风电场选址区主要建设在模拟风速较大的地区,十分符合风电场一般建设在风能资源丰富的地方的特点,间接验证面向无测风区域的复杂地形风场模拟方法是有效的。

Because the building of meteorological stations is limited by economic,terrain,technology and other factors,there is few meteorological station data in some areas with rich wind energy resources and wind field simulation cannot be carried out.Therefore,this paper develops a method of wind field simulation in rugged terrains and windless area by using NCEP reanalysis wind speed data instead of meteorological station data.In this method,NCEP reanalysis wind speed data and SRTM DEM are used as data sources.Firstly,the best analysis unit was calculated and the relief degree of land surface was extracted in windless area by using the mean change-point analysis method.Secondly,to make Cressman interpolation method better,replacing elevation in weight function with relief and root mean square minimum principle in cross-checking were used as the iteration stopping criterion to solve parametric optimal solution in weight function.Thirdly,the encryption of wind was made using parametric optimal solution in weight function.Finally,the experimental results show that the correlation coefficient between the wind speed in simulated wind field and meteorological stations is 0.7782 which indicates that the change trend of the simulated wind speed is basically consistent with the wind speed in meteorological stations;the site selection area of the wind farm is mainly built in the area with large simulated wind speed,which is very consistent with the characteristics that the wind farm is generally built in the place with rich wind energy resources,which indirectly verifies the effectiveness of the proposed wind field simulation in rugged terrains.