超强台风“威马逊”登陆期间近地层风速变化特征分析

利用1409号超强台风“威马逊”登陆广东徐闻期间勇士风电场观测数据，计算分析了“威马逊”风切变、湍流强度、阵风系数和风向等的时程变化特征，拟为沿海台风影响严重区域输电线路设计和风电机组选型提供参考依据。分析发现“威马逊”风切变指数相比年平均风速(即常态风)切变指数减小，随台风中心逼近和经过呈现先减小再增大的规律；台风中心过后风向回南之后，幂指数函数拟合较差。阵风系数呈现随高度增加而减小的趋势，该趋势在台风中心经过前较好地吻合幂函数，而在台风中心经过后吻合较差；各高度阵风系数以及不同高度之间的差值随台风中心逼近、风速增加而趋于减小，随台风中心远离、风速下降而缓慢增大。湍流强度随高度增加而减小，强风时段湍流强度较小且相对平稳，轮毂高度处湍流强度基本不超IEC-B类。测站位于台风中心路径右侧眼壁区时，所测风向随时间呈顺时针旋转。 

STUDY ON THE BOUNDARY LAYER WIND VARIATION CHARACTERISTICS OF SUPER-TYPHOON RAMMASUN DURING LANDING ON XUWEN COUNTY

On the basis of observed wind speed and direction data at Yongshi Wind Farm during the landing of super-typhoon Rammasun on Xuwen county, Guangdong province, wind shear, gust factor, turbulence intensity and wind direction of Rammasun are analyzed to support the design of high-voltage overhead transmission lines and selection of wind turbines for the southeast coast of China that is seriously affected by typhoons. It was found that wind shear index was less than frontal wind, and first decreased and then increased when the typhoon eye approached and then left the observation site. When the typhoon eye went through the observation site and wind direction changed to the southward, wind shear profile did not fit the power law. The gust factor reduced with height, which complied with the power law perfectly when the typhoon eye was going toward to the mast, but did not present such rule any more after the typhoon eye left. The gust factor and its difference between layers decreased when the typhoon eye came close and wind speed increased, but they increased after the typhoon eye left. The turbulence intensity decreased with height. When it comes to temporal variation, the turbulence intensity was smaller and the change was correspondingly steady. Most of the turbulence intensity at the hub height was less than the IEC-B standard. The wind veered from the north to the northeast, then to the east and finally to the south-southeast, presenting a clockwise rotation relative of the station which was at the right side of the typhoon eye-wall.