大跨柔性光伏支架结构风压特性及风振响应

Wind pressure characteristics and wind vibration response of long-span flexible photovoltaic support structure

摘要:

大跨柔性光伏支架结构因具有良好的场地适应性和经济性而得到越来越多的应用。为完善此类光伏支架结构的抗风设计方法,通过对一种可变倾角的大跨柔性光伏支架结构进行刚性模型风洞测压试验,研究了光伏组件板面的平均风压和脉动风压系数在不同风向角和倾角组合下的分布特性以及全风向角下组件的极值风压变化规律,并给出了典型风向角下的脉动风压功率谱图。在此基础上,结合光伏组件的风压分布特点,采用ANSYS有限元软件仿真研究了该种柔性支撑光伏支架的风振响应并进一步计算得到了相应的风振系数。研究结果表明:在0°和180°风向角下,平均风压系数沿来流方向梯度分布且绝对值迅速衰减；随着风向角的增大,风压系数绝对值的最大值出现位置由迎风前缘向迎风端角部附近移动；光伏板面脉动风压分布与平均风压分布趋势类似；相比结构位移响应,钢索张力响应对风速变化不敏感,顺风向和竖向位移风振系数在U=8 m/s取得极大值,其值为2.11和1.98。本文可为光伏结构的抗风设计提供参考。

Abstract:

Long-span flexible photovoltaic support structures have been increasingly used because of their good site adaptability and economy. For improving the wind resistance design method of such structures, wind tunnel pressure test was conducted on a long-span flexible photovoltaic support structure with variable inclination angles, so as to investigate the distribution characteristics of mean and fluctuating wind pressure coefficients of photovoltaic panels under different wind azimuths as well as the extreme wind pressure change law of photovoltaic modules under full range wind azimuths. The power spectrum of the fluctuating wind pressure under typical wind azimuth was also given. On the basis of the wind pressure distribution characteristics of photovoltaic modules, the finite element software ANSYS was employed to simulate the wind-induced response of the flexible photovoltaic support structure, and the corresponding vibration coefficient was obtained. Research results show that at wind azimuths of 0° and 180°, the mean wind pressure coefficient appeared gradient distribution along the incoming flow direction and the absolute value decreased rapidly. With the increase in wind azimuth, the maximum absolute value of the wind pressure coefficient moved from the windward leading edge to the corner of the windward end. The trend of fluctuating wind pressure distribution on photovoltaic panels was similar to that of mean wind pressure distribution. Compared with structural displacement response, the cable tension response was not sensitive to the changes in wind speed. The wind vibration coefficients of the downwind and vertical displacements achieved maximum values at U=8 m/s, and the values were 2.11 and 1.98. The research can provide reference for wind-resistant design of similar photovoltaic structures.