不同风速谱激励下的风力发电机塔架风致响应及风振系数研究

Wind Vibration Response and Wind Vibration Coefficient of Wind Turbine Tower Under Different Wind Speed Spectrum Excitation

为研究不同风速谱激励下,风力发电机塔架的风致响应,建立某兆瓦级风力发电机一体化有限元模型,基于经典随机振动理论对其进行风荷载作用下随机振动分析。得到了几种典型风速谱激励下风力发电机塔架位移响应功率谱密度。分析了不同风速谱激励对风力发电机风致脉动响应影响。根据Davenport峰因子取值法,讨论了不同保证率下的峰因子对风振系数的影响关系。主要结论有:不同风速谱激励下,风力发电机第1、4、5振型被激发;风机塔架作为典型的高耸结构,其风致响应以一阶振型为主振型;基于Simiu谱激励下,风力发电机塔架PSD曲线峰值最大,计算得到的风振系数最大;对于峰因子取值,当风压时距T=600 s,我国规范考虑一定跨越概率建议取值为μ=2.50;由Davenport近似公式计算得到的峰因子为μ=3.25,由此计算得到的风振系数相对安全。

In order to analyze the wind-induced response of wind turbine tower under different wind speed spectrum excitation,a finite element model of megawatt wind turbine was established,and the random vibration analysis under wind load was carried out based on random vibration theory.The power spectral density of wind turbine tower displacement response under several typical wind speed spectrum excitation is obtained.Then,according to the peak factor value method,the influence of peak factor on wind vibration coefficients under different guarantee rates is discussed.The main conclusions are as follows.Under the excitation of different wind speed spectrum,the first,fourth and fifth vibration modes of wind turbine are excited.As a typical high-rise structure,the wind-induced response of wind turbine tower is mainly the first-order mode.Under the excitation of Simiu spectrum,the peak value of PSD curve of wind turbine tower is the largest,and the calculated wind vibration coefficient is the largest.For the value of Peak factor,when the time interval of wind pressure is 600 s,the recommended value of China’s code is 2.50,and the wind factor calculated by Davenport’s approximate formula is 3.25,and the wind-induced vibration coefficient calculated by the latter is relatively safe.