风力发电高塔系统阵风荷载因子法

Gust loading factor method for a wind turbine system

给出了风力发电高塔系统阵风荷载因子法。与传统的阵风荷载因子法不同的是,因桨叶/塔体相互作用的存在,风力发电高塔系统阵风荷载因子包含两项共振分量。一般地,风力发电高塔系统包含桨叶和塔体两个子结构,每个子结构都可视为单自由度体系,二者耦合在一块构成两自由度体系。因桨叶和塔体自振频率可能相近,系统响应的共振分量包含了桨叶/塔体耦合系统前两阶振型的贡献。为获得风力发电高塔系统阵风荷载因子的准确值,给出了塔顶位移和基底弯矩阵风荷载因子数值解以及塔顶位移阵风荷载因子精确解。同时,针对桨叶不同转速给出了一系列考虑桨叶/塔体耦合的两自由度体系阵风荷载因子,并与不考虑桨叶/塔体耦合的单自由度体系阵风荷载因子比较,两者有一定的区别。

A method based on gust loading factor(GLF) for evaluating along-wind response of a wind turbine system was proposed.The approach presented was different from conventional GLF methods as the GLF contained contributions from two resonant modes,mainly due to blade/tower interaction effects.The wind turbine system model considered here contained two interconnected flexible subsystems,the tower and the blade rotor ones.Each component was initially modeled as a single degree-of-freedom(DOF) system,and these were coupled together to form a two DOF reduced order model of the coupled blade/ tower system.Thus,the resonant components of the response contained energy output from the two modes of the coupled system.The GLFs were obtained for both tower tip displacement and base bending moment through numerical integration,and a closed form soultion to the former was also obtained.A series of numerical examples were given to investigate the magnitude of GLFs obtained for the two DOF assembly which allowed blade/tower interaction,and these were compared with GLF values obtained from a single DOF model which ignored blade/tower interaction.