运行状态风力机地震响应的解耦分析方法

对于运行状态的风力发电机,其地震响应涉及风荷载与地震的联合激励。为建立风-地震共同作用下风力机动力响应的解耦分析方法,该文基于最小二乘法,建立水平轴风力机模态气动阻尼比简化模型;将叶轮气动阻力以等效阻尼比施加于支撑结构,形成风力机地震响应的解耦分析方法,与耦合方法模拟结果进行比较,验证解耦方法的可靠性。结果表明:双线性模型能够准确模拟风力机模态气动阻尼比随轮毂高度处10 min平均风速变化的规律,解耦方法得到的风力机塔顶加速度和塔底弯矩峰值与耦合方法所得结果的误差不超过15%,同时,解耦方法的计算效率也高于耦合方法。

UNCOUPLED ANALYSIS METHOD FOR SEISMIC RESPONSE OF WIND TURBINES IN THE OPERATIONAL CONDITION

For the wind tubrines in their running conditions, their seismic responses involve the combined excitation of wind and earthquake loadings. In order to establish an uncoupled analysis method for the dynamic response of wind turbines excited by wind and earthquake, a bilinear simplified model for the aerodynamic damping ratios of horizontal-axis wind turbines was established by the least square method first. An uncoupled seismic response analysis method was built up where the aerodynamic damping forces on the rotor were replaced by equivalent modal aerodynamic damping ratios added to the support structure. The simulation results of this uncoupled method were compared with those of the coupled one to evaluate the reliability of this decoupled model. The analysis result indicates that the bilinear model can describe the regularity of modal aerodynamic damping ratios with respect to mean wind speed at the hub-height. Both errors of tower-top acceleration amplitudes and tower-base bending moment amplitudes obtained by the uncoupled and coupled method are less than 15 %. In addition, the computational efficiency of this uncoupled method is higher than that of the coupled one.