大型风力机地震动力响应研究

Research on Dynamic Response of Large-scale Wind Turbine on Seismic Condition

为研究地震载荷与风载荷联合作用下的大型风力机结构动力学响应,本文研究分别以Wind PACT 1.5 MW和NREL 5 MW风力机为研究对象,采用EI Centro 6.9级地震为输入激励,通过改进版的开源软件FAST(风电载荷仿真软件)计算风力机在正常运行、紧急停机和一直停机3种运行方式下的塔顶振动和塔架结构荷载情况,结果表明:地震载荷极大加剧了塔顶振动,机舱加速度峰值增大2倍以上。紧急停机操作可减小塔尖位移,一定程度上可以保护风力机结构安全。地震载荷主要增大了塔架一阶固有频率及其二倍频的振动。6.9级地震与额定风载荷联合作用下,NREL 5MW风力机塔基弯矩设计需求为159 MN·m,略大于极限风载荷作用。说明地震常发地区,塔架结构强度设计必须考虑地震载荷作用。

To investigate the structural dynamic responses of large-scale wind turbines under the conditions of the coupled load of earthquake and turbulent wind,EI Centro seismic motion was applied to Wind PACT 1. 5 MW and NREL 5 MW wind turbines,and the vibration characteristics and loading of the tower at running,emergency shutdown andparked operating conditions were carried out by using the improved FAST program. The results showed that earthquake load increases the peak of nacelle acceleration above 2 times at running condition. Emergency shutdown can keep structural safety partly by decreasing the displacement of tower tip. The vibration frequencies of tower are the first order natural frequency and the double frequency at seismic condition. The tower-base bending moment demand of NREL 5 MW is 159 MN·m on EI Centro earthquake load and rated aerodynamic load condition,which is greater than extreme turbulent condition. It suggests that for large-scale wind turbines in regions of high seismic hazard,the effect of earthquake load is important to consider for the structural strength design of tower.