以 10 MW固定式海上风机为研究对象,建立了风-浪-地震-故障海上风机整体耦合模型,模拟了发电机断网引发故障停机的过程,利用时频分析方法探究了该过程中海上风机结构响应机理.结果表明,风浪作用时结构响应的控制频率为风频和波频;地震作用时结构响应显著增加,海上风机的二阶频率成为控制频率;故障停机时结构响应进一步增大,顺桨停机显著激发了海上风机的基频,揭示了海上风机结构的安全性设计应充分考虑此类故障停机情况.
Taking the 10 MW fixed offshore wind turbine as research object a wind-wave-seismic-fault coupled model of offshore wind turbine is established to simulate the fault shutdown process caused by generator disconnection from electrical network.The dynamic response mechanism of the offshore wind turbine during the fault shutdown process is investigated by the time-frequency analysis method.The results show that (a) the control frequencies of structural response under wind and wave action are wind frequency and wave frequency; (b) the structural response significantly increases under seismic action and the second-order frequency of the offshore wind turbine becomes the control frequency ;and (c) during fault shutdown the structural response further increases and the blade pitch-to-feather shutdown significantly stimulates the fundamental frequency of the offshore wind turbine revealing that the safety design of offshore wind turbine structures should fully consider such fault shutdown situation.