EFFECTS OF OPERATING CONDITIONS ON THE SEISMIC RESPONSE OF WIND TURBINES

Aerodynamic loading of wind turbines can be divided into aerodynamic damping and dynamic loading which have damping effect and dynamic effect on the seismic response of structures, respectively. A theoretical model is set up for analyzing the regularities and mechanism of how operating conditions affect the seismic response of wind turbine considering the running and parked conditions. The dynamic response of wind turbines is analyzed using FAST software under different wind-earthquake combinations for NREL baseline 5 MW wind turbines to validate the findings obtained in the theoretical model. The effects of input earthquake direction on the seismic response of wind turbines are analyzed. The results show that the effect of operating condition on the dynamic response of wind turbines depends on the seismic amplitude and wind speed. The most unfavorable load combination is seismic excitation in parked condition under strong ground motions. When the seismic action is weaker, it is the rated wind speed-design seismic action combination. The incident angle of earthquake waves significantly affects the dynamic response of wind turbines.