The asymmetric or periodically varying blade loads resulted by wind shear become more significant as the blade length is increased to capture more wind power.Additionally,compared with the onshore wind turbines,their ...The asymmetric or periodically varying blade loads resulted by wind shear become more significant as the blade length is increased to capture more wind power.Additionally,compared with the onshore wind turbines,their offshore counterparts are subjected to additional wave loadings in addition to wind loadings within their lifetime.Therefore,vibration control and fatigue load mitigation are crucial for safe operation of large-scale offshore wind turbines.In view of this,a multi-body model of an offshore bottom-fixed wind turbine including a detailed drivetrain is established in this paper.Then,an individual pitch controller(IPC)is designed using disturbance accommodating control.State feedback is used to add damping in flexible modes of concern,and a state estimator is designed to predict unmeasured signals.Continued,a coupled aero-hydro-servo-elastic model is constructed.Based on this coupled model,the load reduction effect of IPC and the dynamic responses of the drivetrain are investigated.The results showed that the designed IPC can effectively reduce the structural loads of the wind turbine while stabilizing the turbine power out-put.Moreover,it is found that the drivetrain dynamic responses are improved under IPC.展开更多
For the offshore wind turbines installed in earthquake areas,their operation is affected by seismic loads in addition to wind and wave loads.Therefore,it is necessary to study the dynamic responses and vibration contr...For the offshore wind turbines installed in earthquake areas,their operation is affected by seismic loads in addition to wind and wave loads.Therefore,it is necessary to study the dynamic responses and vibration control of the wind turbines.In previous studies,the structural responses of offshore wind turbines are usually investigated in the parked case,while the blade rotation effect is usually not considered.The evaluation on the structural responses may be inaccurate under this condition,further affecting the evaluation on the vibration control performance of a control system.In view of it,this paper established a complete multi-body model of a fixed-bottom offshore wind turbine considering pile-soil interaction,and then performed simulations when the wind turbine was subjected to multiple external excitations.Continued,a single tuned mass damper(STMD)system and a multiple tuned mass dampers(MTMDs)system were applied to control structural vibrations of the wind turbine.Then,based on the construction of a simplified main structure-TMD system,TMD parameters were optimized.Finally,twelve load cases including operating and parked conditions were selected to perform simulations.Results show that the influence of the seismic excitation on blade responses is greater under the parked condition than that under the operating condition.Moreover,STMD/MTMDS exhibit better performance under the parked condition than that under the operating condition.Compared with STMD,MTMDS can better suppress the vibrations at both the fundamental and high-order modes,and exhibits significant robustness under the condition of changing soil parameters.展开更多
基金This paper is financially supported by the Scientific Research Foundation of Chongqing University of Technology(Grant Nos.2020ZDZ023 and 2019ZD124)the Project of Science and Technology Research Program of Chongqing Education Commission of China(Grant No.KJQN202101133)the National Natural Science Foundation Cultivation Program of Chongqing University of Technology(Grant No.2021PYZ14).
文摘The asymmetric or periodically varying blade loads resulted by wind shear become more significant as the blade length is increased to capture more wind power.Additionally,compared with the onshore wind turbines,their offshore counterparts are subjected to additional wave loadings in addition to wind loadings within their lifetime.Therefore,vibration control and fatigue load mitigation are crucial for safe operation of large-scale offshore wind turbines.In view of this,a multi-body model of an offshore bottom-fixed wind turbine including a detailed drivetrain is established in this paper.Then,an individual pitch controller(IPC)is designed using disturbance accommodating control.State feedback is used to add damping in flexible modes of concern,and a state estimator is designed to predict unmeasured signals.Continued,a coupled aero-hydro-servo-elastic model is constructed.Based on this coupled model,the load reduction effect of IPC and the dynamic responses of the drivetrain are investigated.The results showed that the designed IPC can effectively reduce the structural loads of the wind turbine while stabilizing the turbine power out-put.Moreover,it is found that the drivetrain dynamic responses are improved under IPC.
基金sponsored by the Scientific Research Foundation of Chongqing University of Technology (Grant No. 2020ZDZ023)the Project of Science and Technology Research Program of Chongqing Education Commission of China (Grant No. KJQN202101133)+2 种基金the National Natural Science Foundation Cultivation Program of Chongqing University of Technology (Grant No.2021PYZ14)Shanghai Engineering Research Center of Marine Renewable Energy (Grant No. 19DZ2254800)the Science and Technology Research Program of Chongqing Municipal Education Commission (Grant No. KJQN201805801)
文摘For the offshore wind turbines installed in earthquake areas,their operation is affected by seismic loads in addition to wind and wave loads.Therefore,it is necessary to study the dynamic responses and vibration control of the wind turbines.In previous studies,the structural responses of offshore wind turbines are usually investigated in the parked case,while the blade rotation effect is usually not considered.The evaluation on the structural responses may be inaccurate under this condition,further affecting the evaluation on the vibration control performance of a control system.In view of it,this paper established a complete multi-body model of a fixed-bottom offshore wind turbine considering pile-soil interaction,and then performed simulations when the wind turbine was subjected to multiple external excitations.Continued,a single tuned mass damper(STMD)system and a multiple tuned mass dampers(MTMDs)system were applied to control structural vibrations of the wind turbine.Then,based on the construction of a simplified main structure-TMD system,TMD parameters were optimized.Finally,twelve load cases including operating and parked conditions were selected to perform simulations.Results show that the influence of the seismic excitation on blade responses is greater under the parked condition than that under the operating condition.Moreover,STMD/MTMDS exhibit better performance under the parked condition than that under the operating condition.Compared with STMD,MTMDS can better suppress the vibrations at both the fundamental and high-order modes,and exhibits significant robustness under the condition of changing soil parameters.
