Wind turbines undergo degradation due to various factors which induce stress, thereby leading to fatigue damage to various wind turbine components. In addition, the current increase in demand for electrical power has ...Wind turbines undergo degradation due to various factors which induce stress, thereby leading to fatigue damage to various wind turbine components. In addition, the current increase in demand for electrical power has led to the development of large wind turbines, which result in increased structural loads, therefore, increasing the possibility of early failure due to fatigue load. This paper proposes a proportional integral observer (PI-Observer) based disturbance accommodation controller (DAC) with individual pitch control (IPC) for load mitigation to reduce components’ damage and ensure the wind turbine is operational for the expected lifetime. The results indicate a reduction in blades’ bending moments with a standard deviation of 15.9%, which positively impacts several other wind turbine subsystems. Therefore, the lifetime control strategy demonstrates effective structural load mitigation without compromise on power generation, thus, achieving a nominal lifetime control to inhibit premature failure.展开更多
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
In the traditional distributed consensus of multi-vehicle systems, vehicles agree on velocity and position using limited information exchange in their local neighborhoods. Recently, distributed leaderless stationary c...In the traditional distributed consensus of multi-vehicle systems, vehicles agree on velocity and position using limited information exchange in their local neighborhoods. Recently, distributed leaderless stationary consensus has been proposed in which vehicles agree on a position and come to a stop. The proposed stationary consensus schemes are based on all vehicles' access to their own absolute velocity measurements, and they do not guarantee this collective behavior in the presence of disturbances that persistently excite vehicles' dynamics. On the other hand, traditional distributed disturbance rejection leaderless consensus algorithms may result in an uncontrolled increase in the speed of multi-vehicle system. In this paper, we propose a dynamic relative-output feedback leaderless stationary algorithm in which only a few vehicles have access to their absolute measurements. We systematically design the distributed algorithm by transforming this problem into a static feedback robust control design challenge for the low-order modified model of vehicles with fictitious modeling uncertainties. We further propose dynamic leader-follower stationary consensus algorithms for multi-vehicle systems with a static leader, and find closed-form solutions for the consensus gains based on design matrices and communication graph topology. Finally, we verify the feasibility of these ideas through simulation studies.展开更多
文摘Wind turbines undergo degradation due to various factors which induce stress, thereby leading to fatigue damage to various wind turbine components. In addition, the current increase in demand for electrical power has led to the development of large wind turbines, which result in increased structural loads, therefore, increasing the possibility of early failure due to fatigue load. This paper proposes a proportional integral observer (PI-Observer) based disturbance accommodation controller (DAC) with individual pitch control (IPC) for load mitigation to reduce components’ damage and ensure the wind turbine is operational for the expected lifetime. The results indicate a reduction in blades’ bending moments with a standard deviation of 15.9%, which positively impacts several other wind turbine subsystems. Therefore, the lifetime control strategy demonstrates effective structural load mitigation without compromise on power generation, thus, achieving a nominal lifetime control to inhibit premature failure.
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.
文摘In the traditional distributed consensus of multi-vehicle systems, vehicles agree on velocity and position using limited information exchange in their local neighborhoods. Recently, distributed leaderless stationary consensus has been proposed in which vehicles agree on a position and come to a stop. The proposed stationary consensus schemes are based on all vehicles' access to their own absolute velocity measurements, and they do not guarantee this collective behavior in the presence of disturbances that persistently excite vehicles' dynamics. On the other hand, traditional distributed disturbance rejection leaderless consensus algorithms may result in an uncontrolled increase in the speed of multi-vehicle system. In this paper, we propose a dynamic relative-output feedback leaderless stationary algorithm in which only a few vehicles have access to their absolute measurements. We systematically design the distributed algorithm by transforming this problem into a static feedback robust control design challenge for the low-order modified model of vehicles with fictitious modeling uncertainties. We further propose dynamic leader-follower stationary consensus algorithms for multi-vehicle systems with a static leader, and find closed-form solutions for the consensus gains based on design matrices and communication graph topology. Finally, we verify the feasibility of these ideas through simulation studies.