A gain-scheduled feedforward controller, based on pseudo-LIDAR （light detection and ranging） wind speed measurement, is designed to augment the baseline feedback controller for wind turbine＇s load reduction in abov...A gain-scheduled feedforward controller, based on pseudo-LIDAR （light detection and ranging） wind speed measurement, is designed to augment the baseline feedback controller for wind turbine＇s load reduction in above rated operation. The pseudo-LIDAR measurement data are generated from a commercial software- Bladed using a designed sampling strategy. The nonlinear wind turbine model has been simplified and linearised at a set of equilibrium operating points. The feedforward controller is firstly developed based on a linearised model at an above rated wind speed, and then expanded to the full above rated operational envelope by employing gain scheduling strategy. The combined feedforward and baseline feedback control is simulated on a 5MW industrial wind turbine model. Simulation studies demonstrate that the proposed control strategy can improve the rotor and tower load reduction performance for large wind turbines.展开更多
The optimal control is investigated for linear systems affected by external harmonic disturbance and applied to vibration control systems of offshore steel jacket platforms. The wave-induced force is the dominant load...The optimal control is investigated for linear systems affected by external harmonic disturbance and applied to vibration control systems of offshore steel jacket platforms. The wave-induced force is the dominant load that offshore structures are subjected to, and it can be taken as harmonic excitation for the system. The linearized Morison equation is employed to estimate the wave loading. The main result concerns the existence and design of a realizable optimal regulator, which is proposed to damp the forced oscillation in an optimal fashion. For demonstration of the effectiveness of the control scheme, the platform performance is investigated for different wave states. The simulations are based on the tuned mass damper and the active mass damper control devices. It is demonstrated that the control scheme is useful in reducing the displacement response of jacket-type offshore platforms.展开更多
并联型有源电力滤波器(parallel active power filter,PAPF)存在着常规控制和直流侧电压反馈控制两种典型控制方式,但是对于两者之间的内在关联尚缺乏较深入的研究。该文对基于"p-q"理论的并联型APF常规控制进行等效和演化,...并联型有源电力滤波器(parallel active power filter,PAPF)存在着常规控制和直流侧电压反馈控制两种典型控制方式,但是对于两者之间的内在关联尚缺乏较深入的研究。该文对基于"p-q"理论的并联型APF常规控制进行等效和演化,通过数学推导发现:常规控制方法可认为是在直流侧电压反馈的基础上加入了负载基波电流前馈;且不同补偿目标下,前馈电流的成分也不同,可能是全部的负载基波电流,也可能是其中的有功分量。此外,在常规控制策略中的前馈作用和反馈作用大小也存在差别。最后,仿真和实验结果验证了上述分析的正确性。该研究对于理解和把握并联型APF的控制机制具有较重要的参考价值。展开更多
基金supported by UK Engineering and Physical Sciences Research Council(EPSRC)Supergen Wind project(No.EP/N006224/1)
文摘A gain-scheduled feedforward controller, based on pseudo-LIDAR （light detection and ranging） wind speed measurement, is designed to augment the baseline feedback controller for wind turbine＇s load reduction in above rated operation. The pseudo-LIDAR measurement data are generated from a commercial software- Bladed using a designed sampling strategy. The nonlinear wind turbine model has been simplified and linearised at a set of equilibrium operating points. The feedforward controller is firstly developed based on a linearised model at an above rated wind speed, and then expanded to the full above rated operational envelope by employing gain scheduling strategy. The combined feedforward and baseline feedback control is simulated on a 5MW industrial wind turbine model. Simulation studies demonstrate that the proposed control strategy can improve the rotor and tower load reduction performance for large wind turbines.
文摘The optimal control is investigated for linear systems affected by external harmonic disturbance and applied to vibration control systems of offshore steel jacket platforms. The wave-induced force is the dominant load that offshore structures are subjected to, and it can be taken as harmonic excitation for the system. The linearized Morison equation is employed to estimate the wave loading. The main result concerns the existence and design of a realizable optimal regulator, which is proposed to damp the forced oscillation in an optimal fashion. For demonstration of the effectiveness of the control scheme, the platform performance is investigated for different wave states. The simulations are based on the tuned mass damper and the active mass damper control devices. It is demonstrated that the control scheme is useful in reducing the displacement response of jacket-type offshore platforms.
文摘并联型有源电力滤波器(parallel active power filter,PAPF)存在着常规控制和直流侧电压反馈控制两种典型控制方式,但是对于两者之间的内在关联尚缺乏较深入的研究。该文对基于"p-q"理论的并联型APF常规控制进行等效和演化,通过数学推导发现:常规控制方法可认为是在直流侧电压反馈的基础上加入了负载基波电流前馈;且不同补偿目标下,前馈电流的成分也不同,可能是全部的负载基波电流,也可能是其中的有功分量。此外,在常规控制策略中的前馈作用和反馈作用大小也存在差别。最后,仿真和实验结果验证了上述分析的正确性。该研究对于理解和把握并联型APF的控制机制具有较重要的参考价值。
