为满足直流微电网内各电源协调运行的需要,本文提出了一种新的切换策略,使光伏控制器能够在最大功率跟踪(maximum power point tracking,MPPT)和恒压控制(constant voltage control,CVC)模式之间平稳地运行。在这两种模式下,光伏控制器...为满足直流微电网内各电源协调运行的需要,本文提出了一种新的切换策略,使光伏控制器能够在最大功率跟踪(maximum power point tracking,MPPT)和恒压控制(constant voltage control,CVC)模式之间平稳地运行。在这两种模式下,光伏控制器始终作为电压源被控制,其控制变量均为光伏阵列的输出电压。该方法将MPPT与母线电压调整策略相结合,无需通信,无需改变硬件结构和控制参数,从而保证了光伏控制器在两种模式之间的无缝切换。最后,建立了一个由光伏机组、直流负载和储能组成的基本直流组网系统,对所提出的控制策略进行性能测试。结果表明,与传统控制策略相比,所提出的无缝切换控制策略获得了更好的暂态特性。展开更多
Morphing wing has attracted many research attention and effort in aircraft technology development because of its advantage in lift to draft ratio and flight performance.Morphing wing technology combines the lift and c...Morphing wing has attracted many research attention and effort in aircraft technology development because of its advantage in lift to draft ratio and flight performance.Morphing wing technology combines the lift and control surfaces into a seamless wing and integrates the primary structure together with the internal control system.It makes use of the wing aeroelastic deformation induced by the control surface to gain direct force control through desirable redistribution of aerodynamic forces.However some unknown mechanical parameters of the control system and complexity of the integrated structure become a main challenge for dynamic modeling of morphing wing.To solve the problem,a method of test data based modal sensitivity analysis is presented to improve the morphing wing FE model by evaluating the unknown parameters and identifying the modeling boundary conditions.An innovative seamless morphing wing with the structure integrated with a flexible trailing edge control system is presented for the investigation.An experimental model of actuation system driven by a servo motor for the morphing wing is designed and established.By performing a vibration test and the proposed modal sensitivity analysis,the unknown torsional stiffness of the servo motor and the boundary condition of the actuation mechanism model is identified and evaluated.Comparing with the test data,the average error of the first four modal frequency of the improved FE model is reduced significantly to less than 4%.To further investigate the morphing wing modeling,a wing box and then a whole morphing wing model including the skin and integrated with the trailing edge actuation system are established and tested.By using the proposed method,the FE model is improved by relaxing the constraint between the skin and actuation mechanism.The results show that the average error of the first three modal frequency of the improved FE model is reduced to less than 6%.The research results demonstrate that the presented seamless morphing wing integrated with a flexible trailing edge control surface can improve aerodynamic characteristics.By using the test data based modal sensitivity analysis method,the unknown parameter and boundary condition of the actuation model can be determined to improve the FE model.The problem in dynamic modeling of high accuracy for a morphing wing can be solved in an effective manner.展开更多
文摘为满足直流微电网内各电源协调运行的需要,本文提出了一种新的切换策略,使光伏控制器能够在最大功率跟踪(maximum power point tracking,MPPT)和恒压控制(constant voltage control,CVC)模式之间平稳地运行。在这两种模式下,光伏控制器始终作为电压源被控制,其控制变量均为光伏阵列的输出电压。该方法将MPPT与母线电压调整策略相结合,无需通信,无需改变硬件结构和控制参数,从而保证了光伏控制器在两种模式之间的无缝切换。最后,建立了一个由光伏机组、直流负载和储能组成的基本直流组网系统,对所提出的控制策略进行性能测试。结果表明,与传统控制策略相比,所提出的无缝切换控制策略获得了更好的暂态特性。
基金supported by National Natural Science Foundation of China (Grant No. 11102019)
文摘Morphing wing has attracted many research attention and effort in aircraft technology development because of its advantage in lift to draft ratio and flight performance.Morphing wing technology combines the lift and control surfaces into a seamless wing and integrates the primary structure together with the internal control system.It makes use of the wing aeroelastic deformation induced by the control surface to gain direct force control through desirable redistribution of aerodynamic forces.However some unknown mechanical parameters of the control system and complexity of the integrated structure become a main challenge for dynamic modeling of morphing wing.To solve the problem,a method of test data based modal sensitivity analysis is presented to improve the morphing wing FE model by evaluating the unknown parameters and identifying the modeling boundary conditions.An innovative seamless morphing wing with the structure integrated with a flexible trailing edge control system is presented for the investigation.An experimental model of actuation system driven by a servo motor for the morphing wing is designed and established.By performing a vibration test and the proposed modal sensitivity analysis,the unknown torsional stiffness of the servo motor and the boundary condition of the actuation mechanism model is identified and evaluated.Comparing with the test data,the average error of the first four modal frequency of the improved FE model is reduced significantly to less than 4%.To further investigate the morphing wing modeling,a wing box and then a whole morphing wing model including the skin and integrated with the trailing edge actuation system are established and tested.By using the proposed method,the FE model is improved by relaxing the constraint between the skin and actuation mechanism.The results show that the average error of the first three modal frequency of the improved FE model is reduced to less than 6%.The research results demonstrate that the presented seamless morphing wing integrated with a flexible trailing edge control surface can improve aerodynamic characteristics.By using the test data based modal sensitivity analysis method,the unknown parameter and boundary condition of the actuation model can be determined to improve the FE model.The problem in dynamic modeling of high accuracy for a morphing wing can be solved in an effective manner.
