scholarly journals Flap/Lag Stall Flutter Control of Large-Scale Wind Turbine Blade Based on Robust H2Controller

2016 ◽  
Vol 2016 ◽  
pp. 1-15 ◽  
Author(s):  
Tingrui Liu ◽  
Wei Xu

Flap/lag stall nonlinear flutter and active control of anisotropic composite wind turbine blade modeled as antisymmetric beam analysis have been investigated based on robust H2controller. The blade is modeled as single-cell thin-walled beam structure, exhibiting flap bending moment-lag transverse shear deformation, and lag bending moment-flap transverse shear deformation, with constant pitch angle set. The stall flutter control of dynamic response characteristics of composite blade incorporating nonlinear aerodynamic model is investigated based on some structural and dynamic parameters. The aeroelastic partial differential equations are reduced by Galerkin method, with the aerodynamic forces decomposed by strip theory. Robust H2optimal controller is developed to enhance the vibrational behavior and dynamic response to aerodynamic excitation under extreme wind conditions and stabilize structures that might be damaged in the absence of control. The effectiveness of the control algorithm is demonstrated in both amplitudes and frequencies by description of time responses, extended phase planes, and frequency spectrum analysis, respectively.

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
Ki-Hak Lee ◽  
Kyu-Hong Kim ◽  
Dong-Ho Lee ◽  
Kyung-Tae Lee ◽  
Jong-Po Park

A horizontal-axis wind turbine blade is designed using two step optimization procedures with probability approach. For the efficient management of the multiple design variables required for the blade design, the design procedure is divided into two optimization steps. In step 1, the diameter and rotating speed of a blade are determined and design points are extracted from the design space. In step 2-1, blade shapes are optimized by using the strip theory with the minimum energy loss method. The capacity factor and the cost model for each optimized blade shape are calculated in steps 2-2 and 2-3, respectively. To find the global optimum point in the design space, the space is modified into a highly possible region through the use of the probability approach.


2020 ◽  
Vol 155 ◽  
pp. 358-368 ◽  
Author(s):  
Jin Xu ◽  
Lei Zhang ◽  
Xue Li ◽  
Shuang Li ◽  
Ke Yang

2010 ◽  
Vol 3 (2) ◽  
Author(s):  
Sulistyo Atmadi ◽  
Firman Hartono

Structure of the LPN 10000 E wind turbine blade has been manufactured and its structural analysis to find out the strenght of this structure during its operation has also been conducted. The method of aero bending moment and centrifugal bending moment and load has been used while neglegting frcitional and torsional load. The analysis is obtained for composite blade strengthened by high strength carbon unidirectional reinforcement composite. With safety factor of 1.3 minimum, it was concluded that the blade is strong enough to use at its designed operational load.


Author(s):  
Jianping Zhang ◽  
Kaige Zhang ◽  
Aixi Zhou ◽  
Tingjun Zhou ◽  
Danmei Hu ◽  
...  

In this paper, the entity model of a 1.5 MW offshore wind turbine blade was built by Pro/Engineer software. Fluid flow control equations described by arbitrary Lagrange–Euler (ALE) were established, and the theoretical model of geometrically nonlinear vibration characteristics under fluid–structure interaction (FSI) was given. The simulation of offshore turbulent wind speed was achieved by programming in Matlab. The brandish displacement, the Mises stress distribution and nonlinear dynamic response curves were obtained. Furthermore, the influence of turbulence and FSI on blade dynamic characteristics was studied. The results show that the response curves of maximum brandish displacement and maximum Mises stress present the attenuation trends. The region of the maximum displacement and maximum stress and their variations at different blade positions are revealed. It was shown that the contribution of turbulence effect (TE) on displacement and stress is smaller than that of the FSI effect, and its extent of contribution is related to the relative span length. In addition, it was concluded that the simulation considering bidirectional FSI (BFSI) can reflect the vibration characteristics of wind turbine blades more accurately.


2018 ◽  
Vol 140 (4) ◽  
Author(s):  
Mennatullah M. Abdel Hafeez ◽  
Ayman A. El-Badawy

This work presents a new aeroelastic model that governs the extensional, chordwise, flapwise, and torsional vibrations of an isolated horizontal axis wind turbine blade. The model accounts for the sectional offsets between the shear, aerodynamic, and mass centers. The centrifugal stiffening effects are also accounted for by including nonlinear strains based on an ordering scheme that retains terms up to second-order. Aerodynamic loading is derived based on a modified Theodorsen's theory adapted to account for the blade rotational motion. A set of four coupled nonlinear partial differential equations are derived using the Hamiltonian approach that are then linearized about the steady-state extensional position. The finite element method (FEM) is then employed to spatially discretize the resulting equations with the aim of obtaining an approximate solution to the blade's dynamic response, utilizing state space techniques and complex modal analysis. Investigation of the blade's flutter stability limit is carried out. Effects of parameters such as wind speed and blade sectional offsets on the flutter limit and dynamic response are also investigated.


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