| Compared with fossil-fuel energy and nuclear energy, the wind energy has the advantages, such as lower development cost, safety, clean environment, renewable, etc. Wind energy is paid more and more attention around the world because of its renewable.With the wind turbine developing toward to the large or extra large power direction, the wind turbine components also will be large. Therefore, the pitch hydraulic system which is very suitable for the system of large loads, large inertia will be widely used in the wind turbine. Hydraulic pitch control system determines the quality of the dynamic characteristics of the pitch process control effect, its simulation analysis is essential; while the hub and the tower are important components of the wind turbine and the load-bearing components, but also the key components of weight concentrated in the entire wind turbine, if they can meet the strength and stiffness of conditions, to reduce its weight can effectively reduce the cost of wind turbines for wind power companies to make a useful attempt to improve economic efficiency.Firstly, this paper reviews the current situation and development trend in the wind power at home and abroad, presented the purpose and significance of the research; outlines the wind turbine components and working principle, deduced theoretical wind energy utilization coefficient, defined the relationship between the wind energy utilization coefficient and pitch angle based on Betz theory and blade element momentum theory; also gives the blade aerodynamic calculation model and the specific calculation method for the hub and tower, then, did a good theoretical preparation for the load calculations of the hub and tower under a variety of wind.Secondly, this treatise elaborated hydraulic pitch mechanism working principle of variable pitch, analyzed and explained the hydraulic system working process of the variable pitch; finally, carried out simulation for the variable pitch hydraulic system based on SimHydraulics module in the MATLAB-Simulink and got the dynamic analysis results.Finally, the thesis calculated aerodynamic load of the wind turbine blade and fit the load data, obtained the hub and tower loads under various wind; subsequent modeled hub and tower and carried out static analysis, modal analysis in the ANSYS; Finally, the hub and the tower were implemented topology optimization and structural optimization respectively at the limit load, then we obtained two kinds of methods to lose weight:variable thickness and drilling based on the topology optimization of the hub, and then implemented a quality optimization for the hub. At last, tower is conducted on the weight of the objective function to optimize the quality, also achieved a better weight loss purposes. |
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