| With the world’s energy and environmental problems have become more andmore serious, the development and utilization of renewable energy in the worldbecomes urgent. Among all kinds of renewable energy, wind energy is the mostwidely used and fastest growing. As the supporting structure of wind turbines, thetower under all kinds of loads, for which it affects the stability and reliability of windturbines directly. The tower’s cost is high, its manufacturing costs accounted for about15%-20%of the whole cost, and the transportation and installation costs also take alarge proportion. And with the increase of unit capacity of wind turbine, tower heightincreasing, the contradiction between cost and performance of the tower is more andmore serious, which limit the promotion and application of wind power technology insome extent. Therefore, in this paper, a research on structure parameter optimizationof wind turbine tower is carried out considering the tower’s t cost and performance,The research results will have a positive significance on reducing the cost of windturbines and improving the market competitiveness of enterprises. The main contentsand results are as follows:The FEA model of wind turbine tower are established and analyzed. Based on theBEM theory, the FE model of wind turbine tower are established. Then static analysisin extreme loads、modal analysis、transient dynamic analysis and harmonic responseanalysis are made. At last, the tower stress distribution under extreme load, thedynamic natural frequency of tower and the response characteristics under randomloading are obtained.The relationship model between the wind turbine tower structure parameters andstress、the top offset and natural frequency are built. A finite element experiment withsingle factor varied and the mixed experimental design methods which combine theorthogonal experimental with the random combination method to get differentstructure parameters combination had done to obtain the stress、the top offset andnatural frequency. The SVM and BP neural network methods are used to establish themodel between tower structure parameters and maximum stress、 top offset andfirst-order natural frequency to solve the time-consuming problem in the process ofoptimization.Multi-objective optimization of wind turbine tower structure parameters. A multi-objective optimization model was established as the minimum tower mass andthe top offset are selected to be the optimization goal; the strength, natural frequencyand the boundary conditions are selected to be the constraint conditions consideringthe cost and performance of the tower. The NSGA-II algorithm is introduced tooptimize structure parameters. The optimization results show that the quality reducedabout4%of the tower, the cost has been reduced, the maximum stress decreases, thetower natural frequency increase, the performance have improved.The experimental study of wind turbine tower. A vibration test research of a2MW wind turbine tower was took, the relationships between wind speed, speed andvibration of tower was obtained by analyzing the vibration data of the SCADA systemof wind turbine. Then, the results between data analysis and the finite elementdynamic analysis is compared, it shows that the FEM model is right. A stress testresearch of a2kW wind turbine tower was took, the finite element model of the towerwas used to reverse the wind wheel thrust, the relationship between wind speed andwind wheel thrust and thrust coefficient are obtained, which extended the applicationof the finite element model of the tower. |
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