Aerodynamic And Structure Design Technology For 1.5MW Variable Speed Wind Turbine

Aimed at the configuration and operation characteristic of the modern large-scale horizontalaxis wind turbine, combining the external environment and the international standards of windturbine design, the load analysis method of the whole wind turbine system is studied in this.Applying the result of system load analysis and finite element numeric analysis, taking 1.5MWvariable speed constant frequency wind turbine as investigation subject, the analysis method ofthe large-scale wind turbine dynamic response, intensive analysis and fatigue computationcaused by the aerodynamic load and mechanical load are investigated. In the thesis, four partsare mainly included: system-load computing method of wind turbine, blades' three-dimensionalsolid modeling and modal analysis, wind turbine's fatigue analysis and tower designing method.Above all, the aerodynamic and mechanical loads applied on the wind turbine are analyzed.The aerodynamic performance prediction and loading analysis are based on the strip theory,synthesizing Moment and Blade Element theories and considering tip loses, angle effects,solidity, wind shear, yawing effects, etc. This theory can predict the aerodynamic characteristicsof the rotor more accurately, and the work provides a calculating base for the wind turbine'ssubsequent analysis and design.In the third chapter, the whole system loads of horizontal axis wind turbine is carried out.During the process of the computation, the load computation method is studied and computationtool is determined, an analogy method for extern complicated environment and wind turbine'sdynamic response is provided. In the end, the Bladed software is used to compute wind turbine'slimitation load and fatigue load distribution, and some basic works in designing wind turbine arefinished.In the chapter four, a study on blade's three-dimensional modeling and vibrancy modality isgiven, and the common methods used in wind blade's three-dimensional modeling are discussed,which can provide the basis for wind turbine's structure finite element analysis. Considering theinfluence of fiber glass reinforced plastics blade and some other composite material anisotropybrought on wind blade's vibration frequency, the ANSYS finite element software is used toanalyze blade's modality.In the chapter five, the fatigue analysis problem of wind turbine is studied. In the modernlarge-scale wind turbine design, the fatigue problem becomes more and more obviously, so inthis chapter, the fatigue analysis steps and methods are emphasized. The ultimate goal of fatigueanalysis is to estimate the fatigue life. In the worldwide, the commonly method is Palmgren Miner linear fatigue damage accumulation method. As a result of the faults in the method, anequivalent stress computation method to estimate fatigue life of wind turbine's key parts isprovided and a good result is obtained.In the last chapter, a method to design wind turbine tower is given. By using ANSYS9.0, thestatic intensity and stability analyses of 1.5MW wind turbine tower is carried out. An analogymethod for cabin, wind wheel and foundation is provided. Applying ANSYS9.0, thetower-cabin-foundation coupling model is established and the wind turbine tower vibrationmodality is analyzed.