Study On Dynamic Simulation For MW-level Wind Turbine Blades And Their Optimization

Recently, MW-level wind turbine has developed into the mainstream wind powerequipment in wind power utilization. However, as an important part of MW-level windturbine, the blade is the most complex and difficult in designing wind turbine part. That howto effectively research on the aerodynamic performance of blades in the mist of couplingeffect of the aerodynamic force, inertia force and elastic force are expected to be a kind ofeffective measure of solving the safety and reliability of MW-level wind turbine fromtechnology. So far, it has become a popular research area on MW-level wind turbine.Therefore, based on Multidisciplinary design optimization theory and method forMW-level wind turbine blades(Hunan Province Key Laboratory Open FundProject[2011KFJJ001]-Renewable Energy Power Technology), this thesis adopted themethod of combining numerical simulation and experimental verification to make research onanalyzing wind turbine and blade dynamic performance, and also put forwardmultidisciplinary design optimization theory and method for MW-level wind turbineblades.The main work and innovation of this thesis are as follows:Based on the blade element-momentum theory, the aerodynamic load model ofMW-level wind power generator made a calculation of aerodynamic characteristics of the1.65MW variable-speed variable-pitch wind turbine blades by the application of Bladed forWindows software. The results indicate that the blade has good aerodynamic performanceand wide scope of wind speed adaptive capacity when1.65MW variable-speed variable-pitchwind turbine blades is matched with1.80MW wind power generator, and the blade root’sequivalent fatigue load and its extreme flap wise load both are less than the original designedloads.Based on the modal analysis theory, a finite element model of the variable-speedvariable-pitch wind turbine blades was built and then got the first10order natural frequencyand vibration mode of the blades by making a modal analysis on them. The results show thatthe dynamic excitation frequency which has effect on the variable-speed variable-pitch windturbine blades deviates evidently from their natural frequency, and that is the reason why theydo not produce resonance phenomenon when they are normally operated.Taking the MW-level wind turbine blades’ aerodynamic performance, quality and thelimit thrust and noise level of blades root as the objective function, a multidisciplinary designoptimization model was established to get solving by applying adaptive chaotic optimizationalgorithm on multidisciplinary design optimization software with taking coupling effectamong the various disciplines into full consideration. The results indicate that the capability of the MW-level wind turbine blades can be improved greatly after its multidisciplinarydesign optimization.