Dinâmica e controle de vibrações no plano de rotação em pás de turbinas eólicas

• Ano de defesa: 2017
• Autor(a) principal: Cunha, Guilherme Terceiro
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Palavras-chave em Português: Engenharia mecânica; Turbinas eólicas; Vibração; Vibration control; BEM method; Aeroelastic coupling; Rotational sampling
• Link de acesso: http://www.repositorio.ufc.br/handle/riufc/28744

In this research, the dynamic responses of the blades without vibration control, with passive and active control were analyzed to verify the influence of aerodynamic damping on the blade vibrations. The blades were modeled as continuous Euler-Bernoulli beams, including coupling in the in-plane and out-plane vibrations. The equation of motion of the turbine model was obtained with the energy formulation of Euler-Lagrange considering the effects of centrifugal and gravitational force. Tuned mass dampers were inserted near the tip of each blade and on the top of the tower to verify the performance of this system considering aerodynamic damping through the aeroelastic coupling. The dampers were simulated in passive form, considering optimal parameters, and in the active form, calculating the control forces through the linear quadratic regulator (LQR) strategy. The power law equation, the power spectral density function and the spatial coherence function generated a wind speed field to simulate the rotational sampling on the blade. Aerodynamic forces were calculated using the quasi-static blade element momentum (BEM) theory including frame velocities in the calculation to account for the aeroelastic coupling, and thereby add the effect of aerodynamic damping. The validation of the model was performed comparing the natural frequencies and the dynamic response under stable loading with models of turbines already consolidated in the scientific literature. The results showed that the quasi-static BEM method presented a greater aerodynamic damping in the out-plane direction as already mentioned by researchers. Regarding the control, the aerodynamic damping almost completely inhibited the performance of the passive control, making it unnecessary in the reduction of in-plane vibrations in rotating wind turbine blades. The hypothesis of applying the active control LQR calculated at the initial moment was shown inefficient, calculating forces that did not promote the reduction of vibrations and, thus, making it impossible to analyze them with aerodynamic damping.