Vibration analysis of a VAWT

Abstract

This research analyses the vibrations in a special type of vertical axis wind turbine with parabolic blades called Darrieus. The study will be focused on the vibrations of the tower. It is really important to know the tower ́s behaviour against them in order to choose the best material for it and to avoid problems such as frequent maintenance and even wind turbine breakage. For developing this thesis a vast array of in formation has been gathered from technical sources regarding vertical axis wind turb ines. For modeling the wind turbine, the Matlab program was used in order to design the behaviour of the wind turbine. The vibrations were calculated us ing a finite element method. An important step before calculating the tower vibrations is the study of the resulting forces at different points in each blade, which are due to the blade rotation. Once the vibration results were obtained they were compared with the real measurements carried out in a vertical axis wind turbine prototype. They were measured using a National Instrument device. It has four very sensitive sensors that were located in the tower in order to measure its vibrations. Besides, for the data acquisition, we connected the device to a computer that has LabVIEW Signal Express software and we analyzed the results. The conclusion is that our designed program is reliable as the real measurements are very close to the ones obtained with Matlab.