Estudio sobre la mejora de medidas del anemómetro de cazoletas

Abstract

The cup anemometer, a wind speed sensor invented by T.R. Robinson in the 19th century, is still today the best choice in the wind energy and meteorology sectors. Despite the great advances achieved thanks to new technologies such as sonic anemometry, LIDAR and/or SODAR, the cup anemometer is still the most demanded wind speed sensor due to its balance between accuracy, reliability, robustness and cost (including the costs associated with instrument calibration); and in general, it provides sufficiently accurate wind speed measurements within the most interesting wind speed range in the wind energy sector. Leaving aside a number of problems cup anemometers can present in turbulent flow applications, such as excess velocity [1, 2], it is possible to state that a properly calibrated anemometer provides good wind speed measurements (horizontal component). These measurements are of great relevance in the energy industry, since wind energy is proportional to the third wind power of the wind speed [3, 4], directly affecting the capacity of wind generators in the production of electrical energy. The present work is a new contribution to the research lines carried out in the calibration laboratory LAC-IDR/UPM of the IDR/UPM Institute, related to the performance of cup anemometers; which is focused on: • Study of the errors and the behavior of the output signal that the output signal generating systems of the cup anemometers record depending on various external agents that may influence it, as well as its possible effect on the measurement of wind speeds. • Study of the possible use of these devices at high altitude, specifically in hot air balloon missions. being the research work carried out and encompassed in the two blocks described above, the following: o Performance, study and comparison of large series of calibrations of commercial anemometers. o Study of the effect on the performances of the air density and the aging of the components of the optoelectronic system. o Development and use of Fourier analysis for the study of rotor accelerations and rotor condition prediction. o Study of the effect of the rotor accelerations of an anemometer in the calibration process. o Study and analysis of the performance of the cup anemometer as a function of the aerodynamics of the cups. After the achievement of these research studies, it has been seen the need to analyze more in depth the output signal of the cup anemometers to obtain a better understanding of their performances, as well as the inherent errors that the square wave generator systems may have.