• Energy Research

In this article, the behavior of the thrust force on the blades of a 10 kW wind turbine was obtained by considering the characteristic wind speed of the Isthmus of Tehuantepec. Analyzing mechanical forces is essential to efficiently and safely design the different elements that make up the wind turbine because the thrust forces are related to the location point and the blade rotation. For this reason, the thrust force generated in each of the three blades of a low-power wind turbine was analyzed. The angular position (θ) of each blade varied from 0° to 120°, the blades were segmented (r), and different wind speeds were tested, such as cutting, design, average, and maximum. The results demonstrate that the thrust force increases proportionally with increasing wind speed and height, but it behaves differently on each blade segment and each angular position. This method determines the angular position and the exact blade segment where the smallest and the most considerable thrust force occurred. Blade 1, positioned at an angular position of 90°, is the blade most affected by the thrust force on P15. When the blade rotates 180°, the thrust force decreases by 9.09 N; this represents a 66.74% decrease. In addition, this study allows the designers to know the blade deflection caused by the thrust force. This information can be used to avoid collision with the tower. The thrust forces caused blade deflections of 10% to 13% concerning the rotor radius used in this study. These results guarantee the operation of the tested generator under their working conditions.

Mexico has more than 40 years of researching, investing, and obtaining electric power through wind energy. Within the country, there are highly windy areas, such as the Isthmus of Tehuantepec or the state of Tamaulipas, and there are about 2500 MW installed and 70,000 MW tested, all onshore. There are still no offshore wind farms in Mexico, despite having two main coasts, the East and the West, with the Gulf of Mexico and the Pacific Ocean, respectively. Although the Mexican coastal states of the Gulf of Mexico are Tamaulipas, Veracruz, Tabasco, Campeche, and Yucatán, this work focuses on the study and feasibility of offshore wind energy use on the coasts of the states of Tabasco, Campeche, and Yucatán. This is because of the availability of data in that region; however, sustainability criteria that can be used in other regions are also presented. MERRA-2 and ERA5 data were used employing WAsP and Windographer software. It was found that the capacity factor in the area of Tabasco, Campeche, and Yucatán is 32%, 37%, and 46%. It can be noted that, in the WF100% scenario, each of the wind farms could contribute more than 35% of the region’s electricity consumption; those of Campeche and Yucatán stand out with contributions of more than 70%.

AbstractThe development of an optical contact instrument for measuring the geometric shape of aerodynamic profiles on blades of small power wind turbines is presented. The instrument uses the triangulation principle, where a structured line laser pattern is projected onto the surface of one of the faces of the blade under test, a camera captures the image of the line and is processed to interpret the distorted form of the projected line. A linear sweep of the instrument makes it possible to measure the profile in another section of the blade. Comparison and evaluation results of two symmetric profiles of the NACA 0012 family are presented, one manufactured in a 3D printer and the other one is a metal profile AF104 of a subsonic wind tunnel. Additionally, three sections of a blade with profile FX 63‐137 of a 1.5 kW wind turbine were evaluated. An aerodynamic analysis shows a reduction in the lift coefficient and in the efficiency of the aerodynamic profile, as well as an increase in the drag coefficient. The sensitivity of the instrument is 0.1 mm on the Z‐axis.

In the present work, a methodology that allows optimizing the permanent magnet synchronous generator (PMSG) design by establishing limit values of magnet radius and length that maximize efficiency for the nominal parameters of the wind turbine is developed. The methodology consists of two fundamental models. One model calculates the generator parameters from the radius of the magnet base, and the other optimization model determines two optimum generators according to the optimization criteria of maximum efficiency and maximum efficiency with minimum weight starting from the axial length and the radius of the magnet base. For the optimization, the numerical method of the golden section was used. The model was validated from a 10 kW PMSG and the results of two optimum generators are presented according to the optimization criteria. In addition, when the obtained results are compared with the reference electric generator, an increase in efficiency of 1.15% and 0.81% and a reduction in weight of 30.79% and 39.15% of the optimized generators are obtained for maximum efficiency and minimum weight, respectively. Intermediate options between the maximum efficiency generator and the minimum weight generator allows for the selection of the optimum dimensioning for the electric generator as a function of the parameters from the wind turbine design.

This paper presents an analysis of sound pressure levels through theoretical modeling and experimental validation in a 1 kW small wind turbine. The models used in the theoretical analysis are BPM (Brooks, Pope, and Marcolini) and BM (Brooks and Marcolini), where wind turbine blades are divided in sections, and each section has its own contribution with respect to the total emitted sound pressure level. The noise propagation study and its experimental validation were accomplished within the requirements of the standard IEC 61400-11 Ed.3 and the standard NOM-081-SEMARNAT-1994. The comparative study of theoretical and experimental results showed that the BPM and BM methods have a maximum error of 5.5% corresponding to the rated wind speed of 10 m/s. However, at low wind speeds, the theoretical models fit well to experimental data, for example, in the range from 5 to 8 m/s. The experimental data showed that the rotor’s aerodynamic noise is more evident at low wind speed, because under these conditions, environmental noise is much less than wind turbine noise. Finally, to prevent possible negative effects on people’s health, there is a recommended minimum and suitable distance between small wind turbine installations and buildings.

Abstract The use of wind generators has grown exponentially in recent decades to meet the increasing demand for electricity. With both generator design and generation capability growing, the resulting increases in the size of generators require them to withstand multiple and intense dynamic loads. These loads cause greater stresses, fatigue, torsions, deflections, and vibrations, among others, leading to greater failures during a generator's life cycle. These issues are of great significance to the research and technological development involved in improving the design, manufacturing process, and installation of wind turbine towers. This work presents a detailed review of the most notable aspects involved in the analysis and design of towers. These aspects include loads and actuating forces, types of structural analysis, used software, and types of experiments used for validating the aspects themselves. In addition, different perspectives regarding the types of supports for onshore and offshore wind turbines are discussed. Likewise, the proposals for new designs and construction materials are also analyzed. The present review integrates the most relevant aspects and recent developments in the design, manufacture, and installation of wind turbine towers. This has been carried out with the objective of providing a contemporary frame of reference that will facilitate the future research and project development related to wind turbine towers.

This study introduces a metrological approach to measure the aerodynamic shape and the twist of a wind turbine blade. The optical profilometer measurement technique used is laser triangulation. A camera records the image of a line projected onto a section of the blade and, by reconstructing the airfoil shape, the twist angular position of the profile with respect to the axial line of the blade is determined. This methodology is applied to test different sections of a Wortmann FX 63-137 airfoil with a length of 1700 mm. The results of the aerodynamic shape and twist angle are quantitatively verified by comparing them with the ideal or design values. The reconstruction process achieved a resolution of 0.06 mm, and measurement errors in the twist angular position were less than 0.1°. The presented method is efficient, accurate, and low cost to evaluate the blade profiles of low-power wind turbines. However, due to its easy implementation, it is expected to be able to measure any full-scale wind blade profile up to several meters in length.