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Metodología FMECA para un aerogenerador doblemente alimentado
(2021-06-01) Solano Artavia, Andrey; Cruz Jiménez, Brandon; Ramos Fernández, Cristian; Solís Guzmán, Kevin; Núñez Mata, Óscar Fernando; Pérez Mora, Aramis
Debido a la complejidad de los sistemas eólicos, la necesidad de contar con aerogeneradores fiables es de suma importancia, por ello, se han desarrollado metodologías para mejorar sus características y desempeño. El método de análisis de modos de falla, efectos y criticidad se ha utilizado ampliamente para estudiar la confiabilidad de múltiples sistemas y procesos en diversas áreas, entre las cuales se encuentra la de generación de energía eléctrica. En este documento se presenta la aplicación de dicha metodología a un aerogenerador de inducción doblemente alimentado, para realizar una evaluación cualitativa y cuantitativa de las características de falla en el mismo. Además, para tomar en cuenta consideraciones económicas en el análisis, se presenta el enfoque del método basado en el riesgo, con el fin de mitigar las limitaciones que presenta el método tradicional. Como resultado, se determina que las estrategias de mantenimiento deben enfocarse principalmente en el generador, luego el sistema eléctrico y posteriormente en las aspas.
Synthetic time series generation model for analysis of power system operation and expansion with high renewable energy penetration
(2021-06-05) Palma Behnke, Rodrigo; Vega Herrera, Jorge; Valencia, Felipe; Núñez Mata, Óscar Fernando
The increasing integration of renewable energy sources into current power systems has posed the challenge of adequately representing the statistical properties associated with their variable power generation. In this paper, a novel procedure is proposed to select a proper synthetic time series generation model for renewable energy sources to analyze power system problems. The procedure takes advantage of the objective of the specific analysis to be performed and the statistical characteristics of the available time series. The aim is to determine the suitable model to be used for generating synthetic time series of renewable energy sources. A set of indicators is proposed to verify that the statistical properties of synthetic time series fit the statistical properties of the original data. The proposal can be integrated into systematic tools available for data analysis without compromising the representation of the statistical properties of the original time series. The procedure is tested using real data from the New Zealand power system in a midterm analysis on integrating wind power plants into the power system. The results show that the proposed procedure reduces the error obtained in analyzing power systems compared with reference models.
Oral acuity, particle size sensitivity, and food texture preferences in an older adult population
(2023-10-28) Chaffee, Olivia; Montero, María Laura; Keast, Russell; Ross, Carolyn F.
Changes in sensory sensitivity occur as we age but changes in food texture sensitivity in the older adult population remain poorly understood. The objective of this study was to describe the relationship between oral tactile acuity, mouth behaviour, and particle size sensitivity and their potential influence on preferred food textures in older adults. Older adults (n = 79; mean age = 69.7 yrs) participated in an evaluation of oral health and texture perception through survey measurements of mouth behaviour, and preferred food textures. Oral tactile acuity was assessed using the Grating Orientation Task (GOT) with three grating sizes (0.5, 0.75, and 1.5 mm). Food particle sensitivity was evaluated through a difference-from-control (DFC) sensory assessment of ground quinoa mixed into yogurt, utilizing three particle size ranges (<75, 150–250, and 500–600 μm). The results revealed that the sample containing 500–600 mm particle sizes yielded a higher difference (DFC) score compared to the samples with < 75 μm and 150–250 μm particles (p < 0.05). However, no significant relationship (p > 0.05) was found between the R-indices obtained from the GOT assessments and DFC scores, indicating no association between oral tactile acuity and particle size sensitivity. Liking of creamy, leafy, slippery, sticky, with skins, and combination food textures was significantly positively associated with the 0.5 mm GOT tool R-index values, suggesting higher oral acuity influences liking of specific food textures. Significant differences (p < 0.05) were present in liking of food textures among different mouth behaviour groups. These results suggest that texture perception and sensitivity influence texture acceptance in older adults.
Motor bearing failures detection by using vibration data
(2022-12-29) Núñez Mata, Óscar Fernando; Rodríguez Rodríguez, Jose Ignacio; Gómez Ramírez, Gustavo Adolfo
The use of methodologies for condition monitoring of rotating machines has been growing to reduce unplanned downtime and to increase the reliability of the industrial processes. The companies must select a correct maintenance strategy to follow the evolution of rotating machines. Condition monitoring is the collection of data related to the health status of the machine and it has been widely studied so far. Different methodologies have been developed to identify specific behaviors in the condition of induction motors. This paper proposes a methodology for bearing failure detection by using vibrations data, based on the frequency spectrum applied to induction motors. This methodology allows the use of vibration data obtained from motor bearings to establish their condition and therefore determine the type of damage to the bearing. The effectiveness of the proposed methodology is validated using a data set obtained from NASA (National Aeronautics and Space Administration). The results showed that this type of approach is very useful for analyzing bearings and in this way creating maintenance routes based on the condition of the electric machines.
Monitoreo de condición del sistema de aislamiento de motores eléctricos mediante índice de salud
(2021-08-31) Núñez Mata, Óscar Fernando; Herrera Bolaños, Alonso; Gutiérrez Vargas, Steven
Con el paso de los años, la economía ha experimentado un avance creciente por medio de las múltiples actividades industriales, haciendo necesario e imprescindible el funcionamiento constante de las empresas que aportan a tal tendencia. Bajo tal requerimiento, resulta clave mantener en adecuadas condiciones las líneas de producción que incluyen distintos equipos, entre los cuales destacan los motores eléctricos. Se estima que el 60-70% del consumo de la energía eléctrica se debe a equipos electromotrices, acoplados por medio de motores eléctricos [1]. Es decir, los motores son componentes fundamentales en la operación de la industria. Por tal motivo, los responsables de su correcto funcionamiento, requieren de herramientas que aporten al seguimiento de su condición, y al conocimiento de la formación defectos, para, finalmente, guiar la toma de decision.