Revistas UTB ( Universidad Tecnológica de Bolívar)
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Union by Co-Lamination of Aluminum and Magnetic alloy obtained by Rapid Solidification
Full text linkThe aim of this work is to analyze the possibility of producing a joint by lamination of an Al-1050 plate and Fe78Si9B13(%at.) soft magnetic ribbons material obtained by a rapid solidification process by using the Melt Spinning (MS) technique. The lamination conditions are studied on the characteristics of the joint, the microstructure, and the magnetic properties. Mainly the surface preparation, temperature, and reduction of thickness. The material is characterized by X-Ray Diffraction, Optical, and Scanning Electron Microscopy, showing a completely amorphous structure before and after the collamination, the typical defects caused by this rapid solidification technique in ribbons (bubbles, dust particles, roughness imperfections and oxides) and the joint between materials. The microhardness Vickers has been determined in both, the ribbons as quenched and collaminated samples, to observe quantitatively the hardening suffered during colamination and find a possible cause. The Differential Scanning Calorimetry and Compositional Analysis by EDS techniques were also used to determine the crystallization temperatures and chemical exact chemical composition of the ribbons as received. The magnetic hysteresis curve of the amorphous ribbons showed a Hc and Ms around 3.8 A/m and 1.44 T correspondingly
Application of the Sine-Cosine Algorithm to the Optimal Design of a Closed Coil Helical Spring
Full text linkThis paper proposes the application of the sinecosine algorithm (SCA) to the optimal design of a closed coil helical spring. The optimization problem addressed corresponds to the minimization of total spring volume subject to physical constraints that represents the closed coil helical spring such as maximum working load, shear stress, and minimum diameter requirements, among other. The resulting mathematical formulation is a complex nonlinear and non-convex optimization model that is typically addressed in literature with trial and error methods or heuristic algorithms. To solve this problem efficiently, the SCA is proposed in this research. This optimization algorithm belongs to the family of the metaheuristic optimization techniques, it works with controlled random processes guided by sine and cosine trigonometric functions, that allows exploring and exploiting the solution space in order to find the best solution to the optimization problem. By presenting as main advantage an easy implementation at any programming language using sequential quadratic programming; eliminating the need to uses specialized and costly software. Numerical results demonstrating that the proposes SCA allows reaching lower spring volume values in comparison with literature approaches, such as genetic algorithms, particle swarm optimization methods, among others. All the numerical simulations have been implemented in the MATLAB software
Applications of Digital Twins in Power Systems: A Perspective
Full text linkData science-based digital twin models of renewable energy system technologies developed in a real-time data-rich environment help develop better decisions and predictions than those in the present environment. Based on this real-time analysis of countrywide data, digital twin contributes to effective and reduced cost-based power system control at the localised level. Developing digital twin models from the collection of relevant data is an innovative technology. The challenge is how to leverage all the operational data and analyse the use of data from across transmission and distribution networks to help achieve the objectives. This paper presents an overview of the existing applications of digital twins in power systems
High-speed 3D optical sensing for manufacturing research and industrial sensing applications
Full text linkThis paper presents examples of high-speed 3D optical sensing for research and applications in the manufacturing community. Specifically, this paper will focus on the fringe projection technique as a special technology that can be extremely beneficial to manufacturing applications, given its merits of simultaneous high-speed and high-accuracy 3D surface measurements. This paper will introduce the basic principles of 3D optical sensing based on the fringe projection technique as well as the enabled manufacturing research applications, including both in-situ/in-process monitoring and post-process quality assurance
Visualization Proposal for Power System Control Rooms Based on Situational Awareness
Full text linkDue to the increasing size of electric power systems and its monitoring and operation needs, people at control rooms face complex situations, analyzing great amounts of information, protocols, operation states, alarms, and control parameters. Additionally, new renewable energy sources data is taking its place nowadays, hindering the process of quickly reading and interpreting information. This is known as the loss of Situational Awareness, SA, of system operators. This work presents proposals for displaying useful information in control rooms and visualization techniques to support accurate SA. Grid data displays, maps, trending graphics, lists, bars graphics, table plots, hierarchical levels, proximity regions, and connections are also proposed and analyzed, presenting an application case in a microgrid control room
Metodología para la caracterización y planificación de la demanda eléctrica en una zona aislada: Caso de estudio Mitú
No full textThis paper aims a model for the characterization and planning of electricity demand in isolated networks when there is no information from the measurement system, a typical scenario in the Colombian Non-Interconnected Zone. This research is based on Arvidson method of the publication entitled: "Diversified demand method of estimating residential distribution transformer loads". This study proposes consumption indices for typical household appliances based on a statistical analysis of load censuses. Then, a timely contrast is made between the curves of the Arvidson study and the generation curves of the isolated network because there is no direct measurement in the end-users and by macrometers associated with the transformers. With this information, we proceed to complement the validated Arvidson curve with its own index; this index allows the proposed curve to be readjusted to a similar curve, per unit, with the generation profile. The main contribution is to propose a new factor, in order to, contextualizes and diversifies the Arvidson method to specific case studies to building daily electricity demand and diversified demand curves as tools for planning the electrical system and managing the electrical infrastructure.Este trabajo tiene como objetivo un modelo para la caracterización y planificación de la demanda eléctrica en redes aisladas cuando no se cuenta con información del sistema de medición, escenario típico en la Zona No Interconectada de Colombia. Esta investigación se basa en el método de Arvidson de la publicación titulada: "Método de demanda diversificada para estimar cargas de transformadores de distribución residencial". Este estudio propone índices de consumo para electrodomésticos típicos basados en un análisis estadístico de censos de carga. Luego, se hace un oportuno contraste entre las curvas del estudio de Arvidson y las curvas de generación de la red aislada debido a que no hay medición directa en los usuarios finales ni por macromedidores asociados a los transformadores. Con esta información se procede a complementar la curva de Arvidson validada con su propio índice; este índice permite reajustar la curva propuesta a una curva similar, por unidad, con el perfil de generación. La principal contribución es proponer un nuevo factor, con el fin de contextualizar y diversificar el método Arvidson a casos de estudio específicos para la construcción de la demanda eléctrica diaria y las curvas de demanda diversificada como herramientas para la planificación del sistema eléctrico y la gestión de la infraestructura eléctrica
Analysis of Asset Management Models for a Transformer Fleet in the National Laboratory of Smart Grids (LAB+i)
Full text linkThe study of the degradation of power transformers in the electrical network has become a subject of relevant analysis by network operators and companies, associated with the probability of failures and operation quality. For this reason this paper firstly presents the classification of a set of 12 Asset Management models related to power transformers monitoring and, then, the application of three of them in three substations of the National Laboratory of Smart Grids (LAB+i) located at Bogot´a Campus of the Universidad Nacional de Colombia. As a result, the main challenges were identified concerning the Asset Management application in transformer fleets related to data availability and precision. Finally, it was identified that the development of an Asset Management model that uses non-invasive real-time measurements is needed for continuous monitoring of power systems and diagnosis
End-use energy indicator approach to improve energy performance at the National University of Colombia Bogotá, under the parameters of the ISO 50001 standard
Full text linkThe university belongs to the services sector, which is why it cannot implement traditional industry indicators such as energy consumption per unit produced. For this reason, we propose indicators for the final use of energy. The indicators were developed through an energy review process of the information in the database of advanced energy meters with the support of the Specialist in Geographic Information Systems of the Environmental Management Office (EMO). Additionally, we considered several existing reports that characterized the final use of energy for some buildings and essential data for defining the percentages each final use will have within the conglomerate of loads registered. Continuity was also given to this process by collecting face-to-face information with the support of each building’s environmental manager. This article shows the behavior of two buildings of the National University Bogotá, the Uriel Gutiérrez building and the Roberto Franco Station, to propose an indicator of final energy use. This approach enabled determining in which end-use the load has the highest consumption, taking into account that this may contribute to the management system energy of the university. This article uses the guidelines implemented in the ISO 50001 standard.Este artículo tiene como objetivo mostrar el comportamiento de dos edificios de la Universidad Nacional - Bogotá, el Uriel edificio Gutiérrez y la Estación Roberto Franco, para hacer la aproximación a un indicador de consumo final de energía, pudiendo determinar en qué uso final la carga tiene el mayor consumo, teniendo en cuenta que esto puede contribuir a la gestión energía del sistema de la universidad, este artículo utiliza las directrices implementado en la norma ISO 5000
Títulos colectivos, violencia contra civiles y conflicto armado interno en Colombia
Full text linkEl conflicto interno en Colombia, caracterizado como de baja intensidad y larga duración, ha dejado millones de víctimas civiles. Existe evidencia anecdótica que indica que las comunidades afrodescendientes de la región Pacífica que han recibido títulos colectivos han sido duramente golpeadas por la violencia. El objetivo del presente trabajo es establecer si los municipios con presencia de títulos colectivos tienen un mayor número de víctimas de violencia contra los civiles. Con este fin empleamos un método de emparejamiento (propensity score matching) que permite realizar una comparación entre municipios similares. Nuestros resultados indican que para todos los hechos victimizantes que analizamos (amenazas, delitos sexuales, desaparición forzada, homicidios, secuestros y vinculación de niños a grupos armados ilegales) los municipios con presencia de títulos se ven más afectados en comparación con aquellos sin presencia de títulos. En términos de política pública, estos resultados sugieren que es indispensable revisar la implementación del programa de titulación colectiva, garantizar las condiciones de seguridad en estos territorios y mejorar la articulación entre las autoridades locales y nacionales con un mayor respaldo de oferta institucional que cubra las necesidades básicas de la población
Demand Response Program Implementation Methodology: A Colombian Study Case
Full text linkThe industrialization and urbanization are responsible for Greenhouse Gas (GHG) emissions and could generate energy shortage problems. The application of Demand Response (DR) programs enables the user to be empowered towards a conscious consumption of energy, allowing the reduction or displacement of the demand for electrical energy, contributing to the sustainable development of the sector and the operational efficiency of the electrical system, among others. A reference framework for this type of program is detailed along with a literature survey applied to the Colombian case. The considerations on the design of a methodology to the implementation of the DR pilot, considering if the pilot is in an interconnected system zone or non-interconnected system zone and the application of the design methodology in the modeling of three DR pilots in Colombia is presented. For the modeling of the pilots, the characteristics of the area and the base consumption of the users are considered, and the characteristics and assumptions of the pilot are also defined. Furthermore, the DR pilot in each zone considering four types of users is detailed. The results show the potential for energy reduction and displacement in different time bands for each zone, which allows determining the assessment of the benefits from a technical, financial, and environmental point of view, and the costs of each pilot in monetary terms, it not to compare the pilots with each other, but to illustrate the values that must be taken into account in those analyses. The sensitivity analysis of each pilot was also carried out, considering the variation of the benefit/cost relationship with the energy rate in peak hours vs. off-peak hours and the base energy rate in the area. The sensitivity analysis shows that, when varying the level of energy demand response and the number of pilot participants, the values are presented when the benefit/cost ratio is greater than 1. In addition, the paper provides specific recommendations related to the design of a methodology and the implementation in a pilot DR using simulation