1,720,971 research outputs found
Propuesta de Sistema de Telegestion para la Automatización de alumbrado Publico en Sistemas de Distribución Eléctrica
No full textEl presente artículo realiza el estudio de sistemas de gestión, control y administración del alumbrado publico existentes en la literatura con el fin de proponer la infraestructura mas adecuada para la implementación en los sistemas de distribución eléctrica del Ecuador. El sistema de telegestión de alumbrado publico seleccionado debe integrar luminarias multimarcas además de cumplir con la Revisión 05, sección 3: Especificaciones técnicas de materiales y equipos del sistema de distribución del Ministerio de Energías y Minas, y la Regulación 007/23 establecida por la Agencia de Regulación y Control de Energía y Recursos Naturales No Renovables (ARCERNNR), realizando un monitoreo en tiempo real del estado y funcionamiento de las luminarias, alertando cuando el servicio de alumbrado publico presente problemas por fallas técnicas o no técnicas. De este modo, el sistema planteado maximizara la eficiencia en el uso de los recursos institucionales, sin depender del tipo de tecnología de iluminación implementada. También generará informes que servirán para la toma de decisiones y la mejora del servicio. En caso de imprevistos o interrupciones, el sistema permitirá coordinar rápidamente las actividades de mantenimiento para resolver los problemas de manera eficaz.GuayaquilEscuela Superior Politécnica del Litora
Óptima coordinación de protecciones para despejar fallas de alta impedancia en redes de distribución eléctrica
Get PDFLas Fallas de Alta Impedancia (HIF) son perturbaciones que afectan al Sistema Eléctrico de Distribución (SED). Existen dispositivos de protección instalados en los SED que no están configurados o no son capaces de detectar una baja magnitud de corriente cuando ocurre una HIF, la misma que es acompañada por una distorsión armónica de corriente.High Impedance Faults (HIF) are disturbances that affect the Electric Distribution System (EDS). There are protection devices installed in EDS that are not configured or are not capable of detecting a low magnitude current level when a HIF occurs, which is accompanied by a current harmonic distortion
Estudios Dinámicos para la Conexión al S.N.I. de una Central Eólica de Convertidor Completo de Acuerdo con la Regulación Ecuatoriana
No full textEcuador es un país con grandes fuentes de generación renovable no convencional a su disposición, actualmente el sector de la generación eólica se encuentra en pleno desarrollo. No obstante, el carácter variable no controlable de la participación de generación eólica hace necesario un análisis del impacto que produce la integración de este tipo de generación en la estabilidad del sistema nacional interconectado ecuatoriano. Se utilizo el software DIgSILENT PowerFactory para realizar un modelo dinámico de un parque eólico con tecnología de convertidor completo bajo la normativa ecuatoriana e integrarlo en un modelo con la base de datos del SNI. Mediante la implementación de la central eólica se pudieron realizar una serie de estudios estáticos y dinámicos, que mostraron como se ve afectado el comportamiento de la red cuando se agrega la aportación eólica. Finalmente se puede afirmar que el parque diseñado cumple con asegurar la estabilidad y confiablidad de la conexión con la red ante varios escenarios operativos y de fallas.GuayaquilEscuela Superior Politécnica del LitoralEcuador is a country with large sources of non-conventional renewable generation at its disposal, currently the wind generation sector is in full development. However, the non controllable variable nature of the participation of wind generation requires an analysis of the impact produced by the integration of this type of generation on the stability of the Ecuadorian national interconnected system. The DIgSILENT PowerFactory software was used to make a dynamic model of a wind farm with complete converter technology under Ecuadorian regulations and integrate it into a model with the SNI database. Through the implementation of the wind power plant, a series of static and dynamic studies could be carried out, which showed how the behavior of the network is affected when the wind contribution is added. Finally, it can be affirmed that the park designed complies with ensuring the stability and reliability of the connection with the network in the face of various operating and failure scenarios
Estudios de carga, cortocircuito y protecciones para las estaciones de bombeo de la planta "La Toma"
No full textEl presente estudio planea realizar un análisis de cortocircuito y coordinación de protecciones a las estaciones de bombeo 2 y 3 de la planta "La Toma", ubicado en el Km. 26.5 Vía Daule. Esta planta de bombeo perteneciente a Interagua y gestionada por Veolia, es una de las principales fuentes de suministro de agua potable de la ciudad de Guayaquil con un total de 20 bombas de tipo verticales y horizontales. Para el análisis del proyecto, se planea realizar un levantamiento de carga actual de la planta de agua ?La Toma? con el fin de conocer los equipos y capacidades eléctricas de operación, observar los cambios realizados en los últimos años, obtener un diagrama unifilar del sistema y adquirir datos referentes a la red actual como pueden ser el circuito equivalente del sistema, potencias de cortocircuito en el punto de entrega de la energía, entre otras. Además, se propone modelar la red mediante el software DigSilent Power Factory que realizara los estudios de cortocircuitos para conocer las condiciones de trabajo del sistema ante el estímulo de perturbaciones eléctricas. Por último, utilizando las mediciones proporcionadas por el software, se planea coordinar y ajustar algunas funciones de protección en los relés de protecciones de motores de las estaciones de bombeo 2 y 3 para que estos operen con obediencia, fiabilidad y seguridad considerando los estándares y normativas a nivel mundial. Adicionalmente, se obtendrán las curvas de corriente vs tiempo de los relés donde se podrán observar los tiempos de interrupción de las protecciones antes distintos eventos de fallas que servirán para confirmar el adecuado funcionamiento del sistema de protecciones.GuayaquilEscuela Superior Politécnica del LitoralThe present study aims to conduct a short-circuit analysis and protection coordination for pumping stations 2 and 3 of the "La Toma" plant, located at Km. 26.5 Via Daule. This pumping plant, belonging to Interagua and managed by Veolia, is one of the main sources of drinking water supply for the city of Guayaquil, with a total of 20 vertical and horizontal pump units. For the project analysis, a load survey of the "La Toma" water plant is planned in order to understand the equipment and electrical operating capacities, observe changes made in recent years, obtain a one-line diagram of the system, and gather data related to the current network, such as the equivalent circuit of the system, short-circuit power at the point of energy delivery, among others. Additionally, the network will be modeled using the DigSilent Power Factory software, which will perform short-circuit studies to understand the system's behavior under electrical disturbances. Finally, using the measurements provided by the software, the plan is to coordinate and adjust certain protection functions in the motor protection relays of pumping stations 2 and 3, ensuring they operate obediently, reliably, and safely in accordance with global standards and regulations. Furthermore, current vs. time curves of the relays will be obtained where the interruption times of protections can be observed during various fault events, confirming the proper functioning of the protection system
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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