Edwin Rivas

Voltage sag characterization with Matlab/Simulink

This paper describes a methodology for voltage sag characterization using Matlab/Simulink. It includes fault simulations for voltage sag magnitude calculation using Simulink, based on the SimPowerSystems toolbox, and also considering protection-systems modeling for sag duration calculation. Other sag characteristics, such as phase-angle jump and shape, are described and simulated.

State of the art of electricity demand forecasting based on wavelet analisys and a nonlinear autoregressive model NAR

This paper shows a bibliographic review of studies conducted at the international scope in monthly electric energy demand forecasting, and the works developed in Colombia. In addition, reports the state of the art of investigations done with wavelet transform applied to electric energy prediction and studies reported with the nonlinear neural model autoregressive (NAR) in prediction. Finally we present a proposal for electric demand forecasting for the interconnected sector of Colombia.

Phasor measurement unit using GPRS wireless connectivity

This paper describes the development of a phasor measurement unit using data wireless transmission via GPRS. The detailed process in the design and construction of the prototype and the difficulties faced at different stages are presented. The results are finally evaluated using the Total Vector Error (TVE) calculated for each of the testing designs.

Propuesta de modelo de Gestión para redes eléctricas con Generación Distribuida a través de Unidades de Medición Fasorial

espanolEn el presente articulo se propone un modelo de gestion para redes de distribucion electrica que incluyan elementos de Generacion Distribuida (GD), mediante el monitoreo constante a traves de Unidades de Medida Fasorial (PMU). Se analizan los conceptos de PMU, GD, algunos modelos de gestion para redes y el lenguaje de modelado Unificado UML, que es usado como base para el proceso de modelado del sistema de gestion propuesto. Posteriormente, se ilustran las etapas de modelado, los elementos estructurales y la funcionalidad que tiene el modelo de sistema de gestion propuesto. Se concluye que por tratarse de modelos de disenos abiertos y genericos, se permite facilmente incluir nuevos parametros o un nuevo direccionamiento de los elementos de red, o nuevas estrategias de control para cumplir la tarea de gestion que se requiera. EnglishIn this article, a management model for electricity distribution networks is proposed. The electricity distribution network includes elements of distributed generation (DG). The network monitoring is done through Phasor measurement units (PMU). The concepts of PMU, DG, management models for networks and Unified modeling language UML are analyzed. The UML language is used as the basis for modeling process management system proposed. Later, stages of modeling, structural elements and functionalities of the proposed model management system are illustrated. It is concluded that being model of open and generic design it can be easily include new parameters, or change de direction of the network elements, 0r new control strategies that may be needed to fulfill a desired management task.

Primary user characterization for cognitive radio wireless networks using a neural system based on Deep Learning

Cognitive radio is a paradigm that proposes maximizing the utilization of the usable radio-electric spectrum, allowing licensed users (PUs) and non-licensed users (SUs) to simultaneously coexist through the dynamic management and assignment of spectrum resources, by integrating the stages of spectrum sensing, decision, sharing and mobility. Spectrum decision is one of the most important stages, but its optimal operation depends on the characterization sub-stage, which is in charge of efficiently estimating time gaps in which a PU won’t make use of the assigned spectrum, so that it can be used in an opportunistic fashion by SUs. The design and implementation of an algorithm based on the Long Short-Term Memory (LSTM) recurrent neural network is proposed in order to increase the success percentage in the forecasting (presence/absence) of PUs in spectrum channels. The accuracy level exhibited in the results indicates LSTM increases the prediction percentage as compared to the Multilayer Perceptron Neural Network (MLPNN) and the Adaptative Neuro-Fuzzy Inference System (ANFIS) learning models, which means it could be implemented in cognitive networks with centralized physical topologies.

Enfoque técnico-económico para el dimensionamiento de transformadores de distribución

Among the different technologies with important implications today in such areas as education, health and business, videostreaming is highlighted. This considering how this technology facilitates the access to multimedia content remotely, live or offline. The goal of this paper is to propose a test environment for the support of the video streaming service, using open source tools. Moreover, this work proposes, as part of the environment, a stress measurement tool (Hermes), which allows obtaining the response times to establish multiple RTSP connections to streaming servers. The methodology used in this work is divided into four phases: analysis of technologies and tools, configuration of the video streaming environment, design and implementation of Hermes, and finally tests. This methodology allowed the construction of the test environment and its evaluation, through the stress measurement tool Hermes. Finally, in this work we demonstrate how the proposed environment becomes a reference point for different application environments that require the implementation of a video streaming service.Se aplico la mecanica de solidos hiperelasticos al estudio del comportamiento del tubo arterial, ya que es un medio consolidado en la comprension de fenomenos de interes para los profesionales de la medicina y de la ingenieria biomedica. En el caso del organo en cuestion, su estudio se realizo mediante el modelado como un recipiente cilindrico de pared gruesa, donde la funcion de energia empleada permitio considerar aspectos microestructurales como la anisotropia y la dispersion de fibras de colageno. En el problema de equilibrio estatico en el que se implementa esta caracterizacion se representaron las capas media y adventicia de la pared arterial. La solucion expedita del problema de valores en la frontera resultante es posible gracias a la asuncion de un patron de deformacion de simetria axial. Se encontro que el factor de dispersion de fibras y los demas parametros adimensionales del mismo orden de magnitud tienen el rol dominante en la rigidez radial del tubo arterial. Los resultados se presentan utilizando grupos adimensionales, lo cual facilita la interpretacion rapida del efecto de los numerosos parametros que emergen

A technical-economic approach for distribution transformers sizing

Among the different technologies with important implications today in such areas as education, health and business, videostreaming is highlighted. This considering how this technology facilitates the access to multimedia content remotely, live or offline. The goal of this paper is to propose a test environment for the support of the video streaming service, using open source tools. Moreover, this work proposes, as part of the environment, a stress measurement tool (Hermes), which allows obtaining the response times to establish multiple RTSP connections to streaming servers. The methodology used in this work is divided into four phases: analysis of technologies and tools, configuration of the video streaming environment, design and implementation of Hermes, and finally tests. This methodology allowed the construction of the test environment and its evaluation, through the stress measurement tool Hermes. Finally, in this work we demonstrate how the proposed environment becomes a reference point for different application environments that require the implementation of a video streaming service.Se aplico la mecanica de solidos hiperelasticos al estudio del comportamiento del tubo arterial, ya que es un medio consolidado en la comprension de fenomenos de interes para los profesionales de la medicina y de la ingenieria biomedica. En el caso del organo en cuestion, su estudio se realizo mediante el modelado como un recipiente cilindrico de pared gruesa, donde la funcion de energia empleada permitio considerar aspectos microestructurales como la anisotropia y la dispersion de fibras de colageno. En el problema de equilibrio estatico en el que se implementa esta caracterizacion se representaron las capas media y adventicia de la pared arterial. La solucion expedita del problema de valores en la frontera resultante es posible gracias a la asuncion de un patron de deformacion de simetria axial. Se encontro que el factor de dispersion de fibras y los demas parametros adimensionales del mismo orden de magnitud tienen el rol dominante en la rigidez radial del tubo arterial. Los resultados se presentan utilizando grupos adimensionales, lo cual facilita la interpretacion rapida del efecto de los numerosos parametros que emergen

Prototype phasor measurement system for a generator synchronic

This paper presents the development of a prototype system of phasor measurement (PMU) for a synchronous machine including PMU device design, GPRS communications link with a PDC phasor data concentrator through a web services; phasor information is displayed in real time on a standard web browser.

Evaluación de la Inmunidad de un Motor de Inducción Monofásico frente a Huecos de Tensión

This paper shows a methodology for evaluating the immunity of a single-phase induction motor to voltage sags by simulations in Matlab/Simulink. For this, a model of a single-phase voltage sag generator was designed and algorithms were implemented, to obtain, model and improves the sensitivity curve of the induction motor with respect to the voltage drop. The implemented methodology is a simple guide to estimate the impact of voltage sags on induction motors. Additionally, the proposed method reduces the amount of voltage sags to which the motors are usually subjected in lab test using other methodologies.

Rendimiento de tecnologías backbone en el transporte de voz

Este articulo presenta los resultados obtenidos en el estudio de la calidad de servicio sobre redes IP en traficos sensibles al retardo, como la VoIP sobre la tecnologia ATM y MPLS. Se analizaran tambien diferentes topologias con caracteristicas propias que permitiran evaluar valores, tales como el retardo y el ancho de banda.