Estado del Arte de la Predicción de Variables en Sistemas de Ingeniería Eléctrica Basada en Inteligencia Artificial / State of the Art of Predicting Electrical Engineering Variables Based on Artificial Intelligence

Resumen Existe una gran cantidad de sistemas que se estudian y desarrollan en el campo de la Ingeniería Eléctrica en los que se realizan análisis que tienen como uno de sus fines principales la predicción de sus variables, tanto para procesos de planificación como de toma de decisiones. Con el advenimiento de la Inteligencia Artificial, se ha observado cómo distintas técnicas relacionadas con el aprendizaje automático y la optimización se han incorporado a estas tareas de predicción, con las cuales se obtienen generalmente mejores resultados en los valores estimados que aquellos generados a partir de técnicas más tradicionales. La presente investigación tiene como objetivo realizar una revisión de lo publicado sobre predicciones de variables en sistemas de Ingeniería Eléctrica en las bases de datos EBSCO, SciELO, RedAlyc, Springer Link, IEEE Xplorer, y Google Académico, a partir de una delimitación temporal y de palabras clave del área. A partir del análisis de la literatura se obtuvo la tendencia sobre el tema a partir de los años más productivos, áreas de impacto e idiomas más frecuentes. Se observó que los estudios desarrollados han crecido en años recientes, y que las áreas de mayor impacto, de acuerdo con el número de publicaciones y de citas son la predicción del consumo y producción de energía eléctrica, y las variables relacionadas con energías renovables.

Abstract In many systems that are studied and developed in the field of Electrical Engineering, analyzes are carried out that have as one of their main purposes the prediction of their variables, both for planning and decision-making processes. With the advent of Artificial Intelligence, it has been observed how different techniques related to machine learning and optimization have been incorporated into these prediction tasks. Those new techniques generally obtained better results in the estimation of values ​​than those generated from more traditional techniques. The objective of this research is to review what has been published on predictions of variables in Electrical Engineering systems in the databases EBSCO, SciELO, RedAlyc, Springer Link, IEEE Xplorer, and Google Scholar, given specific temporal and keyworks delimitations for the area. From the analysis of the literature, the trend on the subject was obtained from the most productive years, areas of impact, and most frequent languages. It was observed that the studies developed have grown in recent years and that the areas of greatest impact, according to the number of publications and citations, are the prediction of electricity consumption and production, and the variables related to renewable energy.

A review on control and fault-tolerant control systems of AC/DC microgrids.

Microgrids (MG) treat local energy supply issues effectively and from a point of view of the distribution grid, may be a power supply or virtual load. Despite holding a myriad of benefits, MGs also bear a set of challenges, including a higher fault rate. Currently, many articles focus on control techniques; however, little has been written about the techniques of control, hierarchical control, and fault-tolerant control (FTC) applied to MGs, which is the motive of this bibliographic revision on control systems. A brief comparison of the different approaches in the field of present-day research is carried out primarily addressing hierarchical control and fault tolerance. The objective of this investigation is to attract the interest of researchers to the field of control and fault tolerance applied to MGs, such as: modeling, testbed, benchmark systems, control and hierarchical control strategies, fault diagnosis and FTC.

Análisis bibliométrico de los proyectos de graduación de ingeniería eléctrica de la Universidad de Costa Rica 1999-2018 / Bibliometric analysis of the graduation projects in electrical engineering of the University of Costa Rica 1999-2018

Resumen El objetivo de esta investigación fue realizar un análisis bibliométrico de los proyectos de graduación de pregrado en la Escuela de Ingeniería Eléctrica de la Universidad de Costa Rica, entre los años 1999 y 2018. El interés principal es desarrollar un análisis descriptivo de la distribución temporal y temática de estos documentos, los cuales se realizan de forma individual por los estudiantes de esta carrera para optar por el título de Bachillerato en Ingeniería Eléctrica. En tal sentido, se analizaron las siguientes variables: a) número de proyectos por quinquenio, b) áreas temáticas, c) número de páginas por documento, d) género de los autores. Se obtuvo un total de 938 documentos, utilizando la información contenida en las bases de datos del Sistema de Bibliotecas, Documentación e Información de la Universidad de Costa Rica. Los resultados se discutieron en términos de la evolución de las variables y temáticas a lo largo de los veinte años del período estudiado. Entre los hallazgos se encuentran la mayor participación de las mujeres y la reducción del tamaño de los documentos en años recientes, así como la constante actualización de las temáticas. Estos resultados son un reflejo de los intereses y áreas activas de esta carrera, por lo que los resultados pueden constituir un indicador de la evolución de la disciplina de Ingeniería Eléctrica en la institución.

Abstract The purpose of this research was to perform a bibliometric analysis of undergraduate graduation projects at the School of Electrical Engineering of the University of Costa Rica, between the years 1999 and 2018. The main interest is to perform a descriptive analysis of the temporal distribution and thematic areas of these documents, which are carried out individually by the students of this career to opt for the Bachelor's Degree in Electrical Engineering. To perform the analysis, the following variables were obtained: a) number of projects per quinquennium, b) thematic areas, c) number of pages per document, d) gender of the authors. In total, 938 documents were analyzed, using the information contained in the databases of the SIBDI system of the University of Costa Rica. The results were discussed in terms of the evolution of the variables and themes throughout the twenty years of the period studied. Among the findings are the greater participation of women in recent years, the reduction of the size of the documents, and the constant updating of the themes. These results reflect the interests and active areas of this career, so the results can be an indicator of the evolution of the Electrical Engineering discipline in the institution.

Flexible robotic teleoperation architecture for intelligent oil fields.

Teleoperation virtual platforms allow people to send their skills and capacities into machines located in either relative close (few meters away) or far (different continents) locations. With the use of lightweight protocols, people can remotely control the actions and movements of robots so they can avoid physical interaction with dangerous or risky places. Oil and gas well-pads stations are working zones considered hazardous due to the various chemical substances used in their daily processes. This characteristic makes these places the perfect candidates for the implementation of teleoperation solutions in order to reduce the direct interaction of humans with different chemicals and risky situations. The following investigation focuses on the development of a base teleoperation scheme to perform inspection and maintenance tasks in the inside one of these hydrocarbon facilities. The proposed system aims to generate an easily scalable teleoperation solution using distributed control schemes and a lightweight communication protocol to remotely manipulate a KUKA mobile manipulator. As the first stage of this investigation, the main result focuses on the development of the generic control and communication functions that allow the physical testing of the system using a KUKA YouBOT mobile manipulator and the help of a qualified operator of the station.

Efeitos de uma disciplina de relações interpessoais no repertório social de estudantes de exatas / Effects of an interpersonal relations discipline on social repertoire of science exact students / Efectos de una disciplina de relaciones interpersonales en repertorio sociale de estudiantes de exactas

Este estudo teve por objetivo avaliar o repertório de habilidades sociais de estudantes de Ciências Exatas antes e após uma disciplina de Relações Interpessoais. Participaram deste estudo 21 universitários, sendo 17 do curso de Engenharia Elétrica e 4 de Química Industrial, matriculados na disciplina de Relações Interpessoais para o Curso de Engenharia Elétrica. A disciplina teórico-prática foi baseada em vivências e os estudantes responderam ao Inventário de Habilidades Sociais (IHS) e ao Questionário de Avaliação Final da Disciplina (QAFD). Os resultados apontaram diferenças estatisticamente significativas quanto ao escore geral de habilidades sociais e a média no QAVD entre as avaliações do pré e pós-teste. Foram observadas ainda correlações positivas e fortes entre o QAVD antes e após a disciplina. Além disso, (b) o escore geral QAVD após adisciplina se relacionou positiva e moderadamente com o escore geral (IHS) dehabilidades sociais no pós-teste.

This study aimed to evaluate the repertoire of social skills of students of Exact Sciences before and after an Interpersonal Relations discipline. Twenty-one university students participated in this study, of which 17 were from Electrical Engineering and 4 from Industrial Chemistry, enrolled in the discipline of Interpersonal Relationships for the Electrical Engineering Course. The theoretical-practical discipline was based on experiences and the students answered the Social Skills Inventory (IHS) and the Discipline Final Assessment Questionnaire (QAFD). The results showed statistically significant differences in the general social skills score and the mean in the QAVD between the pre and post-test evaluations. Positive and strong correlations were also observed between the QAVD before and after the discipline. In addition, (b) the overall QAVD post-discipline score was positively and moderately related to the overall social skills score (IHS) in the post-test.

Este estudio tuvo por objetivo evaluar el repertorio de habilidades sociales de estudiantes de Ciencias exactas antes y después de una disciplina de relaciones interpersonales. Participaron de este estudio 21 universitarios, siendo 17 del curso de Ingeniería Eléctrica y 4 de Química Industrial, matriculados en la disciplina de Relaciones Interpersonales para el Curso de Ingeniería Eléctrica. La disciplina teórico-práctica fue basada en vivencias y los estudiantes respondieron al inventario de Habilidades Sociales (IHS) y al Cuestionario de Evaluación Final de la Disciplina (QAFD). Los resultados apuntaron diferencias estadísticamente significativas en cuanto al puntaje general de habilidades sociales y la media en el QAVD entre las evaluaciones del pre y post-test. Se observaron correlaciones positivas y fuertes entre el QAVD antes y después de la disciplina. Además, (b) el puntaje general QAVD post la disciplina se relacionó positiva y moderadamente con el puntaje general (IHS) de habilidades sociales en el post-test.

Radial basis function for fast voltage stability assessment using Phasor Measurement Units.

A simple method, based on Machine Learning Radial Basis Functions, RBF, is developed for estimating voltage stability margins in power systems. A reduced set of magnitude and angles of bus voltage phasors is used as input. Observability optimization technique for locating Phasor Measurement Units, PMUs, is applied. A RBF is designed and used for fast calculation of voltage stability margins for online applications with PMUs. The method allows estimating active local and global power margins in normal operation and under contingencies. Optimized placement of PMUs leads to a minimum number of these devices to estimate the margins, but is shown that it is not a matter of PMUs quantity but of PMUs location for decreasing training time or having success in estimation convergence. Compared with previous work, the most significant enhancement is that our RBF learns from PMU data. To test the proposed method, validations in the IEEE 14-bus system and in a real electrical network are done.

Hybrid AC/DC microgrid test system simulation: grid-connected mode.

In this paper, a Microgrid (MG) test model based on the 14-busbar IEEE distribution system is proposed. This model can constitute an important research tool for the analysis of electrical grids in its transition to Smart Grids (SG). The benchmark is used as a base case for power flow analysis and quality variables related with SG and holds distributed resources. The proposed MG consists of DC and AC buses with different types of loads and distributed generation at two voltage levels. A complete model of this MG has been simulated using the MATLAB/Simulink environmental simulation platform. The proposed electrical system will provide a base case for other studies such as: reactive power compensation, stability and inertia analysis, reliability, demand response studies, hierarchical control, fault tolerant control, optimization and energy storage strategies.

Fish-eye camera and image processing for commanding a solar tracker.

The design and implementation of a solar tracker based on panoramic images captured by a fisheye camera are proposed. Such images receive a digital treatment to estimate the sun azimuth and the elevation angles. These angles are fed to a microcontroller, handling an accelerometer with a gyroscope, that positions the solar tracker to the angle of solar elevation and a compass to set the azimuth angle concerning the north, either magnetic or geographic. The proposed system works satisfactorily to guide the solar tracker regardless of whether it is a sunny or cloudy day.

Optimal reactive power compensation in electrical distribution systems with distributed resources. Review.

In this paper an exhaustive bibliographical revision of the mathematical methods used for the optimal selection and location of reactive power compensating elements is developed, the results obtained by different authors for different objective functions are analyzed and a scientific problem in the conflict that the electric variables show when analyzed individually is identified; thus demonstrating the need to analyze this problem in a multi-criteria way and taking into account topologies of distribution grids with distributed generation and energy storage. This research demonstrates that reactive power compensation in distribution grids with distributed resources is a problem that must be analyzed from multiple criteria that consider several objective functions to be optimized; thus achieving a global solution that contemplates an optimal location and dimensioning of reactive power compensating elements that contribute to the joint improvement of the voltage profiles, minimization of power losses, harmonic mitigation, increased line capacity, voltage stability and power factor improvement, all of them to a minimum investment cost. A theoretical heuristic is also proposed to solve the described problem, based on the multicriteria optimization method.

A inserção da engenharia biomédica nos cursos de graduação de engenharia elétrica no Brasil / The insertion of biomedical engineering in electrical engineering undergraduate courses in Brazil

A inserção de temas específicos da Engenharia Biomédica (EB) nos cursos de graduação em Engenharia Elétrica (EE) foi examinada em levantamento da oferta de disciplinas nesta área, realizado nos 214 cursos de EE que possuem dados sobre as grades curriculares e disciplinas em seus sítios na internet. Foram levantadas informações sobre os cursos de pós-graduação (PG) em EB existentes no Brasil, relacionadas à oferta de disciplinas de EB na graduação. Nossos dados indicam que apenas 7,5% dos cursos de EE examinados possuem pelo menos uma disciplina de EB, concentrados nas escolas públicas (87,5%) e nas regiões sul e sudeste do país (75%). Nestes poucos cursos, foram identificadas 40 disciplinas de EB. Apenas 11 delas oferecem introdução geral aos diferentes aspectos da área; os 3/4 restantes restringem-se a aspectos específicos de subáreas da EB. Além disso, 87,5% destas disciplinas são de caráter eletivo (ou não-obrigatório), com abordagem exclusivamente teórica dos temas (14,0% do total de horas-aula nas disciplinas de EB). Dos 10 programasde PG em EB, 60,0% estão em IES cujos cursos de EE possuem disciplinas específicas EB; 62,5% das disciplinas de EB são oferecidas por IES que não têm programas de PG na área, indicando pouca correlação entre a existência de um programa de PG em EB e a oferta de conteúdos nesta área para a graduação em EE. Estes dados sugerem a necessidade de inserção mais substancial e estruturada de temas de EB nos cursos de graduação em EE, em especial nas instituições privadas de ensino, e de estímulo a uma maior contribuição dos programas de PG no ensino de graduação em EE.

The present study surveyed the disciplines on Biomedical Engineering (BE) offered in 214 Electrical Engineering (EE) undergraduate courses in Brazilian Universities. Data on discipline content and other characteristics, as well as their association with graduate courses, were gathered from Internet sites in August and September, 2007. Our data indicate that only 7.5% of the Brazilian EE courses present at least one discipline on EB themes, greatly concentrated in public institutions and in the more developed south/southeast states. In only 25% of these few courses there are introductory disciplines presenting most of the different EB areas. In the remaining courses, only specific aspects of particular EB areas are presented in a fragmentary, isolated and non contextualized way. Furthermore, 87.5% of these EB disciplines are optional in the curriculium, and practical classes or approaches were offered in only 14% of the total class schedule. While 62.5% of the EB disciplines are offered by institutions that have graduating courses in EB, only 60% of the Brazilian graduation courses are involved in undergraduate EB disciplines. These data point to the need of a more structured and intensive inclusion of EB themes in the undergraduate courses (particularly in private institutions), as well as to the importance of a closer involvement of graduate courses in undergraduate instruction.