Evaluation and modeling of the variation of electromagnetic field on the cross section of a transmission line using finite difference method

This paper present a purpose to characterize power lines in order to identify level of operation since the power grid planning. In order to model a power line was required the use of computational tools to generate a mathematical model in MATLAB, which was based on the finite difference method and represent the electromagnetic field (EMF) contribution. The results were contrasted with real and measured values taken from a cross section of a power line that was previously modeled. Statistical analysis showed an accurate estimation of the electric and magnetic field emitted by the line identifying the same shape of the plotted curve and values in an acceptable range

Performance evaluation of a DC-AC inverter controlled with ZAD-FPIC

Introduction− Power converters are used in mi-crogrids to transfer power to the load with a regulated voltage. However, the DC-AC converters present distor-tions in the waveform that can be improved with the help of real-time controllers.Objective−Evaluate the response in alternating cur-rent of the buck converter controlled with the ZAD-FPIC technique.Methodology−Based on the differential equations that describe the buck power converter, the ZAD and FPIC controllers are designed. Afterwards, simulations of the complete controlled system are made using Simulink of MATLAB. Then, the system is implemented experi-mentally and the controller is executed in real-time with the help of a DS1104 from dSPACE. In the end, several tests are carried out to check the effectiveness of the controller.Results− The results show that the controller allows good stability against different variations in the system and in the load.Conclusions−The ZAD-FPIC technique controls the variable and tracks changes in the waveform, magni-tude, and frequency of the reference signal. The control-ler presents good stability to different tests, tracking the reference signal after each event.Introducción− Los convertidores de potencia son utili-zados en las micro redes para transferir la potencia a la carga con una tensión regulada. Sin embargo, los conver-tidores DC-AC presentan distorsiones en la forma de onda que pueden ser mejoradas con la ayuda de controladores en tiempo real.Objetivo− Evaluar la respuesta en corriente alterna del convertidor buck controlado con la técnica ZAD-FPIC.Metodología− Se parte de las ecuaciones diferenciales que describen el convertidor de potencia buck, luego se diseñan los controladores ZAD y FPIC, se hacen simu-laciones del sistema completo controlado en Simulink de Matlab, se implementa el sistema de forma experimental y el controlador se ejecuta en tiempo real con la ayuda de una DS1104 de la empresa dSPACE, al final se realizan varias pruebas para comprobar la efectividad del controlador.Resultados− Los resultados muestran que el controlador permite que una buena estabilidad contra diversas varia-ciones en el sistema y en la carga.Conclusiones− La técnica ZAD-FPIC controla la varia-ble y realiza seguimiento ante cambios en la forma de onda, magnitud y frecuencia de la señal de referencia. El controlador presenta buena estabilidad ante diferentes pruebas, siguiendo la señal de referencia después de cada event

Tendencias y características de la realidad virtual: Una revisión de la literatura

Virtual Reality has greatly evolved between 1940s and 1990s. Since then, it has been implemented in multiple research and knowledge areas, the most recognized being the entertainment industry. In order to establish the state of Virtual Reality and get an idea of its prospects, 537 scientific documents have been reviewed, applying search criteria, more specifically, Virtual Reality applied to education. A bibliometric analysis was realized based on summarizing each document, as well as its keywords and trends, then proceeding to categorize each one, according to the field of application. It was found that Virtual Reality is having relevance in medicine and training area, due to the ability to simulate difficult situations and above all, specific conditions raised by instructors. The future of Virtual Reality as a tool to train professionals in multiples areas is promising.La realidad virtual ha tenido una gran avance entre la década 1940 y 1990. Desde entonces, se ha implementado en múltiples áreas, tanto de la investigación como del conocimiento, siendo más reconocida en la industria del entretenimiento. Con el propósito de establecer el estado de la realidad virtual y obtener una idea de su futuro, 537 documentos científicos han sido revisados aplicando criterios de búsqueda específicos, como realidad virtual aplicada a la educación. Un análisis bibliométrico fue realizado, teniendo como base un resumen y descripción de cada artículo, así como sus palabras claves y tendencias, procediendo a categorizar cada documento de acuerdo con su campo de aplicación. Se encontró que la realidad virtual tiene una gran relevancia en la medicina y en el entrenamiento de personas, debido a su capacidad de simular situaciones difíciles y, sobre todo, condiciones específicas requeridas por instructores. El futuro de la realidad virtual como herramienta de entrenamiento para los profesionales de múltiples áreas es promisori

Monitoring electromagnetic fields and safe operation levels in electrical power transmission lines

Electrical power systems and their elements such as power transformers, transmission lines, capacitors, reactors and other elements, during normal operation generates electromagnetic fields that changes according with design, equipment distribution, current and voltage operation levels. This paper describes the monitoring electromagnetic fields and safe operation levels in electrical power transmission and distribution lines during the last five years in power lines located in warm climate with high salinity, corrosion and pollution level. A literature review was considered during the study. This paper characterizes power lines in order to guarantee safe operation to occupational exposure and general public since planning process. Results will be used in order to characterize power lines and will be used as a tool for utilities with the aim to reduce legal penalties and promote social responsibility. Results also were contrasted with International Commission on Non-Ionizing Radiation Protection (ICNIRP) recommendations with the reference levels for occupational exposure to time-varying electric and magnetic fields. Results provide recommendations for electrical grid utilities also the study compare real values with simulated values in order to guarantee an acceptable approach according with ICNIRP and international standards recommendation

Effects of splitter Blade Length on disc pump performance

The disc pump operates using boundary layer principle and viscous drag with a relatively low efficiency. There are methods to increase head and efficiency, one of them is the placing of blades sectors or splitter blades in discs. This method has been applied only in the low viscosity fluids pumping (v < 0.1 stokes). This study describe an experimental research in a hight viscocity fluid (v = 2 stokes) with exit angle (32 = 35° and different splitter blades Lengths (Ls) (75, 50, 25%). The purpose is to determinate the splitter blades length that achieves the most effective combination between the blade effect and boundary layer effect in order to increase the energy transmission efficiency from the impeller to the fluid. As result, it can be established that the use of spliter blades is an alternative to increase the performance of the disc pump. The highest efficiency and head were obtained for the gapsize between two discs (b) of 12 mm using a 50% spliter blades length of the main blade length

Perspectives of native community in la guajira facing sustainable development and energy supply

Access to electricity as a public service is important issue to promote the economic development of isolated communities. However, this service is not available in many remote communities. Providing electricity service must be accompanied with some identification and characterization plans according to the energy needs, including the service quality and energy efficiency. The direct perception of the native communities is fundamental to define the requirements of new electrification projects. This paper summarizes the perceptions of native communities in La Guajira, Colombia about providing electricity service, and possible actions for improving energy resources available in the area. To achieve these results, a survey that identifies the people's opinion was applied with the following factors: the percentage of households with electricity, the perception of service quality, the proper use of electricity, and its main use. The results show that a high percentage of the native population does not have access to electricity, but they recognize and identify that this service would promote their economic development. However, people's perception about service quality is not good, and most of the population has concern regarding the use of electricity, saving actions and payment mechanisms. Through this research, a new perception of the sustainable energy is determined, relevant to achieve the best application of the electricity use in the region, towards the promotion of the sustainable development. These results show that there is a need to ensure energy supplied to non-interconnected or isolated areas, which represents a great challenge for the Government in providing more resources to the population, and to promote compliance with the proclaimed in the current laws and energy policy.El acceso a la electricidad como servicio público resulta relevante para promover el desarrollo económico de comunidades aisladas. Sin embargo, este servicio no está disponible en muchas comunidades remotas. La prestación de este servicio debe ir acompañado de algunos planes de identificación y caracterización de las necesidades energéticas, incluyendo la calidad de la energía y eficiencia energética. La percepción directa de las comunidades indígenas es fundamental para definir los requerimientos de los proyectos de electrificación. Este artículo resume la percepción de las comunidades indígenas en La Guajira, Colombia frente a la prestación del servicio de energía eléctrica y posibles acciones de mejoramiento con recursos energéticos disponibles en la zona. Para lograr estos resultados, se realizó una encuesta que permite identificar la opinión que tienen las personas, identificando los siguientes factores: el porcentaje de hogares con servicio de electricidad, la percepción de la calidad del servicio, el uso apropiado de la electricidad y su principal uso. Los resultados evidencian que un alto porcentaje de la población indígena no cuenta con el acceso al servicio de electricidad, pero reconocen e identifican que este servicio promovería su desarrollo económico. Sin embargo, su percepción de la calidad del servicio no es buena y la mayoría de la población tiene preocupación respecto al uso de electricidad, las medidas de ahorro y mecanismos de pago. A través de esta investigación, se determinó una nueva percepción de la energía sostenible necesaria para lograr la mejor aplicación del uso de energía eléctrica en la región orientada hacia el fomento del desarrollo sostenible. Estos resultados muestran que existe una necesidad para garantizar el abastecimiento energético a las zonas no interconectadas o aisladas, lo cual representa un gran reto para el gobierno en brindar los recursos a su población y propender por el cumplimiento de lo proclamado en las leyes y la política energética vigente

Research trends in proton exchange membrane fuel cells during 2008–2018: A bibliometric analysis

A bibliometric analysis of proton exchange membrane fuel cells (PEMFCs) content from a total of 15.020 research publications was conducted between 2008 and 2018, the papers being detailed in the online version of SCIExpanded, Thomson Reuters Web of Science. Data processing tools such as Hitscite, CiteSpace, ArcGIS and Ucinet 6 were used to process the information. The parameters analyzed in the analysis were: type of document; the language of publication; volume and characteristics of publication output; publication by journals; performance of countries and research institutions; research trends and visibility. The study showed that "Fuel'', "Cell", "Membrane “and "Proton" were found in most of the titles of the documents, while "Performance", "Pemfc”, "Pem Fuel Cell" and "Fuel Cell" were the keywords most commonly used in documents. The analysis found that PEMFC studies have tended to be growing and that leading peer-reviewed journals have produced numerous publications on the subject. The investigation revealed that the country with the most significant production in the field is USA with a contribution of 3009; 20% of the total publications. Followed by China 2480; 16.5%, South Korea 1273; 8.5% and Germany 1121; 7.5%, showing to the main world powers as the most significant contributors to the research

Solar and wind energy potential characterization to integrate sustainable projects in native communities in La Guajira Colombia

El aprovechar eficientemente el potencial energético solar y eólico para la producción de energía eléctrica es un gran reto mundial. Es más necesario aun cuando se trata de comunidades rurales debido a la falta de proyectos que generen grandes oportunidades como opción de mejora de sus condiciones y sobre todo hacer que estos proyectos sean sostenibles a largo plazo. Este artículo presenta una revisión de los retos actuales en la sostenibilidad energética de comunidades indígenas de la Guajira Colombia y la forma en que pueden realizarse diferentes tipos de proyectos de energía sostenible para mejorar las diferentes necesidades de la población. El estudio se realizó en dos partes principales: la primera fue una consulta a la comunidad sobre las necesidades principales y la segunda la consulta sobre el potencial energético de la zona, con el fin de plantear posibles soluciones a necesidades no suplidas para la población. Como resultado del estudio se obtuvo que hay un alto interés de la comunidad por el desarrollo de diferentes proyectos que ayudan a suplir los requerimientos de las comunidades. Se definen diferentes retos para lograr que las comunidades indígenas de esta región sean más sostenibles y que tengan una mayor competitividad por medio de proyectos sustentables. La generación de posibles proyectos tipo se pueden realizar bajo las necesidades actuales que deben cubrirse para cada comunidad.The efficient use of solar and wind energy has been a great worldwide challenge. Also, it is more necessary when it is required by isolated communities due to the lack of applied projects which promotes innovation, solve problems and guarantee sustainable system in a long term scenario. This paper describe the energy requirements detected in native communities in la Guajira Colombia and propose alternative solutions based in energy applications to improve them in the population. The study was divided in two parts in order to propose possible solution of community’s needs: the first was a survey application to the native community which identified priority related to energy consumption and the second one was a characterization of energy resources of the area. Results evidenced a high motivation of the community in the development of projects based on their requirements and needs. In the paper describe those challenges to raise the sustainable and competitive level of these communities considering sustainable projects. Finally the paper describe projects that can be realized based on actual needs

Demand energy forecasting using genetic algorithm to guarantee safety on electrical transportation system

Demand estimation models are used for energy planning activities. Their primary function is focused on securing energy supply to final users using available resources in generation, transport and interconnection. Long-term planning models typically use non-linear optimization techniques considering an error not exceeding 5%. The reference model used by UPME in Colombia is limited to an average error of 1.6% considering non-linear modeling estimation techniques. However, they are limited in their ability to anticipate uncharacteristic variations in curves or externalities, which increases the probability of an erroneous prediction. Therefore, this research proposes a model to forecast electricity demand using neural networks in order to anticipate non-characteristic variations. The study first documents current methodologies for the prediction of maximum power demand, as well as the current deficiencies in the used forecasts, A new model is then formulated with the application of neural networks using the algorithm Cascade-Forward Back propagation using MATLAB R2017a. During the model comparison process, it was identified that the data obtained reflects the characteristics of demand behavior with an acceptable margin error equal to 0.5%

Evaluación de fallas en un transportador de cangilones. Caso de estudio

A failure in the bottom sheet of a bucket conveyor (KZBQ.AUMUND) during service was investigated. Sheets are coupled to the chain throught a screw connection; they operate in variable load scenarios causing fatigue. A chemical and microstructural analysis was made showing that sheet was built in steel with 0.15 % of Carbone without alloying elements that contribute to the refined grain and resistance increase. Strength calculation, used to determinate safety factor, consider load system and type material. Results concluded that geometry and thickness value do not provide an adequate fatigue resistance coefficient.Es investigada la falla en las láminas del fondo de un transportador de cangilones KZB-Q.AUMUND durante su servicio. Las láminas están acopladas a una cadena a través de uniones atornilladas y operan bajo un régimen de cargas variables causándoles fatiga. Se realiza un análisis químico y microestructural el cual evidencia que las láminas fueron elaboradas de un acero con 0,15 % de carbono sin elementos de aleación que contribuyan al afinamiento del grano y al incremento de la resistencia. Se calculan las tensiones para determinar el coeficiente de seguridad a la fatiga considerando el sistema de cargas y el material de las láminas. Los resultados concluyen que la geometría y los valores de espesor no le proporcionan a las láminas un adecuado coeficiente de resistencia a la fatiga