613 research outputs found

    Design, implementation, and verification of an FPGA-based control system for a permanent-magnet motor drive built upon a three-phase four-level active-clamped inverter

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    At the present time, a DE0 board from Terasic/Altera, which includes a Field Programmable Gate Array (FPGA) Cyclone III, is used to control a three-phase four-level active-clamped inverter which drives a permanent-magnet motor. The project consists in designing a new FPGA-based control system that substitutes the current control system based on the DE0 board. The novel control system will consist of a single board containing a new FPGA more suitable for the specific application, the analog-to-digital converters, and all the necessary auxiliary circuitry. The FPGA content wi[ANGLÈS] The present work summarizes the work and knowledge acquired by the author during its Master’s Thesis in the Research Group in Power Electronics, GREP. The development is based on the Multilevel Active-Clamped (MAC) power converter prototype, which was initially developed by GREP. Serving as a great introduction to the multilevel converter state-of-the-art, the prototype was tested and it was proved the need for a custom FPGA-based control platform board to drive a PMSM. The design of the board is then performed following the requirements established by the research group and the results obtained from the initial tests. Issues as power decoupling, signal conditioning and grounding strategies are discussed in the following chapters.[CASTELLÀ] La memoria aquí presentada recoge el trabajo y el conocimiento adquirido por el autor durante la elaboración de su tesis de Máster dentro del Grupo de Investigación en Electrónica de Potencia de la Universidad Politécnica de Cataluña, GREP. El trabajo elaborado se desarrolla en torno al prototipo, previamente desarrollado por los miembros del GREP, de un convertidor de potencia multinivel de tipo MAC (Multilevel Active-Clamped). La familiarización con los últimos avances en conversores multinivel se lleva a cabo mediante la fase de pruebas experimentales con este dispositivo, que a su vez demuestran la necesidad de diseñar una placa controladora específica basada en FPGA para mover un motor de imanes permanentes. Esta placa de control se diseña siguiendo los requisitos establecidos por el GREP y las necesidades surgidas en la fase de experimentación. En los capítulos del trabajo se tratan temas como el desacoplo de la alimentación, acondicionamiento de señales o metodologías de diseño de planos de masa.[CATALÀ] La memòria aquí presentada recull el treball i el coneixement adquirit per l'autor durant l'elaboració de la seva tesi de Màster dins del Grup de Recerca en Electrònica de Potència de la Universitat Politècnica de Catalunya, GREP. El treball es desenvolupa en torn al prototipus, prèviament desenvolupat pels membres del GREP, d'un convertidor de potència multinivell de tipus MAC (Multilevel Active-Clamped). La familiarització amb els darrers avanços en convertidors multinivell s'ha dut a terme mitjançant la fase de proves experimentals amb aquest prototipus, les quals han demostrat la necessitat de dissenyar una placa controladora específica basada en FPGA per controlar un motor d'imants permanents. Aquesta placa de control s'ha dissenyat seguint els requisits establerts pel GREP i les necessitats aparegudes en la fase d'experimentació. En els capítols del treball es tracten temes com el desacoblament de l'alimentació, condicionament de senyals o metodologies de disseny de plans de massa

    Electric vehicle powertrains with modular battery banks tied to multilevel NPC inverters

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    Nowadays, the internal combustion engine in vehicles is being replaced by electric motors, giving way to the electric vehicle, which results in reduced environmental impact, higher efficiency and lower emission of greenhouse gases. The powertrain of an electric vehicle is its most prominent subsystem, with the batteries and traction inverter being key components. Thus, due to their relevance, advances in the design of both components are of paramount importance. In this paper, the potential benefits achieved through a powertrain design approach based on combining a modular battery bank with multilevel NPC traction inverter topologies were analyzed, in comparison to a conventional two-level powertrain design. Several aspects were analyzed: modularity, complexity, battery-pack state-of-charge balancing, inverter loss, motor ac voltage harmonic distortion, motor common-mode voltage and reliability. Particularly, from the comparison study developed under the selected design scenario, the proposed design approach, based on modular battery packs and multilevel technology, shows a potential reduction of up to 55% in inverter losses, up to 65% in motor ac-voltage total harmonic distortion, and up to 75% in rms common-mode voltage.Peer ReviewedPostprint (published version

    The Q-Pass Index: A Multifactorial IMUs-Based Tool to Assess Passing Skills in Basketball

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    Despite being a key sport-specific characteristic in performance, there is no practical tool to assess the quality of the pass in basketball. The aim of this study is to develop a tool (the quality-pass index or Q-Pass) able to deliver a quantitative, practical measure of passing skills quality based on a combination of accuracy, execution time and pass pattern variability. Temporal, kinematics and performance parameters were analysed in five different types of passes (chest, bounce, crossover, between-the-leg and behind-the-back) using a field-based test, video cameras and body-worn inertial sensors (IMUs). Data from pass accuracy, time and angular velocity were collected and processed in a custom-built excel spreadsheet. The Q-pass index (0–100 score) resulted from the sum of the three factors. Data were collected from 16 young basketball players (age: 16 ± 2 years) with high (experienced) and low (novice) level of expertise. Reliability analyses found the Q-pass index as a reliable tool in both novice (CV from 4.3 to 9.3%) and experienced players (CV from 2.8 to 10.2%). Besides, important differences in the Q-pass index were found between players’ level (p < 0.05), with the experienced showing better scores in all passing situations: behind-the-back (ES = 1.91), bounce (ES = 0.82), between-the-legs (ES = 1.11), crossover (ES = 0.58) and chest (ES = 0.94). According to these findings, the Q-pass index was sensitive enough to identify the differences in passing skills between young players with different levels of expertise, providing a numbering score for each pass executed

    A novel on-site deployment, commissioning and debugging technique to assess and validate WSN based smart systems

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    In this work a novel on-site toolset-based architecture for tackling the main challenges of deploying and commissioning large scale WSN-based systems is proposed. This is one of the first implementations that addresses a complete set of runtime algorithms to efficiently deploy sensor platforms in the target scenarios based on the inclusion of the real behavior of the nodes within the in-situ simulation chain, combined with the integration of runtime diagnosis and reprogramming strategies to analyze the performance of the deployment in-field

    A novel on-site deployment, commissioning and debugging technique to assess and validate WSN based smart systems

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    In this work a novel on-site toolset-based architecture for tackling the main challenges of deploying and commissioning large scale WSN-based systems is proposed. This is one of the first implementations that addresses a complete set of runtime algorithms to efficiently deploy sensor platforms in the target scenarios based on the inclusion of the real behavior of the nodes within the in-situ simulation chain, combined with the integration of runtime diagnosis and reprogramming strategies to analyze the performance of the deployment in-field

    Uso de antibióticos y resistencia antimicrobiana en la unidad de cuidado intensivo neonatal

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    Neonatal sepsis constitutes one of the main causes of neonatal mortality in developing countries. Newborns, particularly premature newborns, have a higher risk of bacterial infections that result in frequent administration of antibiotics in the Neonatal Intensive Care Units (NICU), which is estimated to be as high as 70%. The clinical presentation of neonatal sepsis is nonspecific, prompting the early use of empirical antibiotic prescription to avoid adverse consequences in the patients. Its non-specificity characterizes it as a challenging diagnostic, this aspect led several authors to design strategies to determine which newborns are true candidates for antimicrobial therapy. Microbiology is closely linked to clinical practice. Thus, knowing the most frequent bacteria associated with neonatalsepsis will be closely related to the antibiotic spectrum that should be used to treat it. Furthermore, knowledge on basic pharmacology is key inasmuch as the antimicrobial treatment is not innocuous and can be related to an increase in mortality and morbidity. Clinical course and maternal risk factors are associated with the expected responsible germs that are already described in multiple descriptive studies worldwide. Indiscriminate use of broad-spectrum antibiotics for the management of newborn infections is leading to antibiotic resistance increase. At the same time, this is related to even higher rates of therapeutic failure with empiric antimicrobial treatment. Based on this, Antimicrobial Stewardship Programs play a determinant role to monitor the changes in local resistance to adjust and homogenize medical practice to regulate the use of antibiotics and mitigate the emergent andthreatening antimicrobial bacterial resistance. &nbsp;La sepsis neonatal constituye una de las principales causas de mortalidad neonatal en los países en desarrollo. Los neonatos, en particular los prematuros, tienen un mayor riesgo de infecciones bacterianas, por lo que el manejo con antibióticos constituye la terapia más frecuente en la Unidad de Cuidado Intensivo Neonatal (UCIN), estimándose en hasta un 70%. La presentación clínica de la sepsis neonatal es inespecífica en muchas ocasiones, lo que hace que la antibioticoterapia empírica se inicie tempranamente para evitar consecuencias deletéreas para los pacientes; su inespecificidad la caracteriza como un reto diagnóstico, por lo que diferentes autores han diseñado estrategias para determinar neonatos candidatos a terapia antimicrobiana. La microbiología permanece en contacto estrecho con la clínica ya que conocer los gérmenes frecuentemente asociados a la sepsis neonatal ayuda a determinar el espectro antibiótico a usar. De igual forma, el conocimiento de la farmacología antibiótica es clave puesto que el tratamiento antibiótico no es inocuo y puede asociarse a aumento de morbilidad o mortalidad. El tiempo de evolución y los factores de riesgo maternos están asociados a los gérmenes responsables esperados, ya descritos por &nbsp;múltiples estudios descriptivos a nivel mundial. El uso indiscriminado de antibióticos de amplio espectro para el manejo de infecciones en los recién nacidos ha generado un aumento en la resistencia antibiótica, lo que a su vez lleva a tasas más altas de fallo terapéutico con el uso de las terapias antibióticas empíricas. A razón de lo anterior, los Programas de Vigilancia de Uso de Antibióticos juegan un papel determinante para monitorear el cambio en la resistencia a nivel local para ajustar y homogeneizar la práctica médica que logre regular el uso de antibióticos y mitigar la emergente resistencia bacteriana. &nbsp

    Uso de antibióticos y resistencia antimicrobiana en la unidad de cuidado intensivo neonatal

    Get PDF
    Neonatal sepsis constitutes one of the main causes of neonatal mortality in developing countries. Newborns, particularly premature newborns, have a higher risk of bacterial infections that result in frequent administration of antibiotics in the Neonatal Intensive Care Units (NICU), which is estimated to be as high as 70%. The clinical presentation of neonatal sepsis is nonspecific, prompting the early use of empirical antibiotic prescription to avoid adverse consequences in the patients. Its non-specificity characterizes it as a challenging diagnostic, this aspect led several authors to design strategies to determine which newborns are true candidates for antimicrobial therapy. Microbiology is closely linked to clinical practice. Thus, knowing the most frequent bacteria associated with neonatalsepsis will be closely related to the antibiotic spectrum that should be used to treat it. Furthermore, knowledge on basic pharmacology is key inasmuch as the antimicrobial treatment is not innocuous and can be related to an increase in mortality and morbidity. Clinical course and maternal risk factors are associated with the expected responsible germs that are already described in multiple descriptive studies worldwide. Indiscriminate use of broad-spectrum antibiotics for the management of newborn infections is leading to antibiotic resistance increase. At the same time, this is related to even higher rates of therapeutic failure with empiric antimicrobial treatment. Based on this, Antimicrobial Stewardship Programs play a determinant role to monitor the changes in local resistance to adjust and homogenize medical practice to regulate the use of antibiotics and mitigate the emergent andthreatening antimicrobial bacterial resistance. &nbsp;La sepsis neonatal constituye una de las principales causas de mortalidad neonatal en los países en desarrollo. Los neonatos, en particular los prematuros, tienen un mayor riesgo de infecciones bacterianas, por lo que el manejo con antibióticos constituye la terapia más frecuente en la Unidad de Cuidado Intensivo Neonatal (UCIN), estimándose en hasta un 70%. La presentación clínica de la sepsis neonatal es inespecífica en muchas ocasiones, lo que hace que la antibioticoterapia empírica se inicie tempranamente para evitar consecuencias deletéreas para los pacientes; su inespecificidad la caracteriza como un reto diagnóstico, por lo que diferentes autores han diseñado estrategias para determinar neonatos candidatos a terapia antimicrobiana. La microbiología permanece en contacto estrecho con la clínica ya que conocer los gérmenes frecuentemente asociados a la sepsis neonatal ayuda a determinar el espectro antibiótico a usar. De igual forma, el conocimiento de la farmacología antibiótica es clave puesto que el tratamiento antibiótico no es inocuo y puede asociarse a aumento de morbilidad o mortalidad. El tiempo de evolución y los factores de riesgo maternos están asociados a los gérmenes responsables esperados, ya descritos por &nbsp;múltiples estudios descriptivos a nivel mundial. El uso indiscriminado de antibióticos de amplio espectro para el manejo de infecciones en los recién nacidos ha generado un aumento en la resistencia antibiótica, lo que a su vez lleva a tasas más altas de fallo terapéutico con el uso de las terapias antibióticas empíricas. A razón de lo anterior, los Programas de Vigilancia de Uso de Antibióticos juegan un papel determinante para monitorear el cambio en la resistencia a nivel local para ajustar y homogeneizar la práctica médica que logre regular el uso de antibióticos y mitigar la emergente resistencia bacteriana. &nbsp

    An intelligent electronic fuse for selective isolation of faulty switching cells in power electronic converter legs to guarantee continuous operation

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    © 2022 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting /republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other worksThis article proposes a novel device designated as an intelligent electronic fuse (iFuse) intended to be connected in series with any current-bidirectional voltage-unidirectional active switch present in a power converter. The iFuse duty is to selectively isolate its series-associated switch from the rest of the converter circuit immediately after detecting that this switch has failed in short circuit. Nonetheless, it maintains the reverse (free-wheeling) current path originally offered by the failed switch. The failure detection is typically performed when the failed switch causes a shoot-through event. Therefore, the iFuse is able to block large currents. The iFuse allows increasing the power-converter fault tolerance and reliability with regard to switch short-circuit failures (SCFs), as in converters featuring switches in parallel, redundant legs, and multilevel neutral-point-clamped topologies. The reliability model analysis of a two-level converter leg with two parallel switches per position reveals that its reliability can be increased up to four times when an iFuse is implemented in series with each switch. The iFuse device feasibility and good performance are verified through experimental tests, proving that it can detect and isolate the associated-switch failure in 6 µs , while stopping short-circuit currents of up to 1 kA without incurring in harmful di / dt values.Peer ReviewedPostprint (author's final draft

    Estudio de planta piloto para peletización de residuos madereros y su utilización como combustible en hornos ladrilleros

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    Biomass is one of the most suitable materials as an alternative fuel, but characteristics like moisture, oxygen excess content and low calorific value, this material requires pre-treatment processes. Pelletizing enables biomass for use directly on thermal processes. Brick sector has high energy demand for drying and firing processes and the use of fuels from biomass allows significant reductions in atmospheric emissions. This study compared energy and environmental performance of fuels from two types of pelletized biomass (waste from pruning of grass, shrubs and trees of the city) and sawdust waste. The biomass with best performance was sawdust, because of their lower energy consumption in pre-treatment process. Further, there was found a reduction in the cost of fuel between 7% and 10% supply, replacing 20% of the coal used in the process with biomass pellets.La biomasa es uno de los materiales más adecuados como combustible alternativo, pero por sus características de humedad, exceso de contenido de oxígeno y bajo poder calorífico, requiere ser sometida a procesos de pretratamiento. La pele-tización permite acondicionar la biomasa para su utilización directamente en procesos térmicos. El sector ladrillero tiene una gran demanda energética para sus procesos de secado y cocción y el uso de combustibles a partir de biomasa permite obtener reducciones importantes en emisiones atmosféricas. El estudio piloto comparó el desempeño energético y ambiental del uso de combustibles a partir de dos tipos de biomasas peletizadas —residuos de podas de césped, arbustos y árboles de la ciudad y residuos de producción de muebles y aglomerados, aserrín—. La biomasa con mejor desempeño fue el aserrín, debido a su menor consumo energético en el proceso de pretratamiento, aspecto que arroja una mayor productividad en su uso. Adicionalmente, se observó una reducción en los costos de suministro de combustible entre un 7 % y 10 %, sustituyendo un 20 % del carbón utilizado en el proceso
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