EPIC - Energy Processing and Integrated Circuits
Total activity: 1038
Type
Research group
Type of group
UPC research group
Acronym
EPIC
URL
http://www.eel.upc.edu/investigacion/grupos-de-investigacion-1/electronica-industrial-y-de-pontencia/epic-energy-processing-and-integrated-circuits?set_language=es Open in new window
Objectives
Our research activity has been hitherto focused in energy processing integrated circuits, encompassing both CMOS technologies for future generation multicore processors and RF transmitters, as well as new devices for exploring the ultimate energy density limits. These activities have been driven by ultra-low-power battery operated devices now migrating into energy harvesting enabled wireless sensor networks, pushing down scalability limits through the concurrence of new devices (more than Moore, GaN, graphene), circuit and system perspectives with the aim of a transversal impact to various applications, namely, among others, both downscaled portable terminals and distributed sensors for wireless monitoring, and practically all applications within the integrated system and circuits area. New challenges include wireless networks-on-chip for next generation many-core processors for high performance computing, nano-satellite swarms, wireless energy transfer, smart grids
Keywords
Energy harvesting wireless sensor networks; Energy-aware graphene-enabled wireless communications at the nanoscale; Smart Grids; Wireless energy transfer for small satellite networks

Graphic summary
  • Show / hide key
  • Information


Scientific and technological production
  •  

1 to 50 of 1038 results
  • Access to the full text
    A methodology to introduce sustainability into the Final Year Project to foster sustainable engineering projects  Open access

     Lopez Alvarez, David; Sanchez Carracedo, Fermin; Vidal Lopez, Eva Maria; Pegueroles Valles, Josep Rafel; Alier Forment, Marc; Cabre Garcia, Jose Maria; Garcia Almiñana, Jordi; García, Helena
    Annual Frontiers in Education Conference
    p. 2360-2366
    Presentation's date: 2014-10-24
    Presentation of work at congresses

    Read the abstract Read the abstract Access to the full text Access to the full text Open in new window  Share Reference managers Reference managers Open in new window

    The introduction of sustainability skills into higher education curricula is a natural effect of the increasing importance of sustainability in our daily lives. Topics like green computing, sustainable design or environmental engineering have become part of the knowledge required by today’s engineers. Furthermore, we strongly believe that the introduction of this skill will eventually enable future engineers to develop sustainable products, services and projects. The Final Year Project is the last academic stage facing students and a step towards their future professional engineering projects. As such, it constitutes a rehearsal for their professional future and an ideal opportunity for reflecting on whether their Final Year Project is sustainable or not, and to what extent. It also provides a good tool for reviewing the lessons learned about sustainability during the degree course and for applying them in a holistic and integrated way. In this paper, we present a guide that allows both students and advisors to think carefully about the sustainability of engineering projects, in particular the Final Year Project.

    The introduction of sustainability skills into higher education curricula is a natural effect of the increasing importance of sustainability in our daily lives. Topics like green computing, sustainable design or environmental engineering have become part of the knowledge required by today’s engineers. Furthermore, we strongly believe that the introduction of this skill will eventually enable future engineers to develop sustainable products, services and projects. The Final Year Project is the last academic stage facing students and a step towards their future professional engineering projects. As such, it constitutes a rehearsal for their professional future and an ideal opportunity for reflecting on whether their Final Year Project is sustainable or not, and to what extent. It also provides a good tool for reviewing the lessons learned about sustainability during the degree course and for applying them in a holistic and integrated way. In this paper, we present a guide that allows both students and advisors to think carefully about the sustainability of engineering projects, in particular the Final Year Project.

    Postprint (author’s final draft)

  • Capacitorless DC-DC converter

     Martínez García, Herminio; Grau Saldes, Antoni
    IEEE International Conference on Emerging Technologies and Factory Automation
    p. 1-6
    Presentation's date: 2014-09-19
    Presentation of work at congresses

     Share Reference managers Reference managers Open in new window

  • A Linear–Assisted DC/DC Converter Based on Current-Mode Control

     Martínez García, Herminio; Grau Saldes, Antoni
    IEEE International Conference on Emerging Technologies and Factory Automation
    p. 1-8
    DOI: 10.1109/ETFA.2014.7005203
    Presentation's date: 2014-09-18
    Presentation of work at congresses

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    This article shows the proposal of a current-mode one-cycle control for linear-assisted DC/DC converters. Linear-assisted DC/DC converters are structures that allow to take advantages of the two classic alternatives in the design of power supply systems: voltage linear regulators (classic NPN topology or LDO –low dropout–) and switching DC/DC converters. The current-mode one-cycle control technique is proposed in order to obtain the duty cycle of the linear-assisted converter switch. The proposed structure can provide an output with suitable load and line regulations. Thus, the paper shows the design and simulation results of the proposed current-mode one-cycle linear-assisted converter.

  • Using constant switching frequency control in linear-assisted DC-DC switching converters

     Martínez García, Herminio; Grau Saldes, Antoni
    IEEE International Conference on Emerging Technologies and Factory Automation
    p. 1-6
    Presentation's date: 2014-09-18
    Presentation of work at congresses

     Share Reference managers Reference managers Open in new window

  • Cascoded OTA based low dropout (LDO) voltage regulators

     Martínez García, Herminio
    IEEE International Conference on Emerging Technologies and Factory Automation
    p. 1-5
    DOI: 10.1109/ETFA.2014.7005343
    Presentation's date: 2014-09-18
    Presentation of work at congresses

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    This article aims to present the design of a 4.5-V, 450-mA low drop-out (LDO) voltage linear regulator based on a two stage cascoded operational transconductance amplifier (OTA) as error amplifier. The aforementioned two-stage OTA is designed with cascoded current mirroring technique to boost up the output impedance. The proposed OTA has a DC gain of 101 dB under no load condition. The designed reference voltage included in the LDO regulator is provided by a band gap reference with the temperature coefficient (T¿) of 0.025 mV/ºC. The proposed LDO regulator has a maximum drop-out voltage of 0.5 V @ 450 mA of load current, and has the worst case power supply rejection ratio (PSRR) of [54.5 dB, 34.3 dB] @ [100 Hz, 10 kHz] in full load condition. All the proposed circuits are designed using a 0.35 µm CMOS technology. The design is checked in order to corroborate its performance for wide range of input voltage, founding that the circuit design works fine meeting all the initial specification requirements.

  • Versatility of power gyrator structures for energy processing in photovoltaic solar systems

     Martínez García, Herminio; Grau Saldes, Antoni
    IEEE International Conference on Emerging Technologies and Factory Automation
    p. 1-8
    Presentation's date: 2014-09-18
    Presentation of work at congresses

     Share Reference managers Reference managers Open in new window

  • Access to the full text
    The use of power DC-DC converters and gyrators structures for energy processing in photovotaic solar facilities  Open access

     Martínez García, Herminio
    International Symposium on Energy Challenges & Mechanics
    p. 1-5
    Presentation's date: 2014-08-21
    Presentation of work at congresses

    Read the abstract Read the abstract Access to the full text Access to the full text Open in new window  Share Reference managers Reference managers Open in new window

    This article provides a classification of high efficiency switching power-gyrator structures and their use as cells for energy processing in photovoltaic solar facilities. Having into account the properties of these topologies presented in the article, their inclusion in solar facilities allows increasing the performance of the whole installation. Thus, the design, simulation and implementation of a G-type power gyrator are carried out throughout the text. In addition, in order to obtain the maximum power from the photovoltaic solar panel, a maximum power point tracking (MPPT) is mandatory in the energy processing path. Therefore, the practical implementation carried out includes a control loop of the power gyrator in order to track the aforementioned maximum power point of the photovoltaic solar panel.

  • Access to the full text
    The use of power DC-DC converters and gyrator structures for energy processing  Open access

     Martínez García, Herminio
    International Symposium on Energy Challenges & Mechanics
    p. 1-6
    DOI: 1
    Presentation's date: 2014-08-21
    Presentation of work at congresses

    Read the abstract Read the abstract Access to the full text Access to the full text Open in new window  Share Reference managers Reference managers Open in new window

    This article provides a classification of high efficiency switching power-gyrator structures and their use as cells for energy processing in photovoltaic solar facilities. Having into account the properties of these topologies presented in the article, their inclusion in solar facilities allows increasing the performance of the whole installation. Thus, the design, simulation and implementation of a G-type power gyrator are carried out throughout the text. In addition, in order to obtain the maximum power from the photovoltaic solar panel, a maximum power point tracking (MPPT) is mandatory in the energy processing path. Therefore, the practical implementation carried out includes a control loop of the power gyrator in order to track the aforementioned maximum power point of the photovoltaic solar panel.

  • Design of a linear–assisted DC-DC switching regulator with constant switching frequency

     Martínez García, Herminio
    IEEE International Midwest Symposium on Circuits and Systems
    p. 455-458
    DOI: 10.1109/MWSCAS.2014.6908450
    Presentation's date: 2014-08-05
    Presentation of work at congresses

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    DC-DC Switching Converters; Voltage Linear Regulators; Linear-Assisted DC-DC Voltage Regulators.

  • Power gyrator structures: Versatile cells for energy processing in photovoltaic solar facilities

     Martínez García, Herminio
    IEEE International Midwest Symposium on Circuits and Systems
    p. 447-450
    DOI: 10.1109/MWSCAS.2014.6908448
    Presentation's date: 2014-08-03
    Presentation of work at congresses

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    This paper provides a classification of high efficiency switching power-gyrator structures and their use as cells for energy processing in photovoltaic solar facilities. Having into account the properties of these topologies presented in the article, their inclusion in solar facilities allows increasing the performance of the whole installation. Thus, the design, simulation and implementation of a G-type power gyrator are carried out throughout the text. In addition, in order to obtain the maximum power from the photovoltaic solar panel, a maximum power point tracking (MPPT) is mandatory in the energy processing path. Therefore, the practical implementation carried out includes a control loop of the power gyrator in order to track the aforementioned maximum power point of the photovoltaic solar panel.

  • Design of a linear-assisted DC-DC switching regulator with constant switching frequency

     Martínez García, Herminio
    IEEE International Midwest Symposium on Circuits and Systems
    p. 455-458
    DOI: 10.1109/MWSCAS.2014.6908450
    Presentation's date: 2014-08-03
    Presentation of work at congresses

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    This article shows the proposal of a linear-assisted converter or linear-&-switching hybrid converter with a constant switching frequency. The control loop of the system is based on the current-mode technique. The main disadvantage of a converter with current-mode control is the inherent instability of the loop when switch duty ratios are greater than 0.5. In order to make stable the proposed linear-assisted converter, the article shows the technique based on a slope compensation.

  • Cooperative signal amplification for molecular communication in nanonetworks

     Abadal Cavalle, Sergi; Llatser Marti, Ignacio; Alarcon Cot, Eduardo Jose; Cabellos Aparicio, Alberto
    Wireless networks
    Vol. 20, num. 6, p. 1611-1626
    DOI: 10.1007/s11276-014-0696-z
    Date of publication: 2014-08-01
    Journal article

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    Nanotechnology is enabling the development of devices in a scale ranging from a few to hundreds of nanometers. Communication between these devices greatly expands the possible applications, increasing the complexity and range of operation of the system. In particular, the resulting nanocommunication networks (or nanonetworks) show great potential for applications in the biomedical field, in which diffusion-based molecular communication is regarded as a promising alternative to EM-based solutions due to the bio-stability and energy-related requirements of this scenario. However, molecular signals suffer a significant amount of attenuation as they propagate through the medium, thus limiting the transmission range. In this paper, a signal amplification scheme for molecular communication nanonetworks is presented wherein a group of emitters jointly transmits a given signal after achieving synchronization. This is achieved by means of quorum sensing (QS), a method used by bacteria to both sense their population and coordinate their actions. By using the proposed methodology, the transmission range is extended proportionally to the number of synchronized emitters. An analytical model of QS is provided and validated through simulation. This model is the main contribution of this work and accounts for the activation threshold (which will eventually determine the resulting amplification level) and the delay of the synchronization process.

  • Observation of chaotic behavior in automatic tuning loops for continuous-time filters

     Martínez García, Herminio; Cosp Vilella, Jordi; Manzanares Brotons, Manuel
    IEEE International Midwest Symposium on Circuits and Systems
    p. 742-745
    DOI: 10.1109/MWSCAS.2013.6674756
    Presentation's date: 2014-08
    Presentation of work at congresses

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    he appropriate linear dynamic modeling of continuous-time filters (CTFs) with automatic tuning loops should be obtained to assure stability in case an improved design of the loop controllers is to be carried out. With this aim, starting from a general and systematic analysis in order to obtain an equivalent small-signal linearized incremental model, from which transfer functions between output variables and control voltages are derived, the subsequent design of compensated loops with enhanced stability and dynamic performance is required. This systematic procedure allows obtaining improved controllers for the two involved control loops. However, CTFs with automatic tuning loops are nonlinear feedback systems with potential instability. What is more, nonlinear phenomena, which cannot be predicted by a design-oriented small signal modeling approach, are observed in this kind of tuning systems. The purpose of this work is to highlight that when control parameters are varied, the system could present different kinds of dynamical nonlinear phenomena such as bifurcations and chaotic behavior, which cannot be predicted by the small signal design-oriented model.

  • On frequency optimization of assymetric resonant inductive coupling wireless power transfer links

     Egidos, Nuria; Bou, Elisenda; Sedwick, Raymond; Alarcon Cot, Eduardo Jose
    Progress in Electromagnetics Research Symposium
    p. 885-889
    Presentation's date: 2014-08
    Presentation of work at congresses

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    Resonant Inductive Coupling Wireless Power Transfer (RIC-WPT) is a leading field of research due to the growing number of applications that can benefit from this technology: from biomedical implants to consumer electronics, fractionated spacecraft and electric vehicles amongst others. However, current applications are limited to symetric point-to-point-links. New challenges and applications of RIC-WPT emphasize the necessity to explore, predict and optimize the behavior of these links for different configurations: multi-point RIC-WPT networks and assymetrical systems. In this work a design methodology oriented towards the optimization of assymetric RIC-WPT links is presented, resulting in a closed analytical formulation of the optimal frequency at which an assymetrical RIC-WPT link should operate. Finally, the resulting efficiency-optimized link si explored and compared to previous results obtained in RIC-WPT symetric configurations [1, 2].

  • De la teoría a la práctica: cinco años después de la integración de la competencia genérica de sostenibilidad en el Grado en Ingeniería Informática  Open access

     Garcia Almiñana, Jordi; Sanchez Carracedo, Fermin; Lopez Alvarez, David; Vidal Lopez, Eva Maria; Cabre Garcia, Jose Maria; García García, Helena; Alier Forment, Marc
    Jornadas de Enseñanza Universitaria de la Informática
    p. 253-260
    Presentation's date: 2014-07-09
    Presentation of work at congresses

    Read the abstract Read the abstract Access to the full text Access to the full text Open in new window  Share Reference managers Reference managers Open in new window

    La sostenibilidad es una de las competencias trans- versales básicas que todo ingeniero debería adquirir durante su formación. De hecho, seguir desarrollando ciencia y tecnología de espaldas a la sostenibilidad provocaría en poco tiempo un colapso de nuestro planeta. La puesta en marcha del Espacio Europeo de Educación Superior (EEES) ha propiciado una opor- tunidad única para replantearse diferentes aspectos educativos, entre los cuales destaca la inclusión de esta competencia en los planes de estudio. Existe literatura abundante sobre estrategias y pro- puestas teóricas para incluir esta competencia en las ingenierías. Sin embargo, pocos trabajos han sido llevados a cabo desde una perspectiva más práctica. La Facultat de Informàtica de Barcelona (FIB) posee amplia experiencia en el diseño de titulaciones adap- tadas al EEES y ha integrado la sostenibilidad en su plan de estudios de Grado en Ingeniería Informática. En este trabajo se revisa el proceso de diseño del plan de estudios de Grado en Ingeniería Informática de la FIB, aprobado en el año 2009, y se analiza la experiencia de integración de la sostenibilidad tras cinco años de funcionamiento del grado. Se comentan los mecanismos de organización y coordinación entre las asignaturas implicadas y, finalmente, se extraen las lecciones aprendidas.

    La sostenibilidad es una de las competencias transversales básicas que todo ingeniero debería adquirir durante su formación. De hecho, seguir desarrollando ciencia y tecnología de espaldas a la sostenibilidad provocaría en poco tiempo un colapso de nuestro planeta. La puesta en marcha del Espacio Europeo de Educación Superior (EEES) ha propiciado una oportunidad única para replantearse diferentes aspectos educativos, entre los cuales destaca la inclusión de esta competencia en los planes de estudio. Existe literatura abundante sobre estrategias y propuestas teóricas para incluir esta competencia en las ingenierías. Sin embargo, pocos trabajos han sido llevados a cabo desde una perspectiva más práctica. La Facultat de Informàtica de Barcelona (FIB) posee amplia experiencia en el diseño de titulaciones adaptadas al EEES y ha integrado la sostenibilidad en su plan de estudios de Grado en Ingeniería Informática. En este trabajo se revisa el proceso de diseño del plan de estudios de Grado en Ingeniería Informática de la FIB, aprobado en el año 2009, y se analiza la experiencia de integración de la sostenibilidad tras cinco años de funcionamiento del grado. Se comentan los mecanismos de organización y coordinación entre las asignaturas implicadas y, finalmente, se extraen las lecciones aprendidas.

    SUMMARY -- Sustainability is one of the basic professional skills that every engineer should incorporate during their training. In fact, developing science and technology without sustainability criteria would collapse our planet. The launching of the European Higher Education Area (EHEA) has provided a unique opportunity to rethink different educational aspects, including the integration of this skill into the curriculum. Abundant literature exists on strategies and theoretical proposals to include this skill into engineering. However, few studies have been done from a more practical perspective. The Barcelona School of Informatics (FIB) has wide experience in the design of degrees according to the EHEA, and has integrated sustainability into the Informatics Engineering degree. This paper reviews the process of the design of the FIB’s Informatics Engineering degree curriculum, approved in 2009, and analyses the experience of sustainability integration after five years. The organizational and coordination mechanisms between the subjects are discussed, and finally the lessons learnt are extracted.

  • Optimization of WPT efficiency using a conjugate load in non-impedance matched systems.

     Chabalko, Matthew; Alarcon Cot, Eduardo Jose; Bou Balust, Elisenda; Ricketts, David S.
    IEEE International Symposium on Antennas and Propagation
    p. 645-646
    DOI: 10.1109/APS.2014.6904653
    Presentation's date: 2014-07-06
    Presentation of work at congresses

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    Maximum power transfer and maximum efficiency are two important design constraints in wireless power transfer applications. Several works have investigated the proper load and impedance match conditions to optimize either efficiency or power transfer. In this paper we show that the optimal load for maximum power transfer and maximum efficiency is the same (a conjugate matched load) when the source resistance is zero. This is important, as many WPT systems have a relatively low, unknown source impedance. Since the optimal load for both efficiency and power is the same as the source impedance approaches zero, the designer can use a bi-conjugate load for a near optimal design for both maximum power and efficiency. As the source impedance becomes significant, the bi-conjugate matched system provides higher power, but at the expense of lower efficiency. Maximum efficiency is achieved with a non-bi-conjugate load, when the source impedance is non-negligible.

  • Global MPPT scheme for photovoltaic string inverters based on restricted voltage window search algorithm

     Boztepe, Mutlu; Guinjoan Gispert, Francisco; Velasco Quesada, Guillermo; Silvestre Berges, Santiago; Chouder, Aissa; Karatepe, Engin
    IEEE transactions on industrial electronics
    Vol. 61, num. 7, p. 3302-3312
    DOI: 10.1109/TIE.2013.2281163
    Date of publication: 2014-07-01
    Journal article

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    String inverter photovoltaic (PV) systems with bypass diodes require improved global maximum power point tracking (GMPPT) algorithms to effectively reach the absolute maximum power operating point. Several GMPPT algorithms have been proposed to deal with this problem, but most of them require scanning wide voltage ranges of the PV array from nearly zero voltage to open-circuit voltage that increases the scanning time and, in turn, causes energy loss. This paper presents a novel GMPPT method which significantly restricts the voltage window search range and tracks the global power peak rapidly in all shading conditions. Simulation tests and experimental comparisons with another GMPPT algorithm are presented to highlight the features of the presented approach.

  • Diseño de una plataforma docente para el estudio de los sistemas de recolección de energía (energy harvesting) en los Grados de Ingeniería

     Martínez García, Herminio
    Annual Seminar on Automation, Industrial Electronics and Instrumentation
    p. 1-6
    Presentation's date: 2014-06-27
    Presentation of work at congresses

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    El presente artículo presenta el diseño e implementación física de una plataforma docente recolectora y acondicionadora de energía práctica para aplicaciones de energy harvesting. Concretamente, muestra la realización de un sistema de acondicionamiento de energía solar fotovoltaica a partir de un modelo concreto de panel solar. Con el fin de conseguir una plataforma lo más eficiente posible, se ha implementado un sistema de seguimiento del punto de máxima potencia (MPPT) del panel fotovoltaico que optimiza el rendimiento del mismo, adentrando, a su vez, al estudiante de Ingeniería en este tipo de algoritmos. Además, la plataforma recolectora posee regulación de salida, ofreciendo así una tensión de salida constante, independientemente tanto de variaciones de carga como de la tensión de entrada.

  • Simulación mediante “hardware in the loop” de un convertidor buck

     Velasco Quesada, Guillermo; Casellas Beneyto, Francisco; Guinjoan Gispert, Francisco; Esteban, Jordi; Martínez García, Herminio; Pique Lopez, Robert
    Seminario Anual de Automática, Electrónica Industrial e Instrumentación
    p. 6007.1-6007.5
    Presentation's date: 2014-06-26
    Presentation of work at congresses

     Share Reference managers Reference managers Open in new window

  • Access to the full text
    Linear–assisted DC/DC regulator with modified current-mode one-cycle control  Open access

     Martínez García, Herminio
    Annual Seminar on Automation, Industrial Electronics and Instrumentation
    p. 1-4
    Presentation's date: 2014-06-26
    Presentation of work at congresses

    Read the abstract Read the abstract Access to the full text Access to the full text Open in new window  Share Reference managers Reference managers Open in new window

    Abstract—Linear-assisted DC/DC converters are structures that allow to take advantages of the two classic alternatives in the design of power supply systems: Voltage linear regulators (classic NPN topology or LDO –low dropout–) and switching DC/DC converters. This paper shows the proposal of a modified currentmode one-cycle control for linear-assisted DC/DC converters. The modified current-mode one-cycle control technique is proposed in order to obtain the duty cycle of the linear-assisted converter switch. The proposed structure can provide an output with suitable load and line regulations. The paper shows the design of the proposed modified current-mode one-cycle linear-assisted regulator and simulation results that validate the aforementioned proposal.

  • Access to the full text
    Simulación mediante “hardware in the loop” de un convertidor Buck  Open access

     Casellas Beneyto, Francisco; Esteban, J.; Guinjoan Gispert, Francisco; Pique Lopez, Robert; Martínez García, Herminio; Velasco Quesada, Guillermo
    Annual Seminar on Automation, Industrial Electronics and Instrumentation
    p. 1-5
    Presentation's date: 2014-06-26
    Presentation of work at congresses

    Read the abstract Read the abstract Access to the full text Access to the full text Open in new window  Share Reference managers Reference managers Open in new window

    El presente artículo describe la implementación un convertidor reductor mediante su simulación por un ordenador estándar trabajando en tiempo real. El objetivo es determinar las limitaciones operativas y verificar la viabilidad como equipo HIL ("hardware in the loop") en una aplicación de electrónica de potencia de un ordenador estándar trabajando con un sistema operativo en tiempo real. Para verificar comportamiento del convertidor reductor simulado en tiempo real mediante el equipo HIL se utiliza como referencia el mismo convertidor reductor con modelado basado en SPICE. Finalmente se somete al modelo a diferentes ensayos para determinar el límite en los parámetros de la simulación que provoca el procesador trabajando en tiempo real.

    El presente artículo describe la implementación un convertidor reductor mediante su simulación por un ordenador estándar trabajando en tiempo real. El objetivo es determinar las limitaciones operativas y verificar la viabilidad como equipo HIL (

  • Access to the full text
    Gestión de energía en sistemas híbridos Red-PV-diesel en el proyecto MED-Solar  Open access

     Velasco Quesada, Guillermo; Casellas Beneyto, Francisco; Guinjoan Gispert, Francisco; Pique Lopez, Robert; Martínez García, Herminio; Pineau, A.; Graillot, A.
    Seminario Anual de Automática, Electrónica Industrial e Instrumentación
    p. 3010.1-3010.6
    Presentation's date: 2014-06-26
    Presentation of work at congresses

    Read the abstract Read the abstract Access to the full text Access to the full text Open in new window  Share Reference managers Reference managers Open in new window

    El presente trabajo aborda el diseño de la estructura de un sistema de gestión de energía eléctrica aplicable a sistemas eléctricos híbridos formados por la red eléctrica y sistemas de generación fotovoltaica, generación diésel y almacenamiento. La implementación de estos sistemas híbridos y sus sistemas de gestión será, dentro del marco del Proyecto MED-Solar, en tres países del área del Máshrek (Líbano, Palestina y Jordania), con el fin de demostrar que este tipo de instalaciones puede reducir parte de la problemática energética presente en estos países y, por tanto, mostrarse atractiva para diversos sectores económicos.

  • Banco de pruebas para verificar el rendimiento estático y dinámico del MPPT

     Velasco Quesada, Guillermo; Casellas Beneyto, Francisco; Guinjoan Gispert, Francisco; Pique Lopez, Robert
    Seminario Anual de Automática, Electrónica Industrial e Instrumentación
    p. 3016.1-3016.6
    DOI: -
    Presentation's date: 2014-06-26
    Presentation of work at congresses

     Share Reference managers Reference managers Open in new window

  • Access to the full text
    Design of an on-chip hybrid DC-DC converter  Open access

     Martínez García, Herminio
    Annual Seminar on Automation, Industrial Electronics and Instrumentation
    p. 1-4
    Presentation's date: 2014-06-26
    Presentation of work at congresses

    Read the abstract Read the abstract Access to the full text Access to the full text Open in new window  Share Reference managers Reference managers Open in new window

    This paper shows the design of a hybrid on-chip VLSI DC-DC converter for low to medium integrated circuit power consumption that combines a switching and a linear regulator in parallel. The main goal is to take the best of both approaches, obtaining good power efficiency as in switching converters with small voltage output ripple as in linear converters. While the switching regulator is used to drive most of the load current, the linear regulator supplies the required current to filter out the steady state ripple due to inductor switching without the need of a filtering output capacitor. In addition, the latter regulator supplies the required current when the load changes abruptly and the inductor current is momentarily insufficient. The design has been tested with simulations using a standard 180 nm CMOS technology showing good performance.

  • Access to the full text
    Estudio eléctrico y térmico en transistores IGBT en paralelo con control de reparto de corriente  Open access

     Perez Delgado, Raul; Roman Lumbreras, Manuel; Velasco Quesada, Guillermo
    Annual Seminar on Automation, Industrial Electronics and Instrumentation
    p. 1007-1-1007-6
    Presentation's date: 2014-06-26
    Presentation of work at congresses

    Read the abstract Read the abstract Access to the full text Access to the full text Open in new window  Share Reference managers Reference managers Open in new window

    En este artículo se analiza el comportamiento eléctrico y térmico de transistores PT-IGBT conectados en paralelo utilizando un control activo de reparto equilibrado de corriente. El estudio de la estructura interna y de las ecuaciones que describen el funcionamiento de un transistor IGBT muestra la capacidad de modificar el funcionamiento del transistor según la relación tensión-corriente colector-emisor (VCE-ICE) variando el valor de la tensión puerta-emisor (VGE). Finalmente se comparan los resultados de funcionamiento de los transistores con control de reparto de corriente con los obtenidos sin aplicar ninguna acción de control.

  • Access to the full text
    Burden resistor selection in current transformers for low power applications  Open access

     Conesa Roca, Alfonso; Bargalló Perpiñà, Ramon; Velasco Quesada, Guillermo; Roman Lumbreras, Manuel
    Annual Seminar on Automation, Industrial Electronics and Instrumentation
    p. 5002-1-5002-5
    Presentation's date: 2014-06-26
    Presentation of work at congresses

    Read the abstract Read the abstract Access to the full text Access to the full text Open in new window  Share Reference managers Reference managers Open in new window

    In order to sense AC current with electric isolation in high frequency switching power converters the most simple and low cost solution is to consider a current transformer with a burden resistor. But burden resistor selection is not a simple task because involves a lot of considerations that affect the output voltage and its signal-to-noise ratio and the bandwidth of the measure. In this paper, considering the basic equations of the transformer and applying the Laplace Transformation is obtained a simple model of the current transformer interesting to select burden resistor and even to design the current transformer in case of high frequency applications

  • Access to the full text
    Mejoras en el consumo de energía de los transductores de corriente basados en el efecto flux-gate  Open access

     Roman Lumbreras, Manuel; Velasco Quesada, Guillermo; Perez Delgado, Raul; Conesa Roca, Alfonso; Bonell, Marc; Rojas, Antonio
    Annual Seminar on Automation, Industrial Electronics and Instrumentation
    p. 6005-1-6005-5
    Presentation's date: 2014-06-25
    Presentation of work at congresses

    Read the abstract Read the abstract Access to the full text Access to the full text Open in new window  Share Reference managers Reference managers Open in new window

    En este trabajo se presenta una mejora en el diseño de los transductores de corriente flux-gate, con vistas a la reducción del consumo eléctrico de la electrónica de control. Esta mejora consiste en la substitución del amplificador lineal de compensación de flujo, que proporciona la salida de corriente de medida proporcional a la corriente principal, por un amplificador clase H, con lo cual se consigue reducir apreciablemente el consumo de energía de la electrónica sin afectar a las prestaciones del transducto r en cuanto a precisión, linealidad, etc.

  • A modified current-mode one-cycle control used for linear–assisted DC/DC regulator

     Martínez García, Herminio; Grau Saldes, Antoni
    Workshop on Complexity in Engineering
    p. 30-33
    Presentation's date: 2014-06-16
    Presentation of work at congresses

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    Linear-assisted DC/DC converters are structures that allow to take advantages of the two classic alternatives in the design of power supply systems: Voltage linear regulators (classic NPN topology or LDO –low dropout–) and switching DC/DC converters. This paper shows the proposal of a modified current-mode one-cycle control for linear-assisted DC/DC converters. The modified current-mode one-cycle control technique is proposed in order to obtain the duty cycle of the linear-assisted converter switch. The proposed structure can provide an output with suitable load and line regulations. The paper shows the design of the proposed modified current-mode one-cycle linear-assisted regulator and simulation results that validate the aforementioned proposal.

  • Linear–assisted DC/DC converters with variable frequency: On their control strategies

     Martínez García, Herminio; Grau Saldes, Antoni
    Workshop on Complexity in Engineering
    p. 56-61
    Presentation's date: 2014-06-16
    Presentation of work at congresses

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    Linear-assisted DC/DC converters (or linearswitching hybrid DC/DC converters) consist of a voltage linear regulator (classic NPN or nMOS topologies and LDO) connected in parallel with a switching DC/DC converter. In order to control these hybrid structures, different strategies exist, allowing to fix the switching frequency as a function of some parameters of the linear regulator. This article compares two control strategies that, although can be applied to the same circuital structure of linear-assisted converter, are sensibly different. The first one, reported in previous literature, cancels completely the average current through the linear regulator in steady state to achieve a reduction of the losses. Thus the efficiency of the whole system increases and almost equals the one of the standalone switching converter. The proposed approach, in spite of a slightly increment of linear regulator’s losses, reduces the output ripple due to the crossover distortion of linear regulator output stage.

  • The Use of constant switching frequency control for a linear-assisted DC-DC switching converter

     Grau Saldes, Antoni; Martínez García, Herminio
    Workshop on Complexity in Engineering
    p. 26-29
    Presentation's date: 2014-06-16
    Presentation of work at congresses

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    This article shows the proposal of a linear–assisted converter or linear–&–switching hybrid converter with a constant switching frequency. The control loop of the system is based on the current–mode technique. The main disadvantage of a converter with current–mode control is the inherent instability of the loop when switch duty ratios are greater than 0.5. In order to make stable the proposed linear–assisted converter, the article shows the technique based on a slope compensation.

  • Design and implementations of a microcontroller-based intelligent field transmitter

     Martínez García, Herminio; Grau Saldes, Antoni
    Workshop on Complexity in Engineering
    p. 22-25
    Presentation's date: 2014-06-16
    Presentation of work at congresses

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    In this article the design of a prototype of an Intelligent Transmitter of Field (ITF) is presented. The objective of the work is approaching the engineering students, in the area of Automatic Control, to the functional and technological challenges intrinsic to this type of implementations. Aspects like power consumption of the electronic circuits, energy supply through the wires of communication of the transmitter, the coexistence in these wires of analogical signals of measurement and digital signals of communication, etc., are essential to get the foreseen objective. The article seeks, also, to contribute to a didactic solution for a problem that has been one of the main challenges in instrumentation field.

  • Chaotic behaviour in on-chip automatic tuning loops for continuous–time filters

     Martínez García, Herminio
    Workshop on Complexity in Engineering
    p. 52-55
    Presentation's date: 2014-06-16
    Presentation of work at congresses

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    Continuous-time filters (CTF) with automatic tuning loops are nonlinear feedback systems with potential instability. While an appropriate small signal linear dynamic modeling of the tunable filter should be obtained for design purpose, its ability to predict the real nonlinear dynamic behavior of the system is limited. In order to overcome this problem, a general and systematic procedure is used to obtain a large signal nonlinear model. The obtained model can accurately predict nonlinear phenomena such as bifurcations and chaotic behavior. From this model, some numerical simulations results are presented in this paper. As far as the authors know, the observation of these phenomena in CTF with tuning loops has not been previously presented. Thus, the results obtained in this work can provide some help to obtain improved controllers (with higher bandwidth and better performance) for the two involved control loops.

  • Parametric filters laboratory with a noise generator and data acquisition

     Martínez García, Herminio
    Workshop on Complexity in Engineering
    p. 97-100
    Presentation's date: 2014-06-16
    Presentation of work at congresses

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    Audio filtering systems are used in commercial applications involving equalizers. However, some of the topologies used can be modified to be used in audio signal treatment applications. Parametric filter topologies allow the user to modify independently the central frequency of the filter, the bandwidth and the gain. Using a microprocessor and programmable components will allow the user to modify the parameters of the filter and to acquire the filtered signal so it can be processed in other stages. To improve the functionality of the system, a server will be implemented to process the data sent by the user, will be sent afterwards to the microcontroller. Finally, the results obtained will be thrown back to the user.

  • Modified current-mode one-cycle control for linear–assisted DC/DC regulator

     Martínez García, Herminio; Cosp Vilella, Jordi
    IEEE International Symposium on Circuits and Systems
    p. 2688-2691
    DOI: 10.1109/ISCAS.2014.6865727
    Presentation's date: 2014-06-04
    Presentation of work at congresses

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    Linear-assisted DC/DC converters are structures that allow to take advantages of the two classic alternatives in the design of power supply systems: Voltage linear regulators (classic NPN topology or LDO –low dropout–) and switching DC/DC converters. This paper shows the proposal of a modified current-mode one-cycle control for linear-assisted DC/DC converters. The modified current-mode one-cycle control technique is proposed in order to obtain the duty cycle of the linear-assisted converter switch. The proposed structure can provide an output with suitable load and line regulations. The paper shows the design of the proposed modified current-mode one-cycle linear-assisted regulator and simulation results that validate the aforementioned proposal.

  • Fuzzy logic controller design for battery energy management in a grid connected electro-thermal microgrid

     Arcos Aviles, Diego Gustavo; Vega Muñoz, Christian; Guinjoan Gispert, Francisco; Marroyo Palomo, Luis; Sanchis Gúrpide, Pablo
    IEEE International Symposium on Industrial Electronics
    p. 2014-2019
    DOI: 10.1109/ISIE.2014.6864926
    Presentation's date: 2014-06-01
    Presentation of work at congresses

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    A fuzzy logic controller strategy for battery energy management in a grid connected electro-thermal residential microgrid is presented. The fuzzy control policy manages the power of the microgrid storage elements in order to minimize a set of quality indices involving, among others, the power profile exchanged with the mains. Numerical simulations using real measured data generation and consumption are provided to both validate the control design and to highlight the benefits of including thermal elements in the overall energy management strategy of the system. © 2014 IEEE.

  • Advances in non-radiative resonant inductive coupling wireless power transfer: a comparison of alternative circuit and system models driven by emergent applications

     Bou Balust, Elisenda; Sedwick, Raymond; Hu, Patrick; Alarcon Cot, Eduardo Jose
    IEEE International Symposium on Circuits and Systems
    p. 2037-2040
    DOI: 10.1109/ISCAS.2014.6865565
    Presentation's date: 2014-06-01
    Presentation of work at congresses

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    Recent research in wireless power transfer (WPT) using resonant inductive coupling has demonstrated very high efficiencies at large distances compared to the transmitting element dimensions, thereby increasing the number of potential applications of WPT. Since resonant inductive coupling is a very multidisciplinary field of research, different approaches have been proposed to predict the behaviour of these systems from the physical theory of resonators (coupled-mode theory) and circuit theory. Although the equivalence of these models for a point-to-point link has already been studied together with the performance metrics Power Transferred to the Load (PTL) and Power Transfer Efficiency (PTE), the new challenges and applications of this technology emphasize the necessity of analytical models to predict and assess the behavior of Multiple Input - Multiple Output (MIMO) links. In this article we revisit the current analytical models from the MIMO perspective, derive the analytical equations for the equivalent performance metrics PTE and PTL and demonstrate how to maximize them in a non-radiative resonant wireless power transfer link from a circuit-centric point of view, providing design guidelines in terms of optimal source and load impedances. This work concludes with a prospective discussion on open challenges of WPT. © 2014 IEEE.

  • Unveiling nonlinear dynamics in resonant inductively coupled wireless power transfer

     Bou Balust, Elisenda; El Aroudi, Abdelali; Fisher, Peter; Alarcon Cot, Eduardo Jose
    IEEE International Symposium on Circuits and Systems
    p. 2612-2615
    DOI: 10.1109/ISCAS.2014.6865708
    Presentation's date: 2014-06-01
    Presentation of work at congresses

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    Coupled magnetic resonance is considered to be a key enabling technology for mid-range wireless power transfer. Models and systems have hitherto considered linear resonators as underlying dynamics, thereby limiting practical deployability due to the extreme sensitivity in front of parameter mismatch and resonance detuning. In this work, structural nonlinear modeling of constituent elements of the resonant link-resonant coils- is considered to unveil the existence of nonlinear dynamic regimes. The methodology considered to explore the nonlinear behavior is based on a behavioral model consisting of state equations, Floquet theory and Filippov method to study the stability of the periodic regime through the associated monodromy matrix. The ultimate aim of the investigation is a design-oriented parameter space exploration which characterizes the border of occurrence of the different dynamic modes in wireless power transfer links. © 2014 IEEE.

  • Circuit area optimization in energy temporal sparse scenarios for multiple harvester powered systems

     Gomez Cid-fuentes, Raul; Cabellos Aparicio, Alberto; Alarcon Cot, Eduardo Jose
    IEEE International Symposium on Circuits and Systems
    p. 2486-2489
    DOI: 10.1109/ISCAS.2014.6865677
    Presentation's date: 2014-06-01
    Presentation of work at congresses

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    Multi-source energy harvesters are gaining interest as a robust alternative to power wireless sensors, since the sensor node can maintain its operation regardless of the fact that one of its energy sources might be temporarily unavailable. Interestingly, and less explored, when the energy availability of the energy sources present large temporal variations, combining multiple energy sources reduce the overall sparsity. As a result, the performance of a multiple energy harvester powered sensor node is significantly better compared to a single energy source which harvests the same amount of energy. In this context, a circuit area optimization framework for multiple source energy harvesting powered systems is proposed. This framework takes advantage of this improvement in performance to provide the optimal amount of energy harvesters, the requirements of each energy harvester and the required energy buffer capacity, such that the overall area or volume is minimized. As the results show, by conducting a joint design of the energy harvesters and the energy buffer, the overall area or volume of a sensor node can be significantly reduced. © 2014 IEEE.

  • FPGA-based design of a step-up photovoltaic array emulator for the test of PV grid-connected inverters

     Chavarria Roe, Javier; Biel Sole, Domingo; Guinjoan Gispert, Francisco; Poveda Lopez, Alberto; Masana Nadal, Francisco; Alarcon Cot, Eduardo Jose
    IEEE International Symposium on Industrial Electronics
    p. 485-490
    DOI: 10.1109/ISIE.2014.6864661
    Presentation's date: 2014-06-01
    Presentation of work at congresses

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    In this work, a proof of concept prototype for a photovoltaic array emulator based on a DC-DC Boost converter is presented. This design arises from the need to study in the laboratory new PV inverters based on Silicon Carbide (SiC) devices in order to evaluate their performances. The lack of space for installation of real photovoltaic panels and the high costs of the commercial emulators lead to alternative systems which allow the reproduction of the characteristic curves of the panel arrays as well as their dependence on changing environmental conditions. The control algorithm designed for the emulator prototype is implemented by means of a field programmable gate array (FPGA). Experimental results confirm the proper operation of the PV emulator which is applied to a full-bridge single phase grid-connected inverter. © 2014 IEEE.

  • Temperature gradient sensor from pulsed power supply duty cycle in ultra-low-power energy harvesting system

     Jove Casulleras, Roger; Ramos Castro, Juan Jose; Corimanya, H; Camps Carmona, Adriano Jose; Alarcon Cot, Eduardo Jose; Amezaga Sarries, Adria; Bou Balust, Elisenda
    Electronics Letters
    Vol. 50, num. 11, p. 826-828
    DOI: 10.1049/el.2014.0399
    Date of publication: 2014-05-22
    Journal article

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    Directly interfacing sensors that link sensors to micro-controllers without a signal conditioning circuit or an analogue-to-digital converter on the one side and energy harvesting systems on the other side are two key enabling technologies to create self-powered autonomous low-cost and low-maintenance sensor networks. In this reported work, both technologies are concurrently combined in such a way that the duty cycle of the pulsed power supply provided by the harvesting system itself yields in turn a temperature gradient sensor functionality. Originally conceived to power a low-power satellite beacon in a CubeSat project, it has found application, among other applications, in automatic air conditioning and heating systems aiming smart buildings.

  • Design and comparison of flipped active inductors with high quality factors

     Saberkari, Alireza; Ziabakhsh, Soheil; Martínez García, Herminio; Alarcon Cot, Eduardo Jose
    Electronics Letters
    Vol. 50, num. 13, p. 925-927
    DOI: 10.1049/el.2014.0488
    Date of publication: 2014-05-19
    Journal article

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    A new design based on the flipped-structure for RF active inductors is presented. The conventional flipped-active inductor (FAI) composed of only two transistors is considered as a starting structure. However, it suffers from low-voltage swing, which increases the nonlinearity. Additionally, it requires high power consumption to achieve adequate inductance and quality factor values. A circuit topology named cascoded FAI (CASFAI) based on the basic FAI is proposed. A common-gate transistor added in the feedback path of the proposed CASFAI results in an increase of the voltage swing and linearity as well as the feedback gain. The performance metrics of such active inductors are benchmarked by analytical models and validated in the ADS using a 0.18 µm CMOS process. The results indicate that the CASFAI can achieve a notably higher quality factor and higher inductance values while consuming less power in comparison to the basic FAI.

  • Access to the full text
    Nonlinear dynamics of an ambient noise driven array of coupled graphene nanostructured devices for energy harvesting  Open access

     El Aroudi, Abdelali; Lopez Suarez, Miquel; Alarcon Cot, Eduardo Jose; Rurali, Riccardo; Abadal, Gabriel
    International Conference on Structural Dynamics and Diagnosis
    p. 01001-1-01001-4
    DOI: 10.1051/matecconf/20141601001
    Presentation's date: 2014-05
    Presentation of work at congresses

    Read the abstract Read the abstract Access to the full text Access to the full text Open in new window  Share Reference managers Reference managers Open in new window

    Nonlinearities have been shown to play an important role in increasing the extracted energy of energy harvesting devices at the macro and micro scales. Vibration-based energy harvesting on the nano scale has also received attention. In this paper, we characterize the nonlinear dynamical behavior of an array of three coupled strained nanostructured graphene for its potential use in energy harvesting applications. The array is formed by three compressed vibrating membrane graphene sheet subject to external vibrational noise excitation. We present the continuous time dynamical model of the system in the form of a double-well three degree of freedom system. Random vibrations are considered as the main ambient energy source for the system and its performances in terms of the probability density function, RMS or amplitude value of the position, FFT spectra and state plane trajectories are presented in the steady state non-equilibrium regime when the noise level is considered as a control parameter.

  • Access to the full text
    Nonlinear dynamics and bifurcation behavior of a 2-DOF spring resonator with end stopper for energy harvesting  Open access

     El Aroudi, Abdelali; Blokhina, Elena; O'Connell, D.; Fu, B; Frizzell, R; Feely, Orla; Alarcon Cot, Eduardo Jose
    International Conference on Structural Dynamics and Diagnosis
    p. 08006-1-08006-6
    DOI: 10.1051/matecconf/20141608006
    Presentation's date: 2014-05
    Presentation of work at congresses

    Read the abstract Read the abstract Access to the full text Access to the full text Open in new window  Share Reference managers Reference managers Open in new window

    In this paper, the model of a two-degree-of-freedom (2-DOF) spring resonator with end stopper for an energy harvesting application is presented. Then we characterize its nonlinear dynamical behavior by numerical simulations when some suitable parameters are varied. The system is formed by two resonators subject to external vibrational excitation and with an end stopper. We present the continuous time dynamical model of the system in the form of a switched fourth order differential equation. Harmonic vibrations are considered as the main ambient energy source for the system and its frequency response representing the RMS value of the displacement is first computed. The dynamical behavior is unveiled by computing state-space trajectories, timedomain series and FFT spectra and frequency response as the excitation amplitude is varied.

  • Linear–assisted DC/DC converters with modified current-mode control applied to photovoltaic solar systems

     Martínez García, Herminio
    International Conference on Renewable Energies and Power Quality
    p. 1-5
    Presentation's date: 2014-04-08
    Presentation of work at congresses

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    This article shows the proposal of a current-mode one-cycle control for linear-assisted DC/DC converters. Linearassisted DC/DC converters are structures that allow to take advantages of the two classic alternatives in the design of power supply systems: voltage linear regulators (classic NPN topology or LDO –low dropout–) and switching DC/DC converters. The current-mode one-cycle control technique is proposed in order to obtain the duty cycle of the linear-assisted converter switch. The proposed structure can provide an output with suitable load and line regulations. Thus, the paper shows the design and simulation results of the proposed current-mode one-cycle linear-assisted converter.

  • The use of power gyrator structures as energy processing cells in photovoltaic solar facilities

     Martínez García, Herminio
    International Conference on Renewable Energies and Power Quality
    p. 1-5
    Presentation's date: 2014-04-08
    Presentation of work at congresses

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    This paper will provide a classification of high efficiency switching power-gyrator structures and their use as cells for energy processing in photovoltaic solar facilities. Having into account the properties of these topologies presented in the article, their inclusion in solar facilities allows increasing the performance of the whole installation. Thus, the design, simulation and implementation of a G-type power gyrator are carried out throughout the text. In addition, in order to obtain the maximum power from the photovoltaic solar panel, a maximum power point tracking (MPPT) is mandatory in the energy processing path. Therefore, the practical implementation carried out includes a control loop of the power gyrator in order to track the aforementioned maximum power point of the photovoltaic solar panel.

  • Access to the full text
    Linear-assisted DC/DC converters with modified current-mode control applied to photovoltaic solar systems  Open access

     Martínez García, Herminio
    International Conference on Renewable Energy and Power Quality
    p. 1-5
    Presentation's date: 2014-04-08
    Presentation of work at congresses

    Read the abstract Read the abstract Access to the full text Access to the full text Open in new window  Share Reference managers Reference managers Open in new window

    This article shows the proposal of a current-mode one-cycle control for linear-assisted DC/DC converters. Linearassisted DC/DC converters are structures that allow to take advantages of the two classic alternatives in the design of power supply systems: voltage linear regulators (classic NPN topology or LDO –low dropout–) and switching DC/DC converters. The current-mode one-cycle control technique is proposed in order to obtain the duty cycle of the linear-assisted converter switch. The proposed structure can provide an output with suitable load and line regulations. Thus, the paper shows the design and simulation results of the proposed current-mode one-cycle linear-assisted converter.

  • Access to the full text
    The use of power gyrator structures as energy processing cells in photovoltaic solar facilities  Open access

     Martínez García, Herminio
    International Conference on Renewable Energies and Power Quality
    p. 1-5
    Presentation's date: 2014-04-08
    Presentation of work at congresses

    Read the abstract Read the abstract Access to the full text Access to the full text Open in new window  Share Reference managers Reference managers Open in new window

    This paper will provide a classification of high efficiency switching power-gyrator structures and their use as cells for energy processing in photovoltaic solar facilities. Having into account the properties of these topologies presented in the article, their inclusion in solar facilities allows increasing the performance of the whole installation. Thus, the design, simulation and implementation of a G-type power gyrator are carried out throughout the text. In addition, in order to obtain the maximum power from the photovoltaic solar panel, a maximum power point tracking (MPPT) is mandatory in the energy processing path. Therefore, the practical implementation carried out includes a control loop of the power gyrator in order to track the aforementioned maximum power point of the photovoltaic solar panel.

  • Design-oriented analysis of quantization-induced limit cycles in a multiple-sampled digitally controlled buck converter

     Bradley, Mark; Alarcon Cot, Eduardo Jose; Feely, Orla
    IEEE transactions on circuits and systems I: regular papers
    Vol. 61, num. 4, p. 1192-1205
    DOI: 10.1109/TCSI.2013.2283671
    Date of publication: 2014-04-01
    Journal article

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    Digital control of switching power converters is an area which has seen increased attention in recent years. However, quantization in the feedback loop from the analog-to-digital (A/D) converter and the digital pulse width modulator (DPWM) may cause limit cycle oscillations to manifest, which are generally seen as being undesirable. This paper presents an analysis of the limit cycle behavior found in a multiple-sampled digitally controlled buck converter. The limit cycles which may arise in the system are characterized and conditions to prevent these oscillations from occurring are presented. © 2004-2012 IEEE.

  • Maximum power point tracking based on slidingmode control for output-series connected converters in photovoltaic systems

     Cabal, Cédric; Martínez Salamero, Luis; Séguier, Lionel; Alonso, Corinne; Guinjoan Gispert, Francisco
    IET power electronics
    Vol. 7, num. 4, p. 914-923
    DOI: 10.1049/iet-pel.2013.0348
    Date of publication: 2014-04-01
    Journal article

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    A perturb and observe algorithm based on both the power-current characteristic of a photovoltaic (PV) panel and the sliding-mode control of the input inductor current of an associated converter is investigated in a static application. A single ended primary inductance converter (SEPIC) converter charging a battery from a PV generator illustrates the procedure whose effectiveness is proved with experimental results. The reported technique is appropriate for distributed maximum power point tracking of PV systems with output series connected DC-DC switching converters. In these systems, each converter is supplied by an independent PV panel at the input port whereas its output port is connected in series with the output ports of the other converters. The proposed converter interconnection is based on a transformer-less SEPIC because of the capability of this converter to step-up or step-down the input voltage. The resulting system allows maximum power extraction from each PV source even in cases of non-uniform irradiance. © The Institution of Engineering and Technology 2014.

  • Some limits in peer assessment

     Domingo Peña, Joan; Martínez García, Herminio; Gomariz Castro, Spartacus; Gamiz Caro, Juan
    Journal of technology and science education
    Vol. 4, num. 1, p. 12-24
    Date of publication: 2014-03-25
    Journal article

    Read the abstract Read the abstract  Share Reference managers Reference managers Open in new window

    Nowadays, the educational methodology known as ‘peer assessment’ constitutes one of the pillars of formative assessment at the different levels of the educational system, particularly at the University level. In fact, in recent years, it has been increasingly used to enhance students' meaningful learning, as it is considered to be an element of social learning, in which students benefit from the lessons learned by other classmates, and draw upon the ability to assess the quality of the learning, contrasting it with the level of knowledge that each has about the subject/course being evaluated, and using common evaluation criteria. In this regard, this paper represents the experience of two groups of students. It allows us to determine how many peer assessments should be required of students in a particular course in order to constitute a serious, reliable activity. On the other hand, from the point of view of the student, the assessments are evaluated to the extent that they are seen as a required and mandatory exercise that must be carried out by students simply to pass the course. In the latter case, the activity can become extremely trivial and banal. Statistical analysis of the results indicates that three peer assessments per student appraised represents an adequate number. On the other hand, more than thirty peer assessments fail to contribute to learning, nor do they represent serious activities.