Comunicaciones y ponencias de congresos DIEC - IEKS Biltzarretako komunikazioak eta txostenak

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Open Access
Optical gateway for intelligent buildings: a new open-up window to the optical fibre sensors market?
(SPIE, 2004-06-09) Fernández Valdivielso, Carlos; Matías Maestro, Ignacio; Arregui San Martín, Francisco Javier; Bariáin Aisa, Cándido; López-Amo Sáinz, Manuel; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISC; Gobierno de Navarra / Nafarroako Gobernua
This paper presents the first optical fibre sensor gateway for integrating these special measurement devices in Home Automation Systems, concretely in those buildings that use the KNX European Intelligent Buildings Standard.
Open Access
Modeling solar cavity receivers: a review and comparison of natural convection heat loss correlations
(Elsevier, 2015) Samanes Pascual, Javier; García-Barberena Labiano, Javier; Zaversky, Fritz; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
As the main difficulty of modeling cavity receivers is determining natural convection heat losses, this paper presents a survey of the different natural convection correlations developed by several authors to model natural convective heat losses from cavity receivers of solar thermal power tower plants. The different correlations studied for modeling convective heat losses are later compared by performing simulations on an implemented cavity receiver. For this work a model of a PS10-like cavity receiver, using Solar Salt as the heat transfer fluid, is implemented in Modelica. The simulations have shown how the results of four out of the five studied correlations do agree, while one of the analyzed correlations clearly overestimates convective heat losses for the simulations performed.
Open Access
Hydrogen-based energy storage for a distributed generation system
(Spanish Hydrogen Association, 2016) San Martín Biurrun, Idoia; Berrueta Irigoyen, Alberto; Ursúa Rubio, Alfredo; Sanchis Gúrpide, Pablo; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISC
One of the most typical distributed generation systems are electrical microgrid, which consist on small electrical grids, generally connected to the main grid, with a decentralized management structure. Electrical microgrids allow higher renewable energy integration in the grid, achieving a cost decrease and improving the grid quality [1]. These mi- crogrids incorporate renewable generation systems and energy consumers. Moreover, they have storage systems to balance generation and consumption as well as the exchanged power with the main grid. Traditionally, lead-acid batter- ies have been used in microgrids. However, these batteries have some drawbacks, being the most important its poor performance in partial state of charge, which is critical for a microgrid. A suitable option for the storage system is hy- drogen technology. These systems have high energy density, which makes the storage system able to assume seasonal variability of renewable resources. This paper proposes a sizing methodology for storage systems based on hydrogen for grid-tied electrical microgrids. This methodology optimizes the relationship between the storage system size and the consumption of grid power.
Open Access
Lossy mode resonances biosensor for the detection of C-reactive protein
(Optica Publishing Group, 2016) Zubiate Orzanco, Pablo; Ruiz Zamarreño, Carlos; Sánchez Zábal, Pedro; Matías Maestro, Ignacio; Arregui San Martín, Francisco Javier; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute of Smart Cities - ISC; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
The fabrication and characterization of optical fiber biosensor based on Lossy Mode Resonances (LMR) to detect C-reactive protein (CRP) are presented. Indium tin oxide (ITO) coatings deposited on side-polished D-shaped optical fibers are used as LMR supporting coatings. The aptamer was immobilized on the ITO film using the Layer-by-Layer (LbL) nano-assembly process. The optical fiber sensor presented shows a high selectivity and low limit detection.
Open Access
Optical fiber sensors for asphalt structures monitoring
(Optica Publishing Group, 2016) Bravo Acha, Mikel; Rota Rodrigo, Sergio; Leandro González, Daniel; Loayssa Lara, Alayn; Urricelqui Polvorinos, Javier; Bravo Acha, A.; Bravo Navas, M.; Mitxelena, J. R.; Martínez Mazo, J. J.; López-Amo Sáinz, Manuel; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
A novel optical fiber installation method was explored for asphalt monitoring. Glassfiber polymer encapsulated SMF was installed in the intermediate and surface layers in order to study the strain sensitivity with a distributed strain interrogator.
Open Access
Hydrogen educational activities developed by APERNA: a renewable-energy student association
(Asociación Española del Hidrógeno, 2016) Berrueta Irigoyen, Alberto; San Martín Biurrun, Idoia; Samanes Pascual, Javier; Pascual Miqueleiz, Julio María; Barrios Rípodas, Ernesto; Parra Laita, Íñigo de la; Urtasun Erburu, Andoni; Sanchis Gúrpide, Pablo; Ursúa Rubio, Alfredo; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
In this paper, we present APERNA, a recently-created student association at Public University of Navarre (UPNA) with the aim of promotion of renewable energies.
Open Access
Temperature measurements on overhead lines using fiber Bragg grating sensors
(IEEE, 2017) Barón, F.; Amortegui, F. J.; Daniel, P.; Varón, M.; Álvarez Botero, Germán Andrés; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
This paper shows the results of temperature measurements on an overhead power transmission line segment under controlled conditions using Fiber Bragg Grating (FBG) sensors. An optical fiber with three FBG sensors enclosed in copper was characterized in temperature and then attached along an overhead transmission line to perform the measurements. It was found that variations due to wind and environment temperature can be as high as 30°C and that those variations increase as current and conductor temperature increases and sometimes exceeding the maximum allowable.
Open Access
Sensorless active damping strategy for parallel interleaved voltage source power converters with LCL filter
(IEEE, 2017) Samanes Pascual, Javier; Gubía Villabona, Eugenio; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Grid-connected pulse-width modulation converters with LCL filters are widely extended as an interface for renewable energy generating systems. Those filters arise stability issues due to the filter resonance, which, must be damped, preferably by active damping methods, to avoid additional power losses. In some applications, such as offshore wind energy conversion systems, where high power converters are connected to low voltage networks, the commutation frequency is limited to low values to reduce the power losses and the resulting filter components are bulky. For this reason, in addition to its higher current handling capabilities, the use of power converters in parallel with the application of advanced modulation strategies, such as interleaving, is gaining importance. In this structure the filter components can be reduced, setting the filter resonance frequency at a higher value. As a consequence, the filter resonance frequency is close to the Nyquist frequency, complicating the implementation of some of the existing active damping solutions. In this work, an active damping approach based on a third order digital filter is proposed to stabilize the system. The robustness of the solution is investigated against grid inductance variations and the grid current harmonic content will be tested to comply with the most demanding grid codes. The proposed active damping strategy does not require extra sensors and can be easily designed by examining the open loop Bode plots. It is suitable to stabilize the LCL filter with a resonance frequency close to the Nyquist frequency, where some of the existing active damping approaches are unable to damp the system. The proposed method can be also an appropriate solution for existing grid connected power converters with stability issues due to changes in the effective grid impedance at which they are connected.
Open Access
Microstructured optical fiber sensor for soil moisture measurements
(Optical Society of America, 2018) López Aldaba, Aitor; López Torres, Diego; Campo-Bescós, Miguel; López Rodríguez, José Javier; Yerro Lizarazu, David; Elosúa Aguado, César; Arregui San Martín, Francisco Javier; Auguste, Jean-Louis; Jamier, Raphael; Roy, Philippe; López-Amo Sáinz, Manuel; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Ingeniaritza; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniería
A discrete sensor based on a Sn0₂-FP (Fabry-Pérot) cavity is presented and characterized in real soil conditions. Results are compared, for the first time to our knowledge, with a commercial capacitive sensor and gravimetric measurements.
Open Access
MIMO based decoupling strategy for grid connected power converters controlled in the synchronous reference frame
(IEEE, 2018) Samanes Pascual, Javier; Gubía Villabona, Eugenio; López Taberna, Jesús; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Power converters are frequently connected to the grid through a LCL filter, controlling its power transfer through a current control loop in the synchronous reference frame. In this reference frame, cross coupling terms appear between the current and voltages of the passive components, which, without a proper decoupling strategy, penalize the converter transient response and the current control adjustment. In this work, an intuitive decoupling strategy is presented to improve the dynamic behavior, based on Multiple-Input-Multiple-Output systems theory. The approach developed is particularly interesting in extremely weak grids, allowing an easier adjustment of the main controller.
Open Access
Supervised descent method (SDM) applied to accurate pupil detection in off-the-shelf eye tracking systems
(ACM, 2018) Larumbe Bergera, Andoni; Cabeza Laguna, Rafael; Villanueva Larre, Arantxa; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
The precise detection of pupil/iris center is key to estimate gaze accurately. This fact becomes specially challenging in low cost frameworks in which the algorithms employed for high performance systems fail. In the last years an outstanding effort has been made in order to apply training-based methods to low resolution images. In this paper, Supervised Descent Method (SDM) is applied to GI4E database. The 2D landmarks employed for training are the corners of the eyes and the pupil centers. In order to validate the algorithm proposed, a cross validation procedure is performed. The strategy employed for the training allows us to affirm that our method can potentially outperform the state of the art algorithms applied to the same dataset in terms of 2D accuracy. The promising results encourage to carry on in the study of training-based methods for eye tracking.
Open Access
KISS methodologies for network management and anomaly detection
(IEEE, 2018) Vega, Carlos; Aracil Rico, Javier; Magaña Lizarrondo, Eduardo; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
Current networks are increasingly growing in size, complexity and the amount of monitoring data that they produce, which requires complex data analysis pipelines to handle data collection, centralization and analysis tasks. Literature approaches, include the use of custom agents to harvest information and large data centralization systems based on clusters to achieve horizontal scalability, which are expensive and difficult to deploy in real scenarios. In this paper we propose and evaluate a series of methodologies, deployed in real industrial production environments, for network management, from the architecture design to the visualization system as well as for the anomaly detection methodologies, that intend to squeeze the vertical resources and overcome the difficulties of data collection and centralization.
Open Access
High sensitivity fiber-optic liquid level sensor using biconical tapered fibers
(Optical Society of America, 2018) Júdez Colorado, Aitor; Leandro González, Daniel; Pérez Herrera, Rosa Ana; Galarza Galarza, Marko; López-Amo Sáinz, Manuel; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
A liquid level sensor is presented using a biconical tapered standard single-mode fiber, being its main characteristic an outstanding sensitivity for a low cost transducer. Temperature compensation is enabled with the same interrogation equipment.
Open Access
Dual-mode soft-transition control for single-phase grid-connected photovoltaic inverters
(IEEE, 2018) Elizondo Martínez, David; Urtasun Erburu, Andoni; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
Single-phase grid-connected inverters for photovoltaic power generation have been strongly analysed for improvement. Dual-mode control for two-stage inverters makes it possible to improve the efficiency by alternating between switching the dc/dc boost and the dc/ac buck stages, depending on the grid voltage value. However, according to the literature, the transition from one mode to the other is abrupt, which harms the grid current quality. This paper proposes a dual-mode control method which achieves high efficiency and a soft-transition in the grid current. Applying suitable feed-forward compensations, this control method improves the grid current quality, as demonstrated by the presented simulation results.
Open Access
Ramp-rate control in large PV plants: battery vs. short-term forecast
(IEEE, 2018) Marcos Álvarez, Javier; Parra Laita, Íñigo de la; Cirés Buey, Eulalia; Wang, Guang Chao; García Solano, Miguel; Marroyo Palomo, Luis; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISC
The changeability in the power produced by utility-scale PV plants caused by shadows due to passing clouds can compromise grid stability. Traditionally, some kind of energy storage systems (ESS) is proposed as the solution to reduce power variations below the limits imposed by new grid codes regulations. However, recent short-term forecast sources open the door to control the variability without batteries, using only inverter limitation. This option entails some energy curtailment losses that has not been yet addressed. This paper quantifies these losses for the first time using a meaningful database of 5 s one year data for a 38.5 MW PV plant in a perfect forecast scenery. Finally, we compare the economic cost of installing a lithium-ion battery vs. the inverter limitation solution. The results obtained indicate that battery-less strategies must not be neglected for ramp-rate control, since they can be more cost-effective using perfect forecast for any ramp value.
Open Access
Introducing I2Head database
(ACM (Association for Computing Machinery), 2018) Martinikorena Aranburu, Ion; Cabeza Laguna, Rafael; Villanueva Larre, Arantxa; Porta Cuéllar, Sonia; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
I2Head database has been created with the aim to become an optimal reference for low cost gaze estimation. It exhibits the following outstanding characteristics: it takes into account key aspects of low resolution eye tracking technology; it combines images of users gazing at different grids of points from alternative positions with registers of user's head position and it provides calibration information of the camera and a simple 3D head model for each user. Hardware used to build the database includes a 6D magnetic sensor and a webcam. A careful calibration method between the sensor and the camera has been developed to guarantee the accuracy of the data. Different sessions have been recorded for each user including not only static head scenarios but also controlled displacements and even free head movements. The database is an outstanding framework to test both gaze estimation algorithms and head pose estimation methods.
Open Access
On the optimal current followers for wide-swing current-efficient amplifiers
(IEEE, 2018) López Martín, Antonio; Garde Luque, María Pilar; Carvajal, Ramón G.; Ramírez-Angulo, Jaime; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
The design of various current followers for the implementation of OTAs with high slew rate and current efficiency is addressed. Two basic current follower topologies are compared, and modifications of both followers to improve these parameters are presented. As an application example, an enhanced recycling folded cascode OTA is proposed. Measurement results of the OTA fabricated in a 0.5 μm CMOS process show a 260% and 180% improvement in SR and GBW, respectively, for the same power consumption.
Open Access
Angle-susceptible sensing metasurface in terahertz regime
(EDP Sciences, 2018) Nikolaev, Nazar A.; Kuznetsov, Sergei A.; Beruete Díaz, Miguel; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
Nowadays thin-film coatings and structures are widely used in advanced industrial and scientific ap-plications that makes the tasks of thin-film sensing highly demanded in practice. Last decade, stimulated by progress in terahertz (THz) instrumentation, a keen interest has been attracted to the THz spectral range to develop its potential for detecting and measuring properties of thin films. The THz radiation can be an alternative to visible and IR waves when examining optically opaque coatings. Meanwhile, due to a rela-tively large wavelength λ, the conventional spectro-scopic methods (TDS-, FDS-, FTIR-, BWO-based) are ill-suited for direct characterization of films with the thickness d of about 2−4 orders of magnitude smaller than λ. This problem can be solved with met-amaterials, in particular, with plasmonic metasurfaces (PMSs) [1–5]. The plasmonic resonance exhibits a high sensitivity of its spectral response to the dielec-tric environment due to a strong field localization what makes possible measuring of analyte layers sat-isfying d << λ condition. The traditional approach of THz thin-film sensing with PMSs is based on detecting a frequency shift of the resonance when the analyte is deposited onto the PMS. In this work, we present the idea to substitute THz spectral measurements for tracking the PMS re-sponse at a fixed wavelength upon changing the incidence angle θ of the exciting THz beam. This concept works well for the PMS with a narrowband resonance sensitive to θ. The results of the numerical investigations and experimental study of such PMS designed as a single-layer array of hexagon-shaped annular slots (Fig. 1) with angle-susceptible resonant transmission near 0.85 THz are presented.
Open Access
Influence of the aging model of lithium-ion batteries on the management of PV self-consumption systems
(IEEE, 2018) Berrueta Irigoyen, Alberto; Pascual Miqueleiz, Julio María; San Martín Biurrun, Idoia; Sanchis Gúrpide, Pablo; Ursúa Rubio, Alfredo; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación; Gobierno de Navarra / Nafarroako Gobernua, PI038 INTEGRA-RENOVABLES
Lithium-ion batteries are gaining importance for a variety of applications due to their improving characteristics and decreasing price. An accurate knowledge of their aging is required for a successful use of these ESSs. The vast number of models that has been proposed to predict these phenomena raise doubts about the suitability of a model for a particular battery application. The performance of three models published for a Sanyo 18650 cylindrical cell in a self-consumption system are compared in this work. Measured photovoltaic production and home consumption with a sampling frequency of 15 minutes are used for this comparison. The different aging predictions calculated by these three models are analyzed, compared and discussed. These comparison is particularized for two management strategies. The first of them maximizes the self-consumption PV energy, while the second reduces the maximum power peak demanded from the grid.
Open Access
On the on-site measurement of the degradation rate of crystalline silicon PV modules at plant level
(IEEE, 2018) Pascual Miqueleiz, Julio María; Berrueta Irigoyen, Alberto; Marcos Álvarez, Javier; García Solano, Miguel; Marroyo Palomo, Luis; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
This paper proposes a method for measuring the degradation rate of crystalline silicon PV modules at plant level in two different ways as a form of verification. As actual levels of degradation rate have been observed to be as low as 0.2%/a, the uncertainties make it difficult to measure this value accurately at plant level. However, despite the low value, it is still important to know the actual degradation rate due to its impact on energy yield. In this paper, two ways of measuring the degradation rate at plant level are proposed. These two methods, with different uncertainty sources, are proposed to be used jointly in order to have a better approach to the real value. Finally, an example of measurement in a 1.78 MW PV plant is presented.