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Archivo Digital UPM (50,369 recursos)
This is an institutional repository providing access to the research output of the institution. Primarily contains thesis.

Materia = Electrónica

Mostrando recursos 1 - 20 de 866

1. Evaluation of the utilization of electric vehicles for building energy management in hotels - Gamallo, Carlos; Álvaro, Roberto; Fraile Ardanuy, José Jesús; González, Jairo; Fuentes Gomariz, Manuel
Governments are working in new policies to slow down total energy consumption and greenhouse gases (GHG) emissions, promoting the deployment of electric vehicles (EVs) in all countries. In order to facilitate this deployment and help to reduce the final costs of their batteries, additional utilization of EVs when those are parked has been proposed. EVs can be used to minimize the total electricity cost of buildings (named vehicle to building applications, V2B). In this paper an economic evaluation of EVs in the Building Energy Management System is shown. The optimal storage capacity and its equivalent number of EVs are determined....

2. The counteractive effect of the sensor housing on the unit sensitivity across a series of dynamic temperature profiles. - Badia-Melis, Ricardo; García-Hierro, Javier; Ruiz García, Luis; Jiménez Ariza, Heidi Tatiana; Robla Villalba, Jose Ignacio; Barreiro Elorza, Pilar
The advantages of wireless sensing implemented on the cold chain of fresh products are well known. These sensor systems consist of a combination of delicate internal electronic circuitry enclosed in a special housing unit. Manufacturers however are presented with the challenge that the housing required to withstand the harsh environment in which the sensors are being used all too often take from the functionality of the sensor. Therefore the target of this study is to determine the dynamic behavior and the counteractive effects of the sensor housing on temperature recording accuracy in the wireless nodes of Wireless Sensor Network (WSN)...

3. High-accuracy adaptive simulations of a Petri dish exposed to electromagnetic radiation - Gómez Revuelto, Ignacio; García Castillo, Luis Emilio; Pardo Zubiaur, David
This paper analyses numerically the electric field distribution of a liquid contained in a Petri dish when exposed to electromagnetic waves excited in a rectangular waveguide. Solutions exhibit high-gradients due to the presence of the dielectric liquid contained in the dish. Furthermore, electromagnetic fields within the dielectric have a dramatically lower value than on the remaining part of the domain, which difficults its simulation. Additionally, various singularities of different intensity appear along the boundary of the Petri dish. To properly reproduce and numerically study those effects, we employ a highly-accurate hp-adaptive finite element method. Results of this study demonstrate that...

4. A low-area reference-free power supply sensor - Benito Sánchez, Carlos; Ituero Herrero, Pablo; López Vallejo, Marisa
Power supply unpredictable uctuations jeopardize the functioning of several types of current electronic systems. This work presents a power supply sensor based on a voltage divider followed by buffer-comparator cells employing just MOSFET transistors and provides a digital output. The divider outputs are designed to change more slowly than the thresholds of the comparators, in this way the sensor is able to detect voltage droops. The sensor is implemented in a 65nm technology node occupying an area of 2700?m2 and displaying a power consumption of 50?W. It is designed to work with no voltage reference and with no clock and...

5. Global optimization of solar thermophotovoltaic systems - Datas Medina, Alejandro; Algora del Valle, Carlos
n this paper, we present a theoretical model based on the detailed balance theory of solar thermophotovoltaic systems comprising multijunction photovoltaic cells, a sunlight concentrator and spectrally selective surfaces. The full system has been defined by means of 2n + 8 variables (being n the number of sub-cells of the multijunction cell). These variables are as follows: the sunlight concentration factor, the absorber cut-off energy, the emitter-to-absorber area ratio, the emitter cut-off energy, the band-gap energy(ies) and voltage(s) of the sub-cells, the reflectivity of the cells' back-side reflector, the emitter-to-cell and cell-to-cell view factors and the emitter-to-cell area ratio. We have used...

6. Development and experimental evaluation of a complete solar thermophotovoltaic system - Datas Medina, Alejandro; Algora del Valle, Carlos
We present a practical implementation of a solar thermophotovoltaic (TPV) system. The system presented in this paper comprises a sunlight concentrator system, a cylindrical cup-shaped absorber/emitter (made of tungsten coated with HfO2), and an hexagonal-shaped water-cooled TPV generator comprising 24 germanium TPV cells, which is surrounding the cylindrical absorber/emitter. This paper focuses on the development of shingled TPV cell arrays, the characterization of the sunlight concentrator system, the estimation of the temperature achieved by the cylindrical emitters operated under concentrated sunlight, and the evaluation of the full system performance under real outdoor irradiance conditions. From the system characterization, we have...

7. Leakage and temperature aware server control for improving energy efficiency in data centers - Zapater Sancho, Marina; Ayala Rodrigo, José Luis; Moya Fernández, José Manuel; Vaidyanathan, Kalyan; Gross, Kenny; Coskun, Ayse K.
Reducing the energy consumption for computation and cooling in servers is a major challenge considering the data center energy costs today. To ensure energy-efficient operation of servers in data centers, the relationship among computa- tional power, temperature, leakage, and cooling power needs to be analyzed. By means of an innovative setup that enables monitoring and controlling the computing and cooling power consumption separately on a commercial enterprise server, this paper studies temperature-leakage-energy tradeoffs, obtaining an empirical model for the leakage component. Using this model, we design a controller that continuously seeks and settles at the optimal fan speed to minimize...

8. On the leakage-power modeling for optimal server operation - Arroba García, Patricia; Zapater Sancho, Marina; Ayala, José L.; Moya Fernández, José Manuel; Olcoz, Katzalin; Hermida, Román
Leakage power consumption is a com- ponent of the total power consumption in data cen- ters that is not traditionally considered in the set- point temperature of the room. However, the effect of this power component, increased with temperature, can determine the savings associated with the careful management of the cooling system, as well as the re- liability of the system. The work presented in this paper detects the need of addressing leakage power in order to achieve substantial savings in the energy consumption of servers. In particular, our work shows that, by a careful detection and management of two...

9. DIseño e implementación de un control adaptativo para obteNer ZVS en un convertidor trifasico de puente activo para aplicaciones de vehículos eléctricos - Molina García, José María
En este Trabajo Fin de Máster se ha realizado un estudio sobre un convertidor trifásico de doble puente activo con una red auxiliar, con objeto de conseguir ZVS. Como aportación, este trabajo diseña e implementa un control adaptativo para la red auxiliar ARCN, con el objetivo de disminuir las pérdidas a su valor mínimo.

10. Receptores homodinos a 300 GHz basados en tecnología CMOS - González Posadas, Vicente; Segovia Vargas, Daniel; Montero de Paz, Javier; Portillo López-Mingo, Álvaro; Crooks, Jamie; Huggard, Peter G.; García Muñoz, Enrique; Alderman, B.; Turchetta, R.
Using CMOS transistors for terahertz detection is currently a disruptive technology that offers the direct integration of a terahertz detector with video preamplifiers. The detectors are based on the resistive mixer concept and its performance mainly depends on the following parameters: type of antenna, electrical parameters (gate to drain capacitor and channel length of the CMOS device) and foundry. Two different 300 GHz detectors are discussed: a single transistor detector with a broadband antenna and a differential pair driven by a resonant patch antenna.

11. Robust control of underactuated wheeled mobile manipulators using GPI disturbance observers - Morales Cabrera, Rafael; Sira Ramírez, Hebertt; Somolinos Sanchez , Jose Andres
This article describes the design of a linear observer–linear controller-based robust output feedback scheme for output reference trajectory tracking tasks in the case of nonlinear, multivariable, nonholonomic underactuated mobile manipulators. The proposed linear feedback scheme is based on the use of a classical linear feedback controller and suitably extended, high-gain, linear Generalized Proportional Integral (GPI) observers, thus aiding the linear feedback controllers to provide an accurate simultaneous estimation of each flat output associated phase variables and of the exogenous and perturbation inputs. This information is used in the proposed feedback controller in (a) approximate, yet close, cancelations, as lumped unstructured...

12. Evaluation, energy optimization, and spectrum analysis of an artificial noise technique to improve CWSN security - Blesa Martínez, Javier; Araujo Pinto, Álvaro; Romero Perales, Elena; Nieto-Taladriz García, Octavio
This paper presents the security evaluation, energy consumption optimization, and spectrum scarcity analysis of artificial noise techniques to increase physical-layer security in Cognitive Wireless Sensor Networks (CWSNs). These techniques introduce noise into the spectrum in order to hide real information. Nevertheless, they directly affect two important parameters in Cognitive Wireless Sensor Networks (CWSNs), energy consumption and spectrum utilization. Both are affected because the number of packets transmitted by the network and the active period of the nodes increase. Security evaluation demonstrates that these techniques are effective against eavesdropper attacks, but also optimization allows for the implementation of these approaches in...

13. Wide-angle, high-concentration photovoltaics to compete with flat plate systems - Mohedano, Rubén; Cvetkovic, Aleksandra; Benitez Gimenez, Pablo; Miñano Dominguez, Juan Carlos; Hernández Sanz, Maikel; Zamora Herranz, Pablo; Vilaplana, J.
A novel photovoltaic concentrator enables highly uniform irradiance on a small number of efficient solar cells. The maximum electrical power of a photovoltaic (PV) energy installation depends on three factors: the available irradiance, the size of the systems collecting sunlight, and the rate at which the device transforms light into electricity (the conversion efficiency). Developers can maximize the irradiance by carefully selecting the site and orientation of the solar facility. But they can only expand their sunlight collection systems for standard flat plate PV devices by increasing the number of solar cells, at greater cost. Here, we consider the advantages...

14. Newer optics efficiently mix, dim, and color-tune LED light - Miñano Dominguez, Juan Carlos; Mohedano, Rubén; Benitez Gimenez, Pablo; Álvarez, Roberto
Low-cost, plastic-injected optics mix light from different color LED dies without a significant decrease in average brightness, simplifying luminaire design both optically and electronically. In solid-state lighting, high-flux and high-color rendering index (CRI) light engines may be achieved by arraying and mixing the light from different color dies or phosphors, or a combination of the two, in the LED package. However, these nonhomogeneous sources, when combined with luminaire optics, tend to produce patterns with undesirable artifacts such as spatial and angular nonuniformities and color separation.

15. Temperature controlled light-emitting diode lamp for photovoltaic rural applications - Narvarte Fernández, Luis; Gago Calderón, Alfonso; Fernández-Ramos, José
In recent years, interest in light-emitting diode (LED) lighting has been growing because of its high efficacy, lifetime and ruggedness. This paper proposes a better adaptation of LED lamps to the technical requirements of photovoltaic lighting domestic systems, whose main quality criteria are reliability and that behave as voltage power supplies. As the key element of reliability in LED lamps is temperature, a solution is proposed for driving LED lamps using voltage sources, such as photovoltaic system batteries, with a control architecture based on pulse width modulation signal that regulates the current applied according to the LED lamp temperature. A...

16. NGCPV: a new generation of concentrator photovoltaic cells, modules and systems - Datas Medina, Alejandro; Cristóbal López, Ana Belén; Sala Pano, Gabriel; Anton Hernandez, Ignacio; Miñano Dominguez, Juan Carlos; Benitez Gimenez, Pablo; Bett, Andreas W.; Siefer, G.; Ekins-Daukes, Ned; Roca, Franco; Cancro, C.; Luque-Heredia, Ignacio; Warmuth, Werner; Baudrit, Mathieu; Okada, Y.; Sugiyama, M.; Hishikawa, Y.; Takamoto, Tatsuya; Araki, Kenji; Fukuyama, A.; Nishioka, K.; Suzuki, H.; Kuze, N.; Moriyasu, Y.; Kita, T.; Kotagiri, Akira; Kojima, N.; Martí Vega, Antonio; Yamaguchi, M.; Luque López, Antonio
Starting on June 2011, NGCPV is the first project funded jointly between the European Commission (EC) and the New Energy and Industrial Technology Development Organization (NEDO) of Japan to research on new generation concentration photovoltaics (CPV). The Project, through a collaborative research between seven European and nine Japanese leading research centers in the field of CPV, aims at lowering the cost of the CPVproduced photovoltaic kWh down to 5 ?cents. The main objective of the project is to improve the present concentrator cell, module and system efficiency, as well as developing advanced characterization tools for CPV components and systems. As...

17. VentanaTM power train features and performance - Mohedano, Rubén; Benitez Gimenez, Pablo; Zamora Herranz, Pablo; Miñano Dominguez, Juan Carlos; Mendes Lopes, Joao; Cvetkovic, Aleksandra; Vilaplana, J.; Hernández Sanz, Maikel; Chaves, Julio; Biot Marí, Guillermo
Most CPV systems are based on Fresnel lenses. Among these, LPI-patented Fresnel-Köhler (FK) concentrator outstands owing to performance and practical reasons. The VentanaTM power train is the first off-the-shelf commercial product based on the FK and comprises both the primary (POE) lenses (a 36-units 1×1 m2 acrylic panel manufactured by EVONIK and 10×) and glass (or Savosil) secondary optics (SOE). This high concentration optical train (Cg=1,024×, ~250mm optical depth) fits with 5×5 mm2 (at least) solar cells. The optical train is the fruit of a 1-year development that has included design, modeling, prototyping and characterization, and through the process LPI...

18. Ratio-based temperature-sensing technique hardened against nanometer process variations - Ituero Herrero, Pablo; López Vallejo, Marisa
This letter presents a temperature-sensing technique on the basis of the temperature dependency of MOSFET leakage currents. To mitigate the effects of process variation, the ratio of two different leakage current measurements is calculated. Simulations show that this ratio is robust to process spread. The resulting sensor is quite small-0.0016 mm2 including an analog-to-digital conversion-and very energy efficient, consuming less than 640 pJ/conversion. After a two-point calibration, the accuracy in a range of 40°C-110°C is less than 1.5°C , which makes the technique suitable for thermal management applications.

19. Floating-point exponentiation units for reconfigurable computing - Dinechin, Florent de; Echeverría Aramendi, Pedro; López Vallejo, Marisa; Pasca, Bogdan
The high performance and capacity of current FPGAs makes them suitable as acceleration co-processors. This article studies the implementation, for such accelerators, of the floating-point power function xy as defined by the C99 and IEEE 754-2008 standards, generalized here to arbitrary exponent and mantissa sizes. Last-bit accuracy at the smallest possible cost is obtained thanks to a careful study of the various subcomponents: a floating-point logarithm, a modified floating-point exponential, and a truncated floating-point multiplier. A parameterized architecture generator in the open-source FloPoCo project is presented in details and evaluated.

20. Design techniques for xilinx virtex FPGA configuration memory scrubbers - Herrera Alzu, Ignacio; López Vallejo, Marisa
SRAM-based FPGAs are in-field reconfigurable an unlimited number of times. This characteristic, together with their high performance and high logic density, proves to be very convenient for a number of ground and space level applications. One drawback of this technology is that it is susceptible to ionizing radiation, and this sensitivity increases with technology scaling. This is a first order concern for applications in harsh radiation environments, and starts to be a concern for high reliability ground applications. Several techniques exist for coping with radiation effects at user application. In order to be effective they need to be complemented with...

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