Automatized connection of the layers of planar transformers with parallel windings to improve the component behavior

Transformers with parallel windings are commonly used to reduce the losses in the windings. Windings losses depend on the winding positioning and the frequency effects because each winding affects the current sharing of itself and the neighboring windings. In this paper a methodology for determining the connections of the parallel windings that reduces the power losses (and temperature) in the windings of multi-winding transformers is presented. Other applications of the method, such as balanced current sharing and voltage drop reduction are also explored. In this paper a methodology for determining the connections of the parallel windings that reduces the power losses (and temperature) in the windings of multi-winding transformers is presented. Other applications of the method, such as balanced current sharing and voltage drop reduction are also explored.

An alternative for reducing the layers in the construction of three-phase planar transformers

A modified winding layout for three-phase transformers with PCB windings is proposed in this paper. This modified layout can be used in high current transformers with many PCB layers to simplify the fabrication process. One of the key factors that might increase the cost and complexity in the construction of planar transformers is the number of layers of each PCB winding. This issue becomes even more important in medium-high power three-phase transformers, where the number of PCB layers is higher. In addition to that, the proposed method allows the use of commercial core shapes that are commonly used to design single-phase transformers. This fact makes possible the reduction of cost and flexibility of the design solutions. The proposed solution has been validated and compared using the conventional and the proposed methodologies to design a high power (20 kW) transformer.

Implementación de ingeniería virtual con Joomla!

El Proyecto Final de Carrera(PFC)Implementación de Ingeniería Virtual con Joomla! tiene como objetivo la creación de una plataforma web. Para desarrollar un proyecto de ingeniería multidisciplinar, basado en el trabajo en red, grupos de trabajo y el trabajo flexible. El trabajo en red es desempeñar el trabajo por medio de las Tecnología de la Información y la comunicación (TIC). Los grupos de trabajo están compuestos por personas multidisciplinares, multirraciales, de diferentes religiones, situados en husos horarios distintos y multiculturales donde la colaboración, flexibilidad y la compartición de recursos están a la orden del día. La flexible es la capacidad de adaptación de los propios trabajadores a la demanda de la productividad, los responsables depositan sobre ellos su confianza, recibiendo el trabajo terminado en forma y fecha. Estos trabajadores no necesitan una supervisión constante ni un sitio fijo donde realizar su trabajo. Todo lo que necesitan esta en la red, la información que necesitan como las herramientas. Convirtiéndose este tipo de trabajador en teletrabajadores. Estos trabajadores utilizan de forma intensiva sus conocimientos, no se puede permitir quedarse obsoletos en su conocimientos, sería su gran desgracia. Por está razón, necesitan estar formándose continuamente, aprendiendo y conociendo las nuevas tecnologías que aparecen. Con el objetivo de conseguir nuevas líneas de negocio, con el fin de lograr nuevos ingresos. Los trabajadores que hacen un uso intensivo en la tecnología de la información y comunicación, se caracterizan por la continua innovación y cambio tecnológico. Estos trabajadores necesitan una red profesional, social amplia con enlaces fuertes y poderosos. Las redes son importantes, para estar actualizado con las innovaciones que se realizan en las empresas, optar a nuevos puesto de trabajo, curso en nuevas tecnologías… Gracias a los servicios actuales en Internet facilitan mantener vivos una gran cantidad de enlaces (contactos), en comparación con otras épocas. La plataforma propuesta en este proyecto final de carrera esta compuesta de todas las herramientas necesarias para que estos trabajadores puedan desarrollar su actividad y mantenimiento de sus redes profesionales. Abstract: The aim of this Final Project of Career, Implementation of Virtual Engineering with Joomla!, is to create a web software application where a multidisciplinary engineering project bases on the networking, working groups and the flexible working can be implemented. The networking is the job through the Information Technology and Communication (ITC) where working groups compounded of multidisciplinary and multiracial professions, different religions and located in different time zones are created. The multicultural environment, collaboration, flexibility and to share resources are the order of the day on this kind of groups. The flexibility is the ability to adaptability of workers to the productivity demand, with the trust which is placed on them by supervisor people who wait to receive the work completed in a specific form and date. These workers do not need either constant supervision or a fixed site where to do the job. Everything the workers need is on the network, as the information as the tools, that is why they become teleworkers. These workers demand a high use of their knowledge, so it can not be allowed to become obsolete. This would be a great misfortune. That is why they need to continue learning and knowing the new technologies emerging with the aim of getting new revenues. Workers do an intensive use of the information technology and communication, characterized by continuous innovation and technological change. These workers need a broad social and professional network with great power. This network is important to keep updated with innovations taking place at the companies, to apply for a new job, a new technology course etc.. Thanks to Internet services a bigger number of contacts are provided compared to earlier times. The software application of this project is compounded with enough tools with the aim of the workers can carry out their activity and maintenance of the links on their professional nets.

Novel Inductor‐less Conversion Strategy Based on Multiphase Transformer‐Coupled Converters: Analysis, Design and Applications

There are many the requirements that modern power converters should fulfill. Most of the applications where these converters are used, demand smaller converters with high efficiency, improved power density and a fast dynamic response. For instance, loads like microprocessors demand aggressive current steps with very high slew rates (100A/mus and higher); besides, during these load steps, the supply voltage of the microprocessor should be kept within tight limits in order to ensure its correct performance. The accomplishment of these requirements is not an easy task; complex solutions like advanced topologies - such as multiphase converters- as well as advanced control strategies are often needed. Besides, it is also necessary to operate the converter at high switching frequencies and to use capacitors with high capacitance and low ESR. Improving the dynamic response of power converters does not rely only on the control strategy but also the power topology should be suited to enable a fast dynamic response. Moreover, in later years, a fast dynamic response does not only mean accomplishing fast load steps but output voltage steps are gaining importance as well. At least, two applications that require fast voltage changes can be named: Low power microprocessors. In these devices, the voltage supply is changed according to the workload and the operating frequency of the microprocessor is changed at the same time. An important reduction in voltage dependent losses can be achieved with such changes. This technique is known as Dynamic Voltage Scaling (DVS). Another application where important energy savings can be achieved by means of changing the supply voltage are Radio Frequency Power Amplifiers. For example, RF architectures based on ‘Envelope Tracking’ and ‘Envelope Elimination and Restoration’ techniques can take advantage of voltage supply modulation and accomplish important energy savings in the power amplifier. However, in order to achieve these efficiency improvements, a power converter with high efficiency and high enough bandwidth (hundreds of kHz or even tens of MHz) is necessary in order to ensure an adequate supply voltage. The main objective of this Thesis is to improve the dynamic response of DC-DC converters from the point of view of the power topology. And the term dynamic response refers both to the load steps and the voltage steps; it is also interesting to modulate the output voltage of the converter with a specific bandwidth. In order to accomplish this, the question of what is it that limits the dynamic response of power converters should be answered. Analyzing this question leads to the conclusion that the dynamic response is limited by the power topology and specifically, by the filter inductance of the converter which is found in series between the input and the output of the converter. The series inductance is the one that determines the gain of the converter and provides the regulation capability. Although the energy stored in the filter inductance enables the regulation and the capability of filtering the output voltage, it imposes a limitation which is the concern of this Thesis. The series inductance stores energy and prevents the current from changing in a fast way, limiting the slew rate of the current through this inductor. Different solutions are proposed in the literature in order to reduce the limit imposed by the filter inductor. Many publications proposing new topologies and improvements to known topologies can be found in the literature. Also, complex control strategies are proposed with the objective of improving the dynamic response in power converters. In the proposed topologies, the energy stored in the series inductor is reduced; examples of these topologies are Multiphase converters, Buck converter operating at very high frequency or adding a low impedance path in parallel with the series inductance. Control techniques proposed in the literature, focus on adjusting the output voltage as fast as allowed by the power stage; examples of these control techniques are: hysteresis control, V 2 control, and minimum time control. In some of the proposed topologies, a reduction in the value of the series inductance is achieved and with this, the energy stored in this magnetic element is reduced; less stored energy means a faster dynamic response. However, in some cases (as in the high frequency Buck converter), the dynamic response is improved at the cost of worsening the efficiency. In this Thesis, a drastic solution is proposed: to completely eliminate the series inductance of the converter. This is a more radical solution when compared to those proposed in the literature. If the series inductance is eliminated, the regulation capability of the converter is limited which can make it difficult to use the topology in one-converter solutions; however, this topology is suitable for power architectures where the energy conversion is done by more than one converter. When the series inductor is eliminated from the converter, the current slew rate is no longer limited and it can be said that the dynamic response of the converter is independent from the switching frequency. This is the main advantage of eliminating the series inductor. The main objective, is to propose an energy conversion strategy that is done without series inductance. Without series inductance, no energy is stored between the input and the output of the converter and the dynamic response would be instantaneous if all the devices were ideal. If the energy transfer from the input to the output of the converter is done instantaneously when a load step occurs, conceptually it would not be necessary to store energy at the output of the converter (no output capacitor COUT would be needed) and if the input source is ideal, the input capacitor CIN would not be necessary. This last feature (no CIN with ideal VIN) is common to all power converters. However, when the concept is actually implemented, parasitic inductances such as leakage inductance of the transformer and the parasitic inductance of the PCB, cannot be avoided because they are inherent to the implementation of the converter. These parasitic elements do not affect significantly to the proposed concept. In this Thesis, it is proposed to operate the converter without series inductance in order to improve the dynamic response of the converter; however, on the other side, the continuous regulation capability of the converter is lost. It is said continuous because, as it will be explained throughout the Thesis, it is indeed possible to achieve discrete regulation; a converter without filter inductance and without energy stored in the magnetic element, is capable to achieve a limited number of output voltages. The changes between these output voltage levels are achieved in a fast way. The proposed energy conversion strategy is implemented by means of a multiphase converter where the coupling of the phases is done by discrete two-winding transformers instead of coupledinductors since transformers are, ideally, no energy storing elements. This idea is the main contribution of this Thesis. The feasibility of this energy conversion strategy is first analyzed and then verified by simulation and by the implementation of experimental prototypes. Once the strategy is proved valid, different options to implement the magnetic structure are analyzed. Three different discrete transformer arrangements are studied and implemented. A converter based on this energy conversion strategy would be designed with a different approach than the one used to design classic converters since an additional design degree of freedom is available. The switching frequency can be chosen according to the design specifications without penalizing the dynamic response or the efficiency. Low operating frequencies can be chosen in order to favor the efficiency; on the other hand, high operating frequencies (MHz) can be chosen in order to favor the size of the converter. For this reason, a particular design procedure is proposed for the ‘inductorless’ conversion strategy. Finally, applications where the features of the proposed conversion strategy (high efficiency with fast dynamic response) are advantageus, are proposed. For example, in two-stage power architectures where a high efficiency converter is needed as the first stage and there is a second stage that provides the fine regulation. Another example are RF power amplifiers where the voltage is modulated following an envelope reference in order to save power; in this application, a high efficiency converter, capable of achieving fast voltage steps is required. The main contributions of this Thesis are the following: The proposal of a conversion strategy that is done, ideally, without storing energy in the magnetic element. The validation and the implementation of the proposed energy conversion strategy. The study of different magnetic structures based on discrete transformers for the implementation of the proposed energy conversion strategy. To elaborate and validate a design procedure. To identify and validate applications for the proposed energy conversion strategy. It is important to remark that this work is done in collaboration with Intel. The particular features of the proposed conversion strategy enable the possibility of solving the problems related to microprocessor powering in a different way. For example, the high efficiency achieved with the proposed conversion strategy enables it as a good candidate to be used for power conditioning, as a first stage in a two-stage power architecture for powering microprocessors.

Contribution to the design of waveguide-fed compound-slot arrays by means of equivalent circuit modelling

Los arrays de ranuras son sistemas de antennas conocidos desde los años 40, principalmente destinados a formar parte de sistemas rádar de navíos de combate y grandes estaciones terrenas donde el tamaño y el peso no eran altamente restrictivos. Con el paso de los años y debido sobre todo a importantes avances en materiales y métodos de fabricación, el rango de aplicaciones de este tipo de sistemas radiantes creció en gran medida. Desde nuevas tecnologías biomédicas, sistemas anticolisión en automóviles y navegación en aviones, enlaces de comunicaciones de alta tasa binaria y corta distancia e incluso sistemas embarcados en satélites para la transmisión de señal de televisión. Dentro de esta familia de antennas, existen dos grupos que destacan por ser los más utilizados: las antennas de placas paralelas con las ranuras distribuidas de forma circular o espiral y las agrupaciones de arrays lineales construidos sobre guia de onda. Continuando con las tareas de investigación desarrolladas durante los últimos años en el Instituto de Tecnología de Tokyo y en el Grupo de Radiación de la Universidad Politécnica de Madrid, la totalidad de esta tesis se centra en este último grupo, aunque como se verá se separa en gran medida de las técnicas de diseño y metodologías convencionales. Los arrays de ranuras rectas y paralelas al eje de la guía rectangular que las alimenta son, sin ninguna duda, los modelos más empleados debido a la fiabilidad que presentan a altas frecuencias, su capacidad para gestionar grandes cantidades de potencia y la sencillez de su diseño y fabricación. Sin embargo, también presentan desventajas como estrecho ancho de banda en pérdidas de retorno y rápida degradación del diagrama de radiación con la frecuencia. Éstas son debidas a la naturaleza resonante de sus elementos radiantes: al perder la resonancia, el sistema global se desajusta y sus prestaciones degeneran. En arrays bidimensionales de slots rectos, el campo eléctrico queda polarizado sobre el plano transversal a las ranuras, correspondiéndose con el plano de altos lóbulos secundarios. Esta tesis tiene como objetivo el desarrollo de un método sistemático de diseño de arrays de ranuras inclinadas y desplazadas del centro (en lo sucesivo “ranuras compuestas”), definido en 1971 como uno de los desafíos a superar dentro del mundo del diseño de antennas. La técnica empleada se basa en el Método de los Momentos, la Teoría de Circuitos y la Teoría de Conexión Aleatoria de Matrices de Dispersión. Al tratarse de un método circuital, la primera parte de la tesis se corresponde con el estudio de la aplicabilidad de las redes equivalentes fundamentales, su capacidad para recrear fenómenos físicos de la ranura, las limitaciones y ventajas que presentan para caracterizar las diferentes configuraciones de slot compuesto. Se profundiza en las diferencias entre las redes en T y en ! y se condiciona la selección de una u otra dependiendo del tipo de elemento radiante. Una vez seleccionado el tipo de red a emplear en el diseño del sistema, se ha desarrollado un algoritmo de cascadeo progresivo desde el puerto alimentador hacia el cortocircuito que termina el modelo. Este algoritmo es independiente del número de elementos, la frecuencia central de funcionamiento, del ángulo de inclinación de las ranuras y de la red equivalente seleccionada (en T o en !). Se basa en definir el diseño del array como un Problema de Satisfacción de Condiciones (en inglés, Constraint Satisfaction Problem) que se resuelve por un método de Búsqueda en Retroceso (Backtracking algorithm). Como resultado devuelve un circuito equivalente del array completo adaptado a su entrada y cuyos elementos consumen una potencia acorde a una distribución de amplitud dada para el array. En toda agrupación de antennas, el acoplo mutuo entre elementos a través del campo radiado representa uno de los principales problemas para el ingeniero y sus efectos perjudican a las prestaciones globales del sistema, tanto en adaptación como en capacidad de radiación. El empleo de circuito equivalente se descartó por la dificultad que suponía la caracterización de estos efectos y su inclusión en la etapa de diseño. En esta tesis doctoral el acoplo también se ha modelado como una red equivalente cuyos elementos son transformadores ideales y admitancias, conectada al conjunto de redes equivalentes que representa el array. Al comparar los resultados estimados en términos de pérdidas de retorno y radiación con aquellos obtenidos a partir de programas comerciales populares como CST Microwave Studio se confirma la validez del método aquí propuesto, el primer método de diseño sistemático de arrays de ranuras compuestos alimentados por guía de onda rectangular. Al tratarse de ranuras no resonantes, el ancho de banda en pérdidas de retorno es mucho mas amplio que el que presentan arrays de slots rectos. Para arrays bidimensionales, el ángulo de inclinación puede ajustarse de manera que el campo quede polarizado en los planos de bajos lóbulos secundarios. Además de simulaciones se han diseñado, construido y medido dos prototipos centrados en la frecuencia de 12GHz, de seis y diez elementos. Las medidas de pérdidas de retorno y diagrama de radiación revelan excelentes resultados, certificando la bondad del método genuino Method of Moments - Forward Matching Procedure desarrollado a lo largo de esta tésis. Abstract The slot antenna arrays are well known systems from the decade of 40s, mainly intended to be part of radar systems of large warships and terrestrial stations where size and weight were not highly restrictive. Over the years, mainly due to significant advances in materials and manufacturing methods, the range of applications of this type of radiating systems grew significantly. From new biomedical technologies, collision avoidance systems in cars and aircraft navigation, short communication links with high bit transfer rate and even embedded systems in satellites for television broadcast. Within this family of antennas, two groups stand out as being the most frequent in the literature: parallel plate antennas with slots placed in a circular or spiral distribution and clusters of waveguide linear arrays. To continue the vast research work carried out during the last decades in the Tokyo Institute of Technology and in the Radiation Group at the Universidad Politécnica de Madrid, this thesis focuses on the latter group, although it represents a technique that drastically breaks with traditional design methodologies. The arrays of slots straight and parallel to the axis of the feeding rectangular waveguide are without a doubt the most used models because of the reliability that they present at high frequencies, its ability to handle large amounts of power and their simplicity of design and manufacturing. However, there also exist disadvantages as narrow bandwidth in return loss and rapid degradation of the radiation pattern with frequency. These are due to the resonant nature of radiating elements: away from the resonance status, the overall system performance and radiation pattern diminish. For two-dimensional arrays of straight slots, the electric field is polarized transverse to the radiators, corresponding to the plane of high side-lobe level. This thesis aims to develop a systematic method of designing arrays of angled and displaced slots (hereinafter "compound slots"), defined in 1971 as one of the challenges to overcome in the world of antenna design. The used technique is based on the Method of Moments, Circuit Theory and the Theory of Scattering Matrices Connection. Being a circuitry-based method, the first part of this dissertation corresponds to the study of the applicability of the basic equivalent networks, their ability to recreate the slot physical phenomena, their limitations and advantages presented to characterize different compound slot configurations. It delves into the differences of T and ! and determines the selection of the most suitable one depending on the type of radiating element. Once the type of network to be used in the system design is selected, a progressive algorithm called Forward Matching Procedure has been developed to connect the proper equivalent networks from the feeder port to shorted ending. This algorithm is independent of the number of elements, the central operating frequency, the angle of inclination of the slots and selected equivalent network (T or ! networks). It is based on the definition of the array design as a Constraint Satisfaction Problem, solved by means of a Backtracking Algorithm. As a result, the method returns an equivalent circuit of the whole array which is matched at its input port and whose elements consume a power according to a given amplitude distribution for the array. In any group of antennas, the mutual coupling between elements through the radiated field represents one of the biggest problems that the engineer faces and its effects are detrimental to the overall performance of the system, both in radiation capabilities and return loss. The employment of an equivalent circuit for the array design was discarded by some authors because of the difficulty involved in the characterization of the coupling effects and their inclusion in the design stage. In this thesis the coupling has also been modeled as an equivalent network whose elements are ideal transformers and admittances connected to the set of equivalent networks that represent the antennas of the array. By comparing the estimated results in terms of return loss and radiation with those obtained from popular commercial software as CST Microwave Studio, the validity of the proposed method is fully confirmed, representing the first method of systematic design of compound-slot arrays fed by rectangular waveguide. Since these slots do not work under the resonant status, the bandwidth in return loss is much wider than the longitudinal-slot arrays. For the case of two-dimensional arrays, the angle of inclination can be adjusted so that the field is polarized at the low side-lobe level plane. Besides the performed full-wave simulations two prototypes of six and ten elements for the X-band have been designed, built and measured, revealing excellent results and agreement with the expected results. These facts certify that the genuine technique Method of Moments - Matching Forward Procedure developed along this thesis is valid and trustable.

Optimizing three-phase planar transformer construction

A three-phase transformer with flat conductor layers is proposed in this article. This arrangement is used for high current density transformers. Cost effectiveness in planar magnetic are related with the optimization in the number of layers in each winding. This fact takes more relevance for the medium and high power three-phase transformers where the number of parallels to achieve the required DCR is increased. The proposed method allows the use of off-the-shell core shapes that are used for single phase transformers. Cost impact is significant and design implications become more flexible. The proposed solution has been validated and compared using the conventional and the proposed methodologies to design a high power (20 kW) transformer.

Quality of Service (QoS) in MPLS networks

Telecommunications networks have been always expanding and thanks to it, new services have appeared. The old mechanisms for carrying packets have become obsolete due to the new service requirements, which have begun working in real time. Real time traffic requires strict service guarantees. When this traffic is sent through the network, enough resources must be given in order to avoid delays and information losses. When browsing through the Internet and requesting web pages, data must be sent from a server to the user. If during the transmission there is any packet drop, the packet is sent again. For the end user, it does not matter if the webpage loads in one or two seconds more. But if the user is maintaining a conversation with a VoIP program, such as Skype, one or two seconds of delay in the conversation may be catastrophic, and none of them can understand the other. In order to provide support for this new services, the networks have to evolve. For this purpose MPLS and QoS were developed. MPLS is a packet carrying mechanism used in high performance telecommunication networks which directs and carries data using pre-established paths. Now, packets are forwarded on the basis of labels, making this process faster than routing the packets with the IP addresses. MPLS also supports Traffic Engineering (TE). This refers to the process of selecting the best paths for data traffic in order to balance the traffic load between the different links. In a network with multiple paths, routing algorithms calculate the shortest one, and most of the times all traffic is directed through it, causing overload and packet drops, without distributing the packets in the other paths that the network offers and do not have any traffic. But this is not enough in order to provide the real time traffic the guarantees it needs. In fact, those mechanisms improve the network, but they do not make changes in how the traffic is treated. That is why Quality of Service (QoS) was developed. Quality of service is the ability to provide different priority to different applications, users, or data flows, or to guarantee a certain level of performance to a data flow. Traffic is distributed into different classes and each of them is treated differently, according to its Service Level Agreement (SLA). Traffic with the highest priority will have the preference over lower classes, but this does not mean it will monopolize all the resources. In order to achieve this goal, a set policies are defined to control and alter how the traffic flows. Possibilities are endless, and it depends in how the network must be structured. By using those mechanisms it is possible to provide the necessary guarantees to the real-time traffic, distributing it between categories inside the network and offering the best service for both real time data and non real time data. Las Redes de Telecomunicaciones siempre han estado en expansión y han propiciado la aparición de nuevos servicios. Los viejos mecanismos para transportar paquetes se han quedado obsoletos debido a las exigencias de los nuevos servicios, que han comenzado a operar en tiempo real. El tráfico en tiempo real requiere de unas estrictas garantías de servicio. Cuando este tráfico se envía a través de la red, necesita disponer de suficientes recursos para evitar retrasos y pérdidas de información. Cuando se navega por la red y se solicitan páginas web, los datos viajan desde un servidor hasta el usuario. Si durante la transmisión se pierde algún paquete, éste se vuelve a mandar de nuevo. Para el usuario final, no importa si la página tarda uno o dos segundos más en cargar. Ahora bien, si el usuario está manteniendo una conversación usando algún programa de VoIP (como por ejemplo Skype) uno o dos segundos de retardo en la conversación podrían ser catastróficos, y ninguno de los interlocutores sería capaz de entender al otro. Para poder dar soporte a estos nuevos servicios, las redes deben evolucionar. Para este propósito se han concebido MPLS y QoS MPLS es un mecanismo de transporte de paquetes que se usa en redes de telecomunicaciones de alto rendimiento que dirige y transporta los datos de acuerdo a caminos preestablecidos. Ahora los paquetes se encaminan en función de unas etiquetas, lo cual hace que sea mucho más rápido que encaminar los paquetes usando las direcciones IP. MPLS también soporta Ingeniería de Tráfico (TE). Consiste en seleccionar los mejores caminos para el tráfico de datos con el objetivo de balancear la carga entre los diferentes enlaces. En una red con múltiples caminos, los algoritmos de enrutamiento actuales calculan el camino más corto, y muchas veces el tráfico se dirige sólo por éste, saturando el canal, mientras que otras rutas se quedan completamente desocupadas. Ahora bien, esto no es suficiente para ofrecer al tráfico en tiempo real las garantías que necesita. De hecho, estos mecanismos mejoran la red, pero no realizan cambios a la hora de tratar el tráfico. Por esto es por lo que se ha desarrollado el concepto de Calidad de Servicio (QoS). La calidad de servicio es la capacidad para ofrecer diferentes prioridades a las diferentes aplicaciones, usuarios o flujos de datos, y para garantizar un cierto nivel de rendimiento en un flujo de datos. El tráfico se distribuye en diferentes clases y cada una de ellas se trata de forma diferente, de acuerdo a las especificaciones que se indiquen en su Contrato de Tráfico (SLA). EL tráfico con mayor prioridad tendrá preferencia sobre el resto, pero esto no significa que acapare la totalidad de los recursos. Para poder alcanzar estos objetivos se definen una serie de políticas para controlar y alterar el comportamiento del tráfico. Las posibilidades son inmensas dependiendo de cómo se quiera estructurar la red. Usando estos mecanismos se pueden proporcionar las garantías necesarias al tráfico en tiempo real, distribuyéndolo en categorías dentro de la red y ofreciendo el mejor servicio posible tanto a los datos en tiempo real como a los que no lo son.

Simulación en tiempo real de vehículos industriales con modelos multicuerpo de gran complejidad

El objetivo de esta Tesis ha sido la consecución de simulaciones en tiempo real de vehículos industriales modelizados como sistemas multicuerpo complejos formados por sólidos rígidos. Para el desarrollo de un programa de simulación deben considerarse cuatro aspectos fundamentales: la modelización del sistema multicuerpo (tipos de coordenadas, pares ideales o impuestos mediante fuerzas), la formulación a utilizar para plantear las ecuaciones diferenciales del movimiento (coordenadas dependientes o independientes, métodos globales o topológicos, forma de imponer las ecuaciones de restricción), el método de integración numérica para resolver estas ecuaciones en el tiempo (integradores explícitos o implícitos) y finalmente los detalles de la implementación realizada (lenguaje de programación, librerías matemáticas, técnicas de paralelización). Estas cuatro etapas están interrelacionadas entre sí y todas han formado parte de este trabajo. Desde la generación de modelos de una furgoneta y de camión con semirremolque, el uso de tres formulaciones dinámicas diferentes, la integración de las ecuaciones diferenciales del movimiento mediante métodos explícitos e implícitos, hasta el uso de funciones BLAS, de técnicas de matrices sparse y la introducción de paralelización para utilizar los distintos núcleos del procesador. El trabajo presentado en esta Tesis ha sido organizado en 8 capítulos, dedicándose el primero de ellos a la Introducción. En el Capítulo 2 se presentan dos formulaciones semirrecursivas diferentes, de las cuales la primera está basada en una doble transformación de velocidades, obteniéndose las ecuaciones diferenciales del movimiento en función de las aceleraciones relativas independientes. La integración numérica de estas ecuaciones se ha realizado con el método de Runge-Kutta explícito de cuarto orden. La segunda formulación está basada en coordenadas relativas dependientes, imponiendo las restricciones por medio de penalizadores en posición y corrigiendo las velocidades y aceleraciones mediante métodos de proyección. En este segundo caso la integración de las ecuaciones del movimiento se ha llevado a cabo mediante el integrador implícito HHT (Hilber, Hughes and Taylor), perteneciente a la familia de integradores estructurales de Newmark. En el Capítulo 3 se introduce la tercera formulación utilizada en esta Tesis. En este caso las uniones entre los sólidos del sistema se ha realizado mediante uniones flexibles, lo que obliga a imponer los pares por medio de fuerzas. Este tipo de uniones impide trabajar con coordenadas relativas, por lo que la posición del sistema y el planteamiento de las ecuaciones del movimiento se ha realizado utilizando coordenadas Cartesianas y parámetros de Euler. En esta formulación global se introducen las restricciones mediante fuerzas (con un planteamiento similar al de los penalizadores) y la estabilización del proceso de integración numérica se realiza también mediante proyecciones de velocidades y aceleraciones. En el Capítulo 4 se presenta una revisión de las principales herramientas y estrategias utilizadas para aumentar la eficiencia de las implementaciones de los distintos algoritmos. En primer lugar se incluye una serie de consideraciones básicas para aumentar la eficiencia numérica de las implementaciones. A continuación se mencionan las principales características de los analizadores de códigos utilizados y también las librerías matemáticas utilizadas para resolver los problemas de álgebra lineal tanto con matrices densas como sparse. Por último se desarrolla con un cierto detalle el tema de la paralelización en los actuales procesadores de varios núcleos, describiendo para ello el patrón empleado y las características más importantes de las dos herramientas propuestas, OpenMP y las TBB de Intel. Hay que señalar que las características de los sistemas multicuerpo problemas de pequeño tamaño, frecuente uso de la recursividad, y repetición intensiva en el tiempo de los cálculos con fuerte dependencia de los resultados anteriores dificultan extraordinariamente el uso de técnicas de paralelización frente a otras áreas de la mecánica computacional, tales como por ejemplo el cálculo por elementos finitos. Basándose en los conceptos mencionados en el Capítulo 4, el Capítulo 5 está dividido en tres secciones, una para cada formulación propuesta en esta Tesis. En cada una de estas secciones se describen los detalles de cómo se han realizado las distintas implementaciones propuestas para cada algoritmo y qué herramientas se han utilizado para ello. En la primera sección se muestra el uso de librerías numéricas para matrices densas y sparse en la formulación topológica semirrecursiva basada en la doble transformación de velocidades. En la segunda se describe la utilización de paralelización mediante OpenMP y TBB en la formulación semirrecursiva con penalizadores y proyecciones. Por último, se describe el uso de técnicas de matrices sparse y paralelización en la formulación global con uniones flexibles y parámetros de Euler. El Capítulo 6 describe los resultados alcanzados mediante las formulaciones e implementaciones descritas previamente. Este capítulo comienza con una descripción de la modelización y topología de los dos vehículos estudiados. El primer modelo es un vehículo de dos ejes del tipo chasis-cabina o furgoneta, perteneciente a la gama de vehículos de carga medianos. El segundo es un vehículo de cinco ejes que responde al modelo de un camión o cabina con semirremolque, perteneciente a la categoría de vehículos industriales pesados. En este capítulo además se realiza un estudio comparativo entre las simulaciones de estos vehículos con cada una de las formulaciones utilizadas y se presentan de modo cuantitativo los efectos de las mejoras alcanzadas con las distintas estrategias propuestas en esta Tesis. Con objeto de extraer conclusiones más fácilmente y para evaluar de un modo más objetivo las mejoras introducidas en la Tesis, todos los resultados de este capítulo se han obtenido con el mismo computador, que era el top de la gama Intel Xeon en 2007, pero que hoy día está ya algo obsoleto. Por último los Capítulos 7 y 8 están dedicados a las conclusiones finales y las futuras líneas de investigación que pueden derivar del trabajo realizado en esta Tesis. Los objetivos de realizar simulaciones en tiempo real de vehículos industriales de gran complejidad han sido alcanzados con varias de las formulaciones e implementaciones desarrolladas. ABSTRACT The objective of this Dissertation has been the achievement of real time simulations of industrial vehicles modeled as complex multibody systems made up by rigid bodies. For the development of a simulation program, four main aspects must be considered: the modeling of the multibody system (types of coordinates, ideal joints or imposed by means of forces), the formulation to be used to set the differential equations of motion (dependent or independent coordinates, global or topological methods, ways to impose constraints equations), the method of numerical integration to solve these equations in time (explicit or implicit integrators) and the details of the implementation carried out (programming language, mathematical libraries, parallelization techniques). These four stages are interrelated and all of them are part of this work. They involve the generation of models for a van and a semitrailer truck, the use of three different dynamic formulations, the integration of differential equations of motion through explicit and implicit methods, the use of BLAS functions and sparse matrix techniques, and the introduction of parallelization to use the different processor cores. The work presented in this Dissertation has been structured in eight chapters, the first of them being the Introduction. In Chapter 2, two different semi-recursive formulations are shown, of which the first one is based on a double velocity transformation, thus getting the differential equations of motion as a function of the independent relative accelerations. The numerical integration of these equations has been made with the Runge-Kutta explicit method of fourth order. The second formulation is based on dependent relative coordinates, imposing the constraints by means of position penalty coefficients and correcting the velocities and accelerations by projection methods. In this second case, the integration of the motion equations has been carried out by means of the HHT implicit integrator (Hilber, Hughes and Taylor), which belongs to the Newmark structural integrators family. In Chapter 3, the third formulation used in this Dissertation is presented. In this case, the joints between the bodies of the system have been considered as flexible joints, with forces used to impose the joint conditions. This kind of union hinders to work with relative coordinates, so the position of the system bodies and the setting of the equations of motion have been carried out using Cartesian coordinates and Euler parameters. In this global formulation, constraints are introduced through forces (with a similar approach to the penalty coefficients) are presented. The stabilization of the numerical integration is carried out also by velocity and accelerations projections. In Chapter 4, a revision of the main computer tools and strategies used to increase the efficiency of the implementations of the algorithms is presented. First of all, some basic considerations to increase the numerical efficiency of the implementations are included. Then the main characteristics of the code’ analyzers used and also the mathematical libraries used to solve linear algebra problems (both with dense and sparse matrices) are mentioned. Finally, the topic of parallelization in current multicore processors is developed thoroughly. For that, the pattern used and the most important characteristics of the tools proposed, OpenMP and Intel TBB, are described. It needs to be highlighted that the characteristics of multibody systems small size problems, frequent recursion use and intensive repetition along the time of the calculation with high dependencies of the previous results complicate extraordinarily the use of parallelization techniques against other computational mechanics areas, as the finite elements computation. Based on the concepts mentioned in Chapter 4, Chapter 5 is divided into three sections, one for each formulation proposed in this Dissertation. In each one of these sections, the details of how these different proposed implementations have been made for each algorithm and which tools have been used are described. In the first section, it is shown the use of numerical libraries for dense and sparse matrices in the semirecursive topological formulation based in the double velocity transformation. In the second one, the use of parallelization by means OpenMP and TBB is depicted in the semi-recursive formulation with penalization and projections. Lastly, the use of sparse matrices and parallelization techniques is described in the global formulation with flexible joints and Euler parameters. Chapter 6 depicts the achieved results through the formulations and implementations previously described. This chapter starts with a description of the modeling and topology of the two vehicles studied. The first model is a two-axle chassis-cabin or van like vehicle, which belongs to the range of medium charge vehicles. The second one is a five-axle vehicle belonging to the truck or cabin semi-trailer model, belonging to the heavy industrial vehicles category. In this chapter, a comparative study is done between the simulations of these vehicles with each one of the formulations used and the improvements achieved are presented in a quantitative way with the different strategies proposed in this Dissertation. With the aim of deducing the conclusions more easily and to evaluate in a more objective way the improvements introduced in the Dissertation, all the results of this chapter have been obtained with the same computer, which was the top one among the Intel Xeon range in 2007, but which is rather obsolete today. Finally, Chapters 7 and 8 are dedicated to the final conclusions and the future research projects that can be derived from the work presented in this Dissertation. The objectives of doing real time simulations in high complex industrial vehicles have been achieved with the formulations and implementations developed.

Transformer-coupled converter for voltage modulation techniques

In high performance digital systems as well as in RF systems, voltage scaling and modulation techniques have been adopted to achieve a more efficient processing of the energy. The implementation of such techniques relies on a power supply that is capable of rapidly adjusting the system supply voltage. In this paper, a pulsewidth modulation multiphase topology with magnetic coupling is proposed for its use in voltage modulation techniques. Since the magnetic coupling in this topology is done with transformers instead of coupled inductors, the energy storage is reduced and very fast voltage changes are achieved. Advantages and drawbacks of this topology have been previously presented in the literature and in this paper, the design criteria for implementing a power supply for the envelope elimination and restoration technique in an RF system are presented along with an implementation of the power supply.

Forward micro-inverter with primary-parallel secondary-series multicore transformer

This paper presents a primary-parallel secondary-series multicore forward micro-inverter for photovoltaic AC-module application. The proposed solution changes the number of active phases depending on the grid voltage, thus enabling the usage of low-profile unitary turns ratio transformers. Therefore, the transformers are well coupled and the overall performance of the inverter is improved. Due to the multiphase solution the number of devices increases but, the current stress and losses per device are reduced contributing to an easier thermal management. Furthermore, the decoupling capacitor is split between the phases, contributing to a low-profile solution without electrolytic capacitors suitable to be mounted in the frame of a PV module.

El Poblado Dirigido de Caño Roto: Dialéctica entre morfología urbana y tipología edificatoria

La tesis doctoral titulada “El Poblado Dirigido de Caño Roto. Dialéctica entre morfología urbana y tipología edificatoria” analiza el poblado de Caño Roto, un vecindario de vivienda social construido en Madrid entre 1957 y 1963, a partir de la relación entre la edificación y la forma urbana resultante. También, la investigación desarrolla un análisis historiográfico de la obra así como de las condiciones políticas, sociales, económicas y normativas existentes en el momento de su realización, para concluir con un estudio comparativo entre éste y otros proyectos análogos al poblado en aspectos como el marco temporal y geopolítico, los planteamientos urbanísticos y algunas soluciones tipológicas y constructivas. El trabajo pretende, por un lado, profundizar en el conocimiento que se tiene actualmente de esta obra, considerada por muchos como una de las más relevantes de la arquitectura española contemporánea, y, por otro, extraer a partir de su estudio, pautas, criterios y estrategias de diseño urbano que puedan ser extrapolables al proyecto contemporáneo; a fin de superar los actuales, pero obsoletos, modelos de desarrollo. No obstante, sabemos que cualquier respuesta que plantee una vuelta al pasado está condenada al fracaso. Las circunstancias cambian y, en consecuencia, las soluciones no pueden ser las mismas. Pero si las respuestas ya no nos sirven, las preguntas siguen siendo válidas. Quién es el protagonista del diseño urbano en Caño Roto. Cómo conviven el tráfico peatonal y el rodado. Cuál es la densidad del barrio. Cómo se articulan los usos residencial, comercial y dotacional. De qué manera se organiza el tejido urbano. Qué relación existe entre los tipos edificatorios y la morfología urbana resultante; y entre los espacios de uso privado o restringido y los de uso público. Partimos de la hipótesis de que los análisis, reflexiones y resultados derivados de interrogar al poblado de Caño Roto acerca de estas, y otras muchas, cuestiones nos permitirán alcanzar un entendimiento global de la complejidad urbana y nos revelarán, además, propuestas y soluciones que contribuyan a mejorar la calidad de nuestras ciudades; ahora y en adelante. ABSTRACT The thesis entitled “El Poblado Dirigido de Caño Roto. Dialéctica entre morfología urbana y tipología edificatoria” [Poblado Dirigido of Caño Roto. Dialectic between urban morphology and typology] analyzes Caño Roto, a social housing neighborhood built in Madrid between 1957 and 1963, from the relationship between buildings and the resulting urban form. Also, this research develops a historiographical analysis of this project as well as the social, political, financial and legislative conditions present at time of its construction. This thesis concludes with a comparative study with other similar projects in temporal and geopolitical framework, urban approaches and some typological and constructive solutions. The research aims, on the one hand, to expand the current knowledge about Caño Roto, considered by many as one of the most important project at Spanish contemporary architecture; and, on the other hand, deducing from the study guidelines, criteria and strategies of urban design which can be extrapolated to contemporary architecture and urbanism. This way, we will be able to overcome current, but obsolete development models. However, we know that any response that suggests coming back to the past is destined to failure. Circumstances change and, consequently, solutions cannot be the same. But if the answers do not serve, questions are still right. Who is the protagonist of Caño Roto urban design? How do pedestrian and road traffic coexist together? What is the neighborhood’s density? How are residential, commercial and endowment uses articulated? How is urban fabric organized? What is the relationship between building types and the resulting urban morphology; and between private and public spaces? We start from the hypothesis that analysis, reflections and results arising from questioning Caño Roto about these, and many others, issues will enable us to have a comprehensive understanding of urban complexity, and they will also reveal proposals and solutions which help us to improve the quality of our cities; from now on.

Dispositivos contemporáneos ante el reto del neomadismo

Cuatro dispositivos. Cuatro golpes de vista deteniéndonos sobre aspectos de la realidad contemporánea en los que juzgamos pertinente reparar. Usuarios transeúntes a través de los locutorios[D1], entornos dinámicos mediante la sucesión ecológica[D2], sistema de gestión de la propiedad obsoleto ante la realidad de flujos económicojurídicos[D3] y estructuras topológicas electromagnéticas que permiten desplazarnos con unos mínimos comunes[D4]. Modelos transdisciplinares muy directos elegidos por su efectividad ante la inestabilidad, arquetipos de los que tendremos que transferir claves a nuestra disciplina. ABSTRACT. Four devices. Four glances stopping on aspects of the contemporary reality in which we judge relevant to look at. Transient users across the phone booths[D1], dynamic environments through the ecological succession[D2], obsolete property management system facing the reality of financial and law flows[D3] and topological electromagnetic structures that allow our displacements with a few common minimums[D4]. Very direct transdisciplinary models chosen by their efficiency with the instability, archetypes from which we will have to transfer keys to our discipline

Compensación de energía reactiva en los servicios auxiliares de una central térmica

El proyecto tiene como objeto analizar desde el punto de vista técnico-económico las posibilidades para mejorar el factor de potencia en los consumos auxiliares de la Central térmica Litoral, perteneciente a Endesa Generación. Debido a un cambio normativo, las tarifas de acceso a las redes de transporte y distribución de energía eléctrica aplicarán ahora también a los consumos propios de las empresas productoras de electricidad dentro del ámbito de aplicación de las tarifas de acceso. Como la energía reactiva se facturará en función del factor de potencia se propone para su compensación la instalación de bancos de condensadores para mejorar el mismo y disminuir la penalización. Para el dimensionamiento de los bancos se han utilizado los consumos horarios de los años 2012 y 2013 de tres fronteras: grupos 1 y 2 de 400 kV y los transformadores auxiliares de arranque (OTAAs) de 6 kV , teniendo en cuenta las peculiaridades de una Central de Generación, ya que sólo serán objeto de estudio (a efecto de penalizaciones) las horas en las que el grupo está parado o arrancando. El resultado final muestra la diferencia en cuanto a los periodos de amortización de una instalación con generación y sin generación, siendo esta última más rentable económicamente. ABSTRACT The goal of this project is to analyse the possibilities to better the power factor in the auxiliary consumption of the Thermal Plant Litoral from an economic and technical viewpoint. Due to a normative changes, the access price rates for the transportation and distribution of electrical energy, will also apply now to the electricity productive companies own consumption within the scope of the access rate. Since reactive power is invoiced based on the potency factor, we propose the installation of capacitor banks to improve the aforementioned power factor as compensation so as to reduce sanctions. We have used the time profiles from 2012 and 2013 to dimension the banks, using 3 borders: Group 1 and 2 (400 kV) and the auxiliary starter transformers (OTAA's) of 6kV, taking into account the special characteristics of a Generation Plant , since we will only study the hours that the group was shut down or powering up (since these are what the penalties cover). The final result shows the difference in regards to repayment periods for both generating and nongenerating installation, being the aforesaid the most economically worthwile of the two

Tag detection for preventing unauthorized face image processing

A new technology is being proposed as a solution to the problem of unintentional facial detection and recognition in pictures in which the individuals appearing want to express their privacy preferences, through the use of different tags. The existing methods for face de-identification were mostly ad hoc solutions that only provided an absolute binary solution in a privacy context such as pixelation, or a bar mask. As the number and users of social networks are increasing, our preferences regarding our privacy may become more complex, leaving these absolute binary solutions as something obsolete. The proposed technology overcomes this problem by embedding information in a tag which will be placed close to the face without being disruptive. Through a decoding method the tag will provide the preferences that will be applied to the images in further stages.

Análisis paramétrico de transiciones a bocinas

Las transiciones en guía de onda son las estructuras utilizadas en microondas para transferir y adaptar la señal que viaja en un determinado sistema de transmisión (por ejemplo, un cable coaxial) a otro sistema de transmisión o a un sistema radiante (por ejemplo, una antena de bocina). Los dos sistemas de transmisión entre los que la transición adapta la señal pueden ser distintos o del mismo tipo pero con alguna de sus dimensiones diferente. Existen diferentes transiciones de guía de onda que dependiendo de su utilidad son diseñadas y construidas con diferentes secciones: circular, rectangular, elíptica o incluso combinaciones de éstas. No es necesario que la sección de la guía presente una forma geométrica conocida pero los estándares que se van a seguir hacen referencia en concreto a secciones rectangulares y circulares. En el trabajo que aquí se desarrolla se pretende optimizar por medio de simulaciones paramétricas una transición entre cable coaxial con conector tipo K y una guía de onda de sección circular que sigue el estándar presentado por Flann, Millitech y Antarfs para la banda WR34. La transición que va a ser objeto de este estudio se denomina transición tapered o transición conformada. Este tipo de transiciones se caracterizan por variar una de sus dimensiones progresivamente hasta llegar al tamaño definido en el estándar correspondiente. La manera de realizar la optimización de la transición se basará en el estudio del parámetro S11 que presente la estructura a lo largo de la banda de trabajo. Ya que se sigue el estándar WR34 la banda de trabajo que éste comprende va de 21,7 a 33 GHz. Se pretende conseguir que la respuesta del parámetro S11 se encuentre por debajo de -20 dB en la banda de WR34 como resultado del diseño para poder contar de esta manera con una buena adaptación. Finalmente se propondrá un criterio a seguir para optimizar este tipo de transiciones siguiendo el objetivo de mejor adaptación teniendo en cuenta el impacto de cada tramo sobre el rango de frecuencias en el que influye y se presentarán las características finales que presenta la transición bajo estudio. En este documento se introduce de manera breve la utilidad de los transformadores de impedancias lambda cuartos en líneas de transmisión, el estado del arte de las diferentes técnicas para su diseño, y la propuesta de diseño y caracterización objeto del presente trabajo. Posteriormente, se presenta el caso de estudio para el diseño de la transición para ser integrada a una bocina de choke. Luego, se introduce el marco teórico del trabajo presentando algunos ejemplos ilustrativos de tramos de guía de onda rectangular y guía de onda circular, introduciendo adaptadores de λ/4 en simulaciones. A continuación, se explica la implementación del modelo bajo estudio en CST (Computer Simulation Technology) Studio Suite. Finalmente se presenta la discusión de los resultados obtenidos, las conclusiones y líneas futuras de trabajo. ABSTRACT. Waveguide transitions are structures used in microwave in order to transfer and adapt the signal that travels from a certain transmission system (e.g. coaxial cable) to other transmission system or to a radiant system (e.g. horn antenna). Both transmission systems between which the transition adapts the signal can be different or from the same type, but with differences in some of their dimensions. There are different waveguide transitions that, depending on their utility, are designed and constructed in different sections: circular, rectangular, elliptic or combinations of the former. The section of the guide does not have to have a known geometric shape, although the standards to be followed in this thesis apply to rectangular and circular sections. In the work here presented, we aim to optimize by means of parametric simulations, a transition between a coaxial cable with a K-type connector and a waveguide with circular section following the standard presented by Flann, Millitech y Antarfs for the band WR34. The transition studied is called tapered transition, which is characterized by the progressive variation of its dimensions, until reaching the defined size of the corresponding standard. The way of optimizing the transition will be based in the study of the parameter S11 presented by the structure along the bandwidth. Since the standard used is the WR34, the bandwidth can be defined from 21.7 up to 33 GHz. It is aimed that the response of the S11 parameter be lower equal than -20dB in the frequency band under study according to the design in order to be well matched. Finally, a criterion to follow is proposed in order to optimize these transitions type, following the better-match objective. That will be done taking into account the impact of each section on the frequency range in which influences and the final characteristics of the studied transition will be presented. In this document, it is briefly introduced the utility of quarter-wave impedance transformers in transmission lines, the state-of-art of the different techniques for their design, and the proposal of design and characterization aimed with this work. Afterwards, the study case for the design of the transition to be integrated with a choke horn antenna will be presented. Later, the theoretical frame work is introduced, giving some illustrative examples of rectangular and circular waveguide sections, and also introducing λ/4 adaptors in the simulations. Subsequently, the implementation of the model under study in CST (Computer Simulation Technology) Studio Suite will be explained. Finally, the discussion of the results, conclusion and future lines of the work are presented.