Search

[ES] Las instalaciones fotovoltaicas de autoconsumo permiten reducir la factura de la luz, complementando la energía absorbida de la red con la generación obtenida de paneles fotovoltaicos. Este TFM tiene como objetivo el diseño y la implementación de un sistema que permita programar el consumo energético de acuerdo a una estimación de generación fotovoltaica basada en predicciones meteorológicas. El sistema obtiene la predicción meteorológica mediante la API REST (Application Programming Interface. REpresentational State Transfer) de la Agencia Estatal de Meteorología (AEMET OpenData). El sistema monitorizará y almacenará los datos relacionados con el consumo para establecer, mediante un algoritmo de optimización, la programación del consumo que maximice el aprovechamiento de la generación fotovoltaica y minimice la factura de la luz. El gestor energético constará de un nodo principal y nodos de lectura y registro de datos. El nodo principal dispondrá de conexión a internet y conexión a los nodos de lectura y registro. Este nodo ejecutará los algoritmos necesarios para obtener la estimación de la producción fotovoltaica y la programación del consumo.

Tesis por compendio, [ES] Las microrredes inteligentes se presentan como una solución para integrar las energías renovables así como para mejorar la eficiencia de la red por medio de la incorporación de las Tecnologías de Información y Comunicación (TIC). Sin embargo, la alta penetración de los recursos energéticos distribuidos (RED) en las microrredes, requiere una serie de cambios técnicos en los sistemas de comunicación caracterizados tradicionalmente por esquemas centralizados, donde un controlador central se comunica con todos los recursos energéticos distribuidos y toma decisiones, hacia esquemas descentralizados donde cada recurso energético distribuido tiene capacidad de comunicación y decisión de forma local. En este sentido, el objetivo global de las estrategias de comunicación descentralizadas es dotar al sistema energético de una mayor escalabilidad, fiabilidad, robustez, y flexibilidad que la que presentan los sistemas centralizados. Además, las microrredes con esquemas descentralizados presentan una gran oportunidad para el advenimiento del futuro Internet de la Energía o Internet of Energy (IoE), ya que cada recurso energético distribuido desplegado en la microrred es susceptible de conectarse a la nube y enviar y recibir datos desde hacia la red en tiempo real, en cualquier momento y lugar. Uno de los puntos críticos derivados de la incorporación de las TIC en las microrredes de gestión distribuida es garantizar la conectividad entre los recursos energéticos al tiempo que se satisfacen los requisitos técnicos de estos sistemas energéticos. Los distintos estándares y normas establecidas para el despliegue de microrredes destacan la necesidad de cumplir con algunos parámetros de calidad de servicio (Quality of Service, QoS) como ancho de banda, latencias, throughput (rendimiento), entre otros, ya que un ancho de banda bajo puede dar lugar a cuellos de botella, pérdida de paquetes de datos y distorsión. Por otra parte, si la comunicación no presenta una tasa positiva de pro, [CA] Les micro-xarxes intel·ligents es presenten com una solució per integrar energies renovables així com per millorar l'eficiència de la xarxa mitjançant la incorporació de les Tecnologies de la Informació i la Comunicació (TIC). No obstant, l'alta penetració del recursos energètics distribuïts (RED) en les micro-xarxes requereix d'una sèrie de canvis tècnics en els sistemes de comunicació caracteritzats tradicionalment per esquemes centralitzats, el quals un controlador central es comunica amb tots el recursos energètics distribuïts i pren decisions, cap a esquemes descentralitzats on cada recurs energètic distribuït té capacitats de comunicació i decisió localment. En aquest sentit, l'objectiu global de les estratègies de comunicació descentralitzades es dotar al sistema energètic de major escalabilitat, fiabilitat, robustesa i flexibilitat que els que presenten els sistemes centralitzats. A més, les micro-xarxes amb esquemes descentralitzats presenten una gran oportunitat per l'adveniment de la futura internet de la energia, ja que cada recurs energètic distribuït desplegat en la micro-xarxa es susceptible de connectar-se al núvol i enviar i rebre dades cap a la xarxa en temps real, en qualsevol lloc i moment. Un dels punts crítics derivats de la incorporació de les TIC en les micro-xarxes de gestió distribuïda es garantir la connectivitat entre el recursos energètics distribuïts al temps que es satisfacen els requeriments tècnics de aquests sistemes energètics. Els diferents estàndards i normes establides per al desplegament de micro-xarxes destaquen la necessitat de complir amb alguns paràmetres de qualitat de servici com amplada de banda, latències i rendiment, entre d'altres, ja que una amplada de banda baixa resulta colls d'ampolla, pèrdues de paquets i distorsió. D'una altra banda, si la comunicació no presenta una taxa positiva de mitjana de èxit o sofreix retards o supera el temps requerit, la informació no acompleix la seua comesa i en el pitjor dels c, [EN] Smart microgrids are presented as a solution to integrate renewable energies as well as to improve the efficiency of the network through the incorporation of Information and Communication Technologies (ICT). However, the high penetration of distributed energy resources (DER) in microgrids requires several technical improvements on communication systems that are traditionally characterized by centralized schemes, where a central controller communicates with all distributed energy resources and makes decisions, towards decentralized schemes where each distributed energy resource has communication and decision capacities locally. The main objective of decentralized communication strategies is provide to the energy system with better scalability, reliability, robustness, and flexibility that centralized systems do. Moreover, microgrids with decentralized schemes represent a great opportunity for the future Internet of Energy (IoE) due to each distributed energy resource could connect to the cloud and send and receive data in real time anywhere and anytime. One of the major issues about the ICT integration on microgrids is to guarantee the connectivity among DERs at the same time that technical requirements are met. Different microgrid standards give specifications for these requirements and highlight the need to accomplish with quality of service parameters like bandwidth, delays, throughput, among others. The communication infrastructure in the microgrid must satisfy these timing requirements, because a low bandwidth can lead to bottlenecks, loss of data packets and distortion. Besides, if the communication delay exceeds the required time, the information does not fulfill its purpose and, in the worst case, electric damage in the microgrid could happen. In this Ph.D. thesis the design, development and implementation of synchronous and asynchronous distributed communications infrastructures for the efficient microgrid monitoring and control are studied. In addition

[EN] In order to reduce the cost of PV facilities, the market requires low cost and highly reliable PV inverters, which must comply with several regulations. Some research has focused on decreasing the distortion of the current injected into the grid, reducing the size of the DC-link capacitors and removing sensors, while keeping a good performance of the maximum power point tracking (MPPT) algorithms. Although those objectives are different, all of them are linked to the inverter DC-link voltage control loop. Both the reduction of the DC-link capacitance and the use of sensorless MPPTalgorithms require a voltage control loop faster than that of conventional implementations in order to perform properly, but the distortion of the current injected into the grid might rise as a result. This research studies a complete solution for two-stage grid-connected PV inverters, based on the features of second-order generalized integrators. The experimental tests show that the proposed implementation has a performance similar to that of the conventional control of two-stage PV inverters but at a much lower cost.

[EN] Microgrids are moving toward electric power systems in a sort of an internet of energy (IoE) where a large number of generators can be connected anywhere. In this regard, to realize the envisioned IoE, information and communication technologies (ICT) are crucial for developing innovative applications and services as well as achieving high levels of efficiency in microgrids. However, due to the variety of ICT, there is not a de facto standard solution to implement IoE platforms. Moreover, standards for the current Internet of Things (IoT) platforms are not optimal for developing IoE platforms, which present more demanding challenges. In such context, this paper presents an embedded IoE platform for management of smart microgrids. The performance of this platform has been tested in an experimental microgrid. Results show that the proposed platform fulfills the microgrids requirements and it is able to manage the energy flows, the safety issues, etc. in microgrids.

[EN] This study is focused on two areas: the design of a Battery Energy Storage System(BESS) for a grid-connected DC Microgrid and the power management of that microgrid. The power management is performed by a Microgrid Central Controller (MGCC). A Microgrid operator provides daily information to the MGCC about the photovoltaic generation profile, the load demand profile, and the real-time prices of the electricity in order to plan the power interchange between the BESS and the main grid, establishing the desired state of charge (SOC) of the batteries at any time. The main goals of the power management strategy under study are to minimize the cost of the electricity that is imported from the grid and to maximize battery life by means of an adequate charging procedure, which sets the charging rate as a function of the MG state. Experimental and simulation results in many realistic scenarios demonstrate that the proposed methodology achieves a proper power management of the DC microgrid.

[EN] In this paper, a centralized control strategy for the efficient power management of power converters composing a hybrid AC/DC microgrid is explained. The study is focused on the converters connected to the DC bus. The proposed power management algorithm is implemented in a microgrid central processor which is based on assigning several operation functions to each of the generators, loads and energy storage systems in the microgrid. The power flows between the DC and AC buses are studied in several operational scenarios to verify the proposed control. Experimental and simulation results demonstrate that the algorithm allows control of the power dispatch inside the microgrid properly by performing the following tasks: communication among power converters, the grid operator and loads; connection and disconnection of loads; control of the power exchange between the distributed generators and the energy storage system and, finally, supervision of the power dispatch limit set by the grid operator.

[EN] The concept of microgrid has emerged as a feasible answer to cope with the increasing number of distributed renewable energy sources which are being introduced into the electrical grid. The microgrid communication network should guarantee a complete and bidirectional connectivity among the microgrid resources, a high reliability and a feasible interoperability. This is in a contrast to the current electrical grid structure which is characterized by the lack of connectivity, being a centralized-unidirectional system. In this paper a review of the microgrids information and communication technologies (ICT) is shown. In addition, a guideline for the transition from the current communication systems to the future generation of microgrid communications is provided. This paper contains a systematic review of the most suitable communication network topologies, technologies and protocols for smart microgrids. It is concluded that a new generation of peer-to-peer communication systems is required towards a dynamic smart microgrid. Potential future research about communications of the next microgrid generation is also identified.

[EN] In this paper a centralized control strategy for the efficient power management of the power converters conforming a hybrid distributed generation microgrid is explained. The microgrid is based on a DC and an AC bus. The study is focused on the converters connected to the DC bus. The proposed power management algorithm is implemented in a microgrid central processor. This algorithm is based on assigning several operation functions to each of the generators, loads and energy storage systems in the microgrid. A communication system is used to assign the operation functions to each of the microgrid elements. The power flows between the DC and AC buses are studied in several operation scenarios, in which the proposed control can be verified. Experimental and simulation results demonstrate that the algorithm allows to control the power dispatch inside the microgrid properly, by performing the following tasks: (1) the communications among power converters, the grid operator and intelligent loads, (2) the connection and disconnection of loads, (3) the control of the power exchange between the distributed generators and the energy storage system, (4) the compliance of the power dispatch limit set by the grid operator, (5) the synchronization with the grid and (6) the control of the voltage at the DC bus.

© 2018 IEEE. Personal use of this material is permitted. Permissíon from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertisíng or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works., [EN] Microgrids are moving towards large-scale smart distributed networks which demand an efficient and reliable communication infrastructure to manage, control and monitor energy resources. With regard to this, publisher/subscriber eventbased middleware has become relevant for large-scale distributed time applications because it allows decouple time and space between senders and receivers. Particularly the content publish/subscribe systems over structured peer-to-peer (P2P) networks has emerged to enhance scalability and dynamism of notification middleware systems. However, this type of systems use multicast routing schemes that still generate much network traffic and as a consequence an overload of the communication channel is produced. This results in inefficient network utilization and rapid depletion of network resources leading to unreliable operations, degradation of system performance and even instability of the microgrid. In this paper, a new content-based publish/subscribe notification middleware over structured P2P systems is proposed, such that smart microgrid communication requirements are met. This proposed system organizes the publications and subscriptions in a one dimensional representation using the Hilbert space filling curve. Through this representation, an innovative routing and matching algorithms are developed. Experimental results demonstrate that the proposed publisher/subscribe system significantly enhance efficiency of the system, network performance and the use of computational resources.

[EN] Peer-to-Peer (P2P) overlay communications networks have emerged as a new paradigm for implementing distributed services in microgrids due to their potential benefits: they are robust, scalable, fault-tolerant, and they can route messages even with a large number of nodes which are frequently entering or leaving from the network. However, current P2P systems have been mainly developed for file sharing or cycle sharing applications where the processes of searching and managing resources are not optimized. Locality algorithms have gained a lot of attention due to their potential to provide an optimized path to groups with similar interests for routing messages in order to get better network performance. This paper develops a fully functional decentralized communication architecture with a new P2P locality algorithm and a specific protocol for monitoring and control of microgrids. Experimental results show that the proposed locality algorithm reduces the number of lookup messages and the lookup delay time. Moreover, the proposed communication architecture heavily depends of the lookup used algorithm as well as the placement of the communication layers within the architecture. Experimental results will show that the proposed techniques meet the network requirements of smart microgrids even with a large number of nodes on stream.

[EN] Transmission of train-induced vibrations to buildings located in the vicinity of the track is one of the main negative externalities of railway transport, since both human comfort and the adequate functioning of sensitive equipment may be compromised. In this paper, a 3D FEM model is presented and validated with data from a real track stretch near Barcelona, Spain. Furthermore, a case study is analyzed as an application of themodel, in order to evaluate the propagation and transmission of vibrations induced by the passage of a suburban train to a nearby 3-storey building. As a main outcome, vertical vibrations in the foundation slab are found to be maximum in the corners, while horizontal vibrations keep constant along the edges. The propagation within the building structure is also studied, concluding that vibrations invariably increase in their propagation upwards the building. Moreover, the mitigation capacity of a wave barrier acting as a source isolation is assessed by comparing vibration levels registered in several points of the building structure with and without the barrier. In this regard, the wave barrier is found to effectively reduce vibration in both the soil and the structure.

[EN] The results concerning the integration of a set of power management strategies and serial communications for the efficient coordination of the power converters composing an experimental DC microgrid is presented. The DC microgrid operates in grid connected mode by means of an interlinking converter. The overall control is carried out by means of a centralized microgrid controller implemented on a Texas Instruments TMS320F28335 DSP. The main objectives of the applied control strategies are to ensure the extract/inject power limits established by the grid operator as well as the renewable generation limits if it is required; to devise a realistic charging procedure of the energy storage batteries as a function of the microgrid status; to manage sudden changes of the available power from the photovoltaic energy sources, of the load power demand and of the power references established by the central controller; and to implement a load shedding functionality. The experimental results demonstrate that the proposed power management methodology allows the control of the power dispatch inside the DC microgrid properly.

"(c) 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.", A microgrid can operate in island mode, isolated from the main grid during certain time intervals. When operated in island mode, the electronic converters of the microgrid must keep the voltage and frequency of the microgrid inside the desired range. The converters of a microgrid can be classified into three groups: 1) grid-feeding; 2) grid-supporting; and 3) grid-forming power converters. The grid-forming converters operate as a voltage source, and require an external synchronization signal provided by the microgrid central controller. Both the noise and the delay in the synchronization signals received by the grid-forming converters are critical issues, which deteriorate the quality of the microgrid voltage and may overload those converters. The synchronization signals must be robust and suitable for operating in noisy environments. In this paper, the synchronization signal is frequency-modulated to be transmitted, being robust against noise. The transmission is done through an industrial RS-485 line with a low delay. The demodulation is performed with a low computational load by the control processors of the grid-forming power converters.

[EN] The concept of Microgrid has emerged as a feasible answer to the challenges raised by the increasing introduction of Distributed Energy Resources (DERs) and Renewable Energy Sources (RES) into the electrical grid towards a more active, flexible, efficient and environmental alternative to consider a set of various microgeneration together with storage and loads units as a system that can be operated in a non-autonomous way, if interconnected to the grid, or in an autonomous way, if disconnected from the main grid. From the technological point of view, guaranteeing, highly and bidirectional connectivity between microgrid resources, reliable communications and seamless integration of multiple devices are mandatory in a microgrid. Therefore, the aim of this project is design, development and implementation, on an experimental microgrid, of a communication infrastructure that enables an optimal, safe and reliable execution of microgrid hierarchical control levels to optimize power flows inside itself., [ES] En los últimos años la creciente aparición en el sector energético de sistemas de generación distribuida está produciendo cambios significativos en la estructura de la red eléctrica. En este escenario, ha despertado un gran interés la investigación sobre microrredes inteligentes para entornos residenciales, las cuales presentan un gran potencial para facilitar la integración de la generación distribuida de energía eléctrica, al considerar un conjunto de unidades de generación, almacenamiento y cargas como un ente autónomo, capaz de funcionar en modo isla o conectado a una red de distribución, hacia una alternativa más flexible, eficiente y ecológica. La efectiva integración de los sistemas de generación distribuida a la red eléctrica implica una transformación de la red donde el sistema de control debe estar fuertemente acoplado con la infraestructura de comunicación ya que ésta debe permitir el intercambio fiable de datos/órdenes a tiempo real. El objetivo de este proyecto es, por tanto, el diseño, desarrollo e implementación, en una microrred experimental, de una infraestructura de comunicación óptima que permita implementar de manera segura y fiable, los niveles de control jerárquico más elevados para la optimización de flujos de potencia en la propia microrred.

Results of three years' field measurements on radio propagation in industrial environments have been analyzed using four propagation models: the Saleh-Valenzuela model, the two-cluster model, the indoor power delay profile model, and our more recent adjusted model. In this study, we used the results of measurements performed at a steel mill, a paper mill, and in a laboratory environment for three frequency bands (183-683 MHz, 1640-2140 MHz, and 2200-2700 MHz) and for line-of-sight and non-line-of-sight cases., Part of proceedings: ISBN 978-0-9541146-3-3QC 20111121