305 research outputs found

    Indoor Radio Network Optimization

    Get PDF

    Content

    Get PDF

    Electrical subsystem of the low-power cogeneration plant with low-speed vehicle

    Get PDF
    Nowadays diesel power plants form the basis of distributed power generation in Russia, but they have disadvantages. The alternative variant is cogeneration plant based on the rotary-vane machine. One of the types of such machines is the rotary-vane external combustion vehicle (engine) developed in Pskov State University. Electrical subsystem of the plant requires its effective work to provide both start and generation modes. Development of such subsystem structure, employment of elements for links with other subsystems in the hierarchic control system is an actual task. The paper considers structures of the electrical part of the plant, simulation and experiment results

    Renewable medium-small projects in Spain: Past and present of microgrid development

    Get PDF
    This paper reviews the on-going research studies and microgrid pilot projects focusing on the Spanish case because of its renewable energy potential with the objective set on highlights the main investigation drifts in the field such as the used technologies, control methods and operation challenges. That way, several smart grids have been commented and compared, finding that photovoltaic and wind power are the favourites energy generation technologies. Although batteries are the most widespread energy storage systems, green hydrogen has a strong presence, showing up in a third of the Spanish smart grids. Traditional control strategies are being displaced by advanced ones such as MPC or fuzzy logic due to its higher efficiency. The reader will have a clear view of the potential of renewable energy penetration in the form of smart grids in Spain, through the study of the equipment involved in the different facilities contribution and the main control strategies implemented, in a comparative analysis of the key aspect of this emerging technology.Consejería de Conocimiento, Investigación y Universidad - Junta de Andalucía PY18-RE-002

    Global optimal stabilization of MT-HVDC systems: Inverse optimal control approach

    Get PDF
    The stabilization problem of multi-terminal high-voltage direct current (MT-HVDC) systems feeding constant power loads is addressed in this paper using an inverse optimal control (IOC). A hierarchical control structure using a convex optimization model in the secondary control stage and the IOC in the primary control stage is proposed to determine the set of references that allows the stabilization of the network under load variations. The main advantage of the IOC is that this control method ensures the closed-loop stability of the whole MT-HVDC system using a control Lyapunov function to determine the optimal control law. Numerical results in a reduced version of the CIGRE MT-HVDC system show the effectiveness of the IOC to stabilize the system under large disturbance scenarios, such as short-circuit events and topology changes. All the simulations are carried out in the MATLAB/Simulink environment.Fil: Montoya Giraldo, Oscar Danilo. Universidad Tecnológica de Bolívar; Colombia. Universidad Distrital Francisco José de Caldas; ColombiaFil: Gil González, Walter. Institución Universitaria Pascual Bravo; ColombiaFil: Serra, Federico Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Investigaciones en Tecnología Química. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Investigaciones en Tecnología Química; Argentina. Universidad Nacional de San Luis. Facultad de Ingeniería y Ciencias Agropecuarias. Laboratorio de Control Automático; ArgentinaFil: de Angelo, Cristian Hernan. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; ArgentinaFil: Hernández, Jesus C.. Universidad de Jaén; Españ

    Study of photovoltaic system integration in microgrids through real-time modeling and emulation of its components using HiLeS

    Get PDF
    L'intégration actuelle des systèmes photovoltaïques dans les systèmes d'alimentation conventionnels a montré une croissance importante, ce qui a favorisé l'expansion rapide des micro-réseaux du terme anglais microgrid. Cette intégration a cependant augmenté la complexité du système d'alimentation qui a conduit à de nouveaux défis de recherche. Certains de ces défis de recherche encouragent le développement d'approches de modélisation innovantes en temps réel capables de faire face à cette complexité croissante. Dans ce contexte, une méthodologie innovante est proposée et basée sur les composants pour la modélisation et l'émulation de systèmes photovoltaïques en temps réel integers aux microgrids. L'approche de modélisation proposée peut utiliser le langage de modélisation des systèmes (SysML) pour décrire la structure et le comportement des systèmes photovoltaïques intégrés en tenant compte de leurs caractéristiques multidisciplinaires. De plus, cette étude présente le cadre de spécification de haut niveau des systèmes embarqués (HiLeS) pour transformer les modèles SysML développés en code source destinés à configurer le matériel intégré. Cette caractéristique de la generation automatique de code permet de profiter de dispositifs avec un haut degré d'adaptabilité et de performances de traitement. Cette méthodologie basée sur HiLeS et SysML est axée sur l'étude des systems photovoltaïques partiellement ombragés ainsi que des architectures flexibles en électronique de puissance en raison de leur influence sur les microgrids actuels. En outre, cette perspective de recherche est utilisée pour évaluer les stratégies de contrôle et de supervision dans les conditions normales et de défauts. Ce travail représente la première étape pour développer une approche innovante en temps réel pour modéliser et émuler des systèmes photovoltaïques complexes en tenant compte des propriétés de modularité, de haut degré d'évolutivité et des conditions de travail non uniformes. Les résultats expérimentaux et analytiques valident la méthodologie proposée.Nowadays, the integration of photovoltaic systems into electrical grids is encouraging the expansion of microgrids. However, this integration has also increased the power system complexity leading to new research challenges. Some of these research challenges require the development of innovative modeling approaches able to deal with this increasing complexity. Therefore, this thesis is intended to contribute with an innovative methodology component-based for modeling and emulating in real-time photovoltaic systems integrated to microgrids. The proposed modeling approach uses the Systems Modeling Language (SysML) to describe the structure and behavior of integrated photovoltaic systems. In addition, this study presents the High Level Specification of Embedded Systems (HiLeS) to transform automatically the developed SysML models in embedded code and Petri nets. These characteristics of automatic code generation and design based on Petri nets allow taking advantage of FPGAs for application of real-time emulation of photovoltaic systems. This dissertation is focused on partially shaded photovoltaic systems and flexible power electronics architectures because of their relevant influence on current microgrids. Furthermore, this research perspective is intended to evaluate control and supervision strategies in normal and fault conditions. This work represents the first step to develop an innovative real-time approach to model and emulate complex photovoltaic systems considering properties of modularity, high degree of scalability, and non-uniform working conditions. Finally, experimental and analytical results validate the proposed methodology

    Sampled Signal Description That Is Used in Calculation of Spectrum of This Signal Needs Revision

    Get PDF
    In this paper, we show why the descriptions of the sampled signal used in calculation of its spectrum, that are used in the literature, are not correct. And this finding applies to both kinds of descriptions: the ones which follow from an idealized way of modelling of the signal sampling operation as well as those which take into account its non-idealities. The correct signal description, that results directly from the way A/D converters work (regardless of their architecture), is presented and dis-cussed here in detail. Many figures included in the text help in its understanding

    Sampled Signal Description That Is Used in Calculation of Spectrum of This Signal Needs Revision

    Get PDF
    In this paper, we show why the descriptions of the sampled signal used in calculation of its spectrum, that are used in the literature, are not correct. And this finding applies to both kinds of descriptions: the ones which follow from an idealized way of modelling of the signal sampling operation as well as those which take into account its non-idealities. The correct signal description, that results directly from the way A/D converters work (regardless of their architecture), is presented and dis-cussed here in detail. Many figures included in the text help in its understanding

    USING MODERN TECHNOLOGIES TO UPGRADE EDILITARY URBAN INFRASTRUCTURE

    Get PDF
    Adopting the European laws concerning environmental protection will require sustained efforts of the authorities and communities from Romania; implementing modern solutions will become a fast and effective option for the improvement of the functioning systems, in order to prevent disasters. As a part of the urban infrastructure, the drainage networks of pluvial and residual waters are included in the plan of promoting the systems which protect the environmental quality, with the purpose of integrated and adaptive management. The paper presents a distributed control system for sewer network of Iasi town. Unsatisfactory technical state of the actual sewer system is exposed, focusing on objectives related to implementation of the control system. The proposed distributed control system of Iasi drainage network is based on the implementation of the hierarchic control theory for diagnose, sewer planning and management. There are proposed two control levels: coordinating and local execution. Configuration of the distributed control system, including data acquisition and conversion equipment, interface characteristics, local data bus, data communication network, station configuration are widely described. The project wish to be an useful instrument for the local authorities in the preventing and reducing the impact of future natural disasters over the urban areas by means of modern technologies

    A review of architectures and concepts for intelligence in future electric energy system

    Get PDF
    Renewable energy sources are one key enabler to decrease greenhouse gas emissions and to cope with the anthropogenic climate change. Their intermittent behavior and limited storage capabilities present a new challenge to power system operators to maintain power quality and reliability. Additional technical complexity arises from the large number of small distributed generation units and their allocation within the power system. Market liberalization and changing regulatory framework lead to additional organizational complexity. As a result, the design and operation of the future electric energy system have to be redefined. Sophisticated information and communication architectures, automation concepts, and control approaches are necessary in order to manage the higher complexity of so-called smart grids. This paper provides an overview of the state of the art and recent developments enabling higher intelligence in future smart grids. The integration of renewable sources and storage systems into the power grids is analyzed. Energy management and demand response methods and important automation paradigms and domain standards are also reviewed.info:eu-repo/semantics/publishedVersio
    corecore