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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
651

Proposta de arquitetura de um sistema computacional de gerenciamento de subestações de distribuição aderente às recomendações do IEC para Smart Grid. / Proposed computational architecture of a distribution substation management system adherent to IEC recommendations for Smart Grid.

Rein Junior, Osvaldo 06 December 2016 (has links)
Devido à mudança de paradigma originada pela evolução das redes elétricas inteligentes (Smart Grid), surgiram novos requisitos em automação de subestações de distribuição, sobretudo envolvendo operação, monitoramento, controle e proteção. Um nível mais avançado de automação é esperado na rede de distribuição com implementações do conceito de Smart Grid. O objetivo dos próximos sistemas de automação da distribuição é aperfeiçoar o uso dos recursos computacionais disponíveis, objetivando aumentar a disponibilidade do sistema elétrico, a qualidade da energia e a eficiência das concessionárias. E nessa nova realidade, a troca de informação entre os vários sistemas de informação de uma empresa do setor elétrico não é apenas desejada, mas, na maioria dos casos, necessária. Nesse contexto, se propõe uma arquitetura computacional capaz de transferir todas as informações geradas a partir da implementação de funcionalidades \"inteligentes\" na subestação, envolvendo as funções de supervisão, controle, monitoramento e proteção das subestações de distribuição, para o centro de controle da concessionária (COS), o que não está previsto nos protocolos normalmente utilizados, como DNP, ICCP, e IEC 61850. Para atingir esse objetivo é feita a investigação sobre o uso dos padrões internacionais propostos na arquitetura de referência do IEC para realizar tal integração, mostrando a necessidade de modificação nos objetos de dados definidos. Com o intuito de avaliar a viabilidade da arquitetura proposta foi desenvolvido um protótipo dentro do programa de Pesquisa e Desenvolvimento (P&D) regulado pela ANEEL (Agência Nacional de Energia Elétrica), em parceria com a CPFL (Companhia Paulista de Força e Luz). Nesse protótipo foram desenvolvidos módulos com funcionalidades \"inteligentes\" que promovem a migração de funções do centro de controle para a subestação. Além disso, o protótipo também implementa serviços web (Web Services) que são responsáveis pela integração da informação, tornando a troca de informação independentemente da plataforma onde os serviços são implementados. O texto contempla as anotações que refletem os passos dessa implementação do protótipo, bem como o registro dos testes exigidos pelos trabalhos, os quais compreenderam a implementação das novas funcionalidades, com a obtenção e tratamento dos dados, e seu posterior envio ao centro de controle. / Due to the paradigm shift caused by the evolution of the power grids, resulting in a new concept of Smart Grid, new requirements in automation of distribution substations emerged, especially those involving the operation, monitoring, control and protection. A more advanced level of automation is expected in the distribution network with implementations of the concepts related to Smart Grid. The goal of the next distribution automation systems is to optimize the use of available resources, intending to increase the availability of the power system, the power quality and the efficiency of the utilities. In this new context, the exchange of information between the various information systems of an electrical utility is not only desired, but in most cases, necessary. In this context, it is proposed a computational architecture capable of transferring all the information generated from the implementation of \"smart\" functions in the substation, involving supervisory, control, monitoring and protection of distribution substations, to the utility control center (COS), which is not provided for in the protocols commonly used by the utility, such as DNP, ICCP, and IEC 61850. Research on the use of international standards proposed in the IEC reference architecture to achieve such integration is also performed, revealing the necessity of modifying the defined data model. A prototype was developed in a partnership with CPFL (Companhia Paulista de Força e Luz), in order to assess the feasibility of the proposed architecture, within the R&D program regulated by ANEEL (Brazilian Electric Power Agency). Modules have been developed with the \"smart\" features that promote migration of some control center functions to the substation. In addition, the prototype also implements web services that are responsible for the data integration, with the information being exchanged regardless of the platform where the services are implemented. The text includes notes reflecting the steps of this prototype implementation, as well as the tests required to validate the model, which comprised the implementation of those new features, obtaining and processing the data, and subsequent sending to the utility control center (DMS).
652

Análise experimental da qualidade da energia de uma microrrede fotovoltaica com back-up

Becker, Luís Rodrigo 27 March 2017 (has links)
Submitted by JOSIANE SANTOS DE OLIVEIRA (josianeso) on 2017-07-10T14:32:15Z No. of bitstreams: 1 Luís Rodrigo Becker_.pdf: 4479543 bytes, checksum: 3a9259e64d112cb88c2414eb122552e9 (MD5) / Made available in DSpace on 2017-07-10T14:32:15Z (GMT). No. of bitstreams: 1 Luís Rodrigo Becker_.pdf: 4479543 bytes, checksum: 3a9259e64d112cb88c2414eb122552e9 (MD5) Previous issue date: 2017-03-27 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / PROSUP - Programa de Suporte à Pós-Gradução de Instituições de Ensino Particulares / Este trabalho apresenta uma análise experimental de uma microrrede fotovoltaica formada por dois subsistemas, um isolado com estocagem e outro conectado à rede. Foi verificado o seu comportamento, sua capacidade no fornecimento de energia para uma carga isolada e rede da concessionária, monitorado a qualidade da energia elétrica entregue à diferentes cargas e rede da concessionária e também quantificado os índices de performance do sistema conectado. O subsistema conectado à rede (SFCR) é formado por um painel de 1080 Wp de silício multicristalino e um inversor c.c./c.a. de 1200 W. O subsistema isolado de back-up (SFI-b) é formado por um painel de 600 Wp de silício monocristalino, controlador de carga, banco de estocagem com baterias chumbo-ácido 24 V / 210 Ah e um inversor off-grid c.c./c.a. de 1000 W. O comportamento e a capacidade do sistema são monitorados durante o atendimento de uma carga, representada por um refrigerador. A qualidade da energia é analisada através de medições de energia ativa, reativa e aparente, fator de potência e geração de correntes harmônicas pelos inversores. O SFI-b é monitorado atendendo diferentes tipos e regimes de cargas. Já o SFCR é monitorado em dias de céu claro, parcialmente encobertos e encobertos. Os índices de performance são calculados em dias de céu claro e parcialmente encoberto ao longo dos seis primeiros meses de 2016. Os resultados demonstram que o SFI-b é capaz de atender a carga de forma confiável, comutando-a automaticamente para a concessionária quando o banco de baterias atinge uma profundidade de descarga pré-definida, enquanto o SFCR injeta a energia produzida na rede da concessionária. Os indicadores de qualidade da energia do inversor do SFI-b mostraram-se adequados, permanecendo dentro dos limites citados na legislação e análogos aos apresentados pela rede da distribuidora local. Já o inversor do SFCR apresentou indicadores de qualidade de energia satisfatórios, também na maior parte do tempo dentro dos limites citados na legislação, exceto nos dias encobertos e períodos de baixa irradiância, constatando-se significativa geração de energia reativa e distorções harmônicas de corrente. Considerando a média entre dias de céu claro e parcialmente encoberto, a eficiência média global do SFCR é de 9,9% e a energia média diária entregue à rede é de 4,7 kWh. Foi verificado que a qualidade da energia produzida pelo SFI-b praticamente independe da irradiância, já o SFCR depende diretamente da irradiância e do nível de carregamento do inversor, na geração de uma energia de qualidade. / This work presents an experimental analysis of a photovoltaic micro-grid formed by two subsystems, one off-grid with storage and another grid-connected. It is intended to verify its operation, its capacity to supply power to an isolated charge and electric utility grid, to monitor the quality of the electric power delivered to different charges and the electric grid power, and also to quantify the performance indexes of the connected system. The grid-connected subsystem (SFCR) consists of a panel of 1080 Wp of multicrystalline silicon and a DC/AC. inverter of 1200 W. The off-grid subsystem of back-up (SFI-b) consists of a 600 Wp monocrystalline silicon panel, charge controller, lead-acid battery storage bench 24 V / 210 Ah, and a DC/AC inverter of 1000 W. The operation and capacity of the system are monitored during the supply of a charge, represented by a refrigerator. The quality of the energy is analyzed through measurements of active, reactive and apparent energy, power factor and generation of harmonic currents by the inverters. SFI-b is monitored for different types and charges regimes, and SFCR is monitored on clear sky, partially and totally cloudy days. Performance indexes are calculated on clear sky and partly cloudy days over the first six months of 2016. The results demonstrate that the SFI-b is capable of servicing the charge reliably, switching it automatically to the utility grid when the batteries bank reaches a predetermined discharge depth, while the SFCR injects the power produced in power line grid. The energy quality indicators of the SFI-b inverter were adequate, staying inside the limits mentioned in the legislation, and analogous to those presented by the power line grid of the local distributor. The SFCR inverter presented satisfactory energy quality indicators, also in most of the time inside the limits mentioned in the legislation, except for the cloudy days and periods of low irradiance, showing significant reactive energy generation and current harmonic distortions. Considering the average between clear and partially cloudy days, the global average efficiency of SFCR is 9,9%, and the average daily energy injected on the grid is 4,7 kWh. It was verified that the quality of the energy produced by the SFI-b practically independent of the irradiance, but the SFCR depends directly on the irradiance and the load level of the inverter, in the quality energy generation.
653

L'ambivalence des consommateurs : proposition d'un nouvel outil de mesure / Consumer Ambivalence : Proposition of a new Measurement Tool

Audrezet, Alice 22 May 2014 (has links)
La littérature en méthodologie pointe un important problème lié à l’utilisation des différentiels sémantiques pour mesurer les évaluations globales des individus. Au centre de ces continua bipolaires opposant une paire d’adjectifs antagonistes, sont en effet agrégées de manière artificielle et fâcheuse deux types d’évaluations : les réactions indifférentes et les réactions ambivalentes. Or, la distinction entre ces deux types d’évaluation est un enjeu dans la mesure où elles recouvrent des réalités différentes. En effet, l’indifférence correspond à l’absence de réaction positive ou négative, tandis que l’ambivalence décrit une évaluation composée à la fois de réactions positives et négatives. Cette recherche démontre l’intérêt d’utiliser un nouvel outil de mesure issu de recherches en psychologie, l’Evaluative Space Grid (Larsen & al., 2009), pour saisir la part d’ambivalence contenue dans les évaluations globales de consommateurs. A l’aide d’un design mixte comportant cinq études empiriques, nous montrons que l’Evaluative Space Grid présente des propriétés psychométriques aussi bonnes que le différentiel sémantique tout en permettant de différencier les réactions indifférentes des réactions ambivalentes, ce que ne peut pas faire un différentiel sémantique. Ce travail de recherche constitue donc une contribution méthodologique importante qui devrait intéresser chercheurs et praticiens. / Literature on methodology reveals a serious problem related to the use of semantic differential scales to measure individuals’ global evaluations. Two types of evaluations are incorporated—in an artificial and unsuitable way—into these bipolar continuums that contain two opposing adjectives: indifferent reactions and ambivalent reactions. The distinction between these two types of evaluation is significant because they reflect different realities. While indifference corresponds to an absence of positive or negative reactions, an ambivalent evaluation is composed of both positive and negative reactions. This research demonstrates the advantages of using a new measurement tool, the Evaluative Space Grid (Larsen & al., 2009), developed in psychology research; this tool is able to capture the ambivalent component in consumers’ global evaluations. Using a mixed design method comprising five empirical studies, we demonstrate that the Evaluative Space Grid has psychometric properties that match those of semantic differential scales; however, in contrast to semantic differential scales, the ESG is capable of differentiating between indifferent reactions and ambivalent reactions. This research therefore constitutes a major methodological contribution that will be of interest to both researchers and practitioners.
654

Gestion coorpérative de flotte de véhicules électriques en vue de son intégration optimale au réseau électrique / Cooperative Management of Electric Vehicle Fleets for their optimal integration to the Electrical Grid

Ovalle villamil, Andres 14 December 2016 (has links)
Avec l'importance que prend le parc de véhicules électriques rechargeable (VER) depuis ces dix dernières années et au vu de l'important taux de croissance le caractérisant, se pose alors la question de l'infrastructure de recharge y inhérente. Une manière d'en tirer bénéfice et d'en minimiser l'impact consistera en l'agrégation en flotte et de gérer cette dernière en conséquence. L'objectif général de la thèse est de proposer et de développer des algorithmes décentralisés qui permettront de minimiser les impacts les plus critiques attendus d'une forte pénétration de VERs. La prise en compte de la réversibilité des chargeurs actuels et de leur fonctionnement sur les quatre quadrants, les algorithmes proposés, rendent également possible la fourniture de services système au réseau ; cependant il faut aussi tenir compte du caractère aléatoire de plusieurs variables telles que les heures d'arrivée te de départ des véhicules considérés, de l'état de charge initial entre autres. Cette thèse introduit d'abord une approche globale et une optimisation locale afin d'établir un benchmark solide à des fins d'évaluation des techniques développées dans ce travail. Vient ensuite ce qui est la contribution majeure représentée par deux méthodologies d'optimisation lesquelles sont basées sur la théorie des jeux évolutionniste. Toutes les deux techniques introduisent la notion d'équité dans la répartition des tâches et des ressources entre VERs et donnent plus de poids aux contraintes liées au rôle de l'usager/propriétaire du véhicule et de son implication dans la gestion de la demande. En outre, l'une de ces méthodes comprend des solutions de rechange pour intégrer la charge rapide dans le processus de planification, tandis que l'autre méthode permet au VER de fournir des services auxiliaires comme le remplissage des creux de demande, l'effacement de la pointe le pic de rasage, active, d'équilibrer la puissance active ou encore de fournir de l'énergie réactive. / With a stock of Plug-in electric vehicles (PEVs) under continuous grow during the last ten years, concerns have been raised in terms of their charging infrastructure and their integration into the electricity distribution systems. If PEVs are considered as a fleet, both their impact and benefit for the electrical power system can be substantial. The general objective of this thesis is to propose and develop decentralized algorithms allowing to mitigate the most critical impacts expected to occur with the integration of PEVs. Taking into account the reversibility of chargers, the proposed algorithms are intended to consider re-injection of energy, in order to provide ancillary services to the grid. Moreover, algorithms are supposed to consider the stochastic nature of variables like the arrival and departure of PEVs, their initial state of charge, among others. Under these premises and taking into account earlier contributions, this thesis introduces a centralized approach and a distributed optimization approach in order to have a solid benchmark for the justification of the most elaborate contributions of the last part of this work. After these first experiences, the most important contribution of this thesis is represented in two decentralized optimization methodologies that were developed in details based on concepts of evolutionary game theory. Both of them introduce the concept of fairness in the allocation of tasks and resources among PEVs, and give more weight to social constraints represented on the role of PEV owners in the load managing process. Furthermore, one of these methodologies includes alternatives to integrate fast charging rates in the scheduling process, while the other methodology allows PEVs to provide ancillary services like valley filling, peak shaving, active and reactive power balancing, and reactive power supply.
655

Smart meter integrado a analisador de qualidade de energia para propósitos de identificação de cargas residenciais / Smart meter integrated to power quality analyzer for identification purposes of residential loads

Sergio Date Fugita 20 November 2014 (has links)
Este trabalho consiste em apresentar o desenvolvimento de um Smart meter, integrado a um analisador de qualidade de energia, para análise de distorções harmônicas, utilizando método de redes neurais artificiais embarcado em hardware. Tal Smart meter está incluído dentro dos conceitos de Smart Grid, que serão apresentados também neste trabalho. O intuito do desenvolvimento do Smart meter para análise de distorções harmônicas é auxiliar concessionárias de energia elétrica a identificar que tipo de carga o consumidor utiliza em sua residência, a fim de contribuir para a tomada de decisões apropriadas, tais como a diminuição da emissão de correntes harmônicas, demanda de energia, detecção de falhas no fornecimento de energia elétrica e faturas diferenciadas de acordo com a quantidade de harmônicas injetadas na rede elétrica. Adicionalmente, observou-se que o Smart meter desenvolvido pode ser ainda utilizado para detectar fenômenos de VTCD, como elevação, afundamento e interrupção de energia. Todo o processo de desenvolvimento do Smart meter é apresentado no decorrer desta tese de doutorado. / This thesis consists to present the development of a Smart Meter integrated to power quality analyzer for the analysis of harmonic distortion, using methods based on artificial neural networks in embedded hardware. This Smart Meter is included within the concepts of Smart Grid, which will be also presented in this work. The intention of the development of the Smart Meter for analysis of harmonic distortion is to assist utilities companies to identify what loads type the consumer uses at your residence in order to contribute for supporting decisions, such as reducing the emission of the harmonic currents, power demand and faults detection in electric energy supply and distinct bills according to the amount of harmonics injected into the power grid. In addition, it was observed that this developed Smart Meter can be even used to detect the VTCD phenomena, such as swell, sag and interruption of the energy supply. All development steps of this Smart Meter is presented in this doctoral thesis.
656

Sensor para detec??o de varia??o de tens?o para redes de baixa tens?o utilizando redes sem fio IEEE 802.11

Santos, Alan Henrique Ribeiro dos 24 June 2016 (has links)
Submitted by Fernanda Ciolfi (fernanda.ciolfi@puc-campinas.edu.br) on 2016-08-11T18:46:02Z No. of bitstreams: 1 Alan Henrique Ribeiro dos Santos.pdf: 3411627 bytes, checksum: 9502463608d158f97139964de31fc083 (MD5) / Made available in DSpace on 2016-08-11T18:46:02Z (GMT). No. of bitstreams: 1 Alan Henrique Ribeiro dos Santos.pdf: 3411627 bytes, checksum: 9502463608d158f97139964de31fc083 (MD5) Previous issue date: 2016-06-24 / The increasing technological advances will allow a transformation in the electricity sector, until then, little changed since its implementation, however, this scenario has changed mainly by power generation growth through renewable matrices. The concept Smart Grid has provided significant changes mainly in the basic distribution networks with the inclusion of Information and Communication Technology (ICT), enabling monitoring and control of the grid, but effective and even allowing for the integration of Generation, Transmission and Distribution Power. The utilization of intelligent sensors and automation and control devices will also enable reduction of errors in decision making caused by human error, yet very common in the industry. The quality of electricity supply is currently topic extensively explored and of great importance to the utilities that are concerned with improving the quality of the product delivered to their consumers. This work aims to develop a sensor of long and short duration voltage variation, these are phenomena that are present in the electricity networks and affect the power supply to both industrial customers and to residential consumers, yet it is of great importance that devices intelligent be developed to integrate the distribution network for the generation of data, the main objective is to develop a low-cost sensor for identification and records of these phenomena. To communicate with the supervisory system, the sensors use a wireless telecommunications infrastructure, IEEE 802.11, based on urban Wi-Fi technology, this way the data is sent to a monitoring station reporting any faults captured by the sensors. / O crescente avan?o tecnol?gico permitir? uma transforma??o no setor el?trico, at? ent?o pouco modificado desde a sua implanta??o, no entanto, este cen?rio tem se modificado principalmente pelo crescimento da gera??o de energia atrav?s de matrizes renov?veis. O conceito Smart Grid tem propiciado grandes modifica??es principalmente nas redes de distribui??o b?sica com a inser??o de Tecnologia da Informa??o e Comunica??o (TIC), possibilitando monitoramento e controle mais efetivos da rede el?trica, e at? mesmo possibilitando a integra??o entre a Gera??o, Transmiss?o e Distribui??o de energia. A utiliza??o de sensores inteligentes e dispositivos de automa??o e controle ainda permitir? a redu??o de erros em tomadas de decis?o causadas por falhas humanas, ainda muito comuns no setor. A qualidade do fornecimento de energia el?trica ? t?pico atualmente bastante explorado e de grande import?ncia para as concession?rias que est?o preocupadas em melhorar a qualidade do produto entregue a seus consumidores. Este trabalho tem como objetivo desenvolver um sensor de varia??o de tens?o para redes de baixa tens?o utilizando redes sem fio WI-FI 802.11, estes, s?o fen?menos que est?o presentes nas redes el?tricas e afetam o fornecimento de energia tanto a consumidores industriais como a consumidores residenciais, contudo ? de grande import?ncia que dispositivos inteligentes sejam desenvolvidos de forma a integrar-se ? rede de distribui??o para a coleta de dados. O principal objetivo ? desenvolver um sensor de baixo custo para identifica??o e registros destes fen?menos. Para comunicar-se com o sistema supervis?rio, os sensores utilizar?o uma estrutura de telecomunica??es sem fio, IEEE 802.11, baseado em tecnologia Wi-Fi urbana, desta forma os dados ser?o enviados a uma Central de Monitoramento informando eventuais falhas captadas pelos sensores.
657

Bidirectional Electric Vehicles Service Integration in Smart Power Grid with Renewable Energy Resources

Mohamed, Ahmed A S, Mr 09 November 2017 (has links)
As electric vehicles (EVs) become more popular, the utility companies are forced to increase power generations in the grid. However, these EVs are capable of providing power to the grid to deliver different grid ancillary services in a concept known as vehicle-to-grid (V2G) and grid-to-vehicle (G2V), in which the EV can serve as a load or source at the same time. These services can provide more benefits when they are integrated with Photovoltaic (PV) generation. The proper modeling, design and control for the power conversion systems that provide the optimum integration among the EVs, PV generations and grid are investigated in this thesis. The coupling between the PV generation and integration bus is accomplished through a unidirectional converter. Precise dynamic and small-signal models for the grid-connected PV power system are developed and utilized to predict the system’s performance during the different operating conditions. An advanced intelligent maximum power point tracker based on fuzzy logic control is developed and designed using a mix between the analytical model and genetic algorithm optimization. The EV is connected to the integration bus through a bidirectional inductive wireless power transfer system (BIWPTS), which allows the EV to be charged and discharged wirelessly during the long-term parking, transient stops and movement. Accurate analytical and physics-based models for the BIWPTS are developed and utilized to forecast its performance, and novel practical limitations for the active and reactive power-flow during G2V and V2G operations are stated. A comparative and assessment analysis for the different compensation topologies in the symmetrical BIWPTS was performed based on analytical, simulation and experimental data. Also, a magnetic design optimization for the double-D power pad based on finite-element analysis is achieved. The nonlinearities in the BIWPTS due to the magnetic material and the high-frequency components are investigated rely on a physics-based co-simulation platform. Also, a novel two-layer predictive power-flow controller that manages the bidirectional power-flow between the EV and grid is developed, implemented and tested. In addition, the feasibility of deploying the quasi-dynamic wireless power transfer technology on the road to charge the EV during the transient stops at the traffic signals is proven.
658

Approche à base d'agents pour l'ingénierie et le contrôle de micro-réseaux / Agent based approach for engineering and control of microgrids

Basso, Gillian 09 December 2013 (has links)
La gestion d’énergie est un sujet de plus en plus important dans notre société. Nous faisons actuellement face à un nombre croissant de problèmes tels que l’épuisement des réserves pétrolières, le réchauffement climatique ou encore la diminution de la qualité de l’énergie (principalement due aux coupures pendant les pics de consommation). Les smartgrids sont une des solutions à ces problèmes. En ajoutant une communication bidirectionnelle et de nouvelles capacités en matière de technologies de l’information et de la communication, il est possible de créer un système autonome de gestion intelligente de l’énergie.Les travaux décrits dans ce mémoire s'intéressent particulièrement à la gestion des microgrids à l'aide de systèmes multi-agents (SMA). Les microgrids sont des réseaux de faibles puissances, composés de petits producteurs d’énergie décentralisés (éventuellement renouvelables) et de consommateurs. Ces réseaux peuvent être reliés (ou non) au réseau global ce qui ajoute à leur complexité. De par leurs complexités et leurs répartitions géographiques, les smartgrids, comme les microgrids, ne peuvent pas être gérés facilement par des systèmes centralisés. Les intelligences artificielles distribuées et plus particulièrement les SMA apparaissent comme un moyen cohérent de résoudre les problèmes liés aux smartgrids.Dans un premier temps, nous avons défini une approche mettant en oeuvre des boucles de rétroaction. Une boucle de rétroaction apparaît dans les systèmes complexes qui peuvent être définis avec plusieurs niveaux d'abstraction. Deux niveaux sont ainsi en interaction. Le niveau micro regroupe un ensemble d'agents ayant des comportements qui, une fois combinés, influeront sur l'état du système. Le niveau macro traite ces influences pour définir un nouvel état du système qui influera sur le comportement des agents du niveau micro. Cette boucle de rétroaction permet de séparer les comportements sur plusieurs niveaux.Cette approche est utilisée pour définir un problème de gestion offre-demande dans un microgrid. Ce problème permet de prendre en compte un ensemble d'objectifs qui sont actuellement traités de manière indépendante. Enfin, une application utilisant un SMA a été développée. Cette approche peut s'intégrer dans ce problème. Elle a pour but d'assurer la stabilité du réseau à tout instant grâce au contrôle de systèmes de stockage.Dans un second temps, un simulateur de réseau électrique permettant le contrôle dynamique des périphériques a été développé. Ce simulateur repose sur trois grands principes. Le premier est une modélisation à base d’agents du simulateur lui-même, pour représenter la complexité des réseaux électriques. Le second principe repose sur l’utilisation du paradigme holonique afin de prendre en compte les multiples niveaux inhérents aux réseaux électriques. Enfin, le troisième principe est inspiré du modelé influence/réaction et propose une technique qui permet de gérer les actions simultanées, éventuellement conflictuelles, au sein des SMA. / Energy management is, nowadays, a subject of uttermost importance. Indeed, we are facing growing concerns such as petroleum reserve depletion, earth global warming or power quality (e.g. avoiding blackouts during peak times). Smart grids is an attempt to solve such problems, by adding to power grids bidirectional communications and ICT capabilities in order to provide an intelligent autonomic management for the grid.This thesis focuses on the management of microgrids thanks to multiagent systems (MAS). Microgrids are low-power networks, composed of small and decentralized energy producers (possibly renewable) and consumers. These networks can be connected to the main grid or islanded, this make them more complex. Due to their complexity and their geographical distribution, smart grids and microgrids can not be easily managed by a centralized system. Distributed artificial intelligences especially MAS appear to be a solution to resolve problems related to smart grids.Firstly we defined an approach implementing feedback loops. These feedback loops exist in complex systems which can be defined with several abstraction levels. Two levels are interacting. The micro-level contains a set of agents owning behaviours that can be combined. The result of the combination imapct the state of the system. The macro-level processes these influences to define a new state of the system which will imapct the agents behaviours at the micro-level.This feedback loop separates behaviours on several levels.This approach is used to defined a demand and supply matching problem in microgrid. This problem afford to manage a set of goals which currently are independently processed. Finally, an application is developed using MAS that ensures grid stability thanks to storage systems. This application was thought to be integrated to the approach detailed above.Secondly, a grid simulator id developed. This simulator allows dynamic control of devices. It is based on three main principles.• An agent-based model of the simulator to represent the complexity of electrical networks. • The use of the holonic paradigm to take into account the multiple levels inherent to power grids. • The use of the influence/reaction model and offers a technology that can manage simultaneous actions, possibly conflicting, in MAS.
659

Der Einfluss von Verwaltungskultur auf die Verwendung von Performance-Daten : eine quantitative Untersuchung der deutschen kreisfreien Städte / The influence of administrative culture on the usage of performance data : a quantitative study of the German cities with county-status

Döring, Matthias January 2012 (has links)
In der aktuellen Performance-Management-Forschung wurden bereits eine Vielzahl von Einflussfaktoren untersucht, die eine zielgerichtete Verwendung von Kennzahlen beeinflussen. Verwaltungskultur spielte hierbei nur eine nachgeordnete Rolle. Die vorliegende Untersuchung verwendet die Daten einer Umfrage in allen kreisfreien Städten Deutschlands, um den Zusammenhang zwischen verschiedenen Kulturtypen und der Verwendung von Kennzahlen zu untersuchen. Als Analyseschema für Verwaltungskultur wird die Grid/Group-Analysis verwendet. Die Ergebnisse sind zum Teil überraschend. Individualistische Kulturen scheinen einen negativen, hierarchistische Kulturen einen positiven Einfluss zu haben. Dennoch wird das Fehlen eines geeigneten Operationalisierungsschemas bemängelt. / The current research on performance management considered several factors influencing the purposeful usage of performance data. Administrative culture is a rather neglected one. This work uses the data from a German-wide survey of all cities with county-status to show the relation between different groups of culture and the usage of performance data. Therefore, the Grid/Group-Analysis is used to categorize administrative culture. The results are partly surprising as individual culture is negatively and hierarchical culture is positively related to the dependent variable. Nevertheless, the missing of a useful operationalization scheme is criticized.
660

Hybrid Grid Generation for Viscous Flow Computations Around Complex Geometries

Tysell, Lars January 2009 (has links)
A set of algorithms building a program package for the generation of twoandthree-dimensional unstructured/hybrid grids around complex geometrieshas been developed. The unstructured part of the grid generator is based on the advancing frontalgorithm. Tetrahedra of variable size, as well as directionally stretched tetrahedracan be generated by specification of a proper background grid, initiallygenerated by a Delaunay algorithm. A marching layer prismatic grid generation algorithm has been developedfor the generation of grids for viscous flows. The algorithm is able to handleregions of narrow gaps, as well as concave regions. The body surface is describedby a triangular unstructured surface grid. The subsequent grid layers in theprismatic grid are marched away from the body by an algebraic procedurecombined with an optimization procedure, resulting in a semi-structured gridof prismatic cells. Adaptive computations using remeshing have been done with use of a gradientsensor. Several key-variables can be monitored simultaneously. The sensorindicates that only the key-variables with the largest gradients give a substantialcontribution to the sensor. The sensor gives directionally stretched grids. An algorithm for the surface definition of curved surfaces using a biharmonicequation has been developed. This representation of the surface canbe used both for projection of the new surface nodes in h-refinement, and theinitial generation of the surface grid. For unsteady flows an algorithm has been developed for the deformationof hybrid grids, based on the solution of the biharmonic equation for the deformationfield. The main advantage of the grid deformation algorithm is that itcan handle large deformations. It also produces a smooth deformation distributionfor cells which are very skewed or stretched. This is necessary in orderto handle the very thin cells in the prismatic layers. The algorithms have been applied to complex three-dimensional geometries,and the influence of the grid quality on the accuracy for a finite volumeflow solver has been studied for some simpler generic geometries. / QC 20100812

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