Download or read book Contribution la mod lisation des transformateurs de puissance et de leur comportement en haute fr quence written by Ahmad Ahmad and published by . This book was released on 1992 with total page 125 pages. Available in PDF, EPUB and Kindle. Book excerpt: LA CONNAISSANCE ET LA MAITRISE DE NOMBREUX REGIMES TRANSITOIRES QUI APPARAISSENT ET SE PROPAGENT SUR LES RESEAUX ET DANS LES MATERIELS QUI Y SONT CONNECTES (TRANSFORMATEURS, PARAFOUDRES,...) EST UN PROBLEME D'ACTUALITE. UN TRANSFORMATEUR DE PUISSANCE RELIE A UN RESEAU MOYENNE TENSION OU TRES HAUTE TENSION EST SOUMIS A DIFFERENTS TYPES DE SURTENSION DONT LA CONNAISSANCE PERMET D'EVALUER LES CONTRAINTES AUXQUELLES SONT SOUMISES LES ISOLATIONS INTERNES. D'UNE PART, NOUS AVONS ELABORE UN NOUVEAU MODELE DE TRANSFORMATEUR CUIRASSE VALABLE SUR UNE TRES LARGE GAMME DE FREQUENCES, ISSU DU PRINCIPE DE LA DUALITE MAGNETIQUE ELECTRIQUE AFIN DE CONNAITRE SON COMPORTEMENT INTERNE (FREQUENCES DE RESONANCE, COEFFICIENTS DE SURTENSION). CE MODELE EST DESTINE A ETRE INTRODUIT DANS DES CODES DE CALCUL DE RESEAUX, PAR EXEMPLE L'EMTP. LE MODELE PREND EN COMPTE LES PERTES DANS LE CUIVRE ET DANS LE NOYAU MAGNETIQUE. DES METHODES ONT ETE EGALEMENT DEVELOPPEES POUR UN CALCUL FIABLE DES PARAMETRES DU MODELE. D'AUTRE PART, UNE METHODE D'ANALYSE MODALE PERMETTANT D'ILLUSTRER LE COMPORTEMENT OSCILLATOIRE D'UN TRANSFORMATEUR A ETE DEVELOPPEE. CETTE METHODE CONDUIT A UN SCHEMA EQUIVALENT QUI SERT A ETUDIER LES INTERACTIONS DU TRANSFORMATEUR AVEC LE RESEAU. DANS CES PRECEDENTS MODELES, LES RESULTATS CALCULES DE SIMULATION SONT EN BON ACCORD AVEC CEUX OBTENUS PAR LA MESURE, TANT SUR MODELE REDUIT QUE SUR TRANSFORMATEUR THT REEL. PAR AILLEURS, UN ALGORITHME DE CALCUL DE RESEAUX ELECTRIQUES FONDE SUR L'INVERSION DE LA TRANSFORMEE DE LAPLACE A ETE DEVELOPPE. IL PERMET L'INVERSION DE LA TRANSFORMEE DE LAPLACE DE PLUSIEURS FONCTIONS A LA FOIS, EN Y ADAPTANT LA METHODE NODALE. LES RESULTATS DE CALCUL SONT EN TRES BON ACCORD AVEC CEUX DES MESURES ET PERMETTENT D'ESPERER UNE MEILLEURE SIMULATION DU SYSTEME LIGNE-TRANSFORMATEUR

Download or read book Mod lisation 3D d un transformateur de puissance written by Zin-Eddine Azzouz and published by . This book was released on 1992 with total page 179 pages. Available in PDF, EPUB and Kindle. Book excerpt: DANS CE MEMOIRE NOUS PRESENTONS UNE CONTRIBUTION A LA MODELISATION DES PHENOMENES DE DECHARGES PARTIELLES (DP) SE PRODUISANT DANS UN TRANSFORMATEUR DE PUISSANCE. LE TRANSFORMATEUR DE TYPE CUIRASSE SERT DE SUPPORT A CETTE ETUDE. LE PHENOMENE DE DP EST ETUDIE SOUS UN ASPECT PUREMENT ELECTRIQUE. POUR SIMULER LE COMPORTEMENT DU TRANSFORMATEUR SOUMIS A DES DP, DES REPRESENTATIONS PAR SCHEMAS ELECTRIQUES EQUIVALENTS SONT UTILISEES. A CAUSE DE LA COMPLEXITE DE LA GEOMETRIE DU TRANSFORMATEUR, NOUS AVONS JUGE INTERESSANT D'UTILISER UN LOGICIEL D'ELEMENTS FINIS EN TROIS DIMENSIONS, POUR CALCULER LES PARAMETRES DU SCHEMA ELECTRIQUE EQUIVALENT DU TRANSFORMATEUR. EN OUTRE, UNE ETUDE TEMPORELLE ET FREQUENTIELLE, EST REALISEE AFIN DE DETERMINER LES FREQUENCES DE RESONANCE DU TRANSFORMATEUR. NOUS ANALYSONS ENSUITE, L'INFLUENCE DE LA DISCRETISATION SUR LA BANDE PASSANTE DU SCHEMA EQUIVALENT. UNE ETUDE DE LA PROPAGATION D'UN SIGNAL DP LE LONG DES ENROULEMENTS DU TRANSFORMATEUR, EST PRESENTEE. LE SIGNAL DE DP SIMULE, EST D'ABORD COMPOSE D'UNE SEULE DECHARGE, PUIS DE DEUX DECHARGES SUCCESSIVES. CETTE ETUDE EST COMPLETEE, PAR UNE RECHERCHE BIBLIOGRAPHIQUE CONCERNANT LES DIFFERENTES PERTURBATIONS ELECTROMAGNETIQUES PRESENTES DANS L'ENVIRONNEMENT DU TRANSFORMATEUR, SUIVIE D'UNE ANALYSE DE L'INFLUENCE D'UNE PERTURBATION DE TYPE COURONNE SUR LA REPONSE TEMPORELLE. ENFIN, L'ASSOCIATION D'UN SIGNAL DE DP ET D'UNE PERTURBATION EST EXAMINEE

Download or read book Contribution la mod lisation des transformateurs de puissance en r gimes hautes fr quences written by Andrianirina Rakotomalala and published by . This book was released on 1996 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt: La collaboration du Cegely avec des industriels lui a permis de développer un logiciel interactif, destiné à la modélisation des transformateurs de puissance de type cuirassé, en régime transitoire. Dans ce logiciel, le transformateur est modélisé par un schéma équivalent très détaillé de type rlc. Le calcul des paramètres du schéma équivalent, en utilisant les méthodes numériques, est couteuse en temps de calcul, et les méthodes analytiques sont souvent trop simplistes, et négligent les phénomènes essentiels. Il apparait donc la nécessité de développer des méthodes de calcul présentant un compromis entre précision et temps de calcul. Nous développons dans cette thèse des méthodes analytiques, pour la détermination des paramètres résistifs et inductifs du schéma équivalent du transformateur. Ces méthodes ont été validées, et donnent des résultats en bon accord avec ceux de la littérature et des mesures. Ils sont implantés dans le logiciel existant. Les paramètres capacitifs sont obtenus, en utilisant la mef en 2d. Les résultats de calcul permettent d'espérer une meilleure simulation des transformateurs de puissance, en régimes hautes fréquences, et en particulier la détermination des fréquences de résonance et des coefficients de surtension correspondants.

Download or read book Etude et simulation du comportement du transformateur en hautes fr quences written by Ghazi Bousaleh and published by . This book was released on 1989 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt: LA TACHE DES CONSTRUCTEURS DES TRANSFORMATEURS DE PUISSANCE CONSISTE A PLACER DANS UN VOLUME LE PLUS REDUIT POSSIBLE ET AUTOUR D'UN NOYAU MAGNETIQUE, DES ENROULEMENTS CAPABLES DE SUPPORTER SANS DEFAILLANCE LES SURTENSIONS DUES AUX ONDES DE CHOCS RAPIDES OU AUX OSCILLATIONS INTERNES ENTRETENUES EN PLUS DES CONTRAINTES NOMINALES A LA FREQUENCE DU RESEAU. NOTRE ETUDE EST AXEE SUR LA MODELISATION NUMERIQUE DU TRANSFORMATEUR DANS LE BUT D'AIDER A UN DIMENSIONNEMENT CORRECT DU NIVEAU D'ISOLEMENT AINSI QU'A MIEUX COMPRENDRE LE COMPORTEMENT FREQUENTIEL DU TRANSFORMATEUR. LE PREMIER CHAPITRE EST CONSACRE A UNE ETUDE BIBLIOGRAPHIQUE DES MODELES UTILISES POUR SIMULER UN TRANSFORMATEUR. CETTE ETUDE COUVRE LES MODELES REDUITS OU MAQUETTES, ET PRESENTE EN DETAIL LES MODELES MATHEMATIQUES LES PLUS CONNUS AINSI QUE L'ENSEMBLE DES METHODES PUBLIEES DANS LA LITTERATURE POUR LE CALCUL DES PARAMETRES. LE DEUXIEME CHAPITRE PRESENTE UNE DESCRIPTION DU MODELE, COMPORTANT DES INDUCTANCES PROPRES ET MUTUELLES, LE MIEUX ADAPTE A L'ETUDE FREQUENTIELLE DES RESONANCES INTERNES. DEUX PARTIES Y SONT DEVELOPPEES: LA PREMIERE PARTIE S'ATTACHE AU CALCUL DES PARAMETRES DU MODELE. LA DEUXIEME PARTIE CONCERNE LA MISE EN UVRE D'UN LOGICIEL DE SIMULATION SUR ORDINATEUR. LE TROISIEME CHAPITRE EST CONSACRE A LA DESCRIPTION DE LA PROCEDURE D'ESSAI SUR UNE MAQUETTE DE TRANSFORMATEUR. LES MESURES EFFECTUEES ONT DEUX FINALITES. LA PREMIERE EST LA VALIDATION DU MODELE DECRIT AU CHAPITRE II; LA DEUXIEME EST LA PROPOSITION D'UN MODELE GLOBAL, PLUS SIMPLE DU TRANSFORMATEUR, INSPIRE DE L'ANALYSE MODALE EXPERIMENTALE

Download or read book Contemporary Criminological Issues written by Carolyn Côté-Lussier and published by University of Ottawa Press. This book was released on 2020-05-05 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contemporary Criminological Issues tackles some of today’s most pressing social issues, from the criminalization of Indigenous peoples to interpersonal violence, border control, and armed conflicts. This book advances cutting-edge theories and methods, with the aim of moving beyond the scholarship that reproduces insecurity and exclusion. The breadth of approaches encompasses much of the current critical criminological scholarship, serving as a counterpoint to the growth of managerial and administrative criminologies and the rise of explicitly exclusionary and punitive state policies and practices with respect to ‘crime’ and ‘security.’ This edited collection featuring two books, one in English and one in French, includes important contributions to knowledge and public policy by eminent experts and emerging scholars. This book is published in English.

Download or read book What is the Code of Conduct for Responsible Fisheries written by Food and Agriculture Organization of the United Nations and published by Food & Agriculture Org.. This book was released on 2001 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: The actual Code of conduct is also available (1996) (ISBN 9251038341).

Download or read book The Interpreter Geddes written by Amelia Defries and published by . This book was released on 1928 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Aquaculture Development written by Food and Agriculture Organization of the United Nations and published by Food & Agriculture Org.. This book was released on 1997 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides annotations to the Principles of Article 9 of the Code of Conduct for Responsible Fisheries. These annotations are meant to serve as general guidance, and should be taken as suggestions or observations intended to assist those interested in identifying their own criteria and options for actions, as well as partners for collaboration, in support of sustainable aquaculture development.

Download or read book The CIAM Discourse on Urbanism 1928 1960 written by Eric Paul Mumford and published by MIT Press. This book was released on 2002 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first history of the Congres Internationaux d'Architecture Moderne traces the development and promotion of its influential concept of the "Functional City."

Download or read book Smart Grid and Enabling Technologies written by Shady S. Refaat and published by John Wiley & Sons. This book was released on 2021-08-16 with total page 516 pages. Available in PDF, EPUB and Kindle. Book excerpt: SMART GRID AND ENABLING TECHNOLOGIES Discover foundational topics in smart grid technology as well as an exploration of the current and future state of the industry As the relationship between fossil fuel use and climate change becomes ever clearer, the search is on for reliable, renewable and less harmful sources of energy. Sometimes called the “electronet” or the “energy Internet,” smart grids promise to integrate renewable energy, information, and communication technologies with the existing electrical grid and deliver electricity more efficiently and reliably. Smart Grid and Enabling Technologies delivers a complete vision of smart grid technology and applications, including foundational and fundamental technologies, the technology that enables smart grids, the current state of the industry, and future trends in smart energy. The book offers readers thorough discussions of modern smart grid technology, including advanced metering infrastructure, net zero energy buildings, and communication, data management, and networks in smart grids. The accomplished authors also discuss critical challenges and barriers facing the smart grid industry as well as trends likely to be of importance in its future development. Readers will also benefit from the inclusion of: A thorough introduction to smart grid architecture, including traditional grids, the fundamentals of electric power, definitions and classifications of smart grids, and the components of smart grid technology An exploration of the opportunities and challenges posed by renewable energy integration Practical discussions of power electronics in the smart grid, including power electronics converters for distributed generation, flexible alternating current transmission systems, and high voltage direct current transmission systems An analysis of distributed generation Perfect for scientists, researchers, engineers, graduate students, and senior undergraduate students studying and working with electrical power systems and communication systems. Smart Grid and Enabling Technologies will also earn a place in the libraries of economists, government planners and regulators, policy makers, and energy stakeholders working in the smart grid field.

Download or read book Environmental Aspects of Dredging written by R. N. Bray and published by CRC Press. This book was released on 2008-03-10 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt: Expanding a port, deepening a navigation channel or creating new land for development, introduces changes to our physical, social, economic and political environment. Changes may result from events during the construction process, or relate to the nature of the completed structure. Changes can be positive or negative, short-term or long-term, and may affect the immediate vicinity of the project or a larger geographical area. Predicting and assessing all possible effects of a planned dredging activity in a scientifically-sound and reliable manner is essential, so that appropriate control measures can be taken to avoid or mitigate unwelcome impacts. This book provides guidance for a complete holistic environmental evaluation procedure and for the design and implementation of environmental control measures. The book is of particular interest to engineers, government agencies and port authorities, as well as civil engineering consultants and contractors involved in planning and designing dredging, maritime infrastructure and fluvial projects.

Download or read book Sustainable food planning evolving theory and practice written by André Viljoen and published by Wageningen Academic Publishers. This book was released on 2012-03-30 with total page 600 pages. Available in PDF, EPUB and Kindle. Book excerpt: With over half the world's population now deemed to be urbanised, cities are assuming a larger role in political debates about the security and sustainability of the global food system. Hence, planning for sustainable food production and consumption is becoming an increasingly important issue for planners, policymakers, designers, farmers, suppliers, activists, business and scientists alike. The rapid growth of the food planning movement owes much to the fact that food, because of its unique, multi-functional character, helps to bring people together from all walks of life. In the wider contexts of global climate change, resource depletion, a burgeoning world population, competing food production systems and diet-related public health concerns, new paradigms for urban and regional planning capable of supporting sustainable and equitable food systems are urgently needed. This book addresses this urgent need. By working at a range of scales and with a variety of practical and theoretical models, this book reviews and elaborates definitions of sustainable food systems, and begins to define ways of achieving them. To this end 4 different themes have been defined as entry-points into the discussion of 'sustainable food planning'. These are (1) urban agriculture, (2) integrating health, environment and society, (3) food in urban design and planning and (4) urban food governance.

Download or read book Proof Theory and Automated Deduction written by Jean Goubault-Larrecq and published by Springer Science & Business Media. This book was released on 2001-11-30 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: Interest in computer applications has led to a new attitude to applied logic in which researchers tailor a logic in the same way they define a computer language. In response to this attitude, this text for undergraduate and graduate students discusses major algorithmic methodologies, and tableaux and resolution methods. The authors focus on first-order logic, the use of proof theory, and the computer application of automated searches for proofs of mathematical propositions. Annotation copyrighted by Book News, Inc., Portland, OR

Download or read book Patrick Geddes in India written by Sir Patrick Geddes and published by . This book was released on 1947 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Local Food Systems Concepts Impacts and Issues written by Steve Martinez and published by DIANE Publishing. This book was released on 2010-11 with total page 87 pages. Available in PDF, EPUB and Kindle. Book excerpt: This comprehensive overview of local food systems explores alternative definitions of local food, estimates market size and reach, describes the characteristics of local consumers and producers, and examines early indications of the economic and health impacts of local food systems. Defining ¿local¿ based on marketing arrangements, such as farmers selling directly to consumers at regional farmers¿ markets or to schools, is well recognized. Statistics suggest that local food markets account for a small, but growing, share of U.S. agricultural production. For smaller farms, direct marketing to consumers accounts for a higher percentage of their sales than for larger farms. Charts and tables.

Download or read book Earth Surface Processes Landforms and Sediment Deposits written by John Bridge and published by Cambridge University Press. This book was released on 2008-05 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A unique, advanced textbook combining sedimentology and geomorphology in a comprehensive and integrated way.

Download or read book Philosophy of Blockchain Technology Ontologies written by Nicolae Sfetcu and published by MultiMedia Publishing. This book was released on with total page 35 pages. Available in PDF, EPUB and Kindle. Book excerpt: About the necessity and usefulness of developing a philosophy specific to the blockchain technology, emphasizing on the ontological aspects. After an Introduction that highlights the main philosophical directions for this emerging technology, in Blockchain Technology I explain the way the blockchain works, discussing ontological development directions of this technology in Designing and Modeling. The next section is dedicated to the main application of blockchain technology, Bitcoin, with the social implications of this cryptocurrency. There follows a section of Philosophy in which I identify the blockchain technology with the concept of heterotopia developed by Michel Foucault and I interpret it in the light of the notational technology developed by Nelson Goodman as a notational system. In the Ontology section, I present two developmental paths that I consider important: Narrative Ontology, based on the idea of order and structure of history transmitted through Paul Ricoeur's narrative history, and the Enterprise Ontology system based on concepts and models of an enterprise, specific to the semantic web, and which I consider to be the most well developed and which will probably become the formal ontological system, at least in terms of the economic and legal aspects of blockchain technology. In Conclusions I am talking about the future directions of developing the blockchain technology philosophy in general as an explanatory and robust theory from a phenomenologically consistent point of view, which allows testability and ontologies in particular, arguing for the need of a global adoption of an ontological system for develop cross-cutting solutions and to make this technology profitable. CONTENTS: Abstract Introducere Tehnologia blockchain - Proiectare - Modele Bitcoin Filosofia Ontologii - Ontologii narative - Ontologii de intreprindere Concluzii Note Bibliografie DOI: 10.13140/RG.2.2.24510.33602