Author: Victor Dos Santos (docteur en génie électrique).)
Publisher:
ISBN:
Category :
Languages : fr
Pages : 0
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Book Description
Au cours de ces dernières décennies, les avionneurs n'ont cessé d'augmenter la puissance électrique embarquée à bord des avions. Cette intensification de l'usage de l'électricité, dans le but de rationaliser les énergies secondaires de l'avion (pneumatique, hydraulique, mécanique) constitue le fondement du concept de l'avion plus électrique. Une des contreparties de l'augmentation du nombre de charges électriques réside dans le fait qu'elles doivent fonctionner dans le même environnement électromagnétique, ce qui engendre des problèmes de compatibilité. Cette discipline a été traitée jusqu'à présent en fin de développement d'un système, avant l'étape de la certification et de l'intégration sur avion. La prise en compte de ces contraintes dès la phase de conception, via l'estimation des perturbations électromagnétiques conduites et rayonnées par simulation, peut permettre d'importants gains de temps et de coûts en réduisant les phases d'essais. La première étape de ce projet de recherche est la mise en place d'une approche de modélisation compatible avec les processus d'optimisation. Il est alors indispensable de prendre en compte l'ensemble des sous-systèmes qui composent la chaîne électromécanique, à savoir les RSILs, les câbles, le convertisseur et le moteur. L'approche de modélisation choisie est de type directe ; elle consiste à représenter la chaîne électromécanique dans la base de mode commun par des quadripôles. Ce modèle générique permet d'estimer les courants de mode commun directement dans le domaine fréquentiel en différents points du système. Par ailleurs, afin d'être compétitif vis-à-vis des autres vecteurs d'énergie présents sur avion, la densité de puissance des systèmes électriques doit être drastiquement augmentée. L'introduction des semi conducteurs grands gaps à base de Carbure de Silicium (SiC) permet de contribuer à l'augmentation de la densité de puissance des électroniques de puissance. Cependant, dans ces travaux de thèse, nous veillons à la non régression des performances au niveau système et notamment vis-à-vis de l'impact des émissions électromagnétiques conduites de mode commun. Une fois les modèles en émission établis, diverses solutions de filtrage sont étudiées : filtrage passif externe et interne. Une démarche d'optimisation multi-objectifs (masse, pertes) et multi contraintes (qualité réseau, stabilité, CEM, thermique, etc.) est proposée. Des études de sensibilité mettent en évidence les variables de conception ayant le plus d'impact sur les émissions conduites. Cette approche permet le dimensionnement optimal des composants de l'onduleur (module de puissance, dissipateur, filtres de mode commun et de mode différentiel, paramètres de la commande rapprochée). Les résultats obtenus grâce à l'algorithme génétique employé permettent de construire des courbes de tendance utiles pour l'aide au dimensionnement.
Author: Thierry Bourbié
Publisher: Editions TECHNIP
ISBN: 9782710805168
Category : Science
Languages : en
Pages : 366
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Book Description
Author: Norbert Streitz
Publisher: Springer
ISBN: 3540727272
Category : Computers
Languages : en
Pages : 314
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Book Description
This book examines how the computer, as we currently know it, will be replaced by a new generation of technologies, moving computing off the desktop and ultimately integrating it with real world objects and everyday environments. It provides a unique combination of concepts, methods and prototypes of ubiquitous and pervasive computing reflecting the current interest in smart environments and ambient intelligence.
Author: Berker, Thomas
Publisher: McGraw-Hill Education (UK)
ISBN: 0335217680
Category : Social Science
Languages : en
Pages : 271
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Book Description
This book provides an overview of a key concept in media and technology studies: domestication. Theories around domestication shed light upon the process in which a technology changes its status from outrageous novelty to an aspect of everyday life which is taken for granted. The contributors collect past, current and future applications of the concept of domestication, critically reflect on its theoretical legacy, and offer comments about further development. The first part of Domestication of Media and Technology provides an overview of the conceptual development and theory of domestication. In the second part of the book, contributors look at a diverse range of empirical studies that use the domestication approach to examine the dynamics between users and technologies. These studies include: Mobile information and communications techologies (ICTs) and the transformation of the relationship between private and the public spheres Home-based internet use: the two-way dynamic between the household and its social environment Disadvantaged women in Europe undertaking introductory internet courses Urban middle-class families in China who embrace ICTs and view them as instruments of upward mobility and symbols of success The book offers valuable insights for both experienced researchers and students looking for an introduction to the concept of domestication. Contributors: Maria Bakardjieva, University of Calgary; Thomas Berker, Norwegian University of Science and Technology; Leslie Haddon, Essex University; Maren Hartmann, University of Erfurt; Deirdre Hynes, Dublin City University; Sun Sun Lim, National University of Singapore; Anna Maria Russo Lemor, University of Colorado at Boulder; David Morley, Goldsmiths College, University of London; Jo Pierson, TNO-STB, Delft, Netherlands; Yves Punie, Institute for Prospective Technological Studies (IPTS) in Seville; Els Rommes, Nijmegen University; Roger Silverstone, London School of Economics and Political Science; Knut H. Sørensen, Norwegian University of Science and Technology; Katie J. Ward, University of Sheffield.
Author:
Publisher:
ISBN:
Category : Electric utilities
Languages : en
Pages : 140
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Book Description
Author: Georgios B. Giannakis
Publisher: John Wiley & Sons
ISBN: 047146287X
Category : Technology & Engineering
Languages : en
Pages : 488
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Book Description
Eine vielversprechende Technologie zur Maximierung der Bandbreiteneffizienz in der breitbandigen drahtlosen Kommunikation ist die Raum-Zeit-Kodierung. Theorie und Praxis verbindend, ist dieses Buch die erste umfassende Diskussion von Grundlagen und designorientierten Aspekten von Raum-Zeit-Codes. Single-Carrier und Multi-Carrier-Übertragungen für Einzel- und Mehrnutzerkommunikation werden behandelt.
Author: Jean-Marie Basset
Publisher: John Wiley & Sons
ISBN: 3527627103
Category : Science
Languages : en
Pages : 725
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Book Description
Covering everything from the basics to recent applications, this monograph represents an advanced overview of the field. Edited by internationally acclaimed experts respected throughout the community, the book is clearly divided into sections on fundamental and applied surface organometallic chemistry. Backed by numerous examples from the recent literature, this is a key reference for all chemists.
Author: Miroslav Chomat
Publisher: BoD – Books on Demand
ISBN: 9533075481
Category : Technology & Engineering
Languages : en
Pages : 278
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Book Description
The subject of this book is an important and diverse field of electric machines and drives. The twelve chapters of the book written by renowned authors, both academics and practitioners, cover a large part of the field of electric machines and drives. Various types of electric machines, including three-phase and single-phase induction machines or doubly fed machines, are addressed. Most of the chapters focus on modern control methods of induction-machine drives, such as vector and direct torque control. Among others, the book addresses sensorless control techniques, modulation strategies, parameter identification, artificial intelligence, operation under harsh or failure conditions, and modelling of electric or magnetic quantities in electric machines. Several chapters give an insight into the problem of minimizing losses in electric machines and increasing the overall energy efficiency of electric drives.
Author: Agnes Buka
Publisher: World Scientific
ISBN: 1848167997
Category : Science
Languages : en
Pages : 299
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Book Description
The book intends to give a state-of-the-art overview of flexoelectricity, a linear physical coupling between mechanical (orientational) deformations and electric polarization, which is specific to systems with orientational order, such as liquid crystals. Chapters written by experts in the field shed light on theoretical as well as experimental aspects of research carried out since the discovery of flexoelectricity. Besides a common macroscopic (continuum) description the microscopic theory of flexoelectricity is also addressed. Electro-optic effects due to or modified by flexoelectricity as well as various (direct and indirect) measurement methods are discussed. Special emphasis is given to the role of flexoelectricity in pattern-forming instabilities. While the main focus of the book lies in flexoelectricity in nematic liquid crystals, peculiarities of other mesophases (bent-core systems, cholesterics, and smectics) are also reviewed. Flexoelectricity has relevance to biological (living) systems and can also offer possibilities for technical applications. The basics of these two interdisciplinary fields are also summarized.
Author: William John Palm
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 728
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Book Description
Model, analyze, and solve vibration problems, using modern computer tools. Featuring clear explanations, worked examples, applications, and modern computer tools, William Palm's Mechanical Vibration provides a firm foundation in vibratory systems. You'll learn how to apply knowledge of mathematics and science to model and analyze systems ranging from a single degree of freedom to complex systems with two and more degrees of freedom. Separate MATLAB sections at the end of most chapters show how to use the most recent features of this standard engineering tool, in the context of solving vibration problems. The text introduces Simulink where solutions may be difficult to program in MATLAB, such as modeling Coulomb friction effects and simulating systems that contain non-linearities. Ample problems throughout the text provide opportunities to practice identifying, formulating, and solving vibration problems. KEY FEATURES Strong pedagogical approach, including chapter objectives and summaries Extensive worked examples illustrating applications Numerous realistic homework problems Up-to-date MATLAB coverage The first vibration textbook to cover Simulink Self-contained introduction to MATLAB in Appendix A Special section dealing with active vibration control in sports equipment Special sections devoted to obtaining parameter values from experimental data
