Lab Ampere

Located at 50°30' S, Madre de Dios archipelago is an outstanding natural and archeological heritage, which Chile designated a protected area in January 2008. Together with Diego de Almagro Island (51°30'S), this is the most southerly and inhospitable karst on Earth, owing to a subpolar climate with extreme rainfall (>7-8 meters/year) and strong winds ("roaring fifties"). The Upper Carboniferous and Lower Permian Tarlton Limestones (500 m thick) form part of the pre-Jurassic basement of the Andean Cordillera, the former Pacific margin of Gondwana. Along the fjords and Pacific front, cliff-side exploration with rubber dinghies has revealed three exceptional caves with: 1) archeological artifacts (Pacific Cave); 2) glacial sediments (Moraine Cave); 3) stepped beaches and whale bones (Whale Cave).

Located at 50°30' S, Madre de Dios archipelago is an outstanding natural and archeological heritage, which Chile designated a protected area in January 2008. Together with Diego de Almagro Island (51°30'S), this is the most southerly and inhospitable karst on Earth, owing to a subpolar climate with extreme rainfall (>7-8 meters/year) and strong winds ("roaring fifties"). The Upper Carboniferous and Lower Permian Tarlton Limestones (500 m thick) form part of the pre-Jurassic basement of the Andean Cordillera, the former Pacific margin of Gondwana. Along the fjords and Pacific front, cliff-side exploration with rubber dinghies has revealed three exceptional caves with: 1) archeological artifacts (Pacific Cave); 2) glacial sediments (Moraine Cave); 3) stepped beaches and whale bones (Whale Cave).

The simulation of electromagnetic devices remains an essential research tool for optimization. Nowadays, the miniaturization of devices leads to increase the supply frequency, in this case the material is hardly sollicitated. An accurate description of dynamical material law must be introduced in the magnetic circuit representation. Our team has already created a dynamic behavioural magnetic model which lumps together all dynamic effects developped in the circuit. The main assumption of this model is to consider that all magnitudes are homogeneous in the cross section. The aim of this paper is to analyse this assumption and to define a validity domain and rules of use.

The aim of this study consists in modelling the magnetic behaviour of a nanocrystalline material taking into account temperature variation. Indeed the development of power electronic embedded systems leads to increase the operating temperature range. Besides nanocrystalline material is more and more used in such systems, so temperature influence is a key point in the inductance design.

A technique based on feed forward neural networks (FFNN) for modeling rate-independent scalar magnetic hysteresis is presented in this paper. The neural network discussed here is inspired by several papers presented in the literature. The training set is obtained by a Jiles-Atherton model, just to verify the feasibility of the method and to prevent from measurements difficulties. We choose a FFNN model and in order to improve its accuracy and its ability to generalize, we make a little modification that can avoid some problems. Finally, a modification of the last model by adding the last but one extreme values as inputs of the FFNN is discussed.

Cet article a pour but de présenter une synthèse des études des dernières années faites autour de la caractérisation et de la modélisation des matériaux et composants magnétiques sous contrainte thermique. Les études présentées sont notamment, mais pas exclusivement, issues des travaux du laboratoire AMPERE et plus particulièrement de l'équipe « matériaux pour le génie électrique ».

La conception de disjoncteurs différentiels est une tâche délicate pour laquelle de nombreuses précautions doivent être prises car ils assurent la protection des personnes. La conception de nouveaux prototypes passe par l'étape préalable et indispensable de leur modélisation. Celle-ci doit avoir un domaine de validité large et prendre en compte des phénomènes complexes (hystérésis, courants induits,. . . ). Dans cet article, nous analysons plus particulièrement le capteur de courant, organe essentiel dans la transmission du signal de défaut. Le modèle robuste et temporel utilisé est testé avec différentes sollicitations spécifiques stipulées dans le cahier des charges du disjoncteur.

ABSTRACT: SEDIMENTARY DYNAMICS AND SITE EFFECTS IN FLOODED KARSTIC ENVIRONMENT: THE EXAMPLE OF CHEVALINE SUMP. Downstream of the karst system of Coufin-Chevaline, part of Choranche Caves, the Chevaline sump is a flooded zone forming a sediment trap upstream of the lake of the Cathedral. To study the sediment dynamics and potential site effects of the phreatic endokarstic area, a 234m long allery was investigated by cave diving. For the first time, a precise geomorphological and sedimentological mapping has been achieved; sediments and speleothems have also been collected. This flooded part of the network has been equipped with “luirographe” sensors and a flow measurement monitoring system. A sedimentological study, combining mapping analysis, particle sizing, mineralogical and chemical analyse major elements and radiogenic isotopes) has been conducted to characterize the underground sedimentation in this area. With a very sharp seasonality, alternating between floods and low water p...

The ability to measure, monitor and control energy consumption at several key locations in a manufacturing plant is a major prerequisite for any efficient energy management program. To identify and evaluate energy savings, one must get a clear view of how the energy is used. Furthermore, measuring energy flows is one of the necessary conditions for long lasting energyefficient solutions. Most of the time energy managers are reluctant to put in place power and flow rate measuring devices either because of their cost or because this implies stopping production. To find acceptable and economical solutions for long lasting energy measurements in Industry, EDF R&D launched a 3-year collaborative research project called CHIC. This project is funded by the French National Research Agency (ANR) and involves 7 partners. Its total budget amounts to 2.55 M€. This project serves two purposes: to build a clamp-on power meter that could be installed around multi-conductors power cables without interrupting power supply, and to build power and flow meters that derive the sought-for variable from mathematical models and from simple and easy to collect other physical measurements (e.g. command signals, etc1).