Pilotage de la production décentralisée et des charges non conventionnelles dans le contexte Smart Grid et simulation hybride temps réel

In the electricity distribution network field, because of the electricity market opening and the large-scale insertion of dispersed generators (DJ) in these last years, the network undergoes radical modification in both operation and exploitation. In this context, some new integration solutions are invented in order to be able to connect the DJ, as photo-voltaic panels, micro wind turbines, cogeneration units, etc, and the new loads, as electric vehicles and smart home, without reduce the voltage wave quality or involve a very expensive power systems reinforcement. The objectives of those solutions are to influence the consumer consumption in order to reduce the peak consumption level and shift the consumption on the high renewable production period, and control the DJ output to participate to the service system. The new information and communication technologies (NICT) are strongly used in the development of those control strategies. This PhD work is including in the French project GreenLys supported by the French environment and energy management agency. GreenLys is a 4 years project focus on the development of a real scale Smart Grid in the two French cities Lyon and Grenoble. As a first step, this work evaluating the impact of the DJ and the electric vehicle on the distribution network. From the result of this impact study, two types of decentralized control strategies are investigated. The first one is focus on the phase connection. Since the majority of consumers and DJ connected on the distribution grid are single phases, methods allowing to choose the best phase connection are study. The second one is focus on new DJ reactive power control strategies. In the last part, the strategies are evaluated on a Power Hardware In the Loop simulation and real solar inverter.Dans le domaine des réseaux de distribution d'électricité, l'ouverture du marché de l'énergie à la concurrence et l'insertion massive des génératrices décentralisées d'énergie de ces dernières années conduisent à une profonde modification du fonctionnement et de l'exploitation des réseaux. Dans ce contexte, des solutions de pilotage de la consommation et de la production doivent être apportées, afin de permettre au réseau actuel d'accueillir les nouvelles unités de production et les charges de demain, telles que les panneaux photovoltaïques, les micro-éoliennes, la cogénération, les véhicules électriques, les maisons intelligentes, etc. Ces pilotages permettent d'influencer la consommation et la production instantanées des utilisateurs du réseau. Ainsi, il devient possible d'agir sur la consommation de façon à lisser les pics ou synchroniser la demande aux périodes de forte production des énergies renouvelables. De la même façon, la production peut être pilotée pour participer aux services systèmes. Ces stratégies de pilotage, basées sur l'utilisation des nouvelles technologies de l'information et de la communication, ont pour objectifs d'éviter une dégradation de la qualité de l'onde de tension et une reconstruction complète du réseau de distribution, qui serait économiquement très couteuse. Ces travaux, intégrés au projet GreenLys, financé par l'agence française de l'environnement et de la maitrise de l'énergie, évaluent l'impact des génératrices décentralisées d'énergie et des véhicules électriques sur le réseau de distribution, puis développent des solutions de pilotage. Deux types de pilotage sont étudiés : le pilotage de la phase de raccordement d'une installation monophasée, puis le pilotage de la puissance réactive des génératrices décentralisées d'énergie. Ces pilotages sont développés en s'appuyant sur les nouveaux composants des réseaux électriques de demain, comme les compteurs intelligents. Dans une dernière partie, les stratégies de pilotage développées sont évaluées sur des équipements réels à partir d'une plateforme de simulation hybride temps réel

Approche écologique, épidémiologique et génétique de la biodiversité de Toxoplasma gondii en zone tropicale humide : exemples du Gabon et de la Guyane Française

Toxoplasmosis is a zoonosis due to the protozoan Toxoplasma gondii, widely distributed around the world. Some characteristics of the tropical humid zone may favor its circulation, yet very few studies on this parasite in the tropical area are available.We conducted two field studies to clarify the circulation and diversity of Toxoplasma in this humid tropical environment: (i) in Gabon, in urban and rural environments, with different approaches such as the seroprevalence of toxoplasmosis in human and animal analyzed with GIS and multivariate analysis, but also the study of genetic diversity and population structure of Toxoplasma and (ii) in French Guiana with the characterization and genetic comparison of strains circulating in both the "wild" and the "domestic" cycle of Toxoplasma. The population structure analysis was performed using tree distance (Neighbor -joining), the study of Fst and linkage disequilibrium, Bayesian statistical model (STRUCTURE), and multivariate methods (DAPC) incorporating spatial information (sPCA).In Gabon, animal and human seroprevalence was high in an urban as well as in a rural environment, with a predominant telluric risk in relation to the level of hygiene and climatic conditions. The 69 isolates have been characterized genetically and phenotypically through virulence in mice at isolation. Besides the Type III found all over the world, two major haplogroups were defined and proposed as new major haplogroups for T. gondii in Africa. A link with the strains circulating in Central and South America has been highlighted. The analysis of population structure showed increased circulation of the parasite between the main Gabonese cities in relation to human activities.In French Guiana, the 33 isolates obtained mainly from peridomestic animals were compared to 18 previously published strains, mainly from the wild environment. The wild population was far more diverse. In addition to a spatial and genetic structuring in two populations reflecting the two environmental populations, "anthropized" and "wild", a genetic substructure was found, associated to distinct phenotypic traits (virulence in mice) for some groups. These results also suggested the existence of interpenetration between wild and domestic cycles with potential risks for human health.La toxoplasmose est une zoonose due au protozoaire Toxoplasma gondii largement réparti dans le monde. La zone tropicale humide présente des caractéristiques propices à sa circulation, pourtant elle reste peu étudiée vis-à-vis de ce parasite.Nous avons réalisé deux études de terrain afin de préciser la circulation et la diversité du toxoplasme dans cet environnement tropical humide : (i) au Gabon en milieu urbain et rural, avec différentes approches telles que la séroprévalence de la toxoplasmose humaine et animale analysée à l'aide des SIG et d'analyse multivariée, mais aussi l'étude de la diversité génétique et de la structure des populations du toxoplasme et (ii) en Guyane Française avec la caractérisation et la comparaison génétique des souches circulant dans le cycle « sauvage » et le cycle « domestique » du toxoplasme. Dans ces deux études l'analyse de la structure des populations a été réalisée à l'aide d'arbres de distance (Neighbor-joining), de l'étude des FST et du déséquilibre de liaison, de modèle statistique Bayésien (STRUCTURE) et de méthodes multivariées (DAPC) intégrant pour certaines des informations spatiales (sPCA).Au Gabon, la séroprévalence animale et humaine retrouvée est élevée en milieu urbain et rural, avec un risque tellurique prépondérant en relation avec le niveau d'hygiène et les conditions climatiques. Les 69 isolats obtenus ont été caractérisés génétiquement et phénotypiquement au travers de la virulence chez la souris à l'isolement. Outre le Type III que l'on retrouve partout dans le monde, deux principaux haplogroupes ont été caractérisés et proposés comme nouveaux haplogroupes d'importance pour T. gondii en Afrique. Un lien avec les souches circulant en Amérique Centrale et du Sud a été mis en évidence. L'analyse de la structure de la population montre une circulation accrue du parasite entre les principales villes du pays en relation avec les activités humaines.En Guyane Française, les 33 nouveaux isolats obtenus principalement de la faune péri domestique ont été comparés à 18 souches déjà publiées provenant essentiellement de l'environnement sauvage. La population sauvage était la plus diversifiée. En plus d'une structuration spatiale et génétique en deux populations reflétant les deux populations environnementales, « anthropisée » et « sauvage », une sous structuration génétique a été trouvée, confirmée pour certains groupes par des traits phénotypiques distincts (virulence chez la souris). Ces résultats suggèrent aussi l'existence d‟interpénétration entre les cycles sauvage et domestique avec des risques potentiels pour la santé humaine

Pilotage de la production décentralisée et des charges non conventionnelles dans le contexte Smart Grid et simulation hybride temps réel

In the electricity distribution network field, because of the electricity market opening and the large-scale insertion of dispersed generators (DJ) in these last years, the network undergoes radical modification in both operation and exploitation. In this context, some new integration solutions are invented in order to be able to connect the DJ, as photo-voltaic panels, micro wind turbines, cogeneration units, etc, and the new loads, as electric vehicles and smart home, without reduce the voltage wave quality or involve a very expensive power systems reinforcement. The objectives of those solutions are to influence the consumer consumption in order to reduce the peak consumption level and shift the consumption on the high renewable production period, and control the DJ output to participate to the service system. The new information and communication technologies (NICT) are strongly used in the development of those control strategies. This PhD work is including in the French project GreenLys supported by the French environment and energy management agency. GreenLys is a 4 years project focus on the development of a real scale Smart Grid in the two French cities Lyon and Grenoble. As a first step, this work evaluating the impact of the DJ and the electric vehicle on the distribution network. From the result of this impact study, two types of decentralized control strategies are investigated. The first one is focus on the phase connection. Since the majority of consumers and DJ connected on the distribution grid are single phases, methods allowing to choose the best phase connection are study. The second one is focus on new DJ reactive power control strategies. In the last part, the strategies are evaluated on a Power Hardware In the Loop simulation and real solar inverter.Dans le domaine des réseaux de distribution d'électricité, l'ouverture du marché de l'énergie à la concurrence et l'insertion massive des génératrices décentralisées d'énergie de ces dernières années conduisent à une profonde modification du fonctionnement et de l'exploitation des réseaux. Dans ce contexte, des solutions de pilotage de la consommation et de la production doivent être apportées, afin de permettre au réseau actuel d'accueillir les nouvelles unités de production et les charges de demain, telles que les panneaux photovoltaïques, les micro-éoliennes, la cogénération, les véhicules électriques, les maisons intelligentes, etc. Ces pilotages permettent d'influencer la consommation et la production instantanées des utilisateurs du réseau. Ainsi, il devient possible d'agir sur la consommation de façon à lisser les pics ou synchroniser la demande aux périodes de forte production des énergies renouvelables. De la même façon, la production peut être pilotée pour participer aux services systèmes. Ces stratégies de pilotage, basées sur l'utilisation des nouvelles technologies de l'information et de la communication, ont pour objectifs d'éviter une dégradation de la qualité de l'onde de tension et une reconstruction complète du réseau de distribution, qui serait économiquement très couteuse. Ces travaux, intégrés au projet GreenLys, financé par l'agence française de l'environnement et de la maitrise de l'énergie, évaluent l'impact des génératrices décentralisées d'énergie et des véhicules électriques sur le réseau de distribution, puis développent des solutions de pilotage. Deux types de pilotage sont étudiés : le pilotage de la phase de raccordement d'une installation monophasée, puis le pilotage de la puissance réactive des génératrices décentralisées d'énergie. Ces pilotages sont développés en s'appuyant sur les nouveaux composants des réseaux électriques de demain, comme les compteurs intelligents. Dans une dernière partie, les stratégies de pilotage développées sont évaluées sur des équipements réels à partir d'une plateforme de simulation hybride temps réel

Apprentissage de Dictionnaires Multivariés et Décomposition Parcimonieuse Invariante par Translation et par Rotation 2D

National audienceThis article presents a new tool, Multivariate Dictionary Learning Algorithm, able to learn online the elementary structures associated to a multivariate signals set. Once learned, Multivariate Orthogonal Matching Pursuit codes sparsely all signals of this set. These methods are specified to the 2D rotation-invariant case which induces a small-sized kernels dictionary. Our methods are applied to 2D handwritten data to extract the characteristic patterns of this signals set.Cet article présente le Multivariate Dictionary Learning Algorithm qui apprend en ligne les structures élémentaires associées à un ensemble de signaux multivariés. Une fois apprises, le Multivariate Orthogonal Matching Pursuit décompose tous les signaux de cet ensemble avec parcimonie. Ces méthodes sont spécifiées dans le cas d'invariance par rotation qui produit un dictionnaire restreint de noyaux. Nos méthodes sont appliquées à des données d'écriture manuscrite, afin d'extraire les motifs caractéristiques de cette base de signaux

Shift & 2D Rotation Invariant Sparse Coding for Multivariate Signals

International audienceClassical dictionary learning algorithms (DLA) allow unicomponent signals to be processed. Due to our interest in two-dimensional (2D) motion signals, we wanted to mix the two components to provide rotation invariance. So, multicomponent frameworks are examined here. In contrast to the well-known multichannel framework, a multivariate framework is first introduced as a tool to easily solve our problem and to preserve the data structure. Within this multivariate framework, we then present sparse coding methods: multivariate orthogonal matching pursuit (M-OMP), which provides sparse approximation for multivariate signals, and multivariate DLA (M-DLA), which empirically learns the characteristic patterns (or features) that are associated to a multivariate signals set, and combines shift-invariance and online learning. Once the multivariate dictionary is learned, any signal of this considered set can be approximated sparsely. This multivariate framework is introduced to simply present the 2D rotation invariant (2DRI) case. By studying 2D motions that are acquired in bivariate real signals, we want the decompositions to be independent of the orientation of the movement execution in the 2D space. The methods are thus specified for the 2DRI case to be robust to any rotation: 2DRI-OMP and 2DRI-DLA. Shift and rotation invariant cases induce a compact learned dictionary and provide robust decomposition. As validation, our methods are applied to 2D handwritten data to extract the elementary features of this signals set, and to provide rotation invariant decomposition

Deviation from the normal mode expansion in a coupled graphene-nanomechanical system

We optomechanically measure the vibrations of a nanomechanical system made of a graphene membrane suspended on a silicon nitride nanoresonator. When probing the thermal noise of the coupled nanomechanical device, we observe a significant deviation from the normal mode expansion. It originates from the heterogeneous character of mechanical dissipation over the spatial extension of coupled eigenmodes, which violates one of the fundamental prerequisite for employing this commonly used description of the nanoresonators' thermal noise. We subsequently measure the local mechanical susceptibility and demonstrate that the fluctuation-dissipation theorem still holds and permits a proper evaluation of the thermal noise of the nanomechanical system. Since it naturally becomes delicate to ensure a good spatial homogeneity at the nanoscale, this approach is fundamental to correctly describe the thermal noise of nanomechanical systems which ultimately impact their sensing capacity

Nano-optomechanical measurement in the photon counting regime

Optically measuring in the photon counting regime is a recurrent challenge in modern physics and a guarantee to develop weakly invasive probes. Here we investigate this idea on a hybrid nano-optomechanical system composed of a nanowire hybridized to a single Nitrogen-Vacancy (NV) defect. The vibrations of the nanoresonator grant a spatial degree of freedom to the quantum emitter and the photon emission event can now vary in space and time. We investigate how the nanomotion is encoded on the detected photon statistics and explore their spatio-temporal correlation properties. This allows a quantitative measurement of the vibrations of the nanomechanical oscillator at unprecedentedly low light intensities in the photon counting regime when less than one photon is detected per oscillation period, where standard detectors are dark-noise-limited. These results have implications for probing weakly interacting nanoresonators, for low temperature experiments and for investigating single moving markers

Safe Discharge Home With Telemedicine of Patients Requiring Nasal Oxygen Therapy After COVID-19

Introduction: The COVID-19 pandemic created challenges to healthcare systems worldwide. To allow overwhelmed hospitals to focus on the most fragile and severely ill patients, new types of management had to be set up. During the pandemic, patients with COVID-19 from greater Paris area were monitored at home using a web-based remote system called COVIDOM™, using self-administered questionnaires, which triggered alerts to a regional control center. To ease hospital discharge and to prevent hospital from being overwhelmed, patients still requiring low-flow oxygen therapy discharged home were also included in this telemedicine solution. We aim to evaluate the safety of this original management. Methods: We conducted a retrospective multicenter cohort of patients discharged home from hospital after COVID-19 and still requiring nasal oxygen therapy, who were monitored by questionnaire and trained physicians using COVIDOM. During late follow-up, the status of the patients using a Euro-Qol (EQ-5D-5L) questionnaire, and the Medical Research Council (MRC) Dyspnea scale was collected. Results: From March 21st to June 21st 2020, 73 COVID-19 patients still receiving nasal oxygen at hospital discharge were included. Median [Inter-Quartile Range (IQR)] age was 62.0 [52.5–69.0] years, 64.4% were male. Altogether, risk factors were observed in 49/73 (67%) patients, mainly hypertension (35.6%), diabetes mellitus (15.1%) and active neoplasia (11.0%). Among the cohort, 26% of patients were previously managed in ICU. Oxygen therapy was required for a median [IQR] of 20 [16–31] days. No death or urgent unplanned hospitalization were observed during the COVIDOM telemonitoring. During the late follow-up evaluation (6 months after inclusion), the mean EQ-5D-5L questionnaire score was 7.0 ± 1.6, and the mean MRC dyspnea scale was 0.8 ± 1.0, indicating absence of dyspnea. Five patients have died from non-COVID causes. Conclusions: In this preliminary study, early discharge home of patients with severe COVID-19 disease who still required low-oxygen therapy seems to be safe

The Life Cycle of Toxoplasma gondii in the Natural Environment

Chapitre 1International audienc

Development of Temperature-Controlled Shear Tests to Reproduce White-Etching-Layer Formation in Pearlitic Rail Steel

The formation of a white etching layer (WEL), a very hard and brittle phase on the rail surface, is associated with a progressive transformation of the pearlitic grain to very fragmented grains due to the cumulative passage of trains. Its formation is associated with a complex thermomechanical coupling. To predict the exact conditions of WEL formation, a thermomechanical model previously proposed by the authors needs to be validated. In this study, monotonic and cyclic shear tests using hat-shaped specimens were conducted in the temperature range of 20 C to 400 C to reproduce the WEL formation. The tests showed a strong sensitivity of the material to temperature, which does not necessarily favor WEL formation. For the monotonic tests, no WELs were produced; however, a localization of the plastic deformation was observed for tests performed at 200 C and 300 C. In this temperature range, the material was less ductile than at room temperature, leading to failure before WEL formation. At 400 C, the material exhibited a much more ductile behavior, and nanograins close to WEL stages were visible. For the cyclic tests, a WEL zone was successfully reproduced at room temperature only and confirmed the effect of shear in WEL formation. The same cyclic tests conducted at 200 C and 300 C yielded results consistent with those of the monotonic tests; the deformation was much more localized and did not lead to WEL formation.This work is part of the multi-disciplinary project MOPHAB, which aims to improve our knowledge and understanding of the mechanisms leading to the formation of the white etching layer in the materials used to construct railways and to develop corresponding numerical models. This project was supported by IRT Railenium and other industrial partners (RATP: Régie Autonome des Transports Parisiens, France, SNCF: Société Nationale des Chemins de Fer Francais, France, SAARSTAHL rail)