Condition suffisante pour la stabilisation globale des systèmes en cascade

Dans ce papier, nous proposons une condition sous laquelle un système non linéaire peut être rendu globalement asymptotiquement stable par un feedback régulier. Puis, nous montrons que notre résultat permet d'améliorer le concept des systèmes à phase minimale faible de degré relatif égal à 1 développé récemment, et de généraliser la condition de stabilisation des systèmes obtenus par une cascade d'un système linéaire contrôlable et un système non linéaire général

Robust stabilization of thermal behavior for PEM Fuel Cell

International audienceIn this study, the control of thermal behavior for Proton Exchange Membrane Fuel Cells (PEMFC) is investigated. A description of the thermal behavior for PEMFC is given thanks to a nonhomogenous bilinear state space representation. In order to perform a local stabilization of the thermal behavior in a convex polytope of parameters, a linear approximation is proposed. Linear Matrix Inequality based results are provided to guarantee that a state-feedback controller ensures local closed loop stability of the temperature behavior whatever the uncertain or known parametric effects in some given set

The PV Corrosion Fault Prognosis Based on Ensemble Kalman Filter

International audienceThe degradation of photovoltaic (PV) modules remains a major concern on the control and the development of the photovoltaic field, particularly, in regions with difficult climatic conditions. The main degradation modes of the PV modules are corrosion, discoloration, glass breaks, and cracks of cells. However, corrosion and discoloration remain the predominant degradation modes that still require further investigations. In this paper, a model-based PV corrosion prognostic approach, based on an ensemble Kalman filter (EnKF), is introduced to identify the PV corrosion parameters and then estimate the remaining useful life (RUL). Simulations have been conducted using measured data set, and results are reported to show the efficiency of the proposed approach

Renewable Energy in Lebanon

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Comments on actuator fault accommodation

International audienceThe present work concerns the problem of progressive accommodation to actuator failure. An optimal nonlinear controller synthesis approach is formulated on the basis of the closed loop stability objective. The authors show the interest of the proposed method even for a local analysis when a linear approximation is used. This work focuses on a solution to ensure stability while accommodating to actuator failure. The approach is illustrated in an academic example

Data-driven diagnosis of PEM fuel cell: A comparative study

International audienceThis paper is dedicated to data-driven diagnosis for Polymer Electrolyte Membrane Fuel Cell (PEMFC). More precisely, it deals with water related faults (flooding and membrane drying) by using pattern classification methodologies. Firstly, a method based on physical considerations is defined to label the training data. Secondly, a feature extraction procedure is carried out to pick up the significant features from vectors constructed by individual cell voltages. Finally, a classification is adopted in the feature space to realize the fault diagnosis. Various feature extraction and classification methodologies are employed on a 20-cell PEMFC stack. The performances of these methodologies are compared

Sur la stabilisation globale de systèmes non linéaires par retour d'état régulier

This thesis contains some results on the global stabilization of nonlinear systems by smooth feedback.It is divided in for parts. The first one represents a recall of classical results on the stability and stabilization of non linear systems. The second one proposes a simple and general form of a result concerning the affine in controls sytems with dissipative drift (Jurdjevic-Quinn method). A series of theorical and pratical examples is studied. The third part presents a reduction principale for stabilization of systems : this result represents a generalization of the classical lemme of integrators. To illustrate the contribution of this method, some examples of the literature are studied. The goal of the last part is the study of the stabilization of angular velocity equations of a rigid bodyCette thèse regroupe certains résultats sur la stabilisation des systèmes non linéaires par retour d'état régulier. Elle se compose de quatre parties. La première partie représente un rappel des résultats classiques sur la stabilité et la stabilisation de systèmes non linéaires. La deuxième partie propose une forme simple et générale d'un résultat concernant les systèmes affinés en contrôles à dérivé dissipative (méthode de Jurdjevic-Quinn). Une série d'exemples théoriques et pratiques est traitée. La troisième partie présente un principe de réduction pour la stabilisation des systèmes non linéaires : le résultat représente une généralisation du lemme classique des intégrateurs. Pour illustrer l'apport de cette technique, plusieurs exemples de la littérature sont traités. La dernière partie est consacrée à l'étude de la stabilisation des équations de la vitesse angulaire d'un corps rigid

Stabilizing controllers for Diesel engine speed

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A reduction principle for global stabilization of nonlinear systems

summary:The goal of this paper is to propose new sufficient conditions for dynamic stabilization of nonlinear systems. More precisely, we present a reduction principle for the stabilization of systems that are obtained by adding integrators. This represents a generalization of the well-known lemma on integrators (see for instance [BYIS] or [Tsi1])