Projet DIAPASON 2

National audienceProjet DIAPASON

Encyclopedia of Electrical and Electronic Power Engineering

International audienceFuel Cell cars are a strategic part of research and development in the automotive industry, due to their high environmental compatibility and their high efficiency. Proton Exchange Membranes (PEM) are the most promising fuel cell technologies for transportation applications. PEM Fuel Cells are widely used for other applications either in industry or residential. Independently of the problems of integration and cost, the use of PEM Fuel Cell (PEMFC) in a vehicle requires to fully control its behavior and also all its ancillaries. Indeed, the power efficiency of the PEMFC system does not only depend on the stack but also on the response of the ancillaries that are located around the stack. In order to run the fuel cell in good conditions and to increase the lifetime of the fuel cell system, the whole control has to be carefully operated. In this article, a fuel cell system is described with its local and global controls. Diagnosis methods for fuel cell system are also presented

Supervised classification approach dedicated to proton exchange membrane fuel cell diagnostic

International audienceThis paper deals with a supervised classification approach dedicated to diagnose a PEMFC system. The purpose is to detect and isolate a fault occurring on a fuel cell system based on electrochemical impedance measurements.The air compressor failure, fuel poisoning and stack overheating are the faults considered in this study. Someexperimental tests are performed on two similar stacks (only the power changes). The k-nearest neighbors is the supervised classification method that is used as it is well known for its efficiency and simplicity of implementation

Accelerated stress tests for proton exchange membrane fuel cells: A state-of-art

International audienceTwo major issues are still to be solved in research on fuel cell systems: reducing the costs and increasing the durability. To do this, three main topics have to be addressed: material & design, assembly, and optimization of the stack’s operation inside a system. In order to improve the lifetime and the durability of fuel cell systems, some long and expensive ageing tests are performed to study the behavior of the fuel cell with the aim of making it resistant to permanent change over time. In that case, the accelerated stress tests are a key solution to ageing testing with reasonable time and testing costs. A state-of-the-art of the accelerated stress tests dedicated to PEMFC is proposed in this paper

A review of accelerated stress tests dedicated to proton exchange membrane fuel cells – Part I: Fuel cell component level

International audience<div id="abssec0010"&gt<p id="abspara0010"&gtVarious research are currently done about fuelcells. They can concern the application context, the <a href="https://www.sciencedirect.com/topics/engineering/fuel-cell-technology"title="Learn more about fuel cell technology from ScienceDirect's AI-generated Topic Pages"class="topic-link"&gtfuel cell technology</a&gt by itself or thesocio-economic bolts. This paper deals with <a href="https://www.sciencedirect.com/topics/engineering/fuel-cell-stack"title="Learn more about fuel cells stack from ScienceDirect's AI-generated Topic Pages"class="topic-link"&gtfuel cells stack</a&gt testing and especially theaccelerated stress testing. Long and expensive ageing tests areperformed to study the behavior of the fuel cell with the aim ofmaking it as robust as possible versus permanent degradation overtime. Accelerated stress tests should provide results faster asclassical ageing tests, thus inducing cost reduction. This paperreviews <a href="https://www.sciencedirect.com/topics/engineering/fuel-cell-component"title="Learn more about fuel cell component from ScienceDirect's AI-generated Topic Pages"class="topic-link"&gtfuel cell component</a&gt degradation, including<a href="https://www.sciencedirect.com/topics/engineering/degradation-mechanism"title="Learn more about degradation mechanisms from ScienceDirect's AI-generated Topic Pages"class="topic-link"&gtdegradation mechanisms</a&gt, and the acceleratedstress tests dedicated to all the constituting components (catalystlayer, membrane, gas diffusion layer and bipolar plates).Obviously, the harmonized accelerated stress tests given by theDepartment of Energy (DoE) are presented but all other recentaccelerated test protocols proposed in the literature are alsoreviewed. In addition, several tables are given to detail operatingconditions, specimen, characterization planning and a <a href="https://www.sciencedirect.com/topics/engineering/degradation-rate"title="Learn more about degradation rate from ScienceDirect's AI-generated Topic Pages"class="topic-link"&gtdegradation rate</a&gt that will be relevant andhelpful to converge with an optimal AST solution.</p&gt</div&g

LT-PEMFC remaining useful life prediction for predictive maintenance

International audienceThe Low-Temperature Proton Exchange Membrane Fuel Cell (LT-PEMFC) is one of the most promising systems for decarbonizing key sectors such as the automotive or marine industries. To make this type of system competitive in terms of performance and cost, the discipline of Prognostic and Health Management (PHM) has been applied to LT-PEMFC. This innovative approach makes it possible to optimize maintenance (moving from preventive to predictive maintenance), forecast health status and ultimately extend system lifetime, thanks to sophisticated algorithms enabling real-time monitoring. In ref [1], an ESN was chosen to predict the degradation of a LT-PEMFC over time. The authors report very good results, outperforming particle filtering (PF) in terms of accuracy and computation time. In ref [2], an ESN was also used to predict the voltage degradation of an LT-PEMFC cell. Again, prediction results were good, however, measuring cell voltages is not always accessible in a commercial system. In order to be compatible with a commercial system, in this paper, the voltage of the PEMFC stack will be used as an indicator of Remaining Useful Life (RUL). A data-driven method will be developed on an open source dataset from our lab [3]. This dataset is based on 500W LT-PEMFC, operating under nominal load with current ripples of +-5%, for a total duration of 1,055h. The data-driven approach was used to predict the RUL of an LT-PEMFC, using an Echo State Network (ESN) and a Long-Short Term Memory (LSTM). The aim is to predict the RUL at least 100h in advance to carry out the maintenance intervention before the LT-PEMFC can no longer perform its mission

Etude expérimentale des capacités de démarrage à froid d'une pile à combustible PEM à cathode fermée de 2 KW

International audienceUne pile à combustible produit de l’eau lors de son fonctionnement, dans des conditions de températures négatives cette dernière peut gelée. Lors d’un démarrage à température négative l’objectif est alors d’élever rapidement la température de la pile à combustible au-dessus de 0°C avant que l’eau produite par la réaction ne gèle. Le démarrage à température négative des piles à combustible peut être divisé en deux catégories, les méthodes utilisant un système de réchauffement externe et les méthodes utilisant un réchauffement interne [1,2]. Dans ce papier une étude expérimentale utilisant une méthode de réchauffement interne pour évaluer les performances de démarrage à froid d’une PEMFC est présentée. Le spécimen de test est une pile à combustible à membrane échangeuse de protons (PEMFC). Dans un premier temps, l’impact de la circulation du fluide caloporteur est évalué durant un démarrage à froid. En effet, l’absence de circulation du liquide de refroidissement entraine une surchauffe des cellules et leur assèchement [3,4]. Ensuite, la capacité à démarrer à température négative d’une PEMFC avec une méthode de réchauffement interne est évaluée. La méthode utilisée est un contrôle potentiostatique de la charge électronique. Cette méthode permet de maximiser le courant en imposant un niveau de tension faible aux cellules et donc maximiser le dégagement de chaleur pour élever la température de la PEMFC. Préalablement au démarrage, une procédure d’arrêt spécifique doit être réalisée afin d’évacuer l’excès d’eau résiduel dans la pile à combustible afin d’évité quelle ne gèle lors de l’exposition à une température négative. Les performances de cette méthode sont évaluées selon plusieurs critères ; la durée de démarrage, l’énergie consommée et les dégradations irréversibles engendrées par cette méthode. L’impact des facteurs que sont, le niveau de tension et la température initiale au démarrage, est également évalué

Relative Wavelet Energy as a diagnosis tool for PEM Fuel Cells

International audienceThis paper deals with the relative wavelet energy as a diagnosis tool for PEMFC. The reliability and the durability of the fuel cell system have to be improved and the diagnosis approach is a way to extend the PEMFC lifetime. A signal-based method is used to estimate the state of health of the system. The energetic distribution is given according to different experimental conditions. The energy contents of a voltage signal are selected and analyzed to define the PEMFC’s state of health. A clustering step is added to identify a fault. This study is based on a high air stoichiometry fault

Influence des conditions d’usage et environnementale sur un système pile à combustible dédié aux applications de transport

International audience<div style=""&gt<font face="arial, helvetica"&gt<span style="font-size: 13px;"&gtCet article présente l’influence des contraintes&nbsp;</span&gt</font&gt<span style="font-size: 13px; font-family: arial, helvetica;"&gtd’applications de transport sur un système pile à combustible de&nbsp;</span&gt<span style="font-size: 13px; font-family: arial, helvetica;"&gttype PEM (Proton Exchange Membrane). L’objectif de ces&nbsp;</span&gt<span style="font-size: 13px; font-family: arial, helvetica;"&gttravaux est de comprendre les différentes dégradations propres à&nbsp;</span&gt<span style="font-size: 13px; font-family: arial, helvetica;"&gtun système pile à combustible embarqué dans un véhicule. Un&nbsp;</span&gt<span style="font-size: 13px; font-family: arial, helvetica;"&gtaccent particulier est mis sur les cycles de démarrage/arrêt à&nbsp;</span&gt<span style="font-size: 13px; font-family: arial, helvetica;"&gttempérature négative, qui restent l’un des verrous technologiques&nbsp;</span&gt<span style="font-size: 13px; font-family: arial, helvetica;"&gtpour la production et la commercialisation de masse de cette&nbsp;</span&gt<span style="font-size: 13px; font-family: arial, helvetica;"&gttechnologie. Les démarrages à froid ont en effet une grande</span&gt</div&gt<div style=""&gt<font face="arial, helvetica"&gt<span style="font-size: 13px;"&gtinfluence sur la durée de vie des PEMFCs (Proton Exchange&nbsp;</span&gt</font&gt<span style="font-size: 13px; font-family: arial, helvetica;"&gtMembrane Fuel Cell). Les principales méthodes de démarrage à&nbsp;</span&gt<span style="font-size: 13px; font-family: arial, helvetica;"&gtfroid sont présentées dans cet article. Une discussion autour des&nbsp;</span&gt<span style="font-size: 13px; font-family: arial, helvetica;"&gtdifférentes stratégies est ici présentée en termes de performances&nbsp;</span&gt<span style="font-size: 13px; font-family: arial, helvetica;"&gtet de consommation énergétique.</span&gt</div&g

From non-model based diagnostic to fault tolerant control dedicated to proton exchange membrane fuel cell system

International audienceProton Exchange Membrane Fuel Cell (PEMFC) is widely studied as the hydrogen fuel used to generate electricity should be an alternative solution to fossil fuels [1]. Moreover, the technology is dedicated to transport as well as to stationary applications [2]. Unfortunately, a large-scale deployment stays limited due to the restricted lifetime and reliability of the PEMFC system [3]. Therefore, ensuring nominal operating conditions for PEMFC system during operation is necessary to guarantee a better efficiency, reliability and a longer lifetime. Diagnostic approaches are developed to reach nominal operating conditions by detecting and isolating failures [4]. Different kind of faults could appear when a fuel cell system operates [5]. The aim is to perform long-term tests in laboratory and to design diagnostic algorithms able to detect a failure as soon as possible to avoid irreversible degradation. Non-model based diagnosis methods are well adapted when large amount of data collected during multiple experimental tests are available. This paper presents a non-model based approach for diagnosis of PEMFC system based wavelet analysis [6]. The results are validated on in-lab tests and prove that the method is able to diagnose different faults in a fuel cell system. The philosophy of this paper is to extend the study to a fault tolerant control approach; i. e. after fault occurrence, act on relevant parameters of the system, in order to recover performance and bring the system as close as possible near the nominal operation condition, or to shut down the system and schedule a maintenance operation [7-8]