Dissertations / Theses on the topic 'Fuel cell diagnostics'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 36 dissertations / theses for your research on the topic 'Fuel cell diagnostics.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
Buche, Silvain. "Polymer electrolyte fuel cell diagnostics." Thesis, University of Bath, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.285318.
Full textHerrera, Omar Enrique. "New approaches to fuel cell diagnostics." Thesis, University of British Columbia, 2011. http://hdl.handle.net/2429/36969.
Full textValenzuela, Jorge Ignacio. "Electrochemical impedance spectroscopy options for proton exchange membrane fuel cell diagnostics." Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/266.
Full textMcGettrick, Andrew James. "Novel techniques for tunable diode laser spectroscopy and their application in solid oxide fuel cell diagnostics." Thesis, University of Strathclyde, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.441884.
Full textEsposito, Angelo. "Numerical and Experimental Study of Droplet-Air Flow Interaction on the GDL Surface of PEMFC for Water Management Monitoring, Control and Diagnostics." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1274977066.
Full textJha, Mayank Shekhar. "Diagnostic et Pronostic de Systèmes Dynamiques Incertains dans un contexte Bond Graph." Thesis, Ecole centrale de Lille, 2015. http://www.theses.fr/2015ECLI0027/document.
Full textThis thesis develops the approaches for diagnostics and prognostics of uncertain dynamic systems in Bond Graph (BG) modeling framework. Firstly, properties of Interval Arithmetic (IA) and BG in Linear Fractional Transformation, are integrated for representation of parametric and measurement uncertainties on an uncertain BG model. Robust fault detection methodology is developed by utilizing the rules of IA for the generation of adaptive interval valued thresholds over the nominal residuals. The method is validated in real time on an uncertain and highly complex steam generator system.Secondly, a novel hybrid prognostic methodology is developed using BG derived Analytical Redundancy Relationships and Particle Filtering algorithms. Estimations of the current state of health of a system parameter and the associated hidden parameters are achieved in probabilistic terms. Prediction of the Remaining Useful Life (RUL) of the system parameter is also achieved in probabilistic terms. The associated uncertainties arising out of noisy measurements, environmental conditions etc. are effectively managed to produce a reliable prediction of RUL with suitable confidence bounds. The method is validated in real time on an uncertain mechatronic system.Thirdly, the prognostic methodology is validated and implemented on the electrical electro-chemical subsystem of an industrial Proton Exchange Membrane Fuel Cell. A BG of the latter is utilized which is suited for diagnostics and prognostics. The hybrid prognostic methodology is validated, involving real degradation data sets
Engebretsen, Erik Charles. "Transfer function analysis as a novel diagnostic tool for polymer electrolyte membrane fuel cells." Thesis, University College London (University of London), 2017. http://discovery.ucl.ac.uk/10040348/.
Full textMason, T. J. "Advanced diagnostic techniques to study the electrochemical and mechanical properties of polymer electrolyte fuel cells." Thesis, University College London (University of London), 2013. http://discovery.ucl.ac.uk/1393123/.
Full textZhuo, Shengrong. "Control of interleaved DC-DC converter with switch fault consideration for fuel cell application." Thesis, Bourgogne Franche-Comté, 2020. http://www.theses.fr/2020UBFCA018.
Full textThe relatively low voltage and the nonlinear volt-ampere curve of the fuel cell (FC) stack necessitate the interface with the DC-DC power converter, in order to boost and regulate a constant DC bus voltage to satisfy the load requirement. The multi-phase interleaved converter by associating basic converter units via parallel structure is an attractive choice. It features high reliability, and it enables a low input current ripple via phase interleaving, which is beneficial for the long-time operation of the FC stack. The converter for FC application suffers from the converter uncertainties (parasitic resistance and inductance / capacitance tolerance), the external disturbances (dynamic load demand on the output side and variable source voltage on the input side), and the device fault (e.g., switch fault) uncertainty. Aiming to improve the steady-state and dynamic performance under healthy and switch fault mode of the system, the control of the interleaved converter with switch fault consideration for FC application is studied in this thesis.To better deal with the converter uncertainty and external disturbance, a robust voltage controller based on extended state observer (ESO) within the framework of active disturbance rejection control (ADRC) algorithm is proposed and applied to an interleaved boost converter for FC application. The comparison with PI control shows that the proposed method can achieve better disturbance rejection ability without overshoot in step response. The application of the proposed method to another interleaved converter (i.e., floating interleaved boost converter, FIBC) validates again its feasibility.The switch fault generally leads to the loss of the phase of the interleaved converter, which has considerable adverse effects on the controller performance. Therefore, an improved adaptive controller is proposed and applied to a FIBC with switch fault consideration, based on the previously developed controller. The proposed controller adapts the parameter in real-time. It can maintain continuous operation and achieve good performance in both healthy and switch fault mode. Furthermore, a switch fault diagnosis method based on sliding mode observer is proposed and applied to the FIBC for FC application. The proposed approach can diagnose the switch fault effectively, and it shows strong robustness to the converter uncertainties and external disturbances. Finally, to optimize the undesired high input current ripple of the FIBC caused by the switch fault, a novel post-fault control method by applying uneven phase shift reconfiguration is proposed. In comparison with the even phase shift reconfiguration, the proposed one can achieve significant improvement in reducing the post-fault current ripple. The effectiveness of the proposed methods is validated by the simulation and experimental results
Chadha, Kush. "Improvement of water management in PEM fuel cells using water balance and electrochemical noise analysis." Thesis, Poitiers, 2021. http://www.theses.fr/2021POIT2251.
Full textThis thesis deals to optimize the performance of PEMFC fuel cells, through the development of new flow-field plate designs. Tools such as water balance and electrochemical noise analysis have been used to diagnose water management within a PEMFC single cell. Optimal management of the water transport enables an increase of the performance and durability of fuel cells. Water balance method was used to measure and frame the value of the effective water diffusion coefficient within the membranes of fuel cells. New flow-flied plate geometries have been developed and characterized by conventional polarization curve and pressure measurements. The electrochemical noise technique was used to detect phenomena related to the behavior of water during fuel cell operation for each geometry developed. Electrochemical noise measurements have been associated with source mechanisms through an experimental approach and an appropriate signal processing based on frequency and time analysis. The descriptors obtained by time and frequency analysis shows that it possible to obtain the signature in normal operation of a fuel cell using a classical serpentine. This signature was compared to the new developed designs allowing to characterize the influence of these new geometries on the water transport. Finally, to complete the experimental approach carried out on the water diffusion coefficient within the membranes of PEMFC fuel cells, a model based on polarization curve, considering this coefficient, was developed and compared to the experimental curves of performances. In perspective, the impact of the new developed geometries has been extended in a stack utilization and a prognosis model based on artificial neural networks has been proposed
Phlippoteau, Vincent. "Outils et Méthodes pour le diagnostic d’un état de santé d’une pile à combustible." Thesis, Toulouse, INPT, 2009. http://www.theses.fr/2009INPT013H/document.
Full textA fuel cell system transforms the fuel energy into electricity and heat with electrochemical reaction. There are many kinds of fuel cells and we study here the Proton Exchange Fuelcell (PEMFC), which operates between 50°C and 100°C. At the moment, main issues are fuel cells’ life time and its management. Multiple problems can occur such as drying or flooding due to water management, poisoning with impurities in gas, internal deterioration, etc. The objective of this thesis is to define and carry out experimental and analysing methods to characterize these problems. These experimental methods use electrical perturbation and measurements of their effects. Impedance Spectroscopy is part of these methods, but is greatly improved for instable system (patent). We used two types of tests: low amplitude signal, which can be performed during normal operation of the fuel cell, and large amplitude signal which have a strong impact on the fuel cell response. These tests are complementary and are able to evaluate the state of health of the fuel cell. The analysing process of these measurements is ameliorated, in order to improve the uniqueness of the results. At the end, some problems are generated (drying, flooding, etc) and these methods are performed to follow the variation of performance and determine which parameter is involved with the deterioration
Mrozewski, Kamil Janusz. "Diagnosis of mechanical tightening of a single polymer electrolyte membrane fuel cell (LT-PEM and HT-PEM) in aeronautical applications." Thesis, Toulouse, INPT, 2019. http://www.theses.fr/2019INPT0034/document.
Full textThe aeronautical R&D activities are currently shaped by the issues associated with the pollutantrich nature of the industry and the natural evolution towards more effective and sustainable technologies. In this regard, the development of more electric aircraft would contribute to reducing fossil fuel consumption by incorporating alternative sources and converters of energy, such as FCs. However, a FC system would have to comply with particular reliability and safety constraints, especially as the aeronautical environment is not very indulgent: abundant pressure and temperature cycling as well as mechanical loads, varying both in frequency and amplitude, in all three dimensions. Vibrations and shocks can in particular lead to a sudden or gradual loosening of the FC, thus degrading its performance, and possibly provoking a gas leak. It therefore seems important to be able to monitor the tightening state of a FC over time, ideally in a non-intrusive manner. Results reported in the literature indicate that the quality of the mechanical tightening of a FC assembly might be assessed through its ohmic resistance (Rohm), more precisely through its electronic part (Re-, formed by the bulk resistances of FC layers and the interfacial contact resistances). In nominal operating conditions, the second and more dominant part of Rohm – the protonic resistance (RH+, formed by the membrane and ionomer resistances) – does not depend on clamping pressure. This amalgamation of resistances of different natures prevents an easy extraction of Re- without the use of invasive sensors and thus an estimation of the quality of the mechanical tightening of a FC assembly. This thesis proposes an in situ preventive diagnosis method that is capable of detecting the degradation of clamping conditions of a FC through the modelling of its ohmic resistance. A theoretical study is performed and demonstrates that the RH+ and Re- resistances can be separated from the total Rohm, based on their temperature dependence. The proposed method is verified with experimental data generated during the characterization of low and high temperature Polymer Electrolyte Membrane (PEM) single cells. Although some differences between the values identified by the algorithm and those reported in the literature are observed, they correctly depict the behavior of the mechanical tightening of the tested FCs. Overall, the results are encouraging in the aim of monitoring the quality of mechanical tightening of a FC through the evolution of RH+ and Re-
Taleb, Miassa. "Exploitation des mesures électriques en vue de la surveillance et du diagnostic en temps réel des piles à combustible pour application transport automobile." Thesis, Université Paris-Saclay (ComUE), 2015. http://www.theses.fr/2015SACLC010/document.
Full textIn the current global energy context, proton exchange membrane fuel cells represent a promising solution to the future development of a new generation of electrified vehicles, allowing greater autonomy than electrified vehicles using batteries.Nevertheless, the large-scale development of fuel cells remains limited due to some technological locks, such as water management. To enable mass production of fuel cells, such problems must be solved. Several working axes may be envisaged both on the hardware aspects of the fuel cell structure, and from the point of view of control, by developing algorithmic tools for monitoring the operating state of the system to detect any failures, or degradations that may occur.The work of this thesis falls within this second approach and focuses specifically on the identification of drying and drowning phenomena which can appear in a fuel cell, to diagnose any moisture problems leading to yield reduction.The methods developed in this work are based on the monitoring of relevant parameters of the fuel cell model which changes, compared to reference values, are characteristic of the state of the fuel cell hydration.The real-time monitoring of these parameters can highlight the drying and drowning phenomena.Adopted models for this work are based on a representation of the electrical impedance of the fuel cell.Thus, following this approach, the adopted strategy is then based on the development of two electrical models: an integer order model and a fractional order model. It appears that the second model formulation is closer to the physical reality of transport phenomena occurring in the fuel cell. It allows a better representation of the fuel cell behavior in time and frequency domain. Indeed, the analyzes based on experimental results performed using a single fuel cell (100 cm2 active area designed by UBzM company) have validated that the fractional order model, in return for an increase of complexity, allows better reproduce, in the one hand of the fuel cell time-series voltage response (voltage monitoring for a given current profile), on the other hand a better approximation of the measured impedance. Conventional and of fractional order parametric identification methods are then used to extract the model’s parameters from time-series experimental data (voltage / current from the battery) or frequency data (impedance spectroscopy).A sensitivity analysis allows then the defining of the most indicative parameters of the drowning and drying phenomena. The evolution of these parameters associated with the voltage and impedance spectrum of the fuel cell are then combined to build a diagnosis strategy of the fuel cell water management
Génevé, Thomas. "Méthodes de diagnostic des piles à combustible." Phd thesis, Toulouse, INPT, 2016. http://oatao.univ-toulouse.fr/15589/1/TGENEVE.pdf.
Full textNiane, Moustapha. "Contribution au diagnostic et à la commande de la pile à combustible de type PEM." Thesis, Aix-Marseille, 2018. http://www.theses.fr/2018AIXM0426/document.
Full textThe fuel cell is a device that transforms the chemical energy in electricity. This device requires some auxiliaries for its operation. In order to ensure the performances in terms of security, reliability and life cycle of the fuel cell, adequate diagnostic and control systems are indispensables. This thesis is a contribution to the problem of faults diagnosis and control of PEM Fuel Cell. The first part of this work is dedicated to the development of diagnostic methods applied to the fuel cell. To do this, two approaches are proposed. The first one concerns the synthesis of a H-/H∞ filter allowing the sensors and actuators faults detection while ensuring a level of robustness towards disturbances. Taking into account the fuel cell system characteristics, the conditions for existence and stability of the filter are given in the form of Linear Matrix Inequalities (LMI). The second approach deals with the problem of parametric faults detection. For this purpose, an adaptive observer has been proposed, which makes it possible to estimate the value of the parameter likely to exhibit a failure. This method gives the possibility of simultaneously estimating the parametric faults and the unmeasured states of the system. The second part of the thesis is dedicated to the control of the fuel cell system. The purpose is to synthesize a feedback control law that allows to answer the load request while respecting a nominal operating constraint of the fuel cell. Such a functioning allows to have a better efficiency while preserving the state of health of the fuel cell. The control law is obtained by using the original nonlinear model and without any kind of linearization
Pardon, Gaspard. "From Macro to Nano : Electrokinetic Transport and Surface Control." Doctoral thesis, KTH, Mikro- och nanosystemteknik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-144994.
Full textQC 20140509
Rappid
NanoGate
Norosensor
Hassan, Saima. "The diagnostic and therapeutic role of the stromal cell-derived factor (SDF)-1/CXCR4 axis in breast cancer metastasis." Thesis, McGill University, 2009. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=66712.
Full textLe cancer du sein tue par le processus des métastases. Dans le but d'améliorer le pronostic des patients atteints du cancer du sein, une meilleure compréhension des facteurs sous-jacents qui conduisent à la transformation métastatique est nécessaire. Une théorie qui explique la transformation métastatique propose que les chimiokines, telles que le stromal cell-derived factor (SDF)-1, sont surexprimées dans des organes métastatiques distants spécifiques, tels que le poumon, le foie, et les os et servent à attirer les cellules cancéreuses qui expriment leurs récepteurs, tels CXCR4. L'hypothèse de cette t hèse est donc que l'axe SDF-1/CXCR4 joue un rôle important dans la transformation métastatique dans le cancer du sein, et que cet axe ligand/récepteur peut être exploité dans le diagnostic et la thérapie du cancer du sein. Le premier objectif de cette thèse était de déterminer si les niveaux circulants de SDF-1 peuvent prédire la présence de métastases du cancer du sein. Nous avons découvert que des niveaux peu élevés de SDF-1 dans le plasma représentent un bon déterminant pronostique indépendant, suggérant que le gradient de concentration de faible niveaux de SDF-1 dans le plasma et de niveaux élevés de SDF-1 dans l'organe métastasé peut être un événement critique dans le transfert des cellules cancéreuses de la circulation sanguine jusqu'à l'organe-cible. Nous avons de plus déterminé que les niveaux plasmatiques de SDF-1 sont indépendants des tumeurs, identifiant le premier marqueur sanguin, dérivé de l'hôte, de prédiction de métastases éloignées. Le second objectif était de déterminer si l'expression tumorale de CXCR4 pourrait moduler l'effet pronostique des niveaux plasmatiques de SDF-1. Nous avons découvert que les patients dont les tumeurs expriment de façon élevée la forme activée du récepteur, CXCR4 phosphorylé, et des niveaux plasmatiq
Jullian, Gauthier. "Diagnostic robuste de pile à combustible PEM par modélisation physique et mesures d’impédance : prise en compte de conditions dynamiques et du vieillissement." Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAT009/document.
Full textThe PEMFC fuel cell is an electrochemical generator that has interesting potential for automotive applications and which use could help to meet pollution challenges. Poor management of system auxiliaries or malfunctions can place the fuel cell under operating conditions that accelerate degradation processes and shorten its useful life. The- operating conditions of the fuel cell core (temperature, humidity and partial pressures) must be monitored to identify as soon as possible and without any error abnormal situations, which is particularly difficult in dynamic operating conditions and during ageing.The aim of this thesis is to provide solutions to this problem. To that end, a robust diagnostic approach of operating conditions without direct measurement, in a dynamic environment and taking ageing into account has been developed.In order to characterize the fuel cell, a campaign of experimental tests on a test bench was carried out during 1000 hours of operation, with and without faults. This test campaign also allowed to verify to what extent the easily accessible polarization curves and impedance spectroscopy depend on the internal operating conditions.The approach developed is based on one hand on the use of a physical fuel cell model that capture its behaviour for given operating conditions and on the other hand on easy-access current, voltage and impedance measurements. Thus, this allows the development of an embedded solution that minimizes the number of sensors required.The differences between the experimental measurements and the outputs computed by the physical fuel cell model – called residuals – are indicators which are sensitive to faults in operating conditions, and insensitive to usual operating dynamic conditions. Two residuals, generated from fuel cell output voltage and high frequency impedance, are used to detect abnormal operating conditions thanks to threshold detection. The choice of the detection threshold levels allows to set the detection performance in terms of good detection and false alarm probabilities.In order to take ageing into account, a degradation module computes the decrease of fuel cell voltage with time so that ageing is taken explicitly into account by residuals.Going beyond detection alone, a method to class the operating conditions faults has also been proposed. It uses a database of residuals from various known faults to train a K-nearest-neighbour classifier, so that faults can be identified and classified.The model developed in the CEA was compared with experiments carried out on the test bench. An experimental determination of the model constants was carried out using electrochemical methods (cyclic voltammetry...) and numerical ones (linear regression). It appears that the model correctly computes voltage and high-frequency impedance, confirming the possible use of this specific model for diagnostic purpose. The method has been tested with optimal thresholds that have been empirically determined. The detection score obtained is 80%. The false alarm rate is less than 5% during the test.The K-NN classifier was then validated on experimental data. The classification score during the 1000h test is around 60% with large disparities depending on the faults. This score is more than 99% for two of the studied faults (high pressures and low humidity), 63% for low pressures but only 20% for a temperature drop or humidity increase.This work concluded that the approach using a physical model diagnosed most faults with a low level of false alarms during 1000 hours of ageing. The search of new measurements to increase the score of poorly diagnosed faults thus improving diagnostic performance is a main perspective
Jalal, Ahmed Hasnain. "Multivariate Analysis for the Quantification of Transdermal Volatile Organic Compounds in Humans by Proton Exchange Membrane Fuel Cell System." FIU Digital Commons, 2018. https://digitalcommons.fiu.edu/etd/3886.
Full textAdiutantov, Nikolai. "Développement d'une instrumentation et méthodologie par l'étude des bruits électrochimiques pour le diagnostic des stacks de pile à combustible de type PEMFC." Thesis, Poitiers, 2017. http://www.theses.fr/2017POIT2313/document.
Full textFuel cell technology development requires adequate diagnostic tools, in particular for monitoring the state of health of industrial systems (stacks) under operating conditions. Traditional diagnostic tools require to stop or disrupt the system operating. This thesis aims at the development of an innovative and non-intrusive approach for the diagnostic of PEM (Proton Exchange Membrane) fuel cell stacks. The methodology is based on the measurement of small electrical fluctuations (electrochemical noise). To measure this noise, a high frequency signal acquisition system was used without prior analog filter. These measurements were obtained within the ANR project « Propice » using four measurement campaigns with the collaboration of FCLAB and CEA LITEN. Electrochemical noise Measurements, over several weeks, made it possible to build a rich database. To process these data, different statistical approaches in time, frequency and tempo-frequency domains have been used for the generation of reliable and robust descriptors. It has been shown that the measurement of noise makes it possible to obtain a rich signature of the PEM stacks in a wide frequency range. This signature reflects the various physico-chemical phenomena and it is very sensitive to the operating parameters of the system. The evolution of this signature in short time analysis can be used for an in-situ diagnostic of the state of health of commercial stacks under real operating conditions and for the development of prognostic strategies
Hamaz, Tahar. "Outils de caractérisation et de diagnostic d'une pile à combustible de type PEM par mesure du champ électromagnétique externe." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENT074/document.
Full textProton exchange membrane fuel cell (PEMFC) is a potential alternative energy conversion device for stationary and automotive applications. Wide commercialization of PEMFC depends on progress that can be achieved to enhance its reliability and durability. The PEM fuel cell is subject to several types of complex and not fully mastered degradations which vary with operating conditions. It is desirable to operate the PEMFC at uniform current distribution because non uniform current distribution over the MEA could result in poor reactant and catalyst utilization, overall cell performance degradation as well as corrosion processes inside the PEM fuel cell. Therefore, new diagnostic strategies must be proposed, including choice of information gathered on the system and the fuel cell operation representation. My research is to develop a new diagnostic tool based on a measure of the external electromagnetic field (non-invasive) radiated by the fuel cell. The magnetic field has the advantage of being correlated to the local distribution of the current flowing inside the fuel cell (a physical indicator to obtain information on local performance of a fuel cell); it is linked to the local operating conditions: relative humidity level, temperature etc. It is then possible, from a magnetic signature to trace local information. Baselines (vectors) which contain the magnetic fields data generated by specific current distribution are built to characterize the magnetic field generated by the undesirable operation of the fuel cell. Baselines constitute a representation space of abnormal system behavior. Two methods have been developed to enable: (i) to extract the relevant parameters on the distribution of the current density resulting from PEM fuel cell stack local performance, (ii) to classify different types of undesirables operations. The first method is to generate vector residuals by comparing the actual behavior of the system (characterized by a measurement vector) with the baselines generated. Qualitative variables were created to classify the undesirable modes of PEM fuel cell stack operation. The second method is to extract parameters from the projection of the vector in the direction of measurement baselines. The classification is performed in 2D space. Validation from experimental measurements of the two proposed methods has been carried out on a commercial scale PEMFC (GENEPAC stack of 40 cells built by the CEA and PSA). The relevance of the extracted parameters was verified based on current density distributions measured directly. The undesirable predefined operating modes were used to locate the operating conditions parameters that led to the evolution of the current density distribution. The tools are made easily transferable to other PEMFC stack
Logan, Patrick 1982. "In vivo imaging of liver metastasis using green fluorescent protein labelled human uveal melanoma cells in a mouse model." Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=112536.
Full textIn order to understand the interactions between single malignant cells or sub-clinical metastases and affected organs, we have successfully developed a novel animal model of uveal melanoma. We utilized the unique properties of green fluorescent protein, a skin-flap in vivo imaging technique, and nude mice to accomplish this goal. The precision of green fluorescent protein imaging has allowed us to observe single cells interacting with organ tissues and reveal that these malignant cells are only capable of surviving in the liver.
Chupin, Sylvain. "Comportement local et performances électriques d'une pile à combustible à membrane : vers un outil de diagnostic." Thesis, Université du Québec à Trois-Rivières, 2009. http://www.theses.fr/2009INPL098N/document.
Full textThe present work contributes to the understanding of water management and thermal management of a PEM fuel cell influences on the electrical performances. A bidimensional model representing mass and heat transfer in the cell thickness and along distribution channels is done. A specific part of the study concerns a microscopic representation of reactive agglomerates. This part presents the impact of the liquid water presence on local and global current densities. In te vein of integrating this model in a total fuel cell control system, simplifications have been done and coupled mass, heat and charge transfers are solved analytically. For any operating condition, the model gives a complete view of the hydric, thermal and electric inner situation of the cell. This diagnosis of the inner state of the cell leads to find the operating conditions giving to the optimal electric performances. Water, current and temperature distributions are presenting for different gas feeding strategies and different thermal management configurations. A specific part is dedicated to illustrate how this local diagnosis of the cell state can be used to estimate its global electric performances
Safa, Mohamad. "Modélisation réduite de la pile à combustible en vue de la surveillance et du diagnostic par spectroscopie d'impédance." Phd thesis, Université Paris Sud - Paris XI, 2012. http://tel.archives-ouvertes.fr/tel-00855160.
Full textWang, Kun. "Algorithmes et méthodes pour le diagnostic ex-situ et in-situ de systèmes piles à combustible haute température de type oxyde solide." Phd thesis, Université de Franche-Comté, 2012. http://tel.archives-ouvertes.fr/tel-01017170.
Full textLe, Ny Mathieu. "Diagnostic non invasif de piles à combustible par mesure du champ magnétique proche." Phd thesis, Université de Grenoble, 2012. http://tel.archives-ouvertes.fr/tel-00844407.
Full textAabid, Sami El. "Méthode basée modèle pour le diagnostic de l'état de santé d'une pile à combustible PEMFC en vue de sa maintenance." Thesis, Toulouse, INPT, 2020. http://www.theses.fr/2020INPT0011.
Full textNowadays, Fuel cells (FCs) are considered as an attractive technological solution for energy storage. In addition to their high efficiency conversion to electrical energy and their high energy density, FCs are a potential candidate to reduce the environmental impact of aircrafts. The present PhD thesis can be located within this context, and especially contributes to the development of methodologies dedicated to the monitoring of the state of health (SoH) of Proton Exchange Membrane Fuel Cells (PEMFCs). FCs are submitted to ageing and various operating conditions leading to several failures or abnormal operation modes. Hence, there is a need to develop tools dedicated to the diagnosis and fuel cell ageing monitoring. One of reliable approaches used for the FC SoH monitoring is based on parametric identification of a model through experimental data. Widely used for the FC characterization, the polarization curve (V-I) and the Electrochemical Impedance Spectroscopy (EIS) coupled with a model describing the involved phenomena may provide further information about the FC SoH. Two models were thus developed: a quasi-static model whose parameters are identified from the polarization curve and a dynamic one identified from EIS data. The need to develop a dynamic model whose formulation may vary over time “without a priori” has been reported in this thesis. The original approach of this thesis is to consider conjointly both characterizations during all the proposed analysis process. This global strategy ensures the separation of the different fuel cell phenomena in the quasi-static and dynamic domains by introducing into each parametrization process (one for the quasi-static model and one for the dynamic model) parameters and/or laws stemming from the other part. The global process starting from the a priori knowledge until the identification of the models parameters was developed during the chapters of this thesis. In addition to the good reproduction of experimental data and the separation of the losses in both static and dynamic domains, the method makes it possible to monitor the FC SoH via the evolution of models parameters. The fact to take into account the coupling between quasi-static and dynamic models revealed the notion of a “residualimpedance”. This impedance makes it possible to overcome the recurrent experimental observation made by the daily users of EIS: there is a not-clearly explained difference between the low frequency resistance of the EIS and the slope of the polarization curve for a given currentndensity. Theoretically the two quantities have to tend towards the same value. In others words, a part of the impedance spectra is not clearly and easily exploitable to characterize fuel cell performance. This topic has been discussed in the literature in the last years. An attempt to explain physico-chemical phenomena related to this impedance is also a part of objectives of this thesis. From an experimental point of view, before applying this method to ageing monitoring, it was indeed necessary to “calibrate” it regarding its relative complexity. In this way, experiments with a single cell with different sets of internal components (different membrane thicknesses and different platinum loadings in the Active Layer (AL)) were achieved and analyzed by applying the proposed method. Therefore, the method was evaluated in the framework of three ageing campaigns carried out with three 1 kW PEM stacks
Ifrek, Lyes. "Identification des défauts d'une pile à combustible par la mesure du champ magnétique externe : vers la détermination de défauts locaux." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAT076/document.
Full textA noninvasive technique for identifying the current distribution in a fuel cell from the external magnetic field is developed. The magnetic field measurements are carried out on a set of points chosen in order to detect only the variations of the magnetic field in a case of a faulty fuel cell. Two components of the magnetic field are used because they are sensitive to current heterogeneities. The exploitable measurement of the magnetic field is the difference between a healthy mode and a faulty mode.An ill-posed inverse problem is modeled by investigating several parametrization approaches of the current distribution. The ill-posed property of the problem conducts to a non-uniqueness of the solution and a high sensitivity to the noise. A regularization method is used in order to get a stable solution. The developed tool allows identifying the current distribution independently of the size of the fault within the sensitivity limit. A validation is done on a fuel cell simulator and on a GENEPAC fuel cell in a laboratory conditions
Tognan, Malik. "Etude de dégradations des performances de Piles à Combustible PEM BT alimentées en H2/O2 lors de campagnes d'endurance : du suivi de l'état de santé en opération à la modélisation du vieillissement." Thesis, Toulouse, INPT, 2018. http://www.theses.fr/2018INPT0047/document.
Full textThis thesis work deals with the thematic of the Low Temperature Proton Exchange Membrane (PEM LT) Fuel Cell (FC) aging. The use of a FC inside a H2 battery (association of a FC, an electrolyzer and H2 / O2 tanks) in a stationary context is considered in an island micro-grid based on renewable energies (wind and solar power). Two axes linked with the FC use and aging in this context are investigated in this work: one of the axes is centered in the study of the FC performance decrease dynamics over time and the other on the development of methods and tools dedicated to the state of health monitoring during the FC operation. The first thematic is introduced through the exploitation of several aging campaigns performed on PEM FC stack prototypes under constant current solicitations. The stacks considered are fed with pure O2 on the cathode side. A focus is made on the aging heterogeneity inside the stacks and a decoupling between the nominal voltage degradation dynamics and the development of the H2 internal leak with time is highlighted for the different stacks and campaigns. A generic methodology dissociating the reversible and the irreversible voltage losses dynamics is proposed and is further used as a basis to model the nominal voltage degradation with time. The model built in this way is showing encouraging results and its potential use for prognostic purpose is suggested. Whereas these investigations focus on the FC performance degradations under constant current solicitation, the impact of load current dynamic variations on the FC aging is also treated with an experimental study performed on single cells. An ageing campaign under a dynamic load profile is performed on several single cells directly hybridized or not by supercapacitors. The hybridized cells are cycling on an almost-constant current profile whereas the non-hybridized cells are cycling on a dynamic one. A comparison of the performances evolution with time in both cases (hybridized and nothybridized) is done and highlights the effect of the dynamic cycling on the FC performance degradation. The second thematic dealing with the FC state of health evaluation is introduced with one of the main causes of the FC end-of-life: the development of the H2 internal leak between the anode and cathode compartments. Open Circuit Voltage (OCV) measurements performed during start-up and shut-down routines phases are scanned a posteriori in one of the aging campaign of the database. The objective is to seek some potential correlations between those OCV measurements and the H2 internal leak increase over time in order to develop internal leak indicators. A gases introduction operating sequence highlighting a link between the internal leak level and the OCV drift for some stack’s cells is identified during some start-up phases and reproduced during a complementary campaign. A last part of the manuscript is finally dedicated to the integration of a parasitic mechanism (the Pt oxidation) into the FC theoretical quasi-static and dynamic performance modeling. The model integrating this phenomenon is showing some abilities to explain and analyze several experimental features observed on classical performance characterization measurements (EIS, OCV measurements, large amplitude sinus sweep at very low frequency…), opening some perspectives for the FC state of health monitoring
Lebreton, Carole. "Contrôle tolérant aux fautes en ligne d'une pile à combustible de type PEM. Contribution à la gestion de l'eau." Thesis, La Réunion, 2015. http://www.theses.fr/2015LARE0023/document.
Full textFuel Cell (FC) development is expending due to global energy transition. Power generation using FC results in water and heat as by-products, without emission of greenhouse gases. To continue developing and expanding its use as power generators, FC lifetime and reliability have to be enhanced. This thesis work is dedicated to Fault Tolerant Control System (FTCS) applied to water management in PEM Fuel Cells. An appropriate water management of FC allow to avoid irreversible degradations of FC components and performance that lead to an improvement of FC reliability and lifetime.The proposed FTCS is composed of a model-based diagnosis method applied to fault detection and isolation, and a self-tuning PID strategy for oxygen excess ratio control. This strategy is tested and validated on-line on a real FC system
Septiani, Anita, and 夏艾妮. "REAL-TIME DIAGNOSTIC SYSTEM FOR FUEL CELL VEHICLE." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/w4rjh3.
Full text國立勤益科技大學
冷凍空調系
105
Electric vehicles have long held the promise of zero emission vehicles. A hydrogen-based, fuel cell could provide the power required by an electric vehicle equal to modern gasoline powered vehicle. In this study, the real fuel-cell vehicle system was developed using 500W of proton exchange membrane fuel cell (PEMFC) to power the motor. The performance of the fuel cell vehicle is important to know, and the parameters to be measured for performance are the currents and voltages that flow through in the car. The method for real-time measurement data in the previous study has been done manually, it is still less effective in terms of time and equipment. To make a real-time diagnostic system of fuel cell vehicle become more efficient, this study made a monitoring system and Graphical User Interface (GUI). GUI is a user interface for displaying the data of fuel cell car performance (current and voltage). By using GUI, integrated with the hardware (microcontroller, sensors, and communication data) then the data will be easily observed, recorded continuously, and real-time by using developed GUI. GUI is built by using LabVIEW software. Data displayed in numeric, graph, and tables also can be recorded in .txt or .csv format and stored in automatically. The microcontroller used in this study is myRIO. myRIO (reconfigurable I/O) is a real-time embedded evaluation board made by National Instruments. myRIO has Wi-Fi itself, which can send the data of current and voltage wirelessly. This study use ACS712-20A as a current sensor and using voltage divider principle for measure the voltage. There are four points measured on the fuel cell car such as load, transformer, battery, and motor, From observation and data processing performed during the fuel cell vehicles testing for one hour using myRIO and GUI, it can be known that from the four measuring points showed almost the same result and the similar tendencies. The voltages averages are about 26.409 V and the current averages are about 4.552 A. The fuel cell power generation from the running test is about 112 W. The value obtained is close to the expected setting value of 100 W. The efficiency value obtained from this study is 89 % and the consumption of the car for 1 hour running test is 14.6 g.
Latham, Ruth Anne. "Algorithm development for electrochemical impedance spectroscopy diagnostics in PEM fuel cells." 2004. http://hdl.handle.net/1828/811.
Full textHuang, Ren-De, and 黃任德. "Application flexible multi-functions micro sensors for micro diagnostic inside a fuel cell." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/09466397486515395907.
Full text元智大學
機械工程學系
98
The distributions of temperature, humidity, and voltage of Membrane Electrode assembly (MEA) inside a fuel cell are key factors associated with fuel cell performance. Conventional sensors are typically large, and are only feasible for external measurements of fuel cells. Additionally, centimeter-scale sensors are only suitable for invasive measurements, and are often unable to measure interior changes in an MEA accurately. The purpose of this work is to fabricate flexible micro sensors for measuring temperature and humidity variations in a micro fuel cell within a membrane electrode assembly (MEA) using micro-electro-mechanical systems (MEMS) technology. This research is divided into two sections. 1. Production of flexible micro sensors: The polymer poly-p-xylene is used to cover the sensors completely, as well as produce the double-layer structure of the micro-sensors. 2. In situ diagnosis of the temperature and humidity distributions in the MEA is performed by embedding the flexible micro sensors into the MEA and attaching them to the micro flow channel plate for measuring temperature and humidity distributions within the MEA and cell performance of an operating fuel cell. Inside the MEA, the upper and middle regions reach higher temperatures than the lower region because of an insufficient gas flow or water accumulating in the lower region. The maximum temperature difference inside and outside the cell is 5.99°C. Because the temperature at lower region and supply gas is lower than the middle and upper regions, the lower region has a larger voltage distribution than the middle and upper regions. Additionally, the middle and upper regions have lower internal relative humidity than lower region. Thus, the distribution of internal voltage for middle and upper regions is less than that of the lower regions.
Lee, Ti-Ju, and 李狄儒. "Development of Prototype of Internal Diagnostic Tool for Low Temperature Fuel Cell Range Extender." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/tr39ek.
Full text元智大學
機械工程學系
107
The key points in the R&D of electric motorcycle fuel cell stack range extender are system integration and lightweight of lithium battery and fuel cell stack range extender. The defects in the present fuel cell stack range extender are large volume, heavy weight and high cost. Since the actual operation of the fuel cell stack range extender has many variables and affects the physical quantity inside the fuel cell stack, causes the power output is not stable. At this time, a flexible five-in-one microsensor can be used in combination with the control system to make immediate corrections to keep power output stable. In addition, in order to keep the fuel cell stack range extender working in the optimum condition, the temperature and humidity control of fuel cell is of great importance, and the performance and life of fuel cell stack will be influenced by the internal flow, voltage, current distribution and operating conditions. Therefore, this study use MEMS technology to develop a flexible five-in-one microsensor and complete optimization design and production, durability test and wireless diagnosis, which is embedded in the fuel cell stack range extender for real-time microscopic diagnosis and control, and the reliability are tested to attain the staged research and development goal, so as to master the real operating condition in the fuel cell stack range extender instantly and correctly, and the internal information can be fed back instantly, so that the fuel cell stack range extender control system can be adjusted to optimum operating parameters immediately, so as to enhance its performance and prolong its life effectively to accelerate commercialization and possess international competitiveness.
Tsai, Chao-Hsuan, and 蔡朝軒. "Development of Real-time Wireless Diagnostic Tool inside Low Temperature Proton Exchange Membrane Fuel Cell." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/e9mf5q.
Full text元智大學
機械工程學系
106
In terms of the principle of power generation of fuel cell, when the fuel hydrogen and air are injected, the redox reaction in the fuel cell generates electric energy and water. In the long run, the catalyst layer Pt particles and the contaminants in the input gas (e.g. CO) bond together, so that the catalyst loses reaction activity. The performance degradation and aging of fuel cell are influenced by operating conditions, temperature, flow, voltage, current and CO concentration. At present, there are four common methods for studying the fuel cell performance decay and aging: (1) Transmission Electron Microscopy (TEM) measures Pt catalyst particle size and variation; (2) X-ray Diffractometer (XRD) measures the ratio of Pt to carbon granules in catalyst layer, and judges the corrosion of carbon granules; (3) Electrochemical Impedance Spectroscopy (EIS) measures the impedance of various parts of Membrane Electrode Assembly (MEA) and (4) Cyclic Voltammetry (CV) measures electrochemical active area per unit weight. However, methods (1) and (2) allow observation only after performance degradation and aging of fuel cell; methods (3) and (4) can implement real-time measurement, but the result is the overall performance. Therefore, this study proposes the development of a real-time wireless diagnostic tool for the low temperature fuel cell performance, and uses micro-electro-mechanical systems (MEMS) technology to develop a wireless and thin (<50μm) flexible integrated (temperature, flow, voltage, current and CO) microsensor. The technical advantages include (1) compactness and wireless five-function measurement; (2) flexible measurement position and accurate insert; (3) high accuracy and sensitivity and quick response; (4) real-time wireless monitoring of dynamic performance of low temperature fuel cell; (5) customized design and development. The flexible integrated microsensor is embedded in the low temperature fuel cell, five important physical quantities inside the low temperature fuel cell, including temperature, flow, voltage, current and CO, can be measured simultaneously and instantly, so as to know the actual and complete reaction condition in the low temperature fuel cell, to enhance the fuel cell performance and to prolong the service life. The findings show that the effect of the integrated microsensor on the low temperature fuel cell is less than 1%, the maximum power is about 323.56mW, under the test conditions of constant current 2A, 3.5A and 6A, the wired and wireless results have consistent variation curves, proving the feasibility of wireless sensor. Keywords: Low Temperature Proton Exchange Membrane Fuel Cell; flexible integrated microsensor; real-time microscopic monitoring; wireless diagnosis
Hoff, Brian David. "A time transient technique for performance characterization and degradation diagnostics in solid oxide fuel cells." Thesis, 2006. http://hdl.handle.net/2429/18044.
Full textApplied Science, Faculty of
Mechanical Engineering, Department of
Graduate