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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Modèles à échelle réduite en similitude pour l'ingénierie système et l'expérimentation simulée "temps compacté" : application à un microréseau incluant un stockage électrochimique. / Reduced scale models for system Reduced scale models for system engineering and simulated "compacted time" experimentation : application to a microgrid including electrochemical storage

Varais, Andy 10 January 2019 (has links)
Cette thèse a été réalisée en collaboration avec la société SCLE SFE (Groupe ENGIE) et le laboratoire Laplace. Elle porte sur le développement d’une méthodologie permettant d’élaborer des modèles dits « en similitude », à échelle de puissance et de temps réduites. Ces modèles peuvent servir pour l’analyse des systèmes mais ils sont en particulier utiles pour l’expérimentation en temps réel des systèmes énergétiques. En effet, les expérimentations sont très souvent menées à échelle réduite pour des questions de taille, de coût,… Certaines parties de ces expérimentations peuvent être « émulées » (simulées physiquement par des dispositifs de puissance) d’autres étant constitués de composants physiques : on parle alors de procédure Hardware in the Loop (HIL). Même si, à la base, la démarche de réduction d’échelle a une portée générale, notre gamme d’application principale concerne les micro réseaux avec intégration de sources renouvelables intermittentes couplées à des composants de stockage. En conséquence,nos travaux se focalisent sur la mise en œuvre de modèles de similitudes en puissance/énergie/temps de sources ENR et de stockeurs. La notion de réduction de temps, nous parlerons de « temps virtuel compacté », est un des concepts clés de ces travaux. Une attention particulière est portée sur le développement d’un émulateur physique de batterie électrochimique.En effet, le stockage d’énergie est un point clé dans un micro réseau. De plus, cet élément présente de fortes non-linéarités dont la mise en similitude doit impérativement tenir compte et n’est pas triviale. Une fois ces modèles développés, on les éprouve via la mise en œuvre d’essais en expérimentation simulée par émulateurs physiques à échelle de puissance réduite et en temps virtuel compacté. Ces essais permettent par ailleurs de confronter les notions d’émulateurs «copie-modèle », pour lequel un modèle est utilisé pour reproduire le comportement du système, et d’émulateurs « copie-image », où le comportement du système est reproduit à partir d’un de ses composants réels (par exemple une cellule pour la batterie). / This thesis was carried out in collaboration with SCLE SFE (ENGIE Group) and the Laplacelaboratory. It focuses on the establishment of a methodology allowing the “similarity” modelsdevelopment, with reduced power and time scale. These models can be used for systems analysisbut they are particularly useful for real-time experimentation of energy systems. Indeed, theexperiments are often carried out on a small scale for issues of size, cost, … Some parts of theseexperiments can be "emulated" (physically simulated by power devices) while others consist ofphysical components: this is called the Hardware in the Loop (HIL) procedure. Although, initially,the downscaling approach is broad in scope, our main field of application is microgrids withintegration of intermittent renewable sources coupled with storage components. As a result, ourwork focuses on the implementation of power / energy / time similarity models of ENR sources andstorage facilities. The concept of time reduction, we will talk about "compacted virtual time", is oneof the key concepts of this work. Particular attention is paid to the development of a physicalemulator of electrochemical battery. Indeed, energy storage is a key point in microgrid. In addition,this element has strong nonlinearities whose scaling in similarity must imperatively take intoaccount and is not trivial. Once these models have been developed, they are tested through theimplementation of simulated experiments using physical emulators with reduced power scale andcompacted virtual time. These tests also make it possible to compare the concepts of "copymodel" emulators, for which a model is used to reproduce the behavior of the system, and "copyimage" emulators, where the behavior of the system is reproduced from of one of its realcomponents (for example a cell for the battery).
2

Modèles à échelle réduite en similitude pour l'ingénierie système et l'expérimentation simulée "temps compacté" : application à un microréseau incluant un stockage électrochimique.

Varais, Andy 10 January 2019 (has links) (PDF)
Cette thèse a été réalisée en collaboration avec la société SCLE SFE (Groupe ENGIE) et le laboratoire Laplace. Elle porte sur le développement d’une méthodologie permettant d’élaborer des modèles dits « en similitude », à échelle de puissance et de temps réduites. Ces modèles peuvent servir pour l’analyse des systèmes mais ils sont en particulier utiles pour l’expérimentation en temps réel des systèmes énergétiques. En effet, les expérimentations sont très souvent menées à échelle réduite pour des questions de taille, de coût,… Certaines parties de ces expérimentations peuvent être « émulées » (simulées physiquement par des dispositifs de puissance) d’autres étant constitués de composants physiques : on parle alors de procédure Hardware in the Loop (HIL). Même si, à la base, la démarche de réduction d’échelle a une portée générale, notre gamme d’application principale concerne les micro réseaux avec intégration de sources renouvelables intermittentes couplées à des composants de stockage. En conséquence,nos travaux se focalisent sur la mise en œuvre de modèles de similitudes en puissance/énergie/temps de sources ENR et de stockeurs. La notion de réduction de temps, nous parlerons de « temps virtuel compacté », est un des concepts clés de ces travaux. Une attention particulière est portée sur le développement d’un émulateur physique de batterie électrochimique.En effet, le stockage d’énergie est un point clé dans un micro réseau. De plus, cet élément présente de fortes non-linéarités dont la mise en similitude doit impérativement tenir compte et n’est pas triviale. Une fois ces modèles développés, on les éprouve via la mise en œuvre d’essais en expérimentation simulée par émulateurs physiques à échelle de puissance réduite et en temps virtuel compacté. Ces essais permettent par ailleurs de confronter les notions d’émulateurs «copie-modèle », pour lequel un modèle est utilisé pour reproduire le comportement du système, et d’émulateurs « copie-image », où le comportement du système est reproduit à partir d’un de ses composants réels (par exemple une cellule pour la batterie).
3

Emulación de un aerogenerador conectado a la red a través de un sistema experimental Back-to-Back mediante la técnica "Hardware In The Loop"

Muñoz Jadán, Alexis Yanira January 2016 (has links)
Magíster en Ciencias de la Ingeniería, Mención Eléctrica / En la actualidad, el estudio de generación de electricidad por medio del recurso eólico es de gran importancia, por presentarse como solución para disminuir la contaminación ambiental al reemplazar los sistemas eléctricos a base de generación convencional por energía limpia. También, por constituir una vía de desarrollo para la sociedad al comunicarlo con la tecnología del mundo moderno. Sin embargo, debido a las dificultades que existen para realizar investigaciones de energía eólica con generadores reales, es necesario implementar prototipos que sean capaces de emular, aerogeneradores que serán utilizados en el trabajo de laboratorio. En este trabajo, mediante la técnica Hardware in the Loop , se logra en base a datos reales, emular el comportamiento de una turbina eólica en la plataforma de desarrollo Matlab/Simulink a través del sistema embebido que constituye el conversor de potencia en configuración Back-To-Back contenido en la unidad Triphase PM5F60R. Considerando perfiles de viento de distinta variabilidad con distintos valores medios y con un nivel de detalle adecuado de ingeniería, se estudia el desempeño de los sistemas de control correspondientes al aerogenerador, como: Pitch control y el algoritmo MPPT. En los cuáles se efectúan cambios en algunos parámetros importantes que caracterizan a las turbinas eólicas tales como: inercia, radio del aspa, curva aerodinámica, entre otros. Por otro lado, por medio de estrategias de control de corriente, basadas en múltiples controladores resonantes y amortiguamiento activo se logra compensar las resonancias causadas por los filtros LCL, inyectar corrientes con baja distorsión armónica y entregar potencia activa y reactiva variable a la red. Es así que, en este trabajo se identifican principalmente los siguientes aportes: Debido a que los aerogeneradores varían según su capacidad y modelo; mediante la técnica Hardware In The Loop ; se logra la emulación del aerogenerador y evita el uso de un aerogenerador real, otorgando flexibilidad en el diseño del mismo y su control. Así también, las estrategias de control de corriente por medio de controladores resonantes y metodología Active Damping, permite inyección de corriente a la red con baja distorsión armónica. Finalmente, la plataforma experimental implementada logra presentar un escenario cercano a la realidad de un sistema de generación eólica con conexión a la red por medio de un interface de electrónica de potencia. Su importancia radica debido a la validación de los resultados experimentales, en la habilidad para testear cada uno de los componentes que conforman el sistema implementado y realizar futuras investigaciones a cada uno de ellos de manera rigurosa. Así como también, es objeto de integración a otros sistemas, como por ejemplo, al de una micro-red en operación modo isla y modo red por medio de Droop Control.
4

Design and Hardware-in-the-Loop Testing of Optimal Controllers for Hybrid Electric Powertrains

Sharif Razavian, Reza January 2012 (has links)
The main objective of this research is the development of a flexible test-bench for evaluation of hybrid electric powertrain controllers. As a case study, a real-time near-optimal powertrain controller for a series hybrid electric vehicle (HEV) has been designed and tests. The designed controller, like many other optimal controllers, is based on a simple model. This control-oriented model aims to be as simple as possible in order to minimize the controller computational effort. However, a simple model may not be able to capture the vehicle's dynamics accurately, and the designed controller may fail to deliver the anticipated behavior. Therefore, it is crucial that the controller be tested in a realistic environment. To evaluate the performance of the designed model-based controller, it is first applied to a high-fidelity series HEV model that includes physics-based component models and low-level controllers. After successfully passing this model-in-the-loop test, the controller is programmed into a rapid-prototyping controller unit for hardware-in-the-loop simulations. This type of simulation is mostly intended to consider controller computational resources, as well as the communication issues between the controller and the plant (model solver). As the battery pack is one of the most critical components in a hybrid electric powertrain, the component-in-the-loop simulation setup is used to include a physical battery in the simulations in order to further enhance simulation accuracy. Finally, the driver-in-the-loop setup enables us to receive the inputs from a human driver instead of a fixed drive cycle, which allows us to study the effects of the unpredictable driver behavior. The developed powertrain controller itself is a real-time, drive cycle-independent controller for a series HEV, and is designed using a control-oriented model and Pontryagin's Minimum Principle. Like other proposed controllers in the literature, this controller still requires some information about future driving conditions; however, the amount of information is reduced. Although the controller design procedure is based on a series HEV with NiMH battery as the electric energy storage, the same procedure can be used to obtain the supervisory controller for a series HEV with an ultra-capacitor. By testing the designed optimal controller with the prescribed simulation setups, it is shown that the controller can ensure optimal behavior of the powertrain, as the dominant system behavior is very close to what is being predicted by the control-oriented model. It is also shown that the controller is able to handle small uncertainties in the driver behavior.
5

Design and Hardware-in-the-Loop Testing of Optimal Controllers for Hybrid Electric Powertrains

Sharif Razavian, Reza January 2012 (has links)
The main objective of this research is the development of a flexible test-bench for evaluation of hybrid electric powertrain controllers. As a case study, a real-time near-optimal powertrain controller for a series hybrid electric vehicle (HEV) has been designed and tests. The designed controller, like many other optimal controllers, is based on a simple model. This control-oriented model aims to be as simple as possible in order to minimize the controller computational effort. However, a simple model may not be able to capture the vehicle's dynamics accurately, and the designed controller may fail to deliver the anticipated behavior. Therefore, it is crucial that the controller be tested in a realistic environment. To evaluate the performance of the designed model-based controller, it is first applied to a high-fidelity series HEV model that includes physics-based component models and low-level controllers. After successfully passing this model-in-the-loop test, the controller is programmed into a rapid-prototyping controller unit for hardware-in-the-loop simulations. This type of simulation is mostly intended to consider controller computational resources, as well as the communication issues between the controller and the plant (model solver). As the battery pack is one of the most critical components in a hybrid electric powertrain, the component-in-the-loop simulation setup is used to include a physical battery in the simulations in order to further enhance simulation accuracy. Finally, the driver-in-the-loop setup enables us to receive the inputs from a human driver instead of a fixed drive cycle, which allows us to study the effects of the unpredictable driver behavior. The developed powertrain controller itself is a real-time, drive cycle-independent controller for a series HEV, and is designed using a control-oriented model and Pontryagin's Minimum Principle. Like other proposed controllers in the literature, this controller still requires some information about future driving conditions; however, the amount of information is reduced. Although the controller design procedure is based on a series HEV with NiMH battery as the electric energy storage, the same procedure can be used to obtain the supervisory controller for a series HEV with an ultra-capacitor. By testing the designed optimal controller with the prescribed simulation setups, it is shown that the controller can ensure optimal behavior of the powertrain, as the dominant system behavior is very close to what is being predicted by the control-oriented model. It is also shown that the controller is able to handle small uncertainties in the driver behavior.
6

Digital twin of a safe system

Edenhamn, Johan January 2022 (has links)
At Epiroc’s drill rigs a safe system is installed to make sure the vehicle is driven in a safe manner. In the development both machine tests and hardware-in-the-loop (HIL) tests have been performed but when changes are made the firmware in the safe modules has to be updated. To speed up the process a digital twin would be beneficial. This enables testing of parameters and formulation of criteria detecting faults. The purpose of the work is to develop a digital twin for steering and braking safe functions and evaluate the performance using data from machines as well as data from a HIL-rig. Also, the impact of the hydraulic model used in the HIL-rig is investigated. When the model is built two test cases are used to investigate how well the model replicates the behaviour of the real system and how sensitive it is to what input data is used. The biggest difference in the data is the sampling time, machine logs have 80 ms interval while logs from the rig are logged every 5 ms. It is discovered that some of the fault detection functions work very well no matter what data is used while others must have the better resolution to be trusted. The complexity of the hydraulic model used impacts the pressures but seem to have little effect on which fault codes are activated. With this the main purpose is partly achieved and further investigation is needed before the model can be used for all fault codes.
7

Automation of the creation and execution of system level hardware-in-loop tests through model-based testing

Almasri, Ahmed, Aronsson Karlsson, Viktor January 2022 (has links)
The automatic creation of test cases has been a well-researched area in recent years. Indeed, the industry’s testing procedure still uses the traditional way of manual practices. However, investigations are continued to deliver new methods, but research results have not been fully adopted. In this paper, the investigated method applies the model-based testing (MBT) method to evaluate the ability to automate the creation of hardware-in-the-loop (HIL) test cases, where generated tests are created using MBT tools. The tools’ properties were compared to each other through a literature study, with the result of selecting tools to be used in a case study, and the tools selected were GraphWalker and MoMuT. The generated test cases perform similarly to their manual counterparts regarding how the test cases achieved full requirements coverage. When comparing the effort needed for applying the methods, a comparable effort is required for creating the first iteration, while with every subsequent update, MBT will require less effort compared to the manual process. Both methods achieve 100% requirements coverage, and since manual testing is created and executed by humans, some requirements are favoured over others due to company demands, while MBT tests will be generated randomly.In addition, a comparison between the used tools showcased the differences in the models’ design and their test case generation. The comparison showed that GraphWalker has a more straightforward design method and is better suited for smaller systems, while’s MoMuT can handle more complex systems but has a more involved design method.The results of the thesis showed that using MBT tools proved helpful as it covers the system requirements, can be executed in HIL and helps discover faults within the requirements and HIL system. These facts satisfy the companies’ demands. This thesis shows a promising improvement in automating the test process within the vehicular domain.
8

Simulation of Attitude and Orbit Control for APEX CubeSat

de Graaf, Niels January 2020 (has links)
CubeSats are becoming a game changer in the space industry. Appearing first for univer-sity mission, its popularity is increasing for commercial use and for deep space missionssuch as the on HERA mission that will orbit in 2026 around an asteroid as part of aplanetary defence mission. Standardisation and industrial collaboration is key to a fastdevelopment, assuring the product quality and lower development expenditures.In this study the focus is set elaborating a low cost demonstrator platform to be usedfor developing and testing onboard software on physical hardware: a Hardware-Softwaretesting facility. The purpose of such a platform is to create an interactive and accessibleenvironment for developing on board software. The application chosen to be elaboratedon this platform is a module the subsystem of attitude and orbit control of the satelliteorbiting around asteroid.In order to create this platform the simulation of the asteroid environment of theCubeSat has been made using open source software libraries. During this task the per-formance of open source libraries has been compared to commercial alternatives. In thedevelopment of simulation different orbit perturbations have been studied by modellingthe asteroid as a cube or spheroid and additionally the effect of a third perturbing bodyand radiation pressure.As part of this project two microcontroller have been set up communicating using acommunication bus and communication protocols used for space applications to simulatehow the attitude and orbit control is commanded inside the CubeSat.
9

A New Fuzzy Based Stability Index Using Predictive Vehicle Modeling and GPS Data

Duprey, Benjamin Lawrence Blake 17 June 2009 (has links)
The use of global positioning systems, or GPS, as a means of logistical organization for fleet vehicles has become more widespread in recent years. The system has the ability to track vehicle location, report on diagnostic trouble codes, and keep tabs on maintenance schedules. This helps to improve the safety and productivity of the vehicles and their operators. Additionally, the increasing use of yaw and roll stability control in commercial trucks has contributed to an increased level of safety for truck drivers. However, these systems require the vehicle to begin a yaw or roll event before they assist in maintaining control. This thesis presents a new method for utilizing the GPS signal in conjunction with a new fuzzy logic-based stability index, the Total Safety Margin (TSM), to create a superior active safety system. This thesis consists of four main components: An overview of GPS technology is presented with coverage of several automotive-based applications. The proposed implementation of GPS in the new Hardware-in-the-Loop (HIL) driving simulator under development at the Virginia Tech Center for Vehicle Systems and Safety (CVeSS) is presented. The three degree-of-freedom (3DOF), linear, single track equation set used in the Matlab simulations is derived from first principles. Matlab and TruckSim 7® simulations are performed for five vehicle masses and three forward velocities in a ramp-steer maneuver. Using fuzzy logic to develop the control rules for the Total Safety Margin (TSM), TSM matrices are built for both the Matlab and TruckSim 7® results based on these testing conditions. By comparing these TSM matrices it is shown that the two simulation methods yield similar results. A discussion of the development and implementation of the aforementioned HIL driving simulator is presented, specifically the steering subsystem. Using Matlab/Simulink, dSPACE ControlDesk, and CarSim RT® software it is shown that the steering module is capable of steering the CarSim RT® simulation vehicle accurately within the physical range of the steering sensor used. / Master of Science
10

Exhaust system energy management of internal combustion engines

Wijewardane, M. Anusha January 2012 (has links)
Today, the investigation of fuel economy improvements in internal combustion engines (ICEs) has become the most significant research interest among the automobile manufacturers and researchers. The scarcity of natural resources, progressively increasing oil prices, carbon dioxide taxation and stringent emission regulations all make fuel economy research relevant and compelling. The enhancement of engine performance solely using incylinder techniques is proving increasingly difficult and as a consequence the concept of exhaust energy recovery has emerged as an area of considerable interest. Three main energy recovery systems have been identified that are at various stages of investigation. Vapour power bottoming cycles and turbo-compounding devices have already been applied in commercially available marine engines and automobiles. Although the fuel economy benefits are substantial, system design implications have limited their adaptation due to the additional components and the complexity of the resulting system. In this context, thermo-electric (TE) generation systems, though still in their infancy for vehicle applications have been identified as attractive, promising and solid state candidates of low complexity. The performance of these devices is limited to the relative infancy of materials investigations and module architectures. There is great potential to be explored. The initial modelling work reported in this study shows that with current materials and construction technology, thermo-electric devices could be produced to displace the alternator of the light duty vehicles, providing the fuel economy benefits of 3.9%-4.7% for passenger cars and 7.4% for passenger buses. More efficient thermo-electric materials could increase the fuel economy significantly resulting in a substantially improved business case. The dynamic behaviour of the thermo-electric generator (TEG) applied in both, main exhaust gas stream and exhaust gas recirculation (EGR) path of light duty and heavy duty engines were studied through a series of experimental and modelling programs. The analyses of the thermo-electric generation systems have highlighted the need for advanced heat exchanger design as well as the improved materials to enhance the performance of these systems. These research requirements led to the need for a systems evaluation technique typified by hardware-in-the-loop (HIL) testing method to evaluate heat exchange and materials options. HIL methods have been used during this study to estimate both the output power and the exhaust back pressure created by the device. The work has established the feasibility of a new approach to heat exchange devices for thermo-electric systems. Based on design projections and the predicted performance of new materials, the potential to match the performance of established heat recovery methods has been demonstrated.

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