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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.
131

Acionamento de um motor síncrono de ímãs permanentes sem escovas visando aplicação em veículos elétricos

Valle, Rodolfo Lacerda 07 March 2013 (has links)
Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-04-24T18:25:05Z No. of bitstreams: 1 rodolfolacerdavalle.pdf: 17326163 bytes, checksum: b5bfc03806c064bdf98c9890ed322936 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-04-25T12:14:13Z (GMT) No. of bitstreams: 1 rodolfolacerdavalle.pdf: 17326163 bytes, checksum: b5bfc03806c064bdf98c9890ed322936 (MD5) / Made available in DSpace on 2017-04-25T12:14:13Z (GMT). No. of bitstreams: 1 rodolfolacerdavalle.pdf: 17326163 bytes, checksum: b5bfc03806c064bdf98c9890ed322936 (MD5) Previous issue date: 2013-03-07 / Esta dissertação apresenta as etapas de desenvolvimento de um sistema de acionamento de um motor CC de ímãs permanentes sem escovas para aplicação em veículos elétricos de pequeno porte. O motor é acionado por um inversor fonte de tensão trifásico (VSI, Voltage Source Inverter) baseado em interruptores IGBT (Insulated Gate Bipolar Transistor). Os sinais de comutação dos interruptores são gerados por uma estratégia de modulação vetorial. Sinais gerados por três sensores de efeito Hall são usados para detectar a posição angular do rotor. O motor é controlado a partir de duas malhas. Uma malha externa controla a velocidade enquanto a malha interna controla as correntes de fase do motor. O desempenho de dois tipos de controladores foram investigados para o controle das correntes sintetizadas pelo VSI: (i) controlador proporcional– integral no sistema de coordenadas síncrono e (ii) controlador proporcional–integral com integradores em múltiplos sistemas de coordenadas rotativas. Além das malhas de controle, o sistema de acionamento foi projetado com uma estratégia de desacoplamento das correntes de controle e uma ação preditiva para compensar o efeito das tensões contra–eletromotriz trapezoidais geradas por fase pelo motor. Um protótipo experimental do sistema de 5 kW foi montado em laboratório. Os algoritmos de controle do motor e do VSI, juntamente com o algoritmo de deteção de posição do rotor foi implementado em um controlador digital de sinais TMS320F28335. Resultados experimentais são apresentados, discutidos e utilizados para validar as estratégias de controle. / This dissertation presents the development of a permanent magnet brushless DC motor drive (PMBLDC) for small electric vehicles applications. A three–phase voltage source inverter (VSI) based on IGBT (insulated gate bipolar transistor) is used to drive the electric motor. The semiconductor switches are controlled by space vector modulation (SVM). Signals from three Hall effect sensors are used to detect the rotor angular position. Two closed–loops are used to control the PMBLDC motor. The outer loop controls the rotor velocity while the inner loop controls the motor phase currents. Two types of controllers were investigated to synthesize the currents: (i) proportional– integral controller in synchronous reference frame and (ii) proportional–integral controller with multiple rotating synchronous reference frame integrators. Besides the current control loops, the drive system was designed considering the decoupling of the synthesized phase currents and a feed-forward electromotive force waveform compensation. An experimental prototype of 5 kW was built in laboratory. The motor and VSI control algorithms and the algorithm used to detect the rotor position were implemented in a TMS320F28335, digital signal controller. Experimental results are presented, discussed along with the validation of the control strategy.
132

Méthodes d’optimisation dynamique de systèmes à plusieurs états pour l'efficacité énergétique automobile / Dynamic optimization in multi-states systems for automobile energy efficiency

Maamria, Djamaleddine 06 November 2015 (has links)
La gestion énergétique (EMS) pour véhicules hybrides a pour objectif de déterminer la répartition de puissance entre les différentes sources d'énergie de manière à minimiser la consommation de carburant et/ou les émissions polluantes. L'objectif de cette thèse est de développer un EMS en prenant en compte des températures internes (la température du moteur et/ou la température du système de post-traitement). Dans une première partie et en utilisant une connaissance préalable du cycle de conduite, le calcul d'un EMS est formulé comme un problème de commande optimale. Ensuite, le principe du minimum de Pontryagin (PMP) est utilisé pour résoudre ce problème d'optimisation.~En se basant sur les résultats numériques obtenus, un compromis entre les performances de la stratégie de commande et de la complexité du modèle utilisé pour la calculer est établi. Les différents problèmes étudiés dans cette thèse sont des exemples des simplifications successives de modèle qui peuvent être regroupées dans le concept des perturbations régulières en contrôle optimal sous contrainte de commande discuté ici. Dans une deuxième partie, la formulation de l'ECMS a été généralisée pour inclure les dynamiques thermiques. Ces extensions définissent des stratégies sous-optimales que nous avons testées numériquement et expérimentalement. / Energy management system (EMS) for hybrid vehicles consists on determining the power split between the different energy sources in order to minimize the overall fuel consumption and/or pollutant emissions of the vehicle. The objective of this thesis is to develop an EMS taking into account the internal temperatures (engine temperature and/or catalyst temperature). In a first part and using a prior knowledge of vehicle driving cycle, the EMS design is formulated as an optimal control problem. Then, the PMP is used to solve this optimization problem. Based on the obtained numerical results, some trade-off between performance of the control strategy and complexity of the model used to calculate this strategy is established. The various problems studied in this thesis are examples of successive model simplifications which can be recast in the concept of regular perturbations in optimal control under input constraints discussed here. In a second part, the feedback law of ECMS is generalized to include thermal dynamics. This defines sub-optimal feedback strategies which we have tested numerically and experimentally.
133

Predictive Energy Management of Long-Haul Hybrid Trucks : Using Quadratic Programming and Branch-and-Bound

Jonsson Holm, Erik January 2021 (has links)
This thesis presents a predictive energy management controller for long-haul hybrid trucks. In a receding horizon control framework, the vehicle speed reference, battery energy reference, and engine on/off decision are optimized over a prediction horizon. A mixed-integer quadratic program (MIQP) is formulated by performing modelling approximations and by including the binary engine on/off decision in the optimal control problem. The branch-and-bound algorithm is applied to solve this problem. Simulation results show fuel consumption reductions between 10-15%, depending on driving cycle, compared to a conventional truck. The hybrid truck without the predictive control saves significantly less. Fuel consumption is reduced by 3-8% in this case. A sensitivity analysis studies the effects on branch-and-bound iterations and fuel consumption when varying parameters related to the binary engine on/off decision. In addition, it is shown that the control strategy can maintain a safe time gap to a leading vehicle. Also, the introduction of the battery temperature state makes it possible to approximately model the dynamic battery power limitations over the prediction horizon. The main contributions of the thesis are the MIQP control problem formulation, the strategy to solve this with the branch-and-bound method, and the sensitivity analysis.
134

Zkoumání teplotních změn vlastností olověného akumulátoru v režimu hybridních vozidel / Investigation of temperature change in lead-acid accumulator for HEV

Tošer, Pavel January 2010 (has links)
The oldest and also most used type of secondary cells is lead-acid accumulator. Basic functional principle stayed same as in foundation time, only operation parameters are still improving (for example one of the most important is lifetime). Significant technical problem is temperature of lead-acid battery and her influence on functionality and running reactions. Master thesis is focused on this section, when is necessary to evaluate new pieces of knowledge in development. The work deals with description existing types of accumulators, further deals with theory of temperature balance and in the end by measured datas and theirs analyzing.
135

Zkoumání příčin předčasné ztráty kapacity v olověných akumulátorech pro hybridní elektrická vozidla / Investigation causes of the premature capacity loss in accumulator for hybrid electric vehicles

Vystrčil, Marek January 2010 (has links)
This thesis describes the results of two successive experiments. The first was focused on the influence of impurities in the active mass of negative electrode in PSoC (Partial State of Charge) mode, which simulates the conditions occurring in HEV (hybrid electric vehicle). In the second experiment, cells with the same additives were exposed to optimum downforce 4N/cm2, by which we wanted to prove the influence of pressure on life of VRLA (Valve Regulated Lead Acid) cells working in operating HEV conditions.
136

Vliv oxidu titaničitého na vlastnosti olověných akumulátorů pracujících v režimu hybridních vozidel / Effect of titanium dioxide on the properties of lead-acid batteries operating in hybrid vehicles mode

Konečný, Zdeněk January 2012 (has links)
This work deals with lead-acid batteries operating in hybrid electric vehicles mode, i.e. in a partial state of charge. The adverse effects such as premature capacity loss and large internal resistance can markedly affect the life of a lead battery. The experiment described in this work aims to clarify the influence of the titanium dioxide in the active mass of negative electrodes especially in the life of lead acid batteries.
137

Vliv skelných vláken v olověných akumulátorech pro hybridní elektrická vozidla / Effect of glass fibers in the lead-acid batteries for hybrid electric vehicles

Klojda, Viktor January 2012 (has links)
Master´s thesis deals with the utilization of lead-acid accumulators in hybrid electric vehicle regime. It describes the side effects known as PCL, generated during PSOC regime and connected with the length of the battery lifespan. One possibility how to eliminate these effects, is the use of additives in active mass of the negative electrode, in the form of glass fibres. The project provides the parametres and reactions of additive, that have lead to the improvement of battery properties. The purpose of this thesis is to verify the positive effect of the aditive on the lifespan of the lead-acid accumulator.
138

Vliv aditiv v olověných akumulátorech pro hybridní elektrická vozidla / Effect of additives in lead-acid batteries for hybrid electric vehicles.

Klaner, Pavel January 2012 (has links)
This thesis deals with issues of the issue lead-acid batteries and their application in mode of hybrid electric vehicle. The experiment is focused on the production of electrodes to determine the effect five types of additives in negative active mass in PsoC(Partial State of Charge) mode. This simulates conditions occurring in the mode of hybrid electric vehicles (HEV).
139

Efekt přítlaku vyvozovaného na elektrodový systém olověného akumulátoru s experimentálními elektrodami s příměsí skelných vláken / The effect of pressure on the electrode system in lead acid batteries with experimental glass fibers aditives electrodes

Fryda, Daniel January 2013 (has links)
This Master’s thesis deals with the lead-acid batteries, which are alternativ power supply. The lead-acid batteries are the oldest type of battery cells. This lead-acid batteries have a great use in hybrid electric vehicles (HEVs), which operate in different modes of vehicle operation. These modes correspond to the reactions taking place during discharging and charging the battery. The lead-acid batteries in hybrid electric vehicles work in mode PSoC. The practical part of the Master`s thesis examines how the characteristics of lead-acid batteries are modified due to admixture of glass fibers into negative active material and application of pressure to the electrode system.
140

Gestion énergétique de véhicules hybrides par commande optimale stochastique / Real-time energy management strategies for hybrid electric vehicles

Jiang, Qi 30 January 2017 (has links)
Ce mémoire présente une étude comparative de quatre stratégies de gestion énergétique temps réel, appliquées d'une part à un véhicule hybride thermique-électrique, et d'autre part à un véhicule électrique à pile à combustible : contrôle basé sur des règles empirique (RBS), minimisation de la consommation équivalente (A-ECMS), loi de commande optimale (OCL) établie à partir d'une modélisation analytique du système et programmation dynamique stochastique (SDP) associée à une modélisation des cycles de conduite par chaîne de Markov. Le principe du minimum de Pontryaguin et la programmation dynamique, applicables hors ligne, sont mis en œuvre pour fournir des résultats de référence. Les problèmes d’implémentation numérique et de paramétrage des stratégies sont discutés. Une analyse statistique effectuée sur la base de cycles aléatoires générés par chaînes de Markov permet d’évaluer la robustesse des stratégies étudiées. Les résultats obtenus en simulation, puis sur un dispositif expérimental montrent que les méthodes les plus simples (RBS ou OCL) conduisent à des consommations élevées. SDP aboutit aux meilleures performances avec en moyenne la plus faible consommation de carburant dans les conditions réelles de conduite et un état énergétique final du système de stockage parfaitement maîtrisé. Les résultats d’A-ECMS sont comparables à ceux de SDP en moyenne, mais avec une plus grande dispersion, en particulier pour l'état de charge final. Afin d'améliorer les performances des méthode, des jeux de paramètres dédiés aux différents contextes de conduite sont considérés. / This thesis presents a comparative study between four recent real-time energy management strategies (EMS) applied to a hybrid electric vehicle and to a fuel cell vehicle applications: rule-based strategy (RBS), adaptive equivalent consumption minimization strategy (A-ECMS), optimal control law (OCL) and stochastic dynamic programming (SDP) associated to driving cycle modeling by Markov chains. Pontryagin’s minimum principle and dynamic programming are applied to off-line optimization to provide reference results. Implementation and parameters setting issues are discussed for each strategy and a genetic algorithm is employed for A-ECMS calibration.The EMS robustness is evaluated using different types of driving cycles and a statistical analysis is conducted using random cycles generated by Markov process. Simulation and experimental results lead to the following conclusions. The easiest methods to implement (RBS and OCL) give rather high fuel consumption. SDP has the best overall performance in real-world driving conditions. It achieves the minimum average fuel consumption while perfectly respecting the state-sustaining constraint. A-ECMS results are comparable to SDP’s when using parameters well-adjusted to the upcoming driving cycle, but lacks robustness. Using parameter sets adjusted to the type of driving conditions (urban, road and highway) did help to improve A-ECMS performances.

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