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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.
171

Urban Policy Implications on the Electric Vehicle Transition in Berlin and Washington, DC

Sänger, Tina January 2018 (has links)
This thesis argues for an approach which goes beyond the conventional urban climate governance view. With engagement in social-technical practices, a more sustainable and inclusive way of transforming the city can be accomplished. One way of doing so is with the offering of the urban living lab as a playground for real-life experiments. With a purposive intervention in an urban socio-technical system, the three- dimensional concept of urban environmental governance, socio-technical experiments and strategic experiments with designed policies can create a more sustainable urban transition. The urban electric vehicle transition is just one example of how these three concepts can be applied. In order to demonstrate the interaction of a sustainable urban transition, an empirical case study was conducted.   This thesis makes a conceptual contribution by engaging with current understanding of urban sustainability transition, using the urban electric vehicle transition as a reference point. The insights of this study extend the theories of the socio-technical system and argue that it is not only about social and technological innovation but how multiple innovations are experimented with and combined in an existing urban context. In addition, the research addresses how this transition is governed on a municipality level and is achieved through a multiple case study approach, analysed through the lens of environmental governance and offers an empirical exploration and develops the theoretical and conceptual framework of the socio-technical system further.
172

Fuzzy Logic Based Driving Pattern Recognition for Hybrid Electric Vehicle Energy Management

January 2015 (has links)
abstract: For years the automotive industry has been shifting towards hybridization and electrification of conventional powertrains due to increase in fossil fuel cost and environmental impact due heavy emission of Green House Gases (GHG) and various pollutants into atmosphere by combustion engine powered vehicles. Hybrid Electric Vehicles (HEV) have proved to achieve superior fuel economy and reduced emissions. Supervisory control strategies determining the power split among various onboard power sources are evolving with time, providing better fuel economies. With increasing complexity of control systems driving HEV’s, mathematical modeling and simulation tools have become extremely advanced and have derived whole industry into adopting Model Based Design (MBD) and Hardware-in-the-loop (HIL) techniques to validate the performance of HEV systems in real world. This report will present a systematic mythology where MBD techniques are used to develop hybrid powertrain, supervisory control strategies and control systems. To validate the effectiveness of various energy management strategies for HEV energy management in a real world scenario, Conventional rule-based power split strategies are compared against advanced Equivalent Consumption Minimization Strategy (ECMS), in software and HIL environment. Since effective utilization of the fuel reduction potential of a HEV powertrain requires a careful design of the energy management control methodology, an advanced ECMS strategy involving implementation with Fuzzy Logic to reduce computational overload has been proposed. Conventional real-time implementation of ECMS based strategy is difficult due to the involvement of heavy computation. Methods like Fuzzy Logic based estimation can be used to reduce this computational overload. Real-time energy management is obtained by adding a Fuzzy Logic based on-the-fly algorithm for the estimation of driving profile and adaptive equivalent consumption minimization strategy (A-ECMS) framework. The control strategy is implemented to function without any prior knowledge of the future driving conditions. The idea is to periodically refresh the energy management strategy according to the estimated driving pattern, so that the Battery State of Charge (SOC) is maintained within the boundaries and the equivalent fuel consumption is minimized. The performance of the presented Fuzzy Logic based adaptive control strategy utilizing driving pattern recognition is benchmarked using a Dynamic Programming based global optimization approach. / Dissertation/Thesis / Masters Thesis Engineering 2015
173

EV Battery Performance in the Desert Area and Development of a New Drive Cycle for Arizona

January 2018 (has links)
abstract: Commercial Li-ion cells (18650: Li4Ti5O12 anodes and LiCoO2 cathodes) were subjected to simulated Electric Vehicle (EV) conditions using various driving patterns such as aggressive driving, highway driving, air conditioning load, and normal city driving. The particular drive schedules originated from the Environment Protection Agency (EPA), including the SC-03, UDDS, HWFET, US-06 drive schedules, respectively. These drive schedules have been combined into a custom drive cycle, named the AZ-01 drive schedule, designed to simulate a typical commute in the state of Arizona. The battery cell cycling is conducted at various temperature settings (0, 25, 40, and 50 °C). At 50 °C, under the AZ-01 drive schedule, a severe inflammation was observed in the cells that led to cell failure. Capacity fading under AZ-01 drive schedule at 0 °C per 100 cycles is found to be 2%. At 40 °C, 3% capacity fading is observed per 100 cycles under the AZ-01 drive schedule. Modeling and prediction of discharge rate capability of batteries is done using Electrochemical Impedance Spectroscopy (EIS). High-frequency resistance values (HFR) increased with cycling under the AZ-01 drive schedule at 40 °C and 0 °C. The research goal for this thesis is to provide performance analysis and life cycle data for Li4Ti5O12 (Lithium Titanite) battery cells in simulated Arizona conditions. Future work involves an evaluation of second-life opportunities for cells that have met end-of-life criteria in EV applications. / Dissertation/Thesis / Masters Thesis Engineering 2018
174

Análise econômica e ambiental de sistemas de geração alternativa para suprimento energético de carros elétricos / Economic and environmental analysis of alternative generation systems for energy suppression of electric cars

Castro, Thais Santos [UNESP] 02 March 2018 (has links)
Submitted by Thais Santos Castro (castro-thais@uol.com.br) on 2018-04-26T13:21:58Z No. of bitstreams: 1 THAIS SANTOS CASTRO.pdf: 3920352 bytes, checksum: 8fa2296933330e462938c1902f71c78c (MD5) / Approved for entry into archive by Pamella Benevides Gonçalves null (pamella@feg.unesp.br) on 2018-04-26T18:26:19Z (GMT) No. of bitstreams: 1 castro_ts_dr_guara.pdf: 3671282 bytes, checksum: ce9b5ca08f302fee05a9461f3e191855 (MD5) / Made available in DSpace on 2018-04-26T18:26:19Z (GMT). No. of bitstreams: 1 castro_ts_dr_guara.pdf: 3671282 bytes, checksum: ce9b5ca08f302fee05a9461f3e191855 (MD5) Previous issue date: 2018-03-02 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A preocupação com o meio ambiente e com a qualidade do ar tem sido o foco de vários trabalhos nos meios acadêmico e governamental, sabendo-se que e um dos grandes fatores dessa degradação é o meio de transporte. O poder aquisitivo do cidadão brasileiro unido à facilidade da compra de novos carros está crescendo a cada ano, com isso o número de veículos por habitante também tem aumentado; nesse sentido, é essencial que novas tecnologias mais eficientes e com melhor rendimento sejam estudadas e analisadas. Partindo deste conceito, nota-se que os carros elétricos são uma alternativa inteligente para diminuir a degradação provocada pelos combustíveis fósseis. A produção de energia elétrica por meio de fontes renováveis tais como fotovoltaica, biogás, etc., aliada ao baixo custo de manutenção e à longa vida útil, está se tornando uma alternativa atrativa. Neste trabalho são aplicadas metodologias para dimensionamento e análise do custo da geração de energia elétrica através de fontes renováveis: fotovoltaicas e biogás. Considera-se também o custo operacional do carro elétrico sendo abastecido com a eletricidade fornecida por essas fontes e pela energia da concessionária rede, comparado ao custo operacional de um carro de motor de combustão interna. Também é determinado o CO2eq emitido pela utilização da usina fotovoltaica, usina a biogás, energia da rede e pela gasolina e etanol utilizado no carro de MCI. Foi ainda calculado o passivo ambiental associado a cada tipo de tecnologia de geração de eletricidade renovável. Conclui-se que o retorno de investimento para a energia gerada pelo biogás é menor do que para a energia fotovoltaica, porém as duas opções apresentam viabilidade econômica, considerando ainda que a agressão ao meio ambiente é baixa para ambas as tecnologias. Tais fatores propiciam uma alternativa de estudo eficaz afim de customizar o sistema e diminuir o custo de geração de eletricidade e gerar alternativas de redução de CO2eq. / The concern about the environment and the quality of the air has been the focus of several studies in both academic and government fields, showing that one of the main responsible ones for the degradation of the environment is transportation. The acquisition power of Brazilian people coupled with the ease of buying new vehicles is growing every year; as a result, the rate of vehicles per inhabitant has also increased; in this sense, it is of essence that new and more efficient technologies be studied and analyzed. Starting from this concept, electric vehicles are a smart alternative to reduce the degradation caused by fossil fuels. The production of electricity from renewable sources such as photovoltaic, biogas, etc., combined with the fact that those systems have low maintenance costs and long service life is becoming an attractive alternative. In this study, methodologies are applied to calculate and analyze the costs of electricity generation by renewable sources: solar and biomass energy. It is also considered the operating cost of the electric car being fed with the electricity provided by these sources and by grid energy, compared to the operating cost of an internal combustion engine car. The CO2eq emitted by the use of the photovoltaic plant, the biogas plant, the grid energy and the gasoline and ethanol used in the ICE car is also determined. It was also calculated the environmental liabilities associated with each type of renewable electricity generation technology. As a conclusion, this study shows that the return of investment considering the energy generated by biogas systems is lower than the one required to generate photovoltaic energy, but both options present good return of investment, considering also the low level of aggression to the environment. These factors provide an effective option for a study aiming to customize the system and to reduce the electricity generation costs, decreasing CO2 equivalent levels
175

Um Sistema de Informações Geográficas para Gestão de Energia Elétrica Móvel - SIGGENELM / A geographic information system for management of mobile electric power - SIGGENELM.

Fernando Palma Guimarães Pereira 14 September 2010 (has links)
Um problema que as empresas distribuidoras de energia elétrica convivem são as quedas repentinas no fornecimento, causando inúmeros prejuízos tanto para essas empresas quanto para seus consumidores. Essa dissertação apresentará uma ferramenta que utilizará conhecimentos de sistemas de informações geográficas junto com o uso de inferência nebulosa para orientar a disposição de veículos híbridos (elétricos e à combustão) que podem operar como mini-usinas elétricas no abastecimento de localidades que esteja necessitando de energia em um determinado momento. Para isso, será levantada uma base de dados com características dos veículos híbridos e locais necessitados, dados esses que alimentarão um sistema nebuloso agregado à ferramenta MapServer e a um SIG (Sistema de Informações Geográficas) para, dessa forma, mostrar como saída do sistema qual veículo estará mais apto naquele instante para abastecer o local da demanda de energia. / A problem that electric energy companies have to face is the power outage, which causes innumerable damages for both companies and consumers. This dissertation describes a tool that joins Geographic Information Systems knowledge to Fuzzy Logic knowledge to guide the distribution of hybrid vehicles (electric and combustion) that can operate as mini electric power plants to supply places that need electrical power. For this, a database will be built with the characteristics of vehicles and places in need. The data will supply a Fuzzy system joined to a MapServer tool and a GIS (Geographic Information System), showing which vehicle will be more capable in that moment to supply the place in energy demand.
176

High Frequency Power Converter with ZVT for Variable DC-link in Electric Vehicles

January 2018 (has links)
abstract: The most important metrics considered for electric vehicles are power density, efficiency, and reliability of the powertrain modules. The powertrain comprises of an Electric Machine (EM), power electronic converters, an Energy Management System (EMS), and an Energy Storage System (ESS). The power electronic converters are used to couple the motor with the battery stack. Including a DC/DC converter in the powertrain module is favored as it adds an additional degree of freedom to achieve flexibility in optimizing the battery module and inverter independently. However, it is essential that the converter is rated for high peak power and can maintain high efficiency while operating over a wide range of load conditions to not compromise on system efficiency. Additionally, the converter must strictly adhere to all automotive standards. Currently, several hard-switching topologies have been employed such as conventional boost DC/DC, interleaved step-up DC/DC, and full-bridge DC/DC converter. These converters face respective limitations in achieving high step-up conversion ratio, size and weight issues, or high component count. In this work, a bi-directional synchronous boost DC/DC converter with easy interleaving capability is proposed with a novel ZVT mechanism. This converter steps up the EV battery voltage of 200V-300V to a wide range of variable output voltages ranging from 310V-800V. High power density and efficiency are achieved through high switching frequency of 250kHz for each phase with effective frequency doubling through interleaving. Also, use of wide bandgap high voltage SiC switches allows high efficiency operation even at high temperatures. Comprehensive analysis, design details and extensive simulation results are presented. Incorporating ZVT branch with adaptive time delay results in converter efficiency close to 98%. Experimental results from a 2.5kW hardware prototype validate the performance of the proposed approach. A peak efficiency of 98.17% has been observed in hardware in the boost or motoring mode. / Dissertation/Thesis / Masters Thesis Electrical Engineering 2018
177

Avaliação do desempenho dinâmico de veículo, devido ao incremento de massa não suspensa, decorrente de sistema de propulsão elétrica. / Evaluation of vehicle dynamics performance due to unsprung mass increase in decorrency of electric motors propulsion system.

Rafael Tedim Terra 04 September 2017 (has links)
A utilização de motores elétricos diretamente nos cubos de roda é uma alternativa de propulsão para um veiculo elétrico ou híbrido muito interessante, pois não necessita do uso de sistemas complexos de transmissão, tornando o conjunto mecânico muito mais simples e, consequentemente, reduzindo a sua massa, atritos e custos. Entretanto, a adição dos motores nas rodas causa o incremento da massa não suspensa, e isto irá afetar o comportamento de dirigibilidade do veículo. Dessa forma, com ajuda da ferramenta de multicorpos, será identificado o que ocorrerá devido ao acréscimo de massa compatível com os motores elétricos de última geração. Para isto, uma série de análises comparativas será realizada, com modelos de veículos baseados na técnica de multicorpos, para o caso de um carro de passeio compacto. Primeiramente, uma análise modal comparando um carro convencional aos carros com a utilização dos motores, no eixo traseiro ou no dianteiro, e uma posterior avaliação das frequências obtidas. Em sequência, também foram realizadas manobras padrão com o modelo de veículo completo e foram observadas maiores influências nos resultados das análises em regime transiente, como a manobra de troca de faixa e a manobra do anzol (\"fishhook\"). Com a ajuda destes resultados, foi possível identificar que as instalações dos motores elétricos nos cubos traseiros causam uma menor influência negativa no desempenho de dirigibilidade, quando comparado com o caso instalado no eixo dianteiro. Através de uma otimização realizada com a ajuda de uma análise de sensibilidade das variáveis do sistema (D.O.E.), baseada na manobra do anzol, foi possível identificar que alterações nas molas, amortecedores e barra estabilizadora são capazes de mitigar os efeitos indesejáveis causados pelo incremento de massa não suspensa. / The electric motors directly in wheel hubs usage is an alternative of propulsion for a electric or hybrid vehicle, since it does not need the use of complex systems of transmission, making the mechanical assembly simpler and, consequently, reducing its mass , frictions and costs. However, the addition of the motors in the wheels causes an increase unsprung mass, and this will affect the vehicle handlings behavior. In that way, with the assistance of the multibody tool, it will be identified the consequences of mass addition, compatible with the moderns electric motors of. In this work, a series of comparative analyzes will be carried out, with vehicle models based on multibody techniques, in the situation of a compact car. First, a modal analysis comparing a conventional car to with the vehicle using hub driven motors, in rear or front axle, and an evaluation of the obtained frequencies. In the sequence, standard maneuvers were also performed with the complete vehicle model, and greater influences were observed in the transient analysis results, such as lane change and fishhook maneuver. With help of these results, it was possible to identify; that the installation of the electric motors in the rear hubs causes a smaller negative influence on the handling performance when compared to the case installed on the front axle. Through an optimization performed with the aid of a system variable sensitivity analysis (D.O.E.) based on the fish hook maneuver, it was possible to identify thtat changes on springs, shock absorbers and stabilizer bar are able to mitigate the undesirable effects caused by the increase of unsprung mass.
178

Impact of electric vehicles in the steady state operation of distribution systems / Impacto de veÃculos elÃtricos na operaÃÃo em regime permanente de sistemas de distribuiÃÃo

Erasmo Saraiva de Castro 15 June 2015 (has links)
FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / This work aims to quantify the impact in the steady state operation of a distribution system when electric vehicles are connected. It is worth noting that the connection of them may cause significant changes in the voltage profile, in the degree of voltage unbalance and in the electrical losses of the system. In order to make this analysis, a three-phase power flow program was developed in MATLAB language. This program is based on the Ladder Iterative Technique and it contains models of overhead distribution lines, underground distribution lines, spot loads, distributed loads connected in wye and delta, step voltage regulators, capacitor banks, three-phase transformers and the model of an electric vehicle. This model allows simulation of a real electric vehicle of model Tesla Roadster, produced by Tesla Motors. The test system used in all simulations was the IEEE 13 bus. Moreover, the methodology consisted in simulate the system with the voltage regulator and without the voltage regulator under heavy load and light load conditions. The electric vehicle was connected to a specific systemâs bus and it were considered that it could work as a load or as a distributed generator with or without positive sequence voltage control. Constants configurations of the electric vehicles were considered for the heavy load and light load cases. The results of the simulations reveal there was voltage violation due to the connection of electric vehicles acting as loads in the test system under heavy load conditions without voltage regulator. When they operate as generators, they can maintain the voltage unbalance under the allowed 2%, turning the systemâs voltages more balanced. There were significant reductions when the electric vehicles acted as a load (71.1%) and as generator (77.5%) on the total real power losses when the system operated with voltage regulator on the substation and the electric vehicles operated with positive sequence voltage control (specified at 1,0 pu). / Este trabalho tem o objetivo de quantificar o impacto da conexÃo de veÃculos elÃtricos na operaÃÃo em regime permanente de um sistema de distribuiÃÃo. à visto que a conexÃo dos mesmos pode causar mudanÃas significativas no perfil de tensÃes, no grau de desequilÃbrio de tensÃo e nas perdas elÃtricas do sistema. Para realizar essa anÃlise, desenvolveu-se um programa de fluxo de potÃncia trifÃsico na linguagem MATLAB. O programa à baseado na tÃcnica iterativa de escada. Foram implementados nesse programa modelos de linhas de distribuiÃÃo aÃreas e subterrÃneas, modelos de cargas concentradas e distribuÃdas conectadas em delta e em estrela, modelos de reguladores de tensÃo, modelos de banco de capacitores, modelo de transformadores trifÃsicos e o modelo do veÃculo elÃtrico. Esse modelo permite simular o veÃculo elÃtrico Tesla Roadster da Tesla Motors. O sistema teste utilizado em todas as simulaÃÃes foi o sistema IEEE 13 barras. A metodologia utilizada consistiu em simular o sistema sem regulador de tensÃo e com o regulador de tensÃo, em carga pesada e em carga leve. O veÃculo elÃtrico foi conectado a uma barra do sistema e considerou-se que o mesmo podia funcionar como carga ou gerador distribuÃdo sem e com controle de tensÃo de sequÃncia positiva no ponto de conexÃo. Adotou-se disposiÃÃes constantes de veÃculos elÃtricos para os casos de carga pesada e carga leve. Os resultados das simulaÃÃes revelam que houve violaÃÃo de tensÃo devido à inserÃÃo de veÃculos elÃtricos atuando como carga no sistema teste em carga pesada sem regulador de tensÃo. Jà quando operam como gerador, os veÃculos elÃtricos diminuem o grau de desequilÃbrio em mÃdia, podendo mantÃ-lo abaixo do limite permitido de 2 %, tornando assim as tensÃes das barras trifÃsicas do sistema mais equilibradas. Houve reduÃÃes significativas quando os veÃculos elÃtricos atuaram como carga (71,1 %) e como gerador (77,5 %) na perda de potÃncia ativa total do sistema quando o sistema operou com regulador de tensÃo na subestaÃÃo e os veÃculos elÃtricos operaram com controle de tensÃo de sequÃncia positiva (especificada em 1,0 pu).
179

Study on Microwave-Driven Electric Vehicle for Agriculture / マイクロ波駆動農用電気車両に関する研究

Miyasaka, Juro 24 March 2014 (has links)
Kyoto University (京都大学) / 0048 / 新制・論文博士 / 博士(農学) / 乙第12823号 / 論農博第2796号 / 新制||農||1025(附属図書館) / 学位論文||H26||N4818(農学部図書室) / 31310 / 京都大学農学研究科農業工学専攻 / (主査)教授 清水 浩, 教授 近藤 直, 教授 飯田 訓久 / 学位規則第4条第2項該当
180

An Agent-Based Approach for Automating the Process of Charging Plug-in Electric Vehicles

Civelek, Ülkan Fuat January 2010 (has links)
The study of Power TAC is a Multi-Agent competitive simulation test-bed, providing opportunity to simulate research and developments of electronic agents which can manage the tasks of the consumers and energy resources in a virtual energy infrastructure. According to the Power TAC scenario, Plug-in Electrical Vehicles are a special type of consumers that interact with this infrastructure and sometimes with the producers through aggregators. The aim of this study is modeling an intelligent Plug-in Electric vehicle agent for Power TAC that acts as an intermediary between Power TAC grid and vehicle owners. The proposed agent acts autonomously and is capable of making decisions about its energy needs by learning the driving behaviors and other preferences of these vehicle owners in a specified time interval. These agents will be able to make decisions about buying energy from the grid when the charging process is necessary or sell their energy back to the grid when the conditions of the electricity market are sufficiently attractive. The objective of this study is to model a Multi-Agent system for automating the process of charging the plug-in Vehicle Agents in Power TAC scenario by determining the necessary agents and the simulation environment where the agents constructed and simulated. Аs results of this study, different strategies are defined by considering the preferences of the vehicle owners and the conditions of the vehicle; thereby the agents autonomously bid behalf of their user in order to automate the process of charging.

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