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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.
101

Sustainable green infrastructure and operations planning for plug-in hybrid vehicles (PHEVs) : a Tabu Search approach

Dashora, Yogesh 27 January 2011 (has links)
Increasing debates over a gasoline independent future and the reduction of greenhouse gas (GHG) emissions has led to a surge in plug-in hybrid electric vehicles (PHEVs) being developed around the world. Due to the limited all-electric range of PHEVs, a daytime PHEV charging infrastructure will be required for most PHEVs’ daily usage. This dissertation, for the first time, presents a mixed integer mathematical programming model to solve the PHEV charging infrastructure planning (PCIP) problem. Our case study, based on the Oak Ridge National Laboratory (ORNL) campus, produced encouraging results, indicates the viability of the modeling approach and substantiates the importance of considering both employee convenience and appropriate grid connections in the PCIP problem. Unfortunately, the classical optimization methods do not scale up well to larger practical problems. In order to effectively and efficiently attack larger PCIP problems, we develop a new MASTS based TS algorithm, PCIP-TS to solve the PCIP. The results from computational experiments for the ORNL campus problem establish the dominant supremacy of the PCIP-TS method both in terms of solution quality and computational time. Additional experiments with simulated data representative of a problem that might be faced by a small city show that PCIP-TS outperforms CPLEX based optimization. Once the charging infrastructure is in place, the immediate problem is to judiciously manage this system on a daily basis. This thesis formally develops a mixed integer linear program to solve the daily the energy management problem (DEM) faced by an organization and presented results of a case study performed for ORNL campus. The results from our case study, based on the Oak Ridge National Laboratory (ORNL) campus, are encouraging and substantiate the importance of controlled PHEV fleet charging and realizing V2G capabilities as opposed to uncontrolled charging methods. Although optimal solutions are obtained, the solver requires practically unacceptable computational times for larger problems. Hence, we develop a new MASTS based TS algorithm, DEM-TS, for the DEM models. Results for ORNL campus data set prove the dominant computational efficiency of the DEM-TS. For the simulated extended sized problems that resemble the complexity of a problem faced by a small city, the results prove that DEM-T not only achieves optimality, but also produces sets of multiple alternate optimal solutions. These could be very helpful in practical settings when alternate solutions are necessary because some solutions may not be deployable due to unforeseen circumstances. / text
102

Μελέτη και κατασκευή ηλεκτρονικής διάταξης για υβριδικό όχημα : ανάκτηση ενέργειας

Ζερβάκος, Αθανάσιος 27 April 2009 (has links)
Τα τελευταία 35 χρόνια έχει προκύψει ένα ενεργειακό πρόβλημα το οποίο μας επιβάλει να αλλάξουμε την ενεργειακή μας αντίληψη. Το πετρέλαιο αλλά και άλλα ορυκτά καύσιμα έχουν πεπερασμένα αποθέματα και η χρήση τους επιβαρύνει το περιβάλλον. Επίσης γεωπολιτικά συμφέροντα δεν επιτρέπουν την ανεμπόδιστη διανομή του. Μέσα σε αυτό το κλίμα της ενεργειακής απεξάρτησης από τα ορυκτά καύσιμα αναπτύσσονται τα τελευταία χρόνια τα υβριδικά οχήματα. Τα ηλεκτρικά υβριδικά οχήματα είναι ένα μεταβατικό στάδιο από την πετρελαιοκίνηση στην εξ’ ολοκλήρου κίνηση μέσω ηλεκτρισμού από ενεργειακές κυψέλες. Αποτελούνται από έναν συμβατικό κινητήρα εσωτερικής καύσης και μια ηλεκτρική μηχανή, η οποία τροφοδοτείται από συσσωρευτές. Τα υβριδικά οχήματα χωρίζονται σε διάφορες κατηγορίες ανάλογα με τις τεχνολογίες υβριδοποίησης που διαθέτουν και την διάταξη του ηλεκτρομηχανολογικού τους συστήματος. Στόχος της παρούσας διπλωματικής εργασίας (η οποία είναι η συνέχεια δυο προηγούμενων) είναι η προσπάθεια κατασκευής ενός υβριδικού αυτοκινήτου. Για να γίνει αυτό εφικτό απαιτούνται, ένα όχημα το οποίο να μπορεί να δεχθεί εύκολα μηχανολογικές μετατροπές, ένας ηλεκτρικός κινητήρας και συσσωρευτές. Ο ηλεκτρικός κινητήρας ελέγχεται από έναν αντιστροφέα. Ο αντιστροφέας είναι μια ηλεκτρική συσκευή η οποία μετατρέπει το συνεχές ρεύμα των συσσωρευτών σε εναλλασσόμενο. Βασικό κομμάτι του αντιστροφέα είναι η λογική παλμοδότησής του. Ο αντιστροφέας που κατασκευάστηκε χρησιμοποιεί τον άμεσο έλεγχο ροπής, ο οποίος είναι ένα είδος άμεσου διανυσματικού ελέγχου που χρησιμοποιεί τον μετασχηματισμό Park. / Τα τελευταία 35 χρόνια έχει προκύψει ένα ενεργειακό πρόβλημα το οποίο μας επιβάλει να αλλάξουμε την ενεργειακή μας αντίληψη. Το πετρέλαιο αλλά και άλλα ορυκτά καύσιμα έχουν πεπερασμένα αποθέματα και η χρήση τους επιβαρύνει το περιβάλλον. Επίσης γεωπολιτικά συμφέροντα δεν επιτρέπουν την ανεμπόδιστη διανομή του. Μέσα σε αυτό το κλίμα της ενεργειακής απεξάρτησης από τα ορυκτά καύσιμα αναπτύσσονται τα τελευταία χρόνια τα υβριδικά οχήματα. Τα ηλεκτρικά υβριδικά οχήματα είναι ένα μεταβατικό στάδιο από την πετρελαιοκίνηση στην εξ’ ολοκλήρου κίνηση μέσω ηλεκτρισμού από ενεργειακές κυψέλες. Αποτελούνται από έναν συμβατικό κινητήρα εσωτερικής καύσης και μια ηλεκτρική μηχανή, η οποία τροφοδοτείται από συσσωρευτές. Τα υβριδικά οχήματα χωρίζονται σε διάφορες κατηγορίες ανάλογα με τις τεχνολογίες υβριδοποίησης που διαθέτουν και την διάταξη του ηλεκτρομηχανολογικού τους συστήματος. Στόχος της παρούσας διπλωματικής εργασίας (η οποία είναι η συνέχεια δυο προηγούμενων) είναι η προσπάθεια κατασκευής ενός υβριδικού αυτοκινήτου. Για να γίνει αυτό εφικτό απαιτούνται, ένα όχημα το οποίο να μπορεί να δεχθεί εύκολα μηχανολογικές μετατροπές, ένας ηλεκτρικός κινητήρας και συσσωρευτές. Ο ηλεκτρικός κινητήρας ελέγχεται από έναν αντιστροφέα. Ο αντιστροφέας είναι μια ηλεκτρική συσκευή η οποία μετατρέπει το συνεχές ρεύμα των συσσωρευτών σε εναλλασσόμενο. Βασικό κομμάτι του αντιστροφέα είναι η λογική παλμοδότησής του. Ο αντιστροφέας που κατασκευάστηκε χρησιμοποιεί τον άμεσο έλεγχο ροπής, ο οποίος είναι ένα είδος άμεσου διανυσματικού ελέγχου που χρησιμοποιεί τον μετασχηματισμό Park.
103

System Modeling and Energy Management Strategy Development for Series Hybrid Vehicles

Cross, Patrick Wilson 19 May 2008 (has links)
A series hybrid electric vehicle is a vehicle that is powered by both an engine and a battery pack. An electric motor provides all of the mechanical motive power to the transmission. Engine power is decoupled from the transmission by converting engine power into electricity which powers the electric motor. The mechanical decoupling of the engine from the transmission allows the engine to be run at any operating point (including off) during vehicle operation while the battery back supplies or consumes the remaining power. Therefore, the engine can be operated at its most efficient operating point or in a high-efficiency operating region. The first objective of this research is to develop a dynamic model of a series hybrid diesel-electric powertrain for implementation in Simulink. The vehicle of interest is a John Deere M-Gator utility vehicle. This model serves primarily to test energy management strategies, but it can also be used for component sizing given known load profiles for a vehicle. The second objective of this research is to develop and implement multiple energy management strategies of varying complexity from simple thermostat control to an optimal control law derived using dynamic programming. These energy management strategies are then tested and compared over the criteria of overall fuel efficiency, power availability, battery life, and complexity of implementation. Complexity of implementation is a critical metric for control designers and project managers. The results show that simple point-based control logic can improve upon thermostat control if engine efficiency maps are known. All control method results depend on the load profile being used for a specific application.
104

Power system impacts of plug-in hybrid electric vehicles

Roe, Curtis Aaron 08 July 2009 (has links)
Two studies are presented quantifying the impact of plug-in hybrid vehicles (PHEVs) on power systems. The first study quantifies this impact in terms of (a) primary fuel utilization shifts, (b) pollution shifts, and (c) total cost for consumers. The second study quantifies this impact on distribution transformers. In the first study vehicle and power system simulations are used to compute the expected power system fuels utilized to meet a projected level of power demand. The projected electric power demand includes business as usual electric load and random PHEV charging electric load. In the second study the impact on distribution transformers is quantified through a loss of life calculation. The loss of life calculation is based on distribution transformer hot-spot temperature. The hot-spot temperature is estimated using an electro-thermal distribution transformer model and is a function of the transformer currents. The transformer currents are computed using a center-tapped single phase transformer model. Random business as usual and PHEV charging electric loading is assumed.
105

Electric vehicles in China : past, present and future

Zhang, Zichen January 2015 (has links)
As the world's major car-producing countries and companies are increasing research and development efforts on vehicle electrification, electric vehicles (EVs) are developing rapidly from the development and testing stage to commodity production and application stage. As the largest global vehicle manufacturer and new vehicle market, China has considered the EV as one of the key tools to solve the increasing energy security issues and environmental pollution issues in the road transport sector. However, as a new market, what the challenges and key factors are in the EV promotion process is still not clear. The main objective of this dissertation is to answer this question through evaluating the effectiveness of EV development in China on energy savings, environment protection and policy demonstration. Instead of covering all determinants, this dissertation mainly focuses on four key aspects: the current statues and issues surrounding China's EV development and promotion; the energy consumption and carbon emissions of EVs based on the power mix both at the state level and regional level; the potential diffusion trend of the EV penetration and the sensitivities of the key impact factors; and the evaluation of the effectiveness of the EV demonstration program in China. Applying a mix of qualitative and quantitative research methods (such as lifecycle analysis, diffusion model and evaluation framework), this dissertation found that, in addition to the technology limitation of the EV, there are still many issues surrounding the environmental, industry, infrastructure and policy aspects, which have hindered EV development in China. To accelerate EV promotion, more comprehensive and diversified policy strategies should be developed instead only focusing on the financial subsidies. The charging infrastructures, for example, showed a more important role in EV penetration than the pricing factors, based on current market conditions. For the energy and environmental motivations, although the pure battery EV (BEV) can achieve a great reduction in fossil energy consumption, its benefits in carbon emission savings is not obvious due to China's heavy reliance on coal-fired power generation. The plug-in hybrid EV (PHEV) seems to be the right choice as a transit technology, according to its performance with emission savings in the current market situation. An evaluation framework has been developed in this dissertation to discuss the effectiveness of the EV demonstration program in China, and help to guide a more balanced development of EVs by considering comprehensive aspects, which include the EV industry, market conditions, policy support, and environmental impacts. Ultimately, this dissertation provides recommendations for the policy implementation for developing a diversified and flexible policy strategy for the EV penetration in China based on different technology choices (EV types), different situations (national and regional) and different timelines (short-term, mid-term and long-term).
106

Aligning sustainability and corporate strategies: the case of hybrid-electric vehicles and Fiat-Chrysler Automobiles

Narullo, Andrea 10 March 2015 (has links)
Submitted by Andrea Narullo (andrea.narullo@gmail.com) on 2015-04-01T21:07:41Z No. of bitstreams: 1 Thesis_ANDREA_NARULLO.pdf: 918513 bytes, checksum: 7bf8286368315afd80f709515ad77857 (MD5) / Rejected by Luana Rodrigues (luana.rodrigues@fgv.br), reason: Dear Andrea, I kindly ask you to do these changes: 1) After the abstract, you have to do the "resumo", abstract in Portuguese. 2) Regarding the knowledge field. There are only 3 field of knowledge of MPGI registered in CAPES (The Government Department responsible for the rules of Masters Programs) and they are: Economia e Finanças Internacionais, Internacionalização de Empresas e Gestão e Competitividade em Empresas Globais. Therefore I advise you to put the field of knowledge recorded in CAPES. After you modify them, please post your thesis again. Best regards, Luana de Assis Rodrigues Cursos de Pós-Graduação – Post Graduate Program (55 11) 3799-3492 SRA - Secretaria de Registros Acadêmicos on 2015-04-06T12:44:38Z (GMT) / Submitted by Andrea Narullo (andrea.narullo@gmail.com) on 2015-04-06T16:43:58Z No. of bitstreams: 1 Thesis_ANDREA_NARULLO.pdf: 920119 bytes, checksum: dfc25b860afd1668375a688aed3bfc8a (MD5) / Approved for entry into archive by Luana Rodrigues (luana.rodrigues@fgv.br) on 2015-04-06T19:20:02Z (GMT) No. of bitstreams: 1 Thesis_ANDREA_NARULLO.pdf: 920119 bytes, checksum: dfc25b860afd1668375a688aed3bfc8a (MD5) / Made available in DSpace on 2015-04-07T13:20:11Z (GMT). No. of bitstreams: 1 Thesis_ANDREA_NARULLO.pdf: 920119 bytes, checksum: dfc25b860afd1668375a688aed3bfc8a (MD5) Previous issue date: 2015-03-10 / This study analyses the integration of environmental sustainability into corporate strategy in the context of the car industry. The implementation of sustainability strategies and the development of hybrid-electric vehicles are investigated with reference to the case of a major player in the industry. Among the applications of electric mobility, which will increase the market presence in the forthcoming years due to stringent regulations and customer preferences, the research focused on hybrid-electric vehicles. The sustainability strategies of major car manufacturers and the subsequent implications in terms of product development, with a particular attention to hybrid-electric vehicles, were analysed via secondary data. Additionally, primary data was collected about the sustainability strategy of a major player in the industry and used to perform a case study. The analysis focused on critical drivers and aspects that impact on sustainability strategies aimed at reducing the environmental footprint of the car industry and on the development of hybrid vehicles. The analysis of the data showed that Fiat-Chrysler Automobiles (FCA) had a minor emphasis on electric mobility in terms of sustainability reporting. The conclusion presents an assessment of FCA’s corporate strategy in terms of environmental sustainability and a framework for HEV development with four different approaches that impact on the sustainability strategy of a carmaker. / Este estudo analisa a integração da sustentabilidade ambiental na estratégia das empresas no contexto da indústria automobilística. A implementação de estratégias de sustentabilidade e o desenvolvimento de veículos híbrido-elétricos são investigados com referência ao caso de um ator principal na indústria. Entre as aplicações de mobilidade eléctrica, que irá aumentar a presença no mercado nos próximos anos devido às regulamentações rigorosas e as preferências dos clientes, a pesquisa está focada em veículos híbrido-elétricos. As estratégias de sustentabilidade das grandes fabricantes de automóveis e as implicações subsequentes em termos de desenvolvimento de produtos, com uma atenção especial aos veículos elétricos híbridos, foram analisados através de dados secundários. Além disso, os dados primários foram coletados sobre a estratégia de sustentabilidade de um ator importante na indústria e usados para realizar um estudo de caso. A análise incidiu sobre os fatores críticos e os aspectos que têm impacto sobre as estratégias de sustentabilidade, que visam reduzir o impacto ambiental da indústria automobilística, e sobre o desenvolvimento de veículos híbridos. A análise dos dados mostrou que a Fiat-Chrysler Automobiles (FCA) teve uma ênfase menor na mobilidade eléctrica em termos de relatórios de sustentabilidade. A conclusão apresenta uma avaliação da estratégia corporativa da FCA, em termos de sustentabilidade ambiental, e apresenta um quadro para o desenvolvimento de veículos híbridos com quatro abordagens diferentes que têm impacto sobre a estratégia de sustentabilidade de uma montadora.
107

Analyzing the Performance of Lithium-Ion Batteries for Plug-In Hybrid Electric Vehicles and Second-Life Applications

January 2017 (has links)
abstract: The automotive industry is committed to moving towards sustainable modes of transportation through electrified vehicles to improve the fuel economy with a reduced carbon footprint. In this context, battery-operated hybrid, plug-in hybrid and all-electric vehicles (EVs) are becoming commercially viable throughout the world. Lithium-ion (Li-ion) batteries with various active materials, electrolytes, and separators are currently being used for electric vehicle applications. Specifically, lithium-ion batteries with Lithium Iron Phosphate (LiFePO4 - LFP) and Lithium Nickel Manganese Cobalt Oxide (Li(NiMnCo)O2 - NMC) cathodes are being studied mainly due to higher cycle life and higher energy density values, respectively. In the present work, 26650 Li-ion batteries with LFP and NMC cathodes were evaluated for Plug-in Hybrid Electric Vehicle (PHEV) applications, using the Federal Urban Driving Schedule (FUDS) to discharge the batteries with 20 A current in simulated Arizona, USA weather conditions (50 ⁰C & <10% RH). In addition, 18650 lithium-ion batteries (LFP cathode material) were evaluated under PHEV mode with 30 A current to accelerate the ageing process, and to monitor the capacity values and material degradation. To offset the high initial cost of the batteries used in electric vehicles, second-use of these retired batteries is gaining importance, and the possibility of second-life use of these tested batteries was also examined under constant current charge/discharge cycling at 50 ⁰C. The capacity degradation rate under the PHEV test protocol for batteries with NMC-based cathode (16% over 800 cycles) was twice the degradation compared to batteries with LFP-based cathode (8% over 800 cycles), reiterating the fact that batteries with LFP cathodes have a higher cycle life compared to other lithium battery chemistries. Also, the high frequency resistance measured by electrochemical impedance spectroscopy (EIS) was found to increase significantly with cycling, leading to power fading for both the NMC- as well as LFP-based batteries. The active materials analyzed using X-ray diffraction (XRD) showed no significant phase change in the materials after 800 PHEV cycles. For second-life tests, these batteries were subjected to a constant charge-discharge cycling procedure to analyze the capacity degradation and materials characteristics. / Dissertation/Thesis / Masters Thesis Materials Science and Engineering 2017
108

Look-Ahead Optimization of a Connected and Automated 48V Mild-Hybrid Electric Vehicle

Gupta, Shobhit 19 June 2019 (has links)
No description available.
109

Simulation-based optimization of Hybrid Systems Using Derivative Free Optimization Techniques

Jayakumar, Adithya 27 December 2018 (has links)
No description available.
110

Energy Optimal Routing of Vehicle Fleet with Heterogeneous Powertrains

Arasu, Mukilan T. January 2019 (has links)
No description available.

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