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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

Elbilens påverkan på Falunslågspänningsnät vid hemmaladdning / The impact of home charging of electrical vehicles at Falun's low-voltage distribution grid

Hammarlund, Tomas January 2019 (has links)
The number of electrical vehicles in Sweden are increasing faster for every year and the demand of charging them at home is growing as well. This requires high delivery reliability and a stable low-voltage distribution grid. In this master thesis three different low-voltage networks are modelled and simulated together with load which corresponds home charging of electrical vehicles (EV) to analyse if the grid is able to handle these kinds of stresses. Information of the different grids were gathered from Falu Energi & Vatten and modelled in Matlab together with EV charging loads generated in a separate program. The electricity consumption data used in the simulations were measured at the transformer in each grid. A regression analysis of the consumption data were preformed to calculate values which corresponds to a worst case scenario. The results show that the low-voltage distribution grid in Falun is well dimensioned and can handle these possible future loads even in the worst constructed scenario.
2

Coordinated control for smart charging of EV fleet in solar powered building community

Zalasa, Maciej January 2021 (has links)
Renewable energy integration is increasing – alongside it, the main limiting factors of such sources of energy have to be considered. Each source of energy comes with its unique sets of challenges, namely the way that the generation curves behave. These patterns should be considered, if photovoltaics can contribute at a larger rate to the grid. The current non-renewable sources provide a high response rate and great control over voltage/frequency – key parameters of the grid. Proper utilization of renewable energies is key to sustainable systems of the future.The work considers the possibility of regulating the energy flow through the usage of electric vehicles (EV). The thesis proposes a model within which particle swarm optimization is used to derive EV charging rates, which contribute to the overall performance of a controlled household system. Three control strategies are considered – individual, bottom-up and top-down control. The methodologies are introduced and compared in the study.Top-down control proves to be the most stable and most efficient at reducing energy mismatch when compared to other control strategies. It should however be underlined that any control strategy proposed in the study leads to a greater utilization of renewable energy and can greatly benefit any system with EVs and PV energy present.
3

Joint Routing and Scheduling of Electrical Trucks using Mixed Integer Linear Programming

Schildt, Lukas January 2024 (has links)
This thesis studies the logistical problem of serving customer demands by electric vehicles, a currently important problem given the growing emphasis on sustainability in industry. In optimization, this is called the electric vehicle routing problem (E-VRP), and it is generally to computationally demanding to solve with a single comprehensive model. The method of this thesis is therefore a heuristic approach, in which the routing and the charging of the vehicles are done separately. The routing disregards the energy considerations, and the scheduling assigns routes and charging to a fleet of electric vehicles. When considering the charging separately, it can be model more realistically than what is usually done in E-VRP. A bibliographical review of both E-VRP and of electrical scheduling modeling is conducted, with a focus on which aspects are normally prioritized. Then two different models for the routing, and four different models for the scheduling are described. This routing-scheduling framework is subsequently tested on both artificial trial instances and a real-world problem. Promising results are observed in terms of runtime, with the ability to obtain good solutions on large instances within seconds. The real-world scenario was also solved quickly. Additionally, the results suggest a versatility of the routing-scheduling framework across various E-VRP variations.
4

Analysis and diagnosis of faults in the PEMFC for fuel cell electrical vehicles / Analyse et diagnostique des défauts de PEMFC pour véhicules à pile à combustible

Mohammadi, Ali 12 December 2014 (has links)
Ces dernières années, la pile à combustible à membrane échangeuse de proton (PEMFC) a fait l’objet d’un intérêt particulier pour des applications liées au transport. De par le fait qu’elle fonctionne à une température de fonctionnement relativement basse (50-100°C) combiné à une membrane polymère solide empêchant tout risque de fuite. Dans ce travail, des expérimentations ont été effectuées pour démontrer que la distribution de température à une influence significative sur les performances de la PEMFC. Par ailleurs, ce travail comporte une analyse ayant pour but de d’indiquer une amélioration de la résistivité ionique de la membrane, de la vitesse de réaction et de la diffusion des gaz en fonction de la température. Des expérimentations sur une cellule puis sur un stack complet ont permis d’évaluer l’impact de la température à l’aide d’un modèle 3D développé simulant les performances de la pile en relation avec la distribution de température. Dans cette thèse, deux piles à combustible ont permis de valider le comportement et d’en déduire une relation entre la tension de sortie et la distribution de température dans différentes conditions de fonctionnement. Une étude expérimentale prenant en compte la tension et la température a été effectuée sur une cellule en mesurant la température et le voltage en douze points à l’aide de thermocouples et de sonde de tension. Le modèle 3D proposé permet ainsi d’améliorer la durée de vie d’une pile ainsi que sa fiabilité, il permet aussi d’effectuer un diagnostic et de détecter en ligne un défaut. Ceci est effectué en calculant la densité de courant localement à différentes conditions de fonctionnement en utilisant la méthode de Newton Raphson. De par le développement de ce modèle sensible à un défaut, un algorithme de détection de défaut ainsi que la stratégie de diagnostic ont été développé en utilisant des réseaux de neurones artificiels (RNN). Ces derniers ont été utilisés pour la classification supervisée de défaut permettant ainsi le diagnostic. / In recent years, according to the upcoming challenge of pollution, fuel saving, to use on FCEV is increasing. It can be that fuel cell power train divided in the PEMFC, Batteries, DC/DC converters, DC/AC inverters and electrical motors. The Proton Exchange Membrane Fuel cells (PEMFC) have consistently been considered for transportation application. Characteristic features of PEMFC include lower temperature (50 to 100 °C) and solid polymer electrolyte membrane. In this work, experiments have shown that the temperature distributions can significant influence on the performance of the PEMFC. Also analytical studies have indicated improvement of ionic resistivity of the electrolyte membrane, kinetics of electrochemical reaction and gas diffusion electrodes have directly related to temperature. This work evaluated the effectiveness of temperature on a single and stack fuel cell. In addition, a 3D model is developed by effective of temperature on performance on the fuel cell. In this thesis, two PEM fuel cells have been considered to find out the relationship and analyze the behaviors of the cell voltage and temperature distributions under various operating conditions. An experimental study for voltage and temperature has been executed, using one cell, 12 thermocouples and 12 voltage sensors have been installed at different points of the cell. In this work a new model was proposed to improve the lifetime and reliability of the power train and to detect online faults. Besides, current distributions in different points of the cell based on varying operating conditions are calculated by the Newton Raphson method. On the basis of the developed fault sensitive models above, an ANN based fault detection; diagnosis strategy and the related algorithm have been developed. The identified patterns ANN have been used in the supervision and the diagnosis of the PEMFC drivetrain. The ANN advantages of the ability to include a lot of data made possible to classify the faults in terms of their type.
5

Database and Modeling of Field Test Data fromLithium Ion Batteries in Hybrid Electrical Vehicles.

Höök, Niclas January 2011 (has links)
In this thesis information received from a hybrid vehicle battery test equipment wasstructured and analyzed. This test equipment is currently placed on a fleet of Scaniatrucks with the purpose of emulating hybrid vehicle environment on battery cell level.A Microsoft Access database structure was set up in order to make it possible to savetest data in a structured way. In addition, Matlab scripts were made with the purposeof calculating cell aging from pulse- and capacity tests. Furthermore, drive cycleanalysis was performed looking at statistics for selected parameters. Data collectedfrom late October 2010 until beginning of July does not yet show any aging of the fieldtested battery cells regarding capacity loss or resistance increase. The internalresistance of the batteries was calculated to 2 to 4 milli ohm and the capacity wasfrom the tests found to be around 3 ampere hours. The energy efficiency, which wascalculated from pulse test data, shows an efficiency between 95 to 97%.
6

Έλεγχος ηλεκτρικού υβριδικού οχήματος με κινητήρα εσωτερικής καύσης υδρογόνου

Τσεκούρας, Πέτρος 22 September 2009 (has links)
Αυτή η διπλωματική εργασία παραθέτει όλα τα στοιχεία που χρειάζονται για την εξέλιξη ενός συμβατικού κινητήρα εσωτερικής καύσης σε υβριδικό κινητήρα καύσης υδρογόνου. Στο δεύτερο κεφάλαιο περιγράφεται η λειτουργία ενός συμβατικού βενζινοκινητήρα. Στο τρίτο κεφάλαιο περιγράφονται οι ιδιότητες του υδρογόνου και η λειτουργία ενός ηλεκτρικού υβριδικού οχήματος και η τοπολογία που θα χρησιμοποιηθεί στην μοντελοποίηση. Στο τέταρτο κεφάλαιο αναλύονται τα επιμέρους στοιχεία που πρέπει να μεταβληθούν σε έναν βενζινοκινητήρα για να γίνει καύσης υδρογόνου. Τέλος στο πέμπτο κεφάλαιο παρατίθεται το μοντέλο του υβριδικού κινητήρα σε Simulink και εξηγείται η λειτουργία του. / This diploma thesis indicates all the structural elements that are needed for the development of a conventional internal combustion engine into a hybrid electric vehicle with a hydrogen combustion engine.The second chapter is about description and main functions of a conventional gasoline engine.In the third chapter are discribed the properties of hydrogen for use in a combustion engine, the main function of a hybrid electric vehicle and the structure that will be used into the modelling.In the forth chapter are analysed the further structural elements that have to be changed in an internal combustion engine in order to be fueled with hydrogen.Finally in the fifth chapter a model of a hybrid electric vehicle with a hydrogen combustion engine in Simulink is described and the main functions of it are described along with certain results.
7

Conversores CC-CC elevadores de tensão, não isolados, com ganhos estáticos elevados / Step-up, non-insulated, high-gain Dc-DC converters

Garcia, Fellipe Saldanha 16 August 2018 (has links)
Orientador: José Antenor Pomilio / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-16T18:42:35Z (GMT). No. of bitstreams: 1 Garcia_FellipeSaldanha_M.pdf: 10358371 bytes, checksum: 43197de07c314068d99689affe6298a7 (MD5) Previous issue date: 2010 / Resumo: Os conversores CC-CC possuem importantes aplicações no aproveitamento de fontes renováveis de energia elétrica e nos veículos elétricos. Nestas aplicações, muitas vezes é desejável que o conversor opere com elevado ganho de tensão. Esta dissertação investiga topologias de conversores CC-CC não isolados, que possuem potencial de trabalhar com elevado ganho de tensão. Uma das topologias estudadas, o interleaved double dual boost, é utilizado parademonstrar as técnicas de projeto e controle do conversor. São apresentados resultados experimentais para este conversor. / Abstract: The DC-DC converters have important applications in the electric energy generation using renewable energy sources and in the electric vehicles. In those applications, it is often required that the converter operates with high voltage gain. This work investigates some non-insulated topologies of DC-DC converters that can be used when high voltage gain is necessary or convenient. One of the studied topologies, the six-phase interleaved double dual boost, is used to demonstrate the design and control techniques. Experimental results for this converter are presented. / Mestrado / Energia Eletrica / Mestre em Engenharia Elétrica
8

An Analysis of EV Battery Key Materials Demand on the Path Towards Carbon Neutrality in Sweden

Su, Hui, Lidé, Aron January 2023 (has links)
The Swedish government has set a goal to have zero net greenhouse gas emissions by 2045 andto reduce emissions from domestic transport by at least 70% compared to 2010 levels by 2030.To achieve this, an expansion of the Swedish electric vehicle (EV) personal car fleet is needed.This scientific paper utilizes material flow analysis (MFA) to predict this expansion and thecorresponding demand for battery raw materials in Sweden, examining the growth trajectory ofthe EV market in Sweden and its implications going forward. The study concluded that themarket share of electric vehicles in Sweden will increase significantly in the next ten years,which will lead to a rise in the need for battery raw materials. Depending on possiblebreakthroughs in battery technology, these demands will vary. Given the rising demand for rawmaterials and the high environmental costs associated with mining new minerals, it is importantto underscore the importance of battery recycling as an essential component of sustainablemobility. This highlights the need to improve recycling practices.
9

Malus-systemet : En kvantitativ studie om huruvida avskaffandet av bonusen i bonus-malus-systemet har påverkat konsumtionen av miljöbilar

Larsson, Pontus, Ärnlöv, Jakob January 2023 (has links)
1 juli 2018 lanserades bonus-malus-systemet i Sverige i syfte att öka andelen miljöbilar i den svenska fordonsflottan. Den 8 november 2022, valde regeringen att avskaffa bonusen i systemet, då man menade att marknaden nu hade åtgärdat de problem som systemet var till för att lösa. Den här studien ämnar att undersöka om avskaffandet av bonusen i bonus-malus-systemet har påverkat konsumtionen av miljöbilar. Detta genom att använda sig av en Event study-metodik där en dynamisk paneldataanalys genomförs för att skatta hur andelen miljöbilar har förändrats över tid för att sedermera predicera för hur denna andel hade sett ut om bonusen kvarblivit. Resultatet visar att den faktiska andelen miljöbilar har minskat efter bonusens avskaffande med  15.5 procent. Storleken av effekten bör undersökas vidare av framtida studier då förlängda leveranstider påverkat resultaten och med all sannolikhet dämpat effekten. Däremot bedömer studien att regeringen högst troligt hade fel i sitt uttalande att slopningen av bonusen inte skulle ge några effekter på bilmarknaden. / On July 1, 2018, the bonus-malus system was implemented in Sweden to promote the use of environmentally friendly vehicles. However, on November 8, 2022, the government decided to abolish the bonus, arguing that the market had resolved the issues the systems intended to address. This study investigates the impact of removing the bonus on the consumption of environmentally friendly vehicles. Employing an Event Study Methodology, a dynamic panel data analysis was conducted to assess the change in the vehicle share over time and predict its size if the bonus had remained. The findings reveal a 15.5 percent decrease in the share of environmentally friendly vehicles following the abolition of the bonus. The magnitude of the effect could be further examined in future studies as delivery times have influenced the results and likely dampened the effect. In contrast to the government's claim that the bonus's elimination would not affect the car market, the study concludes that they most likely were mistaken.
10

Tração eletrica como alternativa energetica : uma proposta para a conversão de veiculos automotivos de uso urbano / Electrical traction as an energetic alternative: a proposal for the conversion of urban automotive vehicles

Moraes, Luciano Camara Bueno de 12 July 2006 (has links)
Orientador: Jose Antonio Siqueira Dias / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-08T10:27:05Z (GMT). No. of bitstreams: 1 Moraes_LucianoCamaraBuenode_M.pdf: 4566206 bytes, checksum: 004300417197b06c786d6cac40898584 (MD5) Previous issue date: 2007 / Resumo: Este trabalho tem como objetivo propor um sistema de baixo custo para conversão de veículos urbanos convencionais para propulsão elétrica. Serão abordadas também, técnicas, de paralelismo de dispositivos semicondutores para altas demandas de potência, motores elétricos, baterias, e sistemas de recarga. De uma maneira geral o projeto apresenta a viabilização de uni kit prático de conversão que permite a Substituição do sistema de tração original (gasolina ou álcool) para o sistema de tração elétrica movido à bateria interna recarregável, para uso urbano que, futuramente, possa ser produzido em larga escala. Os resultados dos modelos teóricos são confrontados com os testes práticos. É apresentado, ao final, um veículo completo, que opera apenas com propulsão elétrica, bem como os íesíes realizados neste veículo / Abstract: The objective of the dissertation is to present a low cost system for the utilization of electric propulsion in urban vehicles powered with internal combustion engines, ft will be discussed semiconductor devices parallelism techniques for high demands of power, electric engines, batteries, and re-charge- systems. In a general way. the project has as objective the design of a conversion kit that allows the substitution of the of original traction of the vehicle by an electric traction system with rechargeable interna! batteries, and that can be produced in large scale. The results of the theoretical models are compared with the practical evaluation tests. The experimental results measured in a complete vehicle assembled using the developed kit are presented / Mestrado / Eletrônica, Microeletrônica e Optoeletrônica / Mestre em Engenharia Elétrica

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