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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.
301

Management of electric vehicle systems with self-interested actors / Recharges de véhicules électriques : gestion de l'énergie et des incitations

Shuai, Wenjing 13 September 2016 (has links)
L'arrivée des véhicules électriques (VEs) a un impact non négligeable sur le réseau électrique, à cause de la grande quantité d'énergie demandée. La stabilité du réseau est susceptible d'être menacée. Cependant, dans l'optique de la transition du réseau électrique vers le Smart Grid, les VEs peuvent aussi être vus comme offrant de nouvelles opportunités. Grâce à la flexibilité des VE demande, leur présence ouvre la voie à des optimisations via le processus de recharge ou même par l'utilisation de cette nouvelle capacité de stockage d'énergie distribuée. Dans cette thèse, nous nous intéressons aux aspects économiques liés à la VE recharge, en prenant en compte le fait que l'écosystème associé aux VEs implique un grand nombre d'acteurs divers, aux objectifs rarement alignés et chaque acteur peut prendre des décisions stratégiques. Je présente d'abord un état de l'art structuré des modèles de la littérature introduits pour ces problèmes. Nous décrivons et comparons les principales approches, en mettant en évidence les besoins en communication des mécanismes correspondants, et les principales propriétés économiques afin de souligner les résultats les plus significatifs ainsi que les éventuels manques. Nous faisons ensuite une proposition consistant à utiliser le processus de VE recharge pour fournir un service de régulation au réseau électrique, en adaptant la puissance instantanée de charge. Nous conduisons une analyse économique des incitations en jeu. En particulier, nous analysons les valeurs des incitations à la régulation qui sont suffisantes pour qu'une offre de recharge-régulation soit bénéfique à la fois pour l'agrégateur et le réseau. Cette étude étant initialement conduite dans le cas d'un monopole qui peut offrir une recharge normale ou une recharge-régulation. Nous regardons ensuite l'impact de la compétition, entre un agrégateur n'offrant que des recharges à puissance fixe, et un autre n'offrant que de la recharge-régulation. La compétition semble préférable pour les utilisateurs et pour la société, puisque les prix sont alors plus bas qu'avec le monopole, et que la participation aux services de régulation est bien plus élevée. Enfin, nous proposons d'utiliser une autre propriété des VEs, à savoir leur capacité de stockage d'énergie. En effet, les VEs peuvent se charger pendant les heures de faible demande, donc à des prix réduits, et éventuellement revendre une partie pendant les pics de demande. Nous menons une étude économique des gains et coûts d'une telle approche. A partir de valeurs réalistes des marchés de l'électricité, nous déterminons numériquement les conditions pour qu'un tel scénario soit viable, et quantifions les économies qu'il peut apporter. Cette dissertation se conclut par une prise de recul sur les contributions et sur les extensions qui pourraient y être apportées. / Electric Vehicles (EVs), as their penetration increases, are not only challenging the sustainability of the power grid, but also stimulating and promoting its upgrading. Indeed, EVs can actively reinforce the development of the Smart Grid if their charging processes are properly coordinated through two-way communications, possibly benefiting all types of actors. Because grid systems involve a large number of actors with nonaligned objectives, we focus on the economic and incentive aspects, where each actor behaves in its own interest. We indeed believe that the market structure will directly impact the actors' behaviors, and as a result the total benefits that the presence of EVs can earn the society, hence the need for a careful design. The thesis first provides an overview of economic models considering unidirectional energy flows, but also bidirectional energy flows, i.e., with EVs temporarily providing energy to the grid. We describe and compare the main approaches, summarize the requirements on the supporting communication systems, and propose a classification to highlight the most important results and lacks. We propose to use the recharging processes of EVs to provide regulation to the grid by varying the instantaneous recharging power. We provide an economic analysis of the incentives at play, including the EV owners point of view (longer recharging durations and impact on battery lifetime versus cheaper energy) and the aggregator point of view (revenues from recharging versus regulation gains). In particular, we analyze the range of regulation rewards such that offering a regulation-oriented recharging benefits both EV owners and the aggregator. After that, we split the monopolistic aggregator into two competing entities. We model a non-cooperative game between them and examine the outcomes at the Nash equilibrium, in terms of user welfare, station revenue and electricity prices. As expected, competing stations offer users with lower prices than the monopolistic revenue-maximizing aggregator do. Furthermore, the amount of regulation service increases significantly than that in the monopolistic case. Considering the possibility of discharging, we propose an approach close to Vehicle-to-Grid, where EVs can give back some energy from their batteries during peak times. But we also use EVs as energy transporters, by taking their energy where it is consumed. A typical example is a shopping mall with energy needs, benefiting from customers coming and going to alleviate its grid-based consumption, while EV owners make profits by reselling energy bought at off-peak periods. Based on a simple model for EV mobility, energy storage, and electricity pricing, we quantify the reduction in energy costs for the EV-supported system, and investigate the conditions for this scenario to be viable.
302

Integrering av elbilsladdare och solceller i distributionsnätet : Påverkan och lösningar med smarta elnät

Engdahl, Jesper January 2018 (has links)
This study aims to examine and quantify the impact from increasing penetration of electric car chargers and solar cells in Mälarenergi's distribution grids. Four different types of low voltage grids are examined: a small rural grid, an older suburban grid, a modern suburban grid and a modern urban grid with multi-dwelling houses. The networks are modeled in Matpower, a MATLAB Power System Simulation Package with grid and metering data from Mälarenergi's NIS (Network Information System), insolation data from Swedish Meteorological and Hydrological Institute (SMHI) and simulated data from an electrical vehicle Home-charing model based on residential activity patterns. The idea has been to use as few assumptions as possible and as much real measurements as possible. The results show that problems such as unwanted voltage levels at the customer's connection points and increasing power flux in the low voltage substation's is to be expected based on aforementioned increasing penetration. The various low voltage networks are affected to varying degrees due to its different structure and type of customers. Measures to increase acceptance for the above mentioned changes have also been reviewed. Line gain shows best properties to reduce both losses and voltage variations. Reactive power compensation in the solar cell's inverters can reduce voltage increases, but with the disadvantage that network losses increase. The use of smart chargers that can control when the charging of electrical vehicles begin charging can both reduce network losses but also the risk of unwanted voltage drops.
303

Analýza príčin a dôsledkov insolvencie spoločnosti Saab / Analysis of the causes and consequences of insolvency Saab

Galajdová, Mária January 2013 (has links)
The thesis is focused on the causes and consequences of default of Saab. The aim of this thesis is to define the long-term factors that contributed to insolvency and describe the process of insolvency proceedings in Sweden compared to Czech Republic. Definition of causes which brought company to default is based on analysis of the industry and car sales. Financial analysis and comprehensive evaluation enterprise models are used to assess the financial health of the company. The thesis contains also description of the expected development of the newly established company, which has become the successor of car manufacturer Saab.
304

Gestion optimisée des flux énergétiques dans le véhicule électrique / Optimization of energy flows in an electric vehicle

Florescu, Adrian 19 November 2012 (has links)
Ce travail a trait à la gestion des flux énergétiques électriques au sein du réseau embarqué d’un véhicule électrique. Les éléments constitutifs de la chaîne électrique ont été d’abord modélisés à des fins de commande et de simulation. Il est visé ici la minimisation du stress des batteries au plomb via une hybridation avec des supercondensateurs. Deux familles de lois de commande ont été conçues et développées, à savoir des lois de type « fréquentielles » et des lois optimales de type « Linéaires Quadratiques Gaussiennes ». Un banc de test temps réel hybride a été architecturé afin de tester ces lois. Ce banc de test a pour noyau deux simulateurs temps réel (RT-LAB et dSPACE). Une partie de la chaîne de puissance est soit émulée par des sources contrôlées ou réalisée via des maquettes à échelle réduite mais à facteur de similitude respecté. Les essais sur le banc de test ont permis d’obtenir des résultats satisfaisants et encourageants qui corroborent la théorie. / This work addresses the management of electrical energy flows within the embedded network of anelectric vehicle. The electrical system components were first modeled for purposes of control synthesisand simulation. It is aimed the minimization of lead-acid batteries stress via hybridization withultracapacitors. Two families of control laws have been conceived and developed, namely afrequency-domain-based law and an optimal Linear Quadratic Gaussian law. A real-time hybrid testbench has been built in order to test these laws. This test bench has two core real-time simulators (RTLABand dSPACE). A part of the power chain has been either emulated by using suitably-controlledsources or realized by using small-scale real hardware with the similarity factor being respected. estson the testbed have yielded satisfactory and encouraging results that corroborate the theory.
305

Pre-feasibility study of V2G system in the micro-grid of St. Martine Island, Bangladesh.

Chowdhury, Md Abu Raihan January 2020 (has links)
The goal of the study was to evaluate the potential of the V2G system as a solution to peak load leveling and integrating more renewable energy in the microgrid of St. Martine Island. Simulink Simscape software was used to model a microgrid with a V2G system for the small community of the Island. The result of the study shows a V2G system with 100 electric cars could play an important role for peak shaving by supplying up to 0.8 MW of electric power back to the grid during peak hours, where each car contributes 10 kW of electric power. It also demonstrates that the V2G system effectively helps to promote solar power capacity from 1 MW to 2.5 MW, hence increase 23.59% share of solar energy in the total grid energy uses compared with the current microgrid of St. Martine Island. / The electricity that is generated from non-renewable sources causesenvironmental pollution and climate changes. Fossil fuel uses leads to thedepletion of fossil fuel resources as well as global warming. On the other hand, renewable energy sources can be used to produce electricity with very few or no CO2 emissions. So, now governments are focusing on renewable energy production. But solar, wind, and other types of renewable energy sources have intermittency. They are not continuously available due to natural factors that cannot be controlled. So, renewable energy needs to be utilized when it is available, or its intermittency can be overcome by energy storage. All Electric vehicle uses a battery pack of large capacity to power the electric motors. These batteries can be used to store the energy that is generated from renewable sources and use them when needed. Besides, the electric grid must always stay in balance. With the development of variable renewable energy production, the management of this balance has become complex. Vehicle to grid is a technology that enables energy to be pushed back to the grid from the battery of an electric car and helps to manage fluctuations on the electricity grid. It helps to balance the grid by charging the battery when renewableenergy is available and load demand is low, then sending energy back to the grid when load demand is high. However, St. Martine Island is a small Island in Bay of Bengal about 9km south of the mainland of Bangladesh. Nearly 6000 people are living there. Since the island is far away from the mainland, grid connection is almostimpossible in terms of cost and geographic location. St. Martine Island has a very high solar power potential, but very low average wind speed. Currently, the electricity demand is fulfilled by stand-alone diesel generators, PV panels, and wind turbines. The current microgrid gets a high load demand during peak hours which is between 6 pm to 11 pm. During this time grid become fully dependent on diesel generators which leads to fossil fuel uses andenvironmental pollution. Here, the project's key objective is to determine the prospects of V2Gtechnology on St. Martine Island to level the peak load during peak hours, given that St. Martine Island is a low windy island with a high average number of yearly peak sun hours. Another goal is to examine the degree to which the share of solar power can be increased by a V2G system in St. Martine Island. In the project, at first, we have modeled a microgrid using Simulink Simscape software. Simulink Simscape enables modeling of a system by putting direct physical connections between the block diagram. In the microgrid model, there are five main sections, which have been designed by assemblingfundamental components in the schematic. A V2G system has been modeled which consists of 100 electric cars as aprototype. Each car has a battery of 100 kWh capacity. Considering thecondition of St. Martine Island and the objective of the project, we have made some assumptions while modeling the V2G section. The results of the project showed that the V2G system significantly smoothed out the peak load during peak hours. It also demonstrated that charging electric cars during daytime by solar power and sending energy back to the grid during peak hours enables the V2G system to accommodate more renewable solar energy sources in the microgrid of St. Martine Island. Finally, the project evident that the V2G system can be integrated into the microgrid of St. Martine Island to level the peak load and to increase the share of solar energy in the total energy uses of the Island.
306

Elbilar, en livscykelanalysav två alternativa tekniker : Bränslecellsbilar och batteribilar

Nordén, Simon January 2021 (has links)
In this thesis, two electric vehicles are compared, a fuel cellpowered vehicle and a battery powered vehicle with a conventionalvehicle with an internal combustion engine. The comparison wasdone as a life cycle assessment and consisted of two stages, avehicle stage and a fuel stage. The vehicle stage consisted ofeverything from mining minerals to recycling of the vehicles,every aspect that’s connected to the car. The fuel stage consistedof fuel production and use during the vehicle’s lifetime. The fuelconsist of electricity and hydrogen produced through electrolysis. The goal of the thesis was to understand what aspects of thelifecycle matters most in terms greenhouse gases for each of theelectric vehicles. Since there are no emissions in terms ofgreenhouse gases while driving the electric vehicles, only fuelproduction, electricity and hydrogen through electrolysis, countedtowards the fuel stage. For the vehicle with an internalcombustion engine the fuel stage consisted of gasoline productionand emissions from driving. The results showed that when comparing electric vehicles withinternal combustion vehicles, the most important aspect was theelectricity mix, with a Nordic electricity mix for most use casesthe electric vehicles where more climate friendly then theinternal combustion vehicles. The fuel cell powered vehicle usedmore electricity than the battery powered vehicle when usingelectrolysis to create hydrogen, and therefore was more sensitiveto increases in emissions from the electricity mix. When comparingthe vehicle stage, battery production causes the most emissionsfor the battery powered vehicle and the hydrogen tank caused themost emissions for the fuel cell powered vehicle.
307

Implementation of HomePlug Green Phy standard (ISO15118) into Electric Vehicle Supply Equipment

Pallander, Rama January 2021 (has links)
As the use of electric vehicles increases, the need for electric vehicle supply equipment to have more advanced functionality also increases. The HomePlug Green PHY standard was developed to allow more advanced communication between electric vehicles and electric vehicle supply equipment. This more advanced form of communication can solve problems such as load balancing during busy charging and seamless payment methods. There are some modem solutions that are based on the Qualcomm QCA7000 chip that allows for implementation of the HomePlug Green PHY standard.             This thesis explores and highlights the implementation of the hardware for the HomePlug Green PHY standard into a solution that is nearly plug and play for most electric vehicles. A module in the form of a PCB based around one of these modem solutions is developed that allows modular expansion of a traditional electric vehicle supply equipment to gain the functionality of HomePlug Green PHY. The final PCB is a near plug and play solution on the hardware side however, the software needs further development.
308

Distributed Model Predictive Control with Application to 48V Diesel Mild Hybrid Powertrains

LIU, YUXING 30 September 2019 (has links)
No description available.
309

DC-DC měnič pro palubní dobíjení elektromobilu / DC-DC converter for onboard charging of electric vehicles

Holub, Miroslav January 2019 (has links)
This master thesis deals with design of DC-DC converter for onboard charging of electric vehicle. Developed converter will mainly be used for charging stationary traction battery in laboratory. Output voltage of this charger will be adjustable by user in between 200 V and 450 V depending on the current charged battery configuration. Output current limit is set at 8 A. Since the converter will be supplied from standard household socket, the problem of power factor correction must be solved during the design. That is because a large part of this thesis is focused on describing the problematics of power factor correction. After that, active PFC module is designed, completed and performance of this module is verified. To achieve low overall losses and thus be able to keep small volume of the system, modern switching components based on Silicon Carbide were preferred. Beside laboratory use, completed system will be used to emphasize volumetric difference between onboard chargers based on old versus modern switching components.
310

Design městského jednostopého vozidla na elektrický pohon / Design of an Urban Two-Wheeled Electric Vehicle

Hrubý, Václav January 2020 (has links)
The work deals with the design of an urban two-wheeled electric vehicle. The final product excels in simple shaping, a unique design solution and the possibility of tilting the saddle. Another interesting element is the possibility of extending the range using an additional battery or connecting to a mobile phone. With its features, the concept stands on the border of electric motorbikes, scooters and bicycles.

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