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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

The Impact of Energy Routers on the Planning of Transmission and Electric Vehicle Charging Stations

January 2020 (has links)
abstract: Transmission line capacity is an obstacle for the utilities because there is a load increment annually, and new power plants are being connected, which requires an update. Energy router (ER) is a device that provides an additional degree of freedom to the utilities by controlling the reactive power. The ER reactive power injection is demonstrated by changing the line's reactance value to increase its capacity and give the utility a deferral time for the project upgrade date. Changing the reactance manually and attaching Smart Wire's device to the branches have effectively solved the overload in three locations of a local utility in Arizona (LUA) system. Furthermore, electric vehicle charging stations (EVCSs) have been increasing to meet EV needs, which calls for an optimal planning model to maximize the profits. The model must consider both the transportation and power systems to avoid damages and costly operation. Instead of coupling the transportation and power systems, EVCS records have been analyzed to fill the gap of EV demand. For example, by accessing charging station records, the moment knowledge of EV demand, especially in the lower order, can be found. Theoretically, the obtained low-order moment knowledge of EV demand is equivalent to a second-order cone constraint, which is proved. Based on such characteristics, a chance-constrained (CC) stochastic integer program for the planning problem is formulated. For planning EV charging stations with ER, this method develops a simple ER model to investigate the interaction between the mobile placement of power flow controller and the daily pattern of EV power demand. / Dissertation/Thesis / Masters Thesis Electrical Engineering 2020
2

Electric Vehicle Charging Station Markets : An analysis of the competitive situation

Österberg, Viktor January 2012 (has links)
Electric Vehicles represent a small niche market today, but is predicted to grow rapidly over the next years. In order to prepare for this upcoming trend it is the networks of Electric Vehicle Charging Stations (EVCS) must expand, leading to an increasing demand for EVCSs. The EVCS market is thus becoming increasingly more popular to companies, and therefore this study’s purpose is to investigate this market and its competitive situation. The method used in this study includes a brief market analysis and a competitor analysis. The market analysis includes identification of the EVCS markets together assessing the future of the markets, and identification of EVCS market drivers and restraints. The competitor analysis includes competitor identification, classification and analysis. The top ten competitors are analyzed by the use of document content analysis, the analysis involves understanding the competitors’ target customers, how they do business and how their marketing material is structured. The three most promising EVCS markets, both currently and in the future, are the Asia Pacific, Europe and the North America markets. Most of the top competitors are active within these three markets. Regional developments, and market drivers and restraints of these markets have been identified. The opportunities in the EVCS markets are many as they are relatively unexploited markets without any actual market leaders, and also that all markets are predicted to grow at a very high rate over the coming decade in parallel with the projected mass adoption if Electric Vehicles (EVs). / Idag utgör elfordon endast en liten nischmarknad i transportmarknaden, men denna förväntas växa snabbt under de närmaste åren. För att kunna hantera marknadsetableringen av elfordon måste elfordonsladdningsinfrastrukturen byggas ut, vilket leder till en ökad efterfrågan på elfordonsladdningsstationer. Elfordonsladdningsmarknaden förespås således bli allt mer intressant för företag. Detta examensarbete genomförs på grund av detta växande intresse, då studiens syfte är att undersöka elfordonsladdstationsmarknaden och dess konkurrenssituation. Metoden som används i denna studie inbegriper en kort marknadsanalys och en konkurrensanalys. Marknadsanalysen innehåller identifiering av elfordonsladdningsmarknaderna, vad som driver och hindrar marknaderna, och en bedömning av hur framtiden ser ut för marknaderna. I konkurrensanalysen ingår identifiering, klassificering och analys av de olika konkurrenterna. De tio mest konkurrenskraftiga konkurrenterna analyseras med hjälp av dokumentinnehållsanalys, syftet med analysen är att förstå konkurrenternas målgrupper, hur de gör affärer och hur deras marknadsföringsmaterial är strukturerad. De tre mest lovande elfordonsladdningsmarknaderna, både nu och i framtiden, är marknaderna i Asien och Stillahavsområdet, Europa och Nordamerika. De flesta av de analyserade konkurrenterna är verksamma inom dessa tre marknader. Den regionala utvecklingen, och vad som driver och begränsar marknaderna har identifierats för de tre mest lovande marknaderna. Eftersom dessa marknader är relativt oexploaterade i samband med att de förväntas växa med väldigt hög takt det kommande decenniet parallellt med massanvändningen av elfordon är möjligheterna många för de företag som inriktar sig mot elbilsladdning.
3

A Network Design Framework for Siting Electric Vehicle Charging Stations in an Urban Network with Demand Uncertainty

Tan, Jingzi January 2013 (has links)
We consider a facility location problem with uncertainty flow customers' demands, which we refer to as stochastic flow capturing location allocation problem (SFCLAP). Potential applications include siting farmers' market, emergency shelters, convenience stores, advertising boards and so on. For this dissertation, electric vehicle charging stations siting with maximum accessibility at lowest cost would be studied. We start with placing charging stations under the assumptions of pre-determined demands and uniform candidate facilities. After this model fails to deal with different scenarios of customers' demands, a two stage flow capturing location allocation programming framework is constructed to incorporate demand uncertainty as SFCLAP. Several extensions are built for various situations, such as secondary coverage and viewing facility's capacity as variables. And then, more capacitated stochastic programming models are considered as systems optimal and user oriented optimal cases. Systems optimal models are introduced with variations which include outsourcing the overflow and alliance within the system. User oriented optimal models incorporate users' choices with system's objectives. After the introduction of various models, an approximation method for the boundary of the problem and also the exact solution method, the L-Shaped method, are presented. As the computation time in the user oriented case surges with the expansion of the network, scenario reduction method is introduced to get similar optimal results within a reasonable time. And then, several cases including testing with different number of scenarios and different sample generating methods are operated for model validation. In the last part, simulation method is operated on the authentic network of the state of Arizona to evaluate the performance of this proposed framework.
4

Proposal of wireless charging method and architecture to increase range in electric vehicles

Omar Nabeel Nezamuddin (10292552) 06 April 2021 (has links)
<div>Electric vehicles (EVs) face a major issue before becoming the norm of society, that is, their lack of range when it comes to long trips. Fast charging stations are a good step forward to help make it simpler for EVs, but it is still not as convenient when compared to vehicles with an internal combustion engine (ICE). Plenty of infrastructure changes have been proposed in the literature attempting to tackle this issue, but they typically tend to be either an expensive solution or a difficult practical implementation.</div><div> </div><div> This dissertation presents two solutions to help increase the range of EVs: a novel wireless charging method and a multi-motor architecture for EVs. The first proposed solution involves the ability for EVs to charge while en route from another vehicle, which will be referred to from here on as vehicle-to-vehicle recharging (VVR). The aim of this system is to bring an innovative way for EVs to charge their battery without getting off route on a highway. The electric vehicle can request such a service from a designated charger vehicle on demand and receive electric power wirelessly while en route. The vehicles that provide energy (charger vehicles) through wireless power transfer (WPT) only need to be semi-autonomous in order to ``engage'' or ``disengage'' during a trip. Also, a novel method for wireless power transfer will be presented, where the emitter (TX) or receiver (RX) pads can change angles to improve the efficiency of power transmission. This type of WPT system would be suitable for the VVR system presented in this dissertation, along with other applications.</div><div> </div><div> The second solution presented here will be an architecture for EVs with three or more different electric motors to help prolong the state of charge (SOC) of the battery. The key here is to use motors with different high efficiency regions. The proposed control algorithm optimizes the use of the motors on-board to keep them running in their most efficient regions. With this architecture, the powertrain would see a combined efficiency map that incorporates the best operating points of the motors. Therefore, the proposed architecture will allow the EV to operate with a higher range for a given battery capacity.</div><div> </div><div> The state-of-the-art is divided into four subsections relevant to the proposed solutions and where most of the innovations to reduce the burden of charging EVs can be found: (1) infrastructure changes, (2) device level innovations, (3) autonomous vehicles, and (4) electric vehicle architectures. The infrastructure changes highlight some of the proposed systems that aim to help EVs become a convenient solution to the public. Device level innovations covers some of the literature on technology that addresses EVs in terms of WPT. The autonomous vehicle subsection covers the importance of such technology in terms of safety and reliability, that could be implemented on the VVR system. Finally, the EV architectures covers the current typologies used in EVs. Furthermore, modeling, analysis, and simulation is presented to validate the feasibility of the proposed VVR system, the WPT system, and the multi-motor architecture for EVs.</div>
5

Electric Vehicle Charging Network Design and Control Strategies

Wu, Fei January 2016 (has links)
No description available.
6

Extension of low voltage distribution by pure DC or mixed AC/DC parts for integration of solar PV and EV charging

Jiang, Sofie January 2022 (has links)
This work examines the local distribution system in two residential areas in two Swedish towns, Oxelösund and Karlskrona, and studies how integration of PV systems and electric vehicle (EV) charging stations (CS) will affect the present distribution system. The research questions focus on the economic feasibility of a LVDC system, how it compares to a traditional LVAC (low voltage alternating current) system from an economic and technical perspective, and the possibilities a LVDC system brings to other DC component applications. The Swedish government aims to have a fossil-free vehicle fleet by 2030 and one of the measures is no fossil-fuel burning vehicle will be produced and sold in Sweden. This means the number of CS, and the charging infrastructure around these, need to be developed, to contribute to this goal and sustain this transformation. A connected issue is that updates on the regulations for non concession-regulated networks (IKN) in January 2022 extended the basic preconditions and allows possibilities for energy sharing between buildings. The new regulations are also in favor of micro-production and contribute to more decentralised systems. Connections of Renewable Energy Sources (RES) to the distribution system are expected to increase in the coming years. Grid-connected solar PV systems in Sweden have increased by 56% between 2019 and 2020, and at the same time EVs are becoming more apparent on the roads. These DC-(direct current) based technologies, and the possible need to strengthen local networks to accommodate new sources and loads, are bringing new opportunities for low voltage direct current (LVDC) based distribution systems. To answer the research questions, two different models with different concepts, parallel pure DC and parallel AC/DC, were built in simulation software. The conclusion of this study is that a traditional LVAC system is preferable over pure DC system from both economic and technical perspective for already connected areas, such as the two areas in this project. A parallel pure DC system might be preferable in newly built areas with substantial PV and EV, where exchange is wanted between buildings with separate AC grid connections. / Detta examnesarbetet undersöker det lokala distributionssystemet i två bostadsområden, i Oxelösund och Karlskrona. Arbetet fokuserar på hur (nya) anslutningar av solceller och laddstationer för elfordon (CS) kommer att påverka det nuvarande distributionsnätet i områdena. Forskningsfrågorna fokuserar på den ekonomiska genomförbarheten av ett LVDC-system, och hur det är jämfört med ett traditionellt LVAC-system (lågspänningsväxelström) ur ett ekonomiskt och tekniskt perspektiv, samt vilka möjligheter ett LVDC-system kan bidra med till andra DC-komponenttillämpningar. Den svenska regeringen ämnar ha en fossilfri fordonsflotta år 2030 och en av åtgärderna till målet är att sluta producera och sälja fossildrivna fordon i Sverige. Det innebär att antalet CS samt en laddingsinfrastruktur behöver utvecklas för att kunna bidra till målet och upprätthålla omställningen. De senaste uppdateringarna i regelverket för icke koncessionspliktiga nät (IKN) i januari 2022 vidgade de grundläggande förutsättningarna och bidrog till större möjligheter till energidelning mellan flera huskroppar. Det nya regelverket gynnar mikroproduktion och bidrar också till mer decentraliserade system. Anslutningar av RES till distributionsnätet förväntas öka under de kommande åren. Nätanslutna solcellsanläggningar i Sverige ökade med 56% mellan 2019 och 2020, samtidigt som det blir fler och fler elbilar på vägarna. Dessa DC-(likströms) baserade teknik kan öppna upp nya möjligheter för ett lågspänningslikström- (LVDC) baserad distributionssystem. För att besvara forskningsfrågorna byggdes två olika modeller med olika koncept, parallell ren DC och parallell AC/DC i simuleringsprogram. Slutsatsen av denna studien är att ett traditionellt LVAC-system är att föredra framför rent DC-system ur både ekonomiskt och tekniskt perspektiv för redan anslutna områden, som de två områdena i detta projekt. Ett parallellt rent DC-system kan vara att föredra i oanslutna områden, dvs nya bostadsområden under utveckling.

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