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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

Fleet-wide transit bus energy consumption modelling and techno-economic analysis of stationary energy storage systems for high-power electric bus charging

Wilson, Graham 25 April 2022 (has links)
Electric buses offer a range of benefits, including a drastic reduction of greenhouse gas emissions compared to personal transit, or to conventional diesel buses. Unfortunately, electric buses also require additional planning to ensure affordable and reliable operation. This thesis proposes two contributions that help to model and plan electric bus deployments, and generally examines how system-focused thinking is required for this application. First, a novel data driven method for estimating the energy consumption of a bus is presented and validated against 1 Hz driving data. Rather than requiring ad hoc data collection, or entire theoretical drivecycle patterns, this new method leverages existing low fidelity driving data from public transit feeds. This data driven method can be used to quickly and accurately model the driving patterns and energy consumption of a whole fleet of buses, as is demonstrated for a case study in Victoria, BC, Canada. Second, using the energy estimating methods previously mentioned, the electricity demand profile for a high-power electric bus charging hub is modelled for various locations and charging systems. Using this modelled demand profile, the potential for using a stationary energy storage system to reduce the peak power demand is investigated. The advantages of three different energy storage technologies (lithium ion, redox flow, and flywheel energy storage systems) are explored. Energy storage was found to be optimal for most charging scenarios modelled, with lithium ion providing the most economical solution for 65% of cases considered. Both the data drive energy estimation modelling, and the energy storage feasibility study constitute novel contributions to the literature. These contributions help to advance the knowledge surrounding electric bus planning and modelling, and help to underpin the systems level thinking required for electric bus deployments. / Graduate
2

Electricity consumption and battery lifespan estimation for transit electric buses: drivetrain simulations and electrochemical modelling

Franca, Anaissia 19 March 2018 (has links)
This thesis presents a battery electric bus energy consumption model (ECONS-M) coupled with an electrochemical battery capacity fade model (CFM). The underlying goals of the project were to develop analytical tools to support the integration of battery electric buses. ECONS-M projects the operating costs of electric bus and the potential emission reductions compared to diesel vehicles for a chosen transit route. CFM aims to predict the battery pack lifetime expected under the specific driving conditions of the route. A case study was run for a transit route in Victoria, BC chosen as a candidate to deploy a 2013 BYD electric bus. The novelty of this work mainly lays in its application to battery electric buses, as well as in the coupling of the ECONS-M and the electrochemical model to predict how long the batteries can last if the electric bus is deployed on a specific transit route everyday. An in-depot charging strategy is the only strategy examined in this thesis due to the charging rate limitations of the electrochemical model. The ECONS-M is currently being utilized in industry for the preparations of Phase I and II of the Pan-Canadian Electric Bus Demonstration & Integration Trial led by the Canadian Urban Transit Research and Innovation Consortium (CUTRIC). This project aims to deploy up to 20 battery electric buses for phase I and 60 electric buses for phase II across Canada to support the standardization of overhead fast chargers and in-depot chargers, which in a first in the world. At this time, the developed CFM can not support any final claims due to the lack of electrochemical data in the literature for the high capacity lithium-ion cells used in electric buses. This opens the door to more research in the ageing testing of batteries for heavy-duty applications. / Graduate
3

Design městského elektrobusu / Design of an Urban Electric Bus

Kučera, Tomáš January 2020 (has links)
-Design of a conceptual bus using results to determine current trends in public transport. -Integration of electronic mirrors to increase safety, use of clean electrical components without emissions, use of lidar sensor built into the lights, air purification -Electric bus design in terms of design, production technology and ergonomics, production of a physical model and posters. -Work brings insight into current trends in public transport, and offers solutions for integration into design.
4

An Exploration of the Macroeconomic and Industry Factors Influencing the Implementation of Battery Electric Buses : A Multiple Case Study of the Swedish Public Transport Sector

Thakur, Viraj January 2022 (has links)
Background:Rising greenhouse gas levels through the use of traditional ICE technology in the transport industry have created a worldwide environmental crisis. Battery Electric Bus adoption is a prominent alternative currently being discussed in the public transport industry and represents an inevitable change towards a sustainable future. Purpose:The establishment of a theoretical framework that analyzes primary and secondary data todefine the factors promoting BEB implementation. Method:The study follows a qualitative research approach gathering data in the form of semi-structured interviews which are analyzed to develop an objective theory. Conclusion:The results show that the primary factors influencing diffusion of BEBs are technology factors, macro-economic factors, and socio-political factors. The research defines the relationships between them to further understand their effects on BEB diffusion. The findings develop a theoretical framework around these factors and their effects on one another and the diffusion of BEBs in the industry.
5

Making grid capacity available through heat pump control

Arding, Karin, In de Betou, Siri January 2019 (has links)
In this report the problem of constructing a bus depot with electrical buses despite the lack of grid capacity, was analyzed. A potential solution is investigated, namely smart control of heat pumps in industries. The possibility of allocating grid capacity to the bus depot by reducing power consumption in heat pumps during peak hours, is taken into consideration. The maximum amount of released capacity in an industrial area is calculated through the controlling of heat pumps. This investigation was made through simulations with a simplified building energy model (lumped capacity model) which was applied to a reference building. After mapping the area Boländerna and the geothermal wells located there, IKEA Uppsala was chosen as the reference building, since a third of the total number of wells were found in that area. To take the whole capacity of Boländerna into account, the model was scaled up to estimate the total, possible reduction of power. The bus depot requires 6 MW nighttime and 4 MW daytime, the total amount of electrical power that could be withdrawn, if all heat pumps were on maximum heat, in the chosen area were 0.75 MW and by controlling the heat pumps during an optimized level, the amount of 142 kW could be made available to the electric grid. 142 kW is not enough cover the need for the bus depot but it could supply the need for a slow charger to one of the buses and is therefore a possible sub-solution to the larger problem.
6

Análise do impacto da utilização do transporte elétrico coletivo no sistema elétrico de distribuição / Analysis of the impact of the use of the collective electric transport in the electrical distribution system

Baldissera, Luciano Bonato 26 August 2016 (has links)
The collective electric transport can be considered as one of the best alternatives to reduce the concentration of pollutants in urban centers, because it reduces the number of vehicles in circulation and eliminates most of the problems arising from the use of fossil fuels. Currently, in this alternative, there is a wide range of options available, however, with the advancement occurred in recent years in terms of battery technology, the pure electric bus has stood out due to advantages related to its flexibility, sustainability and adaptability to the existing infrastructure. However, the use of these vehicles requires special recharging stations, which drain a lot of energy of the grid, in a short time, a feature that generates a significant impact on electrical systems. Moreover, the high amount of energy required for the operation of these vehicles precludes the use of technology in certain places, because it requires large investments in infrastructure for power supply, which often do not is available locally in the short term. Based on this, this dissertation presents a study of the impact generated in the electrical distribution system caused by the replacement of a diesel bus fleet by electric buses in a small town in southern Brazil. The study was based on the measurement of energy consumption through data related to the lines and the vehicle driving cycle, applied to an electric bus model, it was developed with Matlab software. Actual data of the lines was used, as distance, speeds, tilt, number of passengers, among others, obtained through a GPS equipment and information provided by the company analyzed. At the end were generated values related to the energy consumption of vehicles in each of the lines, the electricity consumption increase generated by the substitution in question and an estimate of the daily load curves based on the operating hours of the analyzed lines. / O transporte elétrico coletivo atualmente pode ser considerado como uma das melhores alternativas para a redução da concentração de poluentes em centros urbanos, pois reduz o número de veículos em circulação e elimina a maioria dos problemas decorrentes do uso de combustíveis fósseis. Atualmente, neste tipo de alternativa existe uma vasta gama de opções disponíveis, entretanto, com o avanço ocorrido nos últimos anos em termos de tecnologia de baterias, os ônibus elétricos puros vem se destacando devido a vantagens relacionadas a sua flexibilidade, sustentabilidade e adaptabilidade as infraestruturas existentes. Porém a utilização destes veículos requer estações de recarga especiais, as quais causam um impacto significativo nos sistemas elétricos, pois geram um grande acréscimo de demanda de energia, o que em alguns casos pode sobrecarregar os sistemas. Além disso, a elevada quantidade de energia necessária para a operação destes veículos inviabiliza o uso da tecnologia em determinados locais, pois requer um alto investimento em infraestrutura para o fornecimento seguro e confiável de energia. Baseado nisto, esta dissertação apresenta um estudo do impacto gerado no sistema elétrico de distribuição ocasionado pela substituição de uma frota de ônibus a diesel por ônibus elétricos em uma cidade de pequeno porte situada no sul do Brasil. O estudo foi baseado na mensuração do consumo energético através de dados relacionados às linhas e ao ciclo de condução dos veículos, aplicados em um modelo de ônibus elétrico, o qual foi elaborado através do software Matlab®. Foram utilizados dados reais das distâncias nas linhas, velocidades, relevo das vias, número de passageiros, entre outros, obtidos através de um equipamento de GPS e informações fornecidas pela empresa analisada. Ao final foram gerados valores relacionados ao consumo dos veículos em cada uma das linhas, o acréscimo de consumo de energia elétrica gerado pela substituição em questão e uma estimativa das curvas de carga diárias baseadas nos horários de operação das linhas analisadas.
7

Conception of an electric bus line simulation tool : Development of a tool allowing for the design of electric bus lines charging infrastructures at INGEROP / Utveckling av ett elektrisk buslinjeverktyg : Utveckling av ett verktyg som tillåta designen av en elektrisk buslinjes laddningsinfrastruktur på INGEROP

Baillet, Claire January 2019 (has links)
See file / Se filen
8

Övergång till elbussar : En studie om de fördelar och utmaningar som uppstår vid övergången från fossildrivna bussar till elbussar / Transition to electric buses : A study on the benefits and challenges of switching from fossil-fueled buses to electric buses

Alsebai, Anas, Henriksson, Erik January 2024 (has links)
Urbanization has resulted in larger and more densely populated cities, which has intensified the pressure on public transportation systems globally. A consequence of the increased use of public transportation is higher energy consumption and, consequently, increased carbon dioxide emissions. The electrification of bus services has therefore become a central issue in public transportation, leading many to consider switching from fossil-fuel-powered buses to electric buses. Against this background, this study aims to investigate the benefits and challenges that arise in the transition to electric buses for two selected bus operators and a public transport authority. To address this aim, the authors have conducted semi-structured interviews with the aforementioned parties and gathered a theoretical framework based on scientific articles. The study concludes that there are both benefits and challenges with the transition. In the long term, there are economic savings to be made, and the transition to electric buses also contributes to achieving sustainability goals. Among the challenges are managing the limited range of electric buses and the need to procure in a way that distinguishes between traffic operations and charging infrastructure. / Urbaniseringen har resulterat i större och mer tätbefolkade städer, vilket har intensifierat trycket på kollektivtrafiksystemen globalt. En följd av den ökade användningen av kollektivtrafik är högre energiförbrukning och därmed ökade koldioxidutsläpp. Elektrifiering av busstrafiken har därför blivit en central fråga inom kollektivtrafiken, vilket gör att många överväger att byta från fossildrivna bussar till elbussar. Mot bakgrunden syftar studien till att undersöka de fördelar och utmaningar som uppstår vid övergången till elbussar för två utvalda bussoperatörer och en trafikhuvudman. För att besvara syftet har författarna genomfört semistrukturerade intervjuer med ovan nämnda och samlat en teoretisk referensram baserad på vetenskapliga artiklar. Studien drar slutsatsen att det finns både fördelar och utmaningar med övergången. På lång sikt finns ekonomiska besparingar att göra, och övergången till elbussar bidrar också till att uppnå hållbarhetsmålen. Bland utmaningarna finns hanteringen av elbussarnas begränsade räckvidd samt behovet av att upphandla på ett sätt som skiljer mellan trafikdrift och laddinfrastruktur.
9

Improving the acoustics comfort of the 6-metre-long BLUEBUS electric bus / Förbättrad akustisk komfort i den 6 meter långa elbussen BLUEBUS

Flochlay, Corentin January 2024 (has links)
With the electrification of the automotive industry, vehicles tend to be quieter than their internal combustion engine counterparts. Because of this phenomenon, noises and vibrations that were initially imperceptible appear and affect the overall comfort level of the driver and the passengers. It can also lead to structural fatigue witch results in an increase of maintenance and repair costs. In the case of the BlueBus 6m IT3, a disturbance is encountered with the Scroll compressor, placed atop of the driver’s cabin, which supplies the braking system and the suspensions. When running at low speed, it vibrates and enters in resonance with the bus structure. This thesis aims to reduce the resonance between the bus frame and the compressor by focusing on the characteristics frequencies of both systems. The vibrations of the compressor and the bus roof were measured for distinct stiffnesses and positions of the anti-vibration mounts and at the two compressor running speeds: 2000 rpm and 2900 rpm. The Sound Pressure Level (SPL) inside the driver’s cabin and close to the compressor was also acquired to evaluate and compare the different configurations. A reduction of 2 dBA was achieved by increasing the stability of the motor-compressor assembly with a new support made up of wider mounts. The anti-vibration mounts of a shore hardness of 40 Sh were the more efficient with another 2 dBA decrease and a vibration of the roof quartered. A modal analysis confirmed the presence of a coupling between the compressor and the first cavity mode of the bus structure at low speed leading to amplified noise in the bus. Another analysis was performed on a modified compressor structure including the evolutions resulting from the tests. It results in a decoupling between the compressor and the bus frame and reduced bracket vibrations under loads at low speed. / Med elektrifieringen av fordonsindustrin tenderar fordonen att bli tystare än sina motsvarigheter med förbränningsmotorer. På grund av detta fenomen uppstår ljud och vibrationer som från början var omöjliga att uppfatta, vilket påverkar den allmänna komfortnivån för föraren och passagerarna. Det kan också leda till strukturell utmattning, vilket i sin tur leder till ökade underhålls- och reparationskostnader. I fallet med BlueBus 6m IT3 har en störning uppstått i scroll-kompressorn, som är placerad ovanför förarhytten och försörjer bromssystemet och fjädringarna. När den körs med låg hastighet vibrerar den och går i resonans med bussens struktur. Denna avhandling syftar till att minska resonansen mellan bussramen och kompressorn genom att fokusera på de karakteristiska frekvenserna för båda systemen. Vibrationerna från kompressorn och bussens tak mättes för olika styvheter och positioner för antivibrationsfästena och vid de två kompressorhastigheterna: 2000 rpm och 2900 rpm. Ljudtrycksnivån i förarhytten och i närheten av kompressorn mättes också för att utvärdera och jämföra de olika konfigurationerna. En minskning med 2 dBA uppnåddes genom att öka stabiliteten hos motorkompressorenheten med ett nytt stöd som bestod av bredare fasten. De vibrationsdämpande fästena med en shore-hårdhet på 40 Sh var mest effektiva med ytterligare en minskning på 2 dBA och en vibration av taket på en fjärdedel. En modalanalys bekräftade förekomsten av en koppling mellan kompressorn och den första kavitetsmodusen i bussstrukturen vid låga varvtal, vilket ledde till förstärkt buller i bussen. En annan analys utfördes på en modifierad kompressorstruktur som inkluderade de utvecklingar som framkom vid testerna. Det resulterade i en frikoppling mellan kompressorn och bussramen och minskade vibrationer i konsolen under belastning vid låga hastigheter.
10

Evaluating the roll performance of a hydraulic-interconnected suspension system for an electric bus / Utvärdering av krängprestanda för ett hydrauliskt sammankopplat fjädringssystem för en elektrisk buss

Ramachandran, Dinesh January 2021 (has links)
Electric buses often have batteries installed on the roof structure to have a better space utilization. This increases the height of the centre of gravity of the vehicle, affecting its roll stability. The existing vehicle setup uses an anti-roll bar to provide the roll stiffness. However, increasing the roll stiffness of the anti-roll bar for providing the required roll stability of an electric bus is limited due to the increase in weight of the anti-roll bar, its material properties and the design constraints. An alternate for the air suspension system is identified through a literature study. The identified system, an interconnected hydro-pneumatic suspension, is modelled analytically and compared to the air spring system. Multi-body simulations are performed to understand the roll performance.\par The thesis work also estimates the system's energy efficiency, and the feasibility of packaging the system within the existing vehicle architecture is studied in CAD software. The roll gradient of the vehicle is shown to improve compared to the existing air-spring system. The study also find that implementation of hydraulic-interconnected system can result in reduction of the unsprung mass of the vehicle. / Elektriska bussar har ofta batterier installerade på takkonstruktionen för att få ett bättre utrymmesutnyttjande. Detta ökar fordonets tyngdpunktshöjd och påverkar dess krängstabilitet. Den befintliga fordonskonfigurationen använder en krängningshämmaren tillsammans med luftfjädrar för att ge den krängsstabilitet som krävs. Men att öka krängstyvheten hos krängningshämmaren för att ge den nödvändiga krängstabilitet hos en elektrisk buss är begränsad på grund av ökningen av vikten av krängningshämmaren, dess materialegenskaper och konstruktionsbegränsningar. Ett alternativ till luftfjädringssystemet identifieras genom en litteraturstudie. Det identifierade systemet, ett sammanlänkat hydro-pneumatiskt fjädringssystem, modelleras analytiskt och jämförs med luftfjädringssystemet. Multibody-simuleringar utförs för att förstå fordonets krängprestanda. par Avhandlingsarbetet uppskattar också systemets energieffektivitet och möjl-igheten att paketera systemet inom den befintliga fordonsarkitekturen studeras i CAD-programvara. Fordonets krängningsgradient har visat sig förbättras jämfört med det befintliga luftfjädringssystemet. I studien konstateras också att införandet av hydrauliskt sammankopplade system kan leda till en minskning av fordonets ofjädrade massa.

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