Battery electric vehicles and fuel cell vehicles, i.e. hydrogen vehicles, are promising alternatives to internal combustion engine vehicles to reduce GHG emissions from the transport sector. EV charging and hydrogen refuelling infrastructure is crucial to the deployment of alternative fuels in transport. Although several studies have analyzed electric public buses infrastructure, fuel cell buses have not been the target of such extensive analyses. Additionally, there is a gap in the literature regarding the comparison of infrastructure for these two types of vehicles and their cost and refuelling schedule differences. The study aims to conduct a techno-economic analysis of electricity versus hydrogen refuelling infrastructure to decarbonize public buses, using renewable sources to produce renewable electricity and green hydrogen. The outcome is a proposed system design regarding the size of the refuelling station, storage system capacity, renewable energy capacity, on-site hydrogen production system size, and the optimized refuelling schedule. The system is modelled to minimize the overall system cost while maintaining the current bus service level. The impact of electricity market prices, demand charges and varying bus energy demand in the optimal system configuration and schedule is also addressed. Scenarios are developed to study different levels of new installed renewable capacity integration and how these affect the cost, bus refuelling schedules and infrastructure design. The mixed-integer linear programming problem was modelled using Python. The model is applied to the case study of one bus line in Umeå. One terminal station was chosen to place the refuelling stations. The results show that the most economical option is electrifying the line with electricity supply only from the grid. For scenarios with additional renewable energy capacity installed, the option with 50% integration of new installed capacity is the most economically viable. In both these cases, there is no installation of BESS at the charging station. Electric buses infrastructure is cheaper than hydrogen infrastructure in all scenarios, but these values converge as renewable energy integration increases. For hydrogen infrastructure, the scenario with 50% renewable energy integration is the least costly. Although electric bus infrastructure is more economical than hydrogen infrastructure, hydrogen buses present advantages in terms of significantly higher range and thus higher flexibility for refuelling. Therefore, in the decision-making process to replace a fossil fuel bus line with an alternative fuel bus line, one must consider the multi-dimensional level of the different options. / Batterielektriska fordon och bränslecellsfordon, dvs. vätgasfordon, är lovande alternativ till fordon med förbränningsmotorer för att minska växthusgasutsläppen från transportsektorn. Infrastruktur för laddning av elfordon och tankning av vätgas är avgörande för att alternativa bränslen ska kunna användas inom transportsektorn. Även om flera studier har analyserat infrastrukturen för offentliga elbussar har bränslecellsbussar inte varit föremål för sådana omfattande analyser. Dessutom finns det en lucka i litteraturen när det gäller jämförelsen av infrastruktur för dessa två typer av fordon och deras skillnader i fråga om kostnader och tankningsschema. Syftet med studien är att genomföra en teknisk-ekonomisk analys av infrastruktur för tankning av el respektive vätgas för att avkarbonisera offentliga bussar, med hjälp av förnybara källor för att producera förnybar el och grön vätgas. Resultatet är ett förslag till systemutformning med avseende på tankstationens storlek, lagringssystemets kapacitet, kapaciteten för förnybar energi, storleken på systemet för vätgasproduktion på plats och det optimerade tankningsschemat. Systemet modelleras för att minimera den totala systemkostnaden samtidigt som den nuvarande service nivån förbussarna bibehålls. Effekten av elmarknadspriser, efterfrågeavgifter och varierande energiefterfrågan från bussarna på den optimala systemkonfigurationen och schemat behandlas också. Scenarier utvecklas för att studera olika nivåer av nyinstallerad förnybar kapacitet och hur  dessa påverkar kostnaden, bussarnas tankningsscheman och infrastrukturens utformning. Det linjära programmeringsproblemet med blandade heltal modellerades med hjälp av Python. Modellen tillämpas på fallstudien av en busslinje i Umeå. En ändstation valdes ut för att placera tankstationerna. Resultaten visar att det mest ekonomiska alternativet är att elektrifiera linjen med elförsörjning endast från nätet. För scenarier med ytterligare installerad kapacitet för förnybar energi är alternativet med 50 % integrering av ny installerad kapacitet det mest ekonomiskt lönsamma. I båda dessa fall finns det ingen installation av BESS vid laddningsstationen. Infrastrukturen för elbussar är billigare än infrastrukturen för vätgas i alla scenarier, men dessa värden närmar sig varandra när integrationen av förnybar energi ökar. När det gäller vätgasinfrastruktur är scenariot med 50 % integrering av förnybar energi det minst kostsamma. Även om infrastrukturen för elbussar är billigare än infrastrukturen för vätgasbussar har vätgasbussar fördelar i form av betydligt större räckvidd och därmed större flexibilitet när det gäller tankning. I beslutsprocessen för att ersätta en busslinje med fossila bränslen med en busslinje med alternativa bränslen måste man därför ta hänsyn till de olika alternativens flerdimensionella nivå.

Em vigência desde Janeiro de 2012, a regulamentação Proconve P7 para veículos comerciais pesados exige que a demonstração de emissões de poluentes do motor seja realizada no ciclo de teste transiente europeu (ETC), desenvolvido de acordo com perfil de condução tipicamente europeu e assim pouco representativo de diversas situações de tráfego no Brasil. Especialmente quanto a aplicações de ônibus urbanos, altamente dinâmicas e submetidas a perfis de baixa velocidade e média carga, não é possível correlacionar plenamente o funcionamento do motor e seus sistemas de controle de emissões baseando-se apenas neste ciclo. Com essa motivação, o principal objetivo deste estudo é desenvolver ciclos de teste compactos para banco de provas de chassis e de motores que representem as condições reais de condução de ônibus urbanos da cidade de São Paulo. Estes ciclos de teste específicos possibilitam avaliações mais precisas não apenas das emissões de poluentes, mas também do consumo de combustível, além de proporcionarem melhor compreensão do real desempenho de motores e novas tecnologias dos sistemas de propulsão usados em frotas de ônibus urbanos no Brasil. A metodologia aplicada para construção dos ciclos utiliza o conceito de potência específica veicular (VSP), variável que apresenta alta correlação com emissões de poluentes e consumo de combustível e é calculada a partir de dados coletados em condições reais de condução de ônibus (velocidade, aceleração e inclinação das vias). A seleção dos veículos e linhas para realização das aquisições de dados considera tanto as especificações de trem-de-força e de chassis disponíveis na frota, como também os índices operacionais e a topografia dos trajetos como métodos para determinação de linhas com perfil operacional mais representativo. Como resultado do estudo foram propostos cinco ciclos de teste, um para cada tipo de ônibus selecionado (miniônibus, midiônibus, básico, padron e articulado), e as análises comparativas com o ciclo ETC quanto ao comportamento do motor mostram claramente a falta de representatividade do ciclo europeu adotado pela regulamentação brasileira. / Since January 2012, the Proconve P7 regulation is mandatory for heavy duty commercial vehicles requiring that the demonstration of pollutant gases emissions must be carried out by submitting the engine to the European transient test cycle (ETC), which has been developed according to European driving patterns and therefore is not representative of several driving situations in Brazil. Particularly for driving patterns of urban buses, which are highly dynamic with low vehicle speed and medium load profiles, it is not possible to fully correlate the operating conditions of the engine and its emission control systems based only on this test cycle. With this motivation, the main objective of this study is to develop compact test cycles for use in both chassis and engine test benches that represent the actual driving pattern of transit buses in São Paulo city. These specific test cycles may allow more accurate assessment of pollutant gases emissions and fuel consumption, as well as provide a better understanding concerning the real performance of engines and new propulsion technologies used in urban bus fleets in Brazil. The methodology used for construction of the cycles is based on the concept of vehicle specific power (VSP), a variable that is highly correlated with pollutant emissions and fuel consumption and is calculated from data collected under real-world driving conditions (vehicle speed, acceleration and road grade). The selection of the buses and routes for the on-board data collection considers the specifications of powertrain and chassis that are available in the bus fleet of São Paulo\'s public transportation system, operational indexes and route topography as a method for determining the bus routes with a more representative operational pattern. As the result of this study five test cycles were proposed, one for each bus type (minibus, midibus, basic, padron and articulated), and an analysis of the engine\'s operating behavior in comparison to the ETC cycle clearly shows the lack of representativeness of the European cycle adopted by the Brazilian regulation.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1980. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Includes bibliographcial references. / by Helen Louise Graham. / M.S.

<div>Plug-in hybrid electric vehicles (PHEVs) are being considered as an alternative to conventional medium-duty (MD) and heavy-duty (HD) commercial vehicles to reduce fuel consumption and tailpipe emissions. Lithium ion batteries, which are used in PHEVs due to their high energy density, are expensive. The battery contributes significantly towards the life-cycle cost of MD/HD PHEVs, as these vehicles, due to high mass and aggressive battery usage, require multiple battery replacements over their lifetime. Smaller batteries increase the fuel consumption and need more replacements, while bigger batteries increase the initial system cost. Powertrain design from a life-cycle cost perspective is required to explore this trade-off and maximize the economic gains obtained from PHEVs. </div><div><br></div><div>Powertrain design entails component sizing, control strategy selection as well as architecture selection. Different powertrain designs yield different lifetime economic gains. A variety of applications exist for MD/HD vehicles, which differ in their ways of powertrain usage, due to variations in required acceleration, available braking, and average and maximum speeds. Therefore, different powertrain designs are needed depending on the application and usage scenario. The powertrain design space needs to be explored, and solutions that maximize the economic gains within the specified constraints need to be chosen.</div><div><br></div><div>This dissertation compares the economic viability of two PHEV applications (MD Truck and HD Transit Bus), with options of series and parallel hybrid architectures, over multiple drivecycles, for four economic scenarios (years 2015, 2020, 2025 and 2030). It is shown that hybridizing the transit bus achieves payback sooner than hybridizing the truck. Further, the results for the transit bus application, over the Manhattan drivecycle, show that implementation of the parallel architecture is economically viable in the 2015(present) scenario, while the series architecture becomes viable in 2020, due to significantly lower initial costs involved in the parallel architecture.</div><div><br></div><div>A methodology to select a solution out of the explored design space that maximizes the economic gains is demonstrated. Variations in the economic and vehicle usage conditions for which this solution is designed, can be expected. It is therefore necessary to check the robustness of this solution to change in external factors such as vehicle mass, annual vehicle miles travelled (AVMT), component and fuel costs. It is shown that the economic gains are affected by the battery cost, fuel cost, AVMT and vehicle mass, while the number of battery replacements are affected by AVMT and vehicle mass. </div><div><br></div><div>A probability-based approach is demonstrated to obtain confidence in the economic and battery life predictions. Specifically, probability-based variations are provided to variables such as miles traveled between recharge, recharge C-rate and battery temperature. It is shown that battery life is affected the most by battery temperature.</div><div><br></div><div>A battery heating/cooling system is required to maintain constant battery temperature of operation during all seasons, but these systems incur additional fuel costs. A framework that utilizes just the Coefficient of Performance (COP) of the heating/cooling system to calculate the excess fuel cost is proposed and demonstrated. An increase of 0.9-1.8\% in fuel consumption is shown, depending on the drivecycle and ambient temperature.</div><div><br></div><div>Further, the well-to-wheel (WTW) fuel-cycle emissions from conventional and PHEV transit buses operating in Indiana and California are assessed using the ``Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation'' (GREET) Model 2017, developed by Argonne National Labs. It is shown that 59% and 63% greenhouse gas (GHG) reductions can be achieved in Indiana and California respectively, along with reduction in carbon monoxide (CO), nitrogen oxides NOx, particulate matter with diameter less than 2.5 microns PM2.5 and volatile organic compounds (VOC) emissions for both the states. However, an increase in sulfur oxides SOx emissions for both the states, and particulate matter with diameter less than 10 microns PM10 increase for Indiana, are observed. </div><div><br></div>

A mobilidade de pessoas no mundo é não apenas um dos maiores desafios tecnológico e político do século XXI, como também uma área de alto impacto energético e ambiental. O presente trabalho busca analisar o transporte rodoviário de passageiros no Brasil pela perspectiva energética. Para a fundamentação teórica, aborda-se a dinâmica da mobilidade no mundo, alguns conceitos fundamentais e a relação entre o perfil de transportes, o perfil energético do setor e suas externalidades negativas. Em seguida, é apresentado o conceito de Mobilidade Sustentável, que busca apontar diretrizes para mitigação de externalidades e maior eficiência energética, dentre as quais estão a transição modal_ o incentivo a transportes públicos em detrimento dos individuais_ e a eletrificação de veículos. Como metodologia do trabalho, opta-se por simular os impactos energéticos de cenários brasileiros de eletrificação de ônibus (eletrificação progressiva, chegando a 71% da frota de ônibus até 2050) e de transição modal (manutenção de 35% da atividade de passageiros feita por ônibus), tanto individualmente, quanto combinados, através do modelo Global Transportation Roadmap. Os resultados mais expressivos de eficiência energética, economia de energia e demanda de eletricidade são observados na trajetória que combina ambas as estratégias, em que se chega a 105TWh de economia de energia no ano de 2050 e alcança-se uma demanda de energia elétrica de 67TWh. De 2020 a 2050, acumula-se uma economia de 7,6% da energia total demandada por transportes de ônibus e de automóvel no Brasil. Finalmente, analisam-se os resultados das simulações, suas limitações e recomendações de melhorias. / Worldwide, passenger mobility is not only one of the most significant political and technological challenges of the 21st century, but also a sector of high energetic and environmental impact. The present work aims to analyze road passenger transportation from the energy sector perspective. The theoretical basis approaches the dynamics of the mobility sector globally, some of its fundamental concepts and the nexus between transportation, energy consumption and negative externalities. Afterwards, it is conceptualized the Sustainable Mobility approach, and its guidelines for energy efficiency and externality mitigation, among which are Modal Shift (incentivizing the adoption of collective and efficient modes of transport) and vehicle electrification. The chosen work methodology is to simulate in the Global Transport Roadmap Model the energy impact of the following scenarios: 1) EB71: a progressive bus electrification scenario that achieves 71% of the national bus fleet electrified by 2050; 2) MS35: maintaining 35% of bus modal share, despite the historical records of bus-to-car shifts in the country; and 3) EB71.MS35: the combination of the previous strategies in a combined scenario. As a result, the EB71.MS35 scenario shows the highest rates of energy efficiency, energy savings and electricity demand: the projections for 2050 achieve 105TWh in energy savings and 67TWh of electricity demand. The cumulative energy saving from 2020 to 2050 reaches 7,6% of the energy demand for buses and automobiles in the same period. Finally, the simulation results are analyzed, and comments are made regarding limitations of the model, conclusions, and further steps for research.

A mobilidade de pessoas no mundo é não apenas um dos maiores desafios tecnológico e político do século XXI, como também uma área de alto impacto energético e ambiental. O presente trabalho busca analisar o transporte rodoviário de passageiros no Brasil pela perspectiva energética. Para a fundamentação teórica, aborda-se a dinâmica da mobilidade no mundo, alguns conceitos fundamentais e a relação entre o perfil de transportes, o perfil energético do setor e suas externalidades negativas. Em seguida, é apresentado o conceito de Mobilidade Sustentável, que busca apontar diretrizes para mitigação de externalidades e maior eficiência energética, dentre as quais estão a transição modal_ o incentivo a transportes públicos em detrimento dos individuais_ e a eletrificação de veículos. Como metodologia do trabalho, opta-se por simular os impactos energéticos de cenários brasileiros de eletrificação de ônibus (eletrificação progressiva, chegando a 71% da frota de ônibus até 2050) e de transição modal (manutenção de 35% da atividade de passageiros feita por ônibus), tanto individualmente, quanto combinados, através do modelo Global Transportation Roadmap. Os resultados mais expressivos de eficiência energética, economia de energia e demanda de eletricidade são observados na trajetória que combina ambas as estratégias, em que se chega a 105TWh de economia de energia no ano de 2050 e alcança-se uma demanda de energia elétrica de 67TWh. De 2020 a 2050, acumula-se uma economia de 7,6% da energia total demandada por transportes de ônibus e de automóvel no Brasil. Finalmente, analisam-se os resultados das simulações, suas limitações e recomendações de melhorias. / Worldwide, passenger mobility is not only one of the most significant political and technological challenges of the 21st century, but also a sector of high energetic and environmental impact. The present work aims to analyze road passenger transportation from the energy sector perspective. The theoretical basis approaches the dynamics of the mobility sector globally, some of its fundamental concepts and the nexus between transportation, energy consumption and negative externalities. Afterwards, it is conceptualized the Sustainable Mobility approach, and its guidelines for energy efficiency and externality mitigation, among which are Modal Shift (incentivizing the adoption of collective and efficient modes of transport) and vehicle electrification. The chosen work methodology is to simulate in the Global Transport Roadmap Model the energy impact of the following scenarios: 1) EB71: a progressive bus electrification scenario that achieves 71% of the national bus fleet electrified by 2050; 2) MS35: maintaining 35% of bus modal share, despite the historical records of bus-to-car shifts in the country; and 3) EB71.MS35: the combination of the previous strategies in a combined scenario. As a result, the EB71.MS35 scenario shows the highest rates of energy efficiency, energy savings and electricity demand: the projections for 2050 achieve 105TWh in energy savings and 67TWh of electricity demand. The cumulative energy saving from 2020 to 2050 reaches 7,6% of the energy demand for buses and automobiles in the same period. Finally, the simulation results are analyzed, and comments are made regarding limitations of the model, conclusions, and further steps for research.

ARINC 664/AFDX (Avionics Full Duplex Switched Ethernet) protocol is a leading onboard communication technology in civil aviation. As AFDX is a new technology, unit cost of the hardware devices are high and protocol is open to changes. This thesis discusses the design of an AFDX End System application for test environment with a software based solution with cheap COTS (Commercial offthe shelf) equipment, explains the implementation of the software and analysis the performance.

published_or_final_version / Transport Policy and Planning / Master / Master of Arts in Transport Policy and Planning

Thesis (M. Econ.)--University of Hong Kong, 1995. / Xeror copy of typescript. Includes bibliographical references (leaf 83-87).

Thesis (M.Econ.)--University of Hong Kong, 1995. / Includes bibliographical references (leaf 83-87). Also available in print.