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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.
31

Vehicle powertrain model to predict energy consumption for ecorouting purposes

Tamaro, Courtney Alex 27 June 2016 (has links)
The automotive industry is facing some of the most difficult design challenges in industry history. Developing innovative methods to reduce fossil fuel dependence is imperative for maintaining compliance with government regulations and consumer demand. In addition to powertrain design, route selection contributes to vehicle environmental impact. The objective of this thesis is to develop a methodology for evaluating the energy consumption of each route option for a specific vehicle. A 'backwards' energy tracking method determines tractive demand at the wheels from route requirements and vehicle characteristics. Next, this method tracks energy quantities at each powertrain component. Each component model is scalable such that different vehicle powertrains may be approximated. Using an 'ecorouting' process, the most ideal route is selected by weighting relative total energy consumption and travel time. Only limited powertrain characteristics are publicly available. As the future goal of this project is to apply the model to many vehicle powertrain types, the powertrain model must be reasonably accurate with minimal vehicle powertrain characteristics. Future work expands this model to constantly re-evaluate energy consumption with real-time traffic and terrain information. While ecorouting has been applied to conventional vehicles in many publications, electrified vehicles are less studied. Hybrid vehicles are particularly complicated to model due to additional components, systems, and operation modes. This methodology has been validated to represent conventional, battery electric, and parallel hybrid electric vehicles. A sensitivity study demonstrates that the model is capable of differentiating powertrains with different parameters and routes with different characteristics. / Master of Science
32

Analysera miljöpåverkan ur ett processperspektiv med DES och LCA / Analyze environmental imact from a process perspective with DES and LCA

Svantesson, Fredrik, Grönborg, Jimmy January 2019 (has links)
Volvo Powertrain i Skövde tillverkar motorer och motorkomponenter som levereras till Volvokoncernens globala fabriker. Gjuteriet är en av flera produktionsprocesser i Skövde och är i dagsläget norra Europas största gjuteri. Här produceras över 100 000 gjutgods varje år i form av cylinderblock, cylinderhuvud och svänghjul. I gjuteriet och framförallt smältverket blir miljöpåverkan och miljökonsekvenser allt viktigare att ta hänsyn till. På sikt vill gjuteriet förbättra produktionsprocesserna ur ett miljöperspektiv och minimera miljöpåverkan. Syftet med examensarbetet är att identifiera fokusområden och parametrar som bidrar till potentiell miljöpåverkan med kombinationen av DES och LCA. Med syftet i åtanke och viljan att analysera miljöpåverkan ur ett processorienterat perspektiv byggdes en lämplig projektmetod fram. Med stöd av relevanta metoder, teoretisk referensram och litteraturstudie utvecklades projektmetoden. Examensarbetet fortlöpte genom att bygga upp en konceptuell modell som grundlade möjligheterna till datainsamling. Utifrån den konceptuella modellen och insamlade data påbörjades uppbyggnaden av simuleringsmodell. Simuleringsmodellen byggdes upp på ett användarvänligt tillvägagångsätt med en integrerad Excel-fil för att enkelt kunna justera indata. Huvudsyftet med simuleringsmodellen är att direkt kunna analysera miljöpåverkan i form av global uppvärmning, försurning och övergödning utifrån automatiskt genererade data. I simuleringsmodellen sammanställs data i en kvantifierad inventeringsanalys som sedan beräknas om med tillhörande potentiella miljöpåverkansfaktorer. En miljökonsekvensanalys sammanställs sedan automatiskt i simuleringsmodellen med möjligheten att exporteras till Excel-fil. I detta examensarbete presenteras analysresultatet över identifierade parametrar i en procentuell fördelning till varandra och i förhållande till vald funktionell enhet. Analysresultatet indikerar var eventuella insatser bör läggas och vidare analyser bör utföras. Resultatet visar att resurstillsatsen koks är en stor bidragande parameter till potentiell miljöpåverkan. Därför bör fokusinsatser och vidare analyser genomföras på koks och eventuella alternativa lösningar identifieras.  Utöver miljökonsekvensanalysen genomfördes en jämförande elektricitetsanalys på ett historiskt och alternativt produktionsscenario i förhållande till den funktionella enheten. Analysen påvisar att det alternativa produktionsscenariot nyttjar 28%-enheter mindre elektricitet i förhållande till den funktionella enheten. / Volvo Powertrain in Skövde manufactures engines and engine components for the Volvo Group's global factories. The foundry is one of the production facilities in Skövde and is the largest foundry in Northern Europe. Over 100 000 castings are produced every year in the form of cylinder blocks, cylinder heads and flywheels. In the foundry and especially the smelter, environmental impacts are becoming significant due to its large energy demand. In the long term, the foundry needs to improve production processes from to minimize its environmental impact. The purpose of the thesis work is to identify focus areas and parameters that contribute to potential environmental impacts with the combination of DES and LCA. An analysing methodology was developed based on a process-oriented perspective. Based on relevant methods, theoretical reference framework and literature study, the project was developed. The thesis work continued by building a conceptual model for data collection. Based on the conceptual model and collected data, the simulation model is developed on an integrated Excel file for easy interface of the input data. The main purpose of the simulation model is to estimate the environmental impacts in terms of global warming, acidification and eutrophication. Two data processes are performed in the simulation model. Firstly, the input data from the conceptual model is compiled into a quantified inventory analysis. Secondly, the quantified inventory results are further categorized into potential environmental impacts, thereafter the results of the assessed environmental impacts are compiled and export to Excel file. The analysis results are presented over identified parameters with regards to the defined functional unit. The results indicate that the usage of coke is the major contributor to potential environmental impact. Therefore, efforts and further analyses should be focus on the usage of coke and identifying alternative solutions. In addition to the environmental impact assessment, a comparative analysis was conducted on a historical and alternative production scenario.  The analysis shows that the alternative production scenario utilizes 28% less electricity compared to the historical scenario.
33

Optimization of Vehicle Powertrain Model Complexity for Different Driving Tasks

Zetterlund, Olof January 2015 (has links)
This master thesis has examined how the understanding of different driving tasks can be used to develop a suitable powertrain model to be used in the Sim III simulator at VTI. Studies performed in the simulator have been statistically analyzed using parameters commonly used to describe driving patterns in drive cycles. It has been shown that the studies can be divided into three driving tasks: "High constant velocity", "High velocity with evasive maneuver", and "Mixed driving". Furthermore, a powertrain model from a former master thesis has been further developed. The new model utilizes a 3D torque map that takes engine speed, accelerator pedal position and gear as input. Using measurements, from the chassis dynamometers laboratory at LiU, that resembles the derived driving tasks, it has been shown that the performance of the new model has significantly increased for high velocity driving and during maximum acceleration. However, when using the clutch at low speeds and gears the model still performs poorly and needs further development.
34

Contribution à l'étude du vieillissement et à l'intégration des supercondensateurs dans une chaîne de propulsion électrique haute tension pour des applications véhicule électrique / A contribution to the study of aging and the integration of ultracapacitor in a high voltage powertrain for electric vehicle applications

Alcicek, Guven 08 December 2014 (has links)
Les supercondensateurs présentent un intérêt grandissant pour des applications embarquées. De récentes études (Supercapacitors USA, 2013) montrent que leur intégration dans un véhicule hybridé électriquement peut contribuer à multiplier par deux la durée de vie des batteries. Cependant, leur vieillissement n’est pas totalement maîtrisé et suscite encore de nombreuses interrogations.L’étude menée dans le cadre de cette thèse aborde la problématique du vieillissement du supercondensateur, et sa mise en application dans une chaîne de propulsion électrique haute tension. Les travaux ont porté sur les modes de vieillissements accéléré par floating (tension et température constantes) et par cyclage (charge décharge à courant constant), et ont permis l’élaboration d’un protocole d’essai fiable et répétitif permettant de minimiser les perturbations lors des mesures en modes fréquentiel et continu dites respectivement AC et DC. Les études faites sur le vieillissement par floating ont permis non seulement d’aboutir à une estimation de la durée de vie des supercondensateurs mais aussi d’analyser certaines causes du vieillissement de ces éléments.Durant cette étude nous avons également intégré un pack de supercondensateurs dans une plateforme d’un véhicule électrique équipé d’un pack de batteries au lithium fer phosphate. Cette étude a permis de mettre expérimentalement en évidence l’apport des supercondensateurs lors de phases transitoires (accélération, freinage, sollicitations brusques) et la réduction induite des sollicitations dynamiques sur la batterie. / Ultracapacitors present a growing interesting in at various the embedded applications. Recently published studies show that different integrations of ultracapacitor in the Hybrid Electric Vehicle (HEV) permits to increase the battery’s lifetime up to twice. In the meantime, the aging of ultracapacitor is not fully known and still waits many questions have to be responded.This thesis is studying the aging of the ultracapacitor and their integration in a HEV. The work focused on the accelerated aging in floating mode such as constant voltage and temperature and also in cycling mode such as charge-discharge for a constant current. This study permits us to find a reliable and a repeatable test protocol in order to minimize the noise during the measurement of a frequencial and a continuous mode. In the meantime, the floating mode allows to estimate the supercapacitors’ lifespan and also to determine some reasons of the aging.Besides, we have also included a pack of ultracapacitors in an EV platform based on a pack of lithium iron phosphate. The experimental test demonstrated clearly a contribution of the ultracapacitors during a transient phase (acceleration, braking, sudden stress) and the dynamic strain reduction on the battery.
35

Effect of Temperature on Lithium-Iron Phosphate Battery Performance and Plug-in Hybrid Electric Vehicle Range

Lo, Joshua January 2013 (has links)
Increasing pressure from environmental, political and economic sources are driving the development of an electric vehicle powertrain. The advent of hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and battery electric vehicles (BEVs) bring significant technological and design challenges. The success of electric vehicle powertrains depends heavily on the robustness and longevity of the on-board energy storage system or battery. Currently, lithium-ion batteries are the most suitable technology for use in electrified vehicles. The majority of literature and commercially available battery performance data assumes a working environment that is at room temperature. However, an electrified vehicle battery will need to perform under a wide range of temperatures, including the extreme cold and hot environments. Battery performance changes significantly with temperature, so the effects of extreme temperature operation must be understood and accounted for in electrified vehicle design. In order to meet the aggressive development schedules of the automotive industry, electrified powertrain models are often employed. The development of a temperature-dependent battery model with an accompanying vehicle model would greatly enable model based design and rapid prototyping efforts. This paper empirically determines the performance characteristics of an A123 lithium iron-phosphate battery, re-parameterizes the battery model of a vehicle powertrain model, and estimates the electric range of the modeled vehicle at various temperatures. The battery and vehicle models will allow future development of cold-weather operational strategies. As expected the vehicle range is found to be far lower with a cold battery back. This effect is seen to be much more pronounced in the aggressive US06 drive cycle where the all-electric range was found to be 44% lower at -20°C than at 25°C. Also it was found that there was minimal impact of temperature on range above 25°C
36

Design, simulation, and construction of a series hybrid electric vehicle

Northcott, Daniel Ross 27 September 2007 (has links)
This thesis evaluates a series hybrid electric drivetrain design for use in parking patrol vehicles. Due to the particular attributes of this application, it is proposed that the design would improve the energy efficiency of such a vehicle. The scheme is evaluated in depth through the use of electromagnetic transient simulation tools, which are used to create a highly accurate model of the vehicle. A prototype vehicle of the same design is built, and used to verify and improve the accuracy of the simulation model. The simulation model is then used to predict the energy efficiency of the series hybrid design for parking patrol. This simulation based design strategy is proposed as a method for more rapid and cost effective design of hybrid electric vehicles. / October 2007
37

Hybrid Fuel Cell Vehicle Powertrain Development Considering Power Source Degradation

Stevens, Matthew 21 January 2009 (has links)
Vehicle design and control is an attractive area of research in that it embodies a convergence of societal need, technical limitation, and emerging capability. Environmental, political, and monetary concerns are driving the automotive industry towards sustainable transportation, manifested as increasing powertrain electrification in a gradual transition to fossil-free energy vectors. From an electrochemical degradation and control systems perspective, this transition introduces significant technical uncertainty. Initial indications are that the initial battery designs will have twice the required capacity due to degradation concerns. As the battery is a major contributor to the cost of these vehicles the over-sizing represents a significant threat to the ability of OEMs to produce cost-competitive vehicles. This potential barrier is further amplified when the combustion engine is removed and battery-electric or fuel-cell hybrid vehicles are considered. This thesis researches the application of model-based design for optimal design of fuel cell hybrid powertrains considering power source degradation. The intent is to develop and evaluate tools that can determine the optimal sizing and control of the powertrain; reducing the amount of over-sizing by numerically optimization rather than a sub-optimal heuristic design. A baseline hybrid fuel cell vehicle model is developed and validated to a hybrid fuel cell SUV designed and built at the University of Waterloo. Lithium-ion battery degradation models are developed and validated to data captured off a hybrid powertrain test stand built as part of this research. A fuel cell degradation model is developed and integrated into the vehicle model. Lifetime performance is modeled for four hybrid control strategies, demonstrating a significant impact of the hybrid control strategy on powertrain degradation. A plug-in variation of the architecture is developed. The capacity degradation of the battery is found to be more significant than the power degradation. Blended and All-electric charge-depleting hybrid control strategies are integrated and lifetime performance is simulated. The blended charge-depleting control strategy demonstrated significantly less degradation than the all-electric strategy. An oversized battery is integrated into the vehicle model and the benefit of oversizing on reducing the battery degradation rate is demonstrated.
38

Hybrid Fuel Cell Vehicle Powertrain Development Considering Power Source Degradation

Stevens, Matthew 21 January 2009 (has links)
Vehicle design and control is an attractive area of research in that it embodies a convergence of societal need, technical limitation, and emerging capability. Environmental, political, and monetary concerns are driving the automotive industry towards sustainable transportation, manifested as increasing powertrain electrification in a gradual transition to fossil-free energy vectors. From an electrochemical degradation and control systems perspective, this transition introduces significant technical uncertainty. Initial indications are that the initial battery designs will have twice the required capacity due to degradation concerns. As the battery is a major contributor to the cost of these vehicles the over-sizing represents a significant threat to the ability of OEMs to produce cost-competitive vehicles. This potential barrier is further amplified when the combustion engine is removed and battery-electric or fuel-cell hybrid vehicles are considered. This thesis researches the application of model-based design for optimal design of fuel cell hybrid powertrains considering power source degradation. The intent is to develop and evaluate tools that can determine the optimal sizing and control of the powertrain; reducing the amount of over-sizing by numerically optimization rather than a sub-optimal heuristic design. A baseline hybrid fuel cell vehicle model is developed and validated to a hybrid fuel cell SUV designed and built at the University of Waterloo. Lithium-ion battery degradation models are developed and validated to data captured off a hybrid powertrain test stand built as part of this research. A fuel cell degradation model is developed and integrated into the vehicle model. Lifetime performance is modeled for four hybrid control strategies, demonstrating a significant impact of the hybrid control strategy on powertrain degradation. A plug-in variation of the architecture is developed. The capacity degradation of the battery is found to be more significant than the power degradation. Blended and All-electric charge-depleting hybrid control strategies are integrated and lifetime performance is simulated. The blended charge-depleting control strategy demonstrated significantly less degradation than the all-electric strategy. An oversized battery is integrated into the vehicle model and the benefit of oversizing on reducing the battery degradation rate is demonstrated.
39

A Hardware-in-the-Loop Test Platform for Planetary Rovers

Yue, Bonnie January 2011 (has links)
Hardware-in-the-Loop (HIL) test platform for planetary rovers was designed, fabricated and tested in the present work. The ability for planetary rover designers and mission planners to estimate the rover’s performance through software simulation is crucial. HIL testing can further the benefits of software simulations by allowing designers to incorporate hardware components within traditionally pure software simulations. This provides more accurate performance results without having access to all hardware components, as would be required for a full prototype testing. The test platform is designed with complete modularity such that different types of tests can be performed for varying types of planetary rovers and in different environments. For demonstrating the operation of the test platform, however, the power system operation of a solar powered rover was examined. The system consists of solar panels, a solar charge controller, a battery, a DC/DC converter, a DC motor and a flywheel. In addition, a lighting system was designed to simulate the solar radiation conditions solar panels would experience throughout a typical day. On the software side, a library of component models was developed within MapleSim and model parameters were tuned to match the hardware on the test bench. A program was developed for real-time simulations within Labview allowing communication between hardware components and software models. This program consists of all the component models, hardware controls and data acquisitioning. The GUI of this program allows users to select which component is to be tested and which component is to be simulated, change model parameters as well as see real time sensor measurements for each component. A signal scaling technique based on non-dimensionalization is also presented, which can be used in an HIL application for obtain scaling factors to ensure dynamic similarity between two systems. A demonstration of power estimation was performed using the pure software model simulations as well as the pure hardware testing. Hardware components were then added into the software simulation progressively with results showing better accuracy as hardware is added. The rover’s power flow was also estimated under different load conditions and seasonal variation. These simulations clearly demonstrate the effectiveness of an HIL platform for testing a rover’s hardware performance.
40

Validation of Bus Specific Powertrain Components in STARS

Karlsson, Karl January 2007 (has links)
<p>The possibilities to simulate fuel consumption and optimize a vehicle's powertrain to fit to the customer's needs are great strengths in the competitive bus industry where fuel consumption is one of the main sales arguments. In this master's thesis, bus specific powertrain component models, used to simulate and predict fuel consumption, are validated using measured data collected from buses.</p><p>Additionally, a sensitivity analysis is made where it is investigated how errors in the powertrain parameters affect fuel consumption. After model improvements it is concluded that the library components can be used to predict fuel consumption well.</p><p>During the work, possible model uncertainties which affect fuel consumption are identified. Hence, this study may serve as foundation for further investigation of these uncertainties.</p>

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