Complex engineering systems involve large numbers of functional elements. Each functional element can exhibit complex behavior itself. Ensuring the ability of such systems to meet the customer's needs and requirements requires modeling the behavior of these systems. Behavioral modeling allows a quantitative assessment of the ability of a system to meet specific requirements. However, modeling the behavior of complex systems is difficult due to the complexity of the elements involved and more importantly the complexity of these elements' interactions. In prior work, formal functional modeling techniques have been applied as a means of performing a qualitative decomposition of systems to ensure that needs and requirements are addressed by the functional elements of the system. Extending this functional decomposition to a quantitative representation of the behavior of a system represents a significant opportunity to improve the design process of complex systems. To this end, a functionality-based behavioral modeling framework is proposed along with a sensitivity analysis method to support the design process of complex systems. These design tools have been implemented in a computational framework and have been used to model the behavior of various engineering systems to demonstrate their maturity, application and effectiveness. The most significant result is a multi-fidelity model of a hybrid internal combustion-electric racecar powertrain that enabled a comprehensive quantitative study of longitudinal vehicle performance during various stages in the design process. This model was developed using the functionality-based framework and allowed a thorough exploration of the design space at various levels of fidelity. The functionality-based sensitivity analysis implemented along with the behavioral modeling approach provides measures similar to a variance-based approach with a computation burden of a local approach. The use of a functional decomposition in both the behavioral modeling and sensitivity analysis significantly contributes to the flexibility of the models and their application in current and future design efforts. This contribution was demonstrated in the application of the model to the 2009 Texas A&M Formula Hybrid powertrain design.

This dissertation proposes an Intelligent Energy Management Agent (IEMA) for parallel hybrid vehicles. A key concept adopted in the development of an IEMA is based on the premise that driving environment would affect fuel consumption and pollutant emissions, as well as the operating modes of the vehicle and the driver behavior do. IEMA incorporates a driving situation identification component whose role is to assess the driving environment, the driving style of the driver, and the operating mode (and trend) of the vehicle using long and short term statistical features of the drive cycle. This information is subsequently used by the torque distribution and charge sustenance components of IEMA to determine the power split strategy, which is shown to lead to improved fuel economy and reduced emissions.

Advanced hybrid vehicle architectures can exploit multiple power sources and optimal control to achieve high efficiency operation. In this work, a method for generating the best-possible energy efficiency benchmark for a hybrid architecture is introduced. The benchmark program uses Dynamic Programming to analyse a reduced-fidelity MATLAB model over standard driving cycles, and bypasses vehicle controls to identify the optimal control actions and resulting fuel consumption of the Series-Parallel Multiple-Regime retrofitted PHEV of the UVic EcoCAR2 program. The simulation results indicate an optimal fuel consumption value of 4.74L/100km, in the parallel regime, compared to the stock Malibu's 8.83L/100km. The results are found to be sensitive to the allowed level of regenerative braking, with an optimal consumption value of 6.56L/100km obtained with restricted regen power limits. The parallel regime provided more efficient operation overall, especially during more aggressive driving conditions. However, the series regime provided more desirable operation during gentle driving conditions, where opportunities for regenerative braking are limited. The generated powertrain control profiles were then used to drive a higher-fidelity Simulink model. Due to the significant difference between the model structures of the MATLAB and Simulink models, comparison of results were not conclusive. A different simulation approach is required to make this proof-of-concept more useful for controls development. This research forms the foundation for further studies. / Graduate / 0540 / snkaban@gmail.com

Increasing environmental, economic, and political concerns regarding the consumption of fossil fuels have highlighted the need for more efficient and alternative energy solutions. Hybrid electric vehicles represent a near-term opportunity for reducing liquid fossil fuel consumption and green-house gas emissions in the transportation industry, and as a result, many automotive manufacturers have invested heavily in hybrid vehicle development. The increased complexity of hybrid electric vehicles over standard internal combustion engine-powered vehicles has subsequently placed significant emphasis on development of advanced control methods geared towards efficient energy management. Real-time optimization-based methods represent the current state-of-the-art in terms of hybrid vehicle control and energy management. This thesis summarizes the development of an optimization-based real-time control system – which determines the optimal instantaneous system operating point, including gear, traction split between front rear axles, and engine speed and torque – and its application to an all-wheel drive extended-range electric vehicle that uses a General Motor’s front-wheel drive 2-Mode electronic continuously variable transmission and an additional rear traction motor. The real-time control system was developed and validated using a plant model and preliminarily tested in the vehicle using a four-wheel drive chassis dynamometer. Results of simulation and in-vehicle testing demonstrate engine operation focused on high-efficiency operating regions and minimal use of the rear traction motor. Further testing revealed that a rule-based traction split system may be sufficient to replace the optimization-based traction split determination, and that the limited rear traction motor use was not a function of the motor itself, but rather an inherent result of the selected architecture. / Graduate

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

Depuis l'essor des ordinateurs et des capacités de calcul, la conception des composants du génie électrique repose largement sur des simulations informatiques et sur des calculs numériques. Dans les systèmes complexes, où de nombreux composants interagissent pour le bon fonctionnement du système, le dimensionnement optimal du composant dépend nécessairement de son environnement systémique. La conception de celui-ci est fortement liée au fonctionnement du système global. La conception intégré du composant dans son environnement systémique permet ainsi de repousser les limites de l'efficacité énergétique, pour des systèmes plus performants et moins consommateurs. En support à ce contexte méthodologique, nous proposons de dimensionner par optimisation un moteur électrique pour un véhicule hybride dans le but d'améliorer l'efficacité énergétique globale du véhicule. Dans ce travail, nous avons modélisé le moteur électrique par un schéma réluctant, et nous proposons deux approches méthodologiques différentes du même problème. Les points clés de notre approches sont : la prise en compte de l'environnement du moteur, du cycle de fonctionnement et de la gestion de l'énergie du système. / Since the development of computers and calculation capacities, the design of electrical components in electrical engineering is widely based on computing simulations and on numeral calculations. In complex systems, where numerous components interact for the working of the system, the optimal sizing of the component deeply depends on its systemic environment. The design of each component is strongly linked to the functioning of the global system. Therefore, the joint design of the component into its systemic environment allows to improve the efficiency of the system. In this methodological context, we optimize an electric machine for a hybrid vehicle. The aim of this work is to improve the global efficiency of the vehicle. In this work, we build a magnetic circuit model, and we propose two approaches for solving the optimization problem. The key points of this work are : the consideration of the environment of the electrical machine, the driving cycle and the energy management of the system.

Submitted by Marlene Santos (marlene.bc.ufg@gmail.com) on 2016-08-31T19:21:29Z No. of bitstreams: 2 Dissertação - Edson Bernardes Júnior - 2016.pdf: 3130810 bytes, checksum: 48b6c19a01be5016f11a79ad110e47f9 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-09-01T12:09:42Z (GMT) No. of bitstreams: 2 Dissertação - Edson Bernardes Júnior - 2016.pdf: 3130810 bytes, checksum: 48b6c19a01be5016f11a79ad110e47f9 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2016-09-01T12:09:42Z (GMT). No. of bitstreams: 2 Dissertação - Edson Bernardes Júnior - 2016.pdf: 3130810 bytes, checksum: 48b6c19a01be5016f11a79ad110e47f9 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-03-14 / The current world situation distinguishes itself through measures that preserve natural resources and they can be less harmful to the environment. This view could not be different for the auto industry, which in turn accounts for 5% of the brazilian GDP, employs over 1.5 million people and receives prominent position worldwide. Now exist a greater concern to produce more energy efficient vehicles and less polluting. Emerge hybrid vehicles as a possible solution to the chaos seen in large cities, appearing the car as the biggest polluter. However, some drawbacks, mainly linked to car price formation, still hinder the access of a majority of the population to the type of hybrid powertrain. In this sense this research analyzes to verify how behave a possible gradual replacement of vehicles for a vehicle fleet composed entirely by internal combustion vehicles for other hybrids. And then proposes such action in a higher education institution (IFES), the Federal University of Goiás (UFG), which was observed the main variables for six possible scenarios, where 20% of the existing fleet would be gradually replaced, for a sample that is 20.48%of the total to reach the completeness with hybrid vehicles. This proved that the hybrids are more efficient in all the proposals made, but that the high cost of purchasing replacement make it impossible for a short term, requiring more than six years of use. / A atual conjuntura mundial preza por medidas que preservem os recursos naturais e que consigam serem menos agressivas ao meio ambiente. Esta perspectiva não poderia ser diferente para a indústria automobilística, que por sua vez é responsável por 5%do PIB brasileiro, emprega mais de 1,5 milhões de pessoas e recebe posição de destaque mundialmente. Vêse agora, uma maior preocupação em produzir veículos mais eficientes energeticamente e menos poluidores. É assim que despontamos veículos híbridos como uma possível solução ao caos observado nas grandes metrópoles, onde aparece o automóvel como o maior poluidor. No entanto, alguns empecilhos, principalmente ligados à formação de preço dos automóveis, ainda dificultam o acesso de uma maior parte da população ao tipo de motorização híbrida. É neste sentido que surge esta pesquisa com o intuito de verificar de que forma se comportaria uma possível substituição gradativa de veículos para uma frota veicular composta integralmente por veículos a combustão interna por outros híbridos. Sendo então proposta tal ação em uma Instituição de Ensino Superior (IFES), a UFG , onde foi observada as principais variáveis para seis possíveis cenários, onde seriam gradualmente substituídos 20% da frota existente, para uma amostra que representa 20,48% da totalidade, até atingir a integralidade com veículos híbridos. Esta comprovou que os veículos híbridos são mais eficientes em todas as proposições feitas,mas que, os altos preços de aquisição tornam inviável a substituição para um curto prazo, sendo necessário um período superior a seis anos de uso.

Les travaux de recherche sont consacrés au vieillissement des supercondensateurs (SC) à double couche électrique dans un réseau électrique embarqué soumis à des ondulations de courant de haute fréquence (par exemple celui d'un véhicule hybride). Les SC étudiés sont des composants commerciaux représentatifs de la technologie la plus utilisée (acetonitrile / charbon actif) dans les applications de transport. Les travaux présentent des résultats d'essais de vieillissement calendaires (c'est-à-dire à tension et à température constantes). Le suivi de l'état de santé des SC s'effectue à l'aide de l'évolution de leur impédance au cours des essais de vieillissement. Plusieurs modèles d'impédances classiques sont présentés (modèle CPE et modèle simple pore) ainsi qu'un modèle récent (modèle multipore). Les paramètres de chaque modèle d'impédance sont systématiquement liés à des grandeurs électrochimiques des SC représentatives de l'état de leurs électrodes. Grâce au modèle multipore, les pores des électrodes du SC peuvent être classés selon leur constante de temps électrique (liée sous certaines hypothèses au diamètre d'ouverture des pores). L'application du modèle multipore aux résultats du vieillissement calendaire permet de mettre en évidence un effet drastique du début de vieillissement sur les pores possédant un faible diamètre d'ouverture. Les ondulations de courant haute fréquence semblent quant à elles transparentes en ce qui concerne le vieillissement c'est-à-dire qu'elles influencent très peu le vieillissement des SC. On note enfin un effet non négligeable des arrêts de vieillissement sur l'état de santé des SC / Those research works are about double layer supercapacitors ageing placed in an onboard power network subject to high frequency current ripple (in a hybrid vehicle for instance). Studied SC are commercial components, representative of the most used technology (i.e. Acetonitrile / Active carbon) in transports domain. SC floating ageing results (constant temperature and constant voltage) are presented. SC health monitoring is achieved by using SC impedance evolution through ageing test. Classic impedance models (CPE and single pore model) are presented as well as a newer model (called multipore model). Model parameters are systematically linked to electrochemical data related to SC state of health. Multipore model enable to classify pores thanks to their electrical time constant (related to pore diameter under some hypothesis). The evolution of multipore model parameters under floating constraints shows that the smaller pores are more affected by beginning of ageing test. HF current ripple seem not to affect supercapacitors floating ageing. Whereas we notice effect of ageing stopping periods on SC state of health

The diploma thesis focuses on the analysis of the current development of electromobility and the description of different types of drives. The first part deals with the basic theory of electric vehicles on batteries, hybrid vehicles and fuel cell vehicles. The second part provides analysis and data on the offered electric cars. At the end of the work is an evaluation of the situation.

The future of aviation technology is transitioning to cleaner, more efficient and higher endurance aircraft solutions. As fully electric propulsion systems still fall short of the operational requirements of modern day aircraft, there is increasing pressure and demand for the aviation industry to explore alternatives to fossil fuel driven propulsion systems. The primary focus of this research is to experimentally evaluate hybrid electric propulsion systems (HEPS) for Unmanned Aerial Vehicles (UAV) which combine multiple power sources to improve performance. HEPS offer several potential benefits over more conventional propulsion systems such as a smaller environmental impact, lower fuel consumption, higher endurance and novel configurations through distributed propulsion. Advanced operating modes are also possible with HEPS, increasing the vehicle’s versatility and redundancy in case of power source failure. The primary objective of the research is to combine all of the components of a small-scale HEPS together in a modular test bench for evaluation. The test bench uses components sized for a small-scale UAV including a 2.34kW two-stroke 35cc engine and a 1.65kW brushless DC motor together with an ESC capable of regenerative braking. Individual components were first tested to characterize performance, and then all components were assembled together in a parallel configuration to observe system-level performance. The parallel HEPS is capable of functioning in the four required operating modes: EM Only, ICE Only, Dash Mode (combined EM and ICE power) as well as Regenerative Mode where the onboard batteries get recharged. Further, the test bench was implemented with a supervisory controller to optimize system performance and run each component in the most efficient region to achieve torque requirements programmed into mission profiles. The logic based controller operates with the ideal operating line (IOL) concept and is implemented with a custom LabView GUI. The system is able to run on electric power or ICE power interchangeably without making any modifications to the transmission as the one-way bearing assembly engages for whichever power source is rotating at the highest speed. The most impressive of these sets of tests is the Dash mode testing where the output torque of the propeller is supplied from both the EM and ICE. Working in tandem, it was proved that the EM was drawing 19.9A of current which corresponds to an estimated 0.57Nm additional torque to the propeller for a degree of hybridization of 49.91%. Finally, the regenerative braking mode was proven to be operational, capable of recharging the battery systems at 13A. All of these operating modes attest to the flexibility and convenience of having a hybrid-electric propulsion system. The results collected from the test bench were validated against the models created in the aircraft simulation framework. This framework was created in MATLAB to simulate the performance of a small UAV and compare the performance by swapping in various propulsion systems. The purpose of the framework is to make direct comparisons of HEPS performance for parallel and series architectures against conventional electric and gasoline configuration UAVs, and explore the trade-offs. Each aircraft variable in the framework was modelled parametrically so that parameter sweeps could be run to observe the impact on the aircraft’s performance. Finally, rather than comparing propulsion systems in steady-state, complex mission profiles were created that simulate real life applications for UAVs. With these experiments, it was possible to observe which propulsion configurations were best suited for each mission type, and provide engineers with information about the trade-offs or advantages of integrating hybrid-electric propulsion into UAV design. In the Pipeline Inspection mission, the exact payload capacities of each aircraft configuration could be observed in the fuel burn versus CL,cruise parameter sweep exercise. It was observed that the parallel HEPS configuration has an average of 3.52kg lower payload capacity for the 35kg aircraft (17.6%), but has a fuel consumption reduction of up to 26.1% compared to the gasoline aircraft configuration. In the LIDAR Data collection mission, the electric configuration could be suitable for collection ranges below 100km but suffers low LIDAR collection times. However, at 100km LIDAR collection range, the series HEPS has an endurance of 16hr and the parallel configuration has an endurance of 19hr. In the Interceptor mission, at 32kg TOW, the parallel HEPS configuration has an endurance/TOW of 1.3[hr/kg] compared to 1.15[hr/kg] for the gasoline aircraft. This result yields a 13% increase in endurance from 36.8hr for gasoline to 41.6hr for the parallel HEPS. Finally, in the Communications Relay mission, the gasoline configuration is recommended for all TOW above 28kg as it has the highest loiter endurance. / Graduate