Flywheel systems are attractive in hybrid and electric vehicles due to their ability to handle power during acceleration and braking. The combination of a flywheel device with a battery source has several advantages such as high peak power capacity, high energy density and reduction in the number of charge/discharge cycles of the battery. A flywheel based all-electric driveline is investigated in this thesis. The novelty of the system consists in the use of a double wound flywheel machine, which divides the system in two different power levels. Due to this configuration, the system becomes efficient and can handle the power developed during fast dynamical processes. The complete driveline consists of three main components: the battery, the flywheel machine and the wheel motor. The High-Power (HP) side of the driveline connects the flywheel machine to the wheel motor, whereas the Low-Power (LP) side connects the flywheel machine to the battery. The connections of different components of the system are made electrically through power converter devices. The present thesis focuses on the electrical converters and control strategies used in the flywheel based all-electric driveline. The control of power converters is responsible for the logic and functionality of the driveline, being a challenging step within this project. Different power converter topologies have been investigated: a DC/DC plus a DC/AC converter on the LP side, and an AC/DC/AC converter on the HP side. The design and assembly of the power electronics and their control scheme have been successfully implemented. Different control strategies have been suggested and a complete scaled driveline has been assembled and tested based on previous simulation results. Results have confirmed the functionality of the driveline, where smoothed output power has been obtained from the battery, whereas the flywheel handles power transients on the traction side. An average efficiency of about 87% (battery to wheels) has been obtained. The power converter systems have been shown to be efficient and robust, with control strategies able to handle the peak energy flow in the system. A regenerative braking strategy has been simulated and a wheel-to-wheel efficiency of about 80% has been estimated.

Thesis (M. Sc.)--University of Hong Kong, 1995. / Includes bibliographical references (leaf [110-114]).

Thesis (MScEng)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: The focus of this thesis is on the optimal design and evaluation of FI-PM machines to be used with a MG transmission drive-train for EV application. The machines presented are optimised using a gradient-based optimisation algorithm of the VisualDoc software together with FE software and Python scripts. Each machine is optimised for its own objective function. The focus is to reduce expensive rare earth material. High torque ripple issues of the optimised machines are solved by implementing a relatively new topology where the rotor poles/barriers are made asymmetric. The asymmetric rotor topology implemented is effective and can be used as an alternative for rotor stack skewing. PM demagnetisation and rotor deformation studies are conducted on the optimum designed machines to ensure that no PM demagnetisation on the surface of the PMs and critical rotor deformation occur. The FE performance results of the optimum designed machines are shown and discussed. One of the optimum designed FI-PM machines is manufactured and tested in the laboratory. The FE and measured results of the machine are compared and shows good correlation. The saliency performance of the optimum designed machines are evaluated as it determines its position sensorless control capability. It is shown that the saliency ratios increase linearly with load, making it favourable for position sensorless control. It is also shown that the asymmetric rotor topologies introduced a larger mutual inductance compared to their symmetric counterparts, thus higher cross-coupling is present in these rotors and therefore a higher saliency shift, which is undesirable. Two case studies are performed in order to improve saliency performance. The objective of the first case study is to improve the saliency shift by reducing the flux leakage paths in the rotor. The objective of the second case study is to optimise a FI-PM machine in order to improve the saliency ratio and -shift. The results of the two case studies are compared with the saliency performance of the other machines. / AFRIKAANSE OPSOMMING: Die fokus van hierdie tesis is op die optimale ontwerp en evaluering van veld versterking permanente magneet masjiene vir veelvoudige-rat elektriese voertuig toepassings. Die masjiene teenwoordig is geoptimeer met behulp van ’n helling-gebaseerde optimering algoritme. Elke masjien is geoptimeer vir sy eie doel funksie. Die fokus is om duur seldsame permanent magneet materiaal te verminder. Hoë wringkrag-rimpeleffek van die optimale masjiene word opgelos deur die implementering van ’n relatief nuwe topologie waar die rotor pole/vloedbarrière asimmetries gemaak word. Die asimmetriese rotor topologie wat geimplementeer is, is effektief en kan dus as ’n alternatief vir die rotor stapel skeef metode gebruik word. Permanent magneet demagnetisering en rotor vervorming studies is ook uitgevoer op die optimum ontwerpte masjiene om te verseker dat geen demagnetisering plaasvind nie en ook geen kritiese rotor vervorming nie. Die eindige-element resultate van die optimum ontwerpte masjiene word getoon en bespreek. Een van die optimum ontwerpte veld versterking permanente magneet masjiene is vervaardig en getoets in die laboratorium . Die eindige-element en gemete resultate van die masjien word vergelyk en toon goeie korrelasie. Die speek prestasie van die optimum ontwerpte masjiene word geëvalueer aangesien dit die sensorlose posisie beheer vermoë bepaal. Daar word getoon dat die speek koëffisiënt verhoog lineêr met vrag wat dit gunstig maak vir posisie sensorlose beheer . Daar word ook gewys dat die asimmetriese rotor topologie ’n groter wedersydse induktansie het in vergelyking met hul simmetriese eweknieë, dus is daar hoër kruis-koppeling teenwoordig in die rotors en dus ’n ho¨er speek skuif, wat ongewens is. Twee gevallestudies om speek prestasie te verbeter is uitgevoer. Die doel van die eerste gevallestudie is om die speek skuif te verbeter deur die vermindering van die vloed lekkasie paaie in die rotor. Die doel van die tweede gevallestudie is om ’n veld versterking permanente magneet masjiene te optimeer ten einde die speek koëffisiënt en - skuif te verbeter. Die resultate van die twee gevallestudies word vergelyk met die speek prestasie van die ander masjiene.

Submitted by Andrea Narullo (andrea.narullo@gmail.com) on 2015-04-01T21:07:41Z No. of bitstreams: 1 Thesis_ANDREA_NARULLO.pdf: 918513 bytes, checksum: 7bf8286368315afd80f709515ad77857 (MD5) / Rejected by Luana Rodrigues (luana.rodrigues@fgv.br), reason: Dear Andrea, I kindly ask you to do these changes: 1) After the abstract, you have to do the "resumo", abstract in Portuguese. 2) Regarding the knowledge field. There are only 3 field of knowledge of MPGI registered in CAPES (The Government Department responsible for the rules of Masters Programs) and they are: Economia e Finanças Internacionais, Internacionalização de Empresas e Gestão e Competitividade em Empresas Globais. Therefore I advise you to put the field of knowledge recorded in CAPES. After you modify them, please post your thesis again. Best regards, Luana de Assis Rodrigues Cursos de Pós-Graduação – Post Graduate Program (55 11) 3799-3492 SRA - Secretaria de Registros Acadêmicos on 2015-04-06T12:44:38Z (GMT) / Submitted by Andrea Narullo (andrea.narullo@gmail.com) on 2015-04-06T16:43:58Z No. of bitstreams: 1 Thesis_ANDREA_NARULLO.pdf: 920119 bytes, checksum: dfc25b860afd1668375a688aed3bfc8a (MD5) / Approved for entry into archive by Luana Rodrigues (luana.rodrigues@fgv.br) on 2015-04-06T19:20:02Z (GMT) No. of bitstreams: 1 Thesis_ANDREA_NARULLO.pdf: 920119 bytes, checksum: dfc25b860afd1668375a688aed3bfc8a (MD5) / Made available in DSpace on 2015-04-07T13:20:11Z (GMT). No. of bitstreams: 1 Thesis_ANDREA_NARULLO.pdf: 920119 bytes, checksum: dfc25b860afd1668375a688aed3bfc8a (MD5) Previous issue date: 2015-03-10 / This study analyses the integration of environmental sustainability into corporate strategy in the context of the car industry. The implementation of sustainability strategies and the development of hybrid-electric vehicles are investigated with reference to the case of a major player in the industry. Among the applications of electric mobility, which will increase the market presence in the forthcoming years due to stringent regulations and customer preferences, the research focused on hybrid-electric vehicles. The sustainability strategies of major car manufacturers and the subsequent implications in terms of product development, with a particular attention to hybrid-electric vehicles, were analysed via secondary data. Additionally, primary data was collected about the sustainability strategy of a major player in the industry and used to perform a case study. The analysis focused on critical drivers and aspects that impact on sustainability strategies aimed at reducing the environmental footprint of the car industry and on the development of hybrid vehicles. The analysis of the data showed that Fiat-Chrysler Automobiles (FCA) had a minor emphasis on electric mobility in terms of sustainability reporting. The conclusion presents an assessment of FCA’s corporate strategy in terms of environmental sustainability and a framework for HEV development with four different approaches that impact on the sustainability strategy of a carmaker. / Este estudo analisa a integração da sustentabilidade ambiental na estratégia das empresas no contexto da indústria automobilística. A implementação de estratégias de sustentabilidade e o desenvolvimento de veículos híbrido-elétricos são investigados com referência ao caso de um ator principal na indústria. Entre as aplicações de mobilidade eléctrica, que irá aumentar a presença no mercado nos próximos anos devido às regulamentações rigorosas e as preferências dos clientes, a pesquisa está focada em veículos híbrido-elétricos. As estratégias de sustentabilidade das grandes fabricantes de automóveis e as implicações subsequentes em termos de desenvolvimento de produtos, com uma atenção especial aos veículos elétricos híbridos, foram analisados através de dados secundários. Além disso, os dados primários foram coletados sobre a estratégia de sustentabilidade de um ator importante na indústria e usados para realizar um estudo de caso. A análise incidiu sobre os fatores críticos e os aspectos que têm impacto sobre as estratégias de sustentabilidade, que visam reduzir o impacto ambiental da indústria automobilística, e sobre o desenvolvimento de veículos híbridos. A análise dos dados mostrou que a Fiat-Chrysler Automobiles (FCA) teve uma ênfase menor na mobilidade eléctrica em termos de relatórios de sustentabilidade. A conclusão apresenta uma avaliação da estratégia corporativa da FCA, em termos de sustentabilidade ambiental, e apresenta um quadro para o desenvolvimento de veículos híbridos com quatro abordagens diferentes que têm impacto sobre a estratégia de sustentabilidade de uma montadora.

O presente trabalho tem por objetivo propor uma metodologia para o dimensionamento da potência tracionária em função do percurso percorrido por veículos elétricos, assim como realizar o projeto básico de uma máquina elétrica para suprir a carga tracionária exigida. Os cálculos foram realizados através de um algoritmo onde o usuário insere as variáveis mecânicas do veículo e recebe a potência e conjugado necessários, e o projeto elementar da máquina que deverá equipar o veículo. Realizou-se um estudo de caso a partir de uma scooter elétrica para validar os resultados, foi projetada uma máquina brushless dc com fluxo radial e rotor externo. Os resultados experimentais atenderam as espectativas de conjugado de 46 Nm, o máximo conjugado estático atingiu 48 Nm e a rotação a vazio obteve valor de 613 rpm à tensão nominal. Os ensaios de frenagem regenerativa com supercapacitores apresentaram resultados promissores com 50% da energia mecânica recebida durante a frenagem entregue na partida do veículo. / The present study aims to propose a methodology for the design of power traction depending on the distance traveled by electrical vehicles, and perform the basic design of an electrical machine to supply the traction load required. The calculations will be performed through an algorithm where the user enters the mechanical variables of the vehicle and receives the power and torque required and the basic machine design that should equip the vehicle. A case study was conducted for an electric scooter considering the designed dc brushless machine with radial flow and external rotor in order to validate the results. The experimental results met the target of 46 Nm of torque, the maximum static torque 48 Nm was reached, and the no-load rotation obtained was 613 rpm at nominal voltage. Regenerative braking tests with super capacitors showed a promising result: 50% of the received mechanical energy during braking was delivered to the vehicle starting.

abstract: The automotive industry is committed to moving towards sustainable modes of transportation through electrified vehicles to improve the fuel economy with a reduced carbon footprint. In this context, battery-operated hybrid, plug-in hybrid and all-electric vehicles (EVs) are becoming commercially viable throughout the world. Lithium-ion (Li-ion) batteries with various active materials, electrolytes, and separators are currently being used for electric vehicle applications. Specifically, lithium-ion batteries with Lithium Iron Phosphate (LiFePO4 - LFP) and Lithium Nickel Manganese Cobalt Oxide (Li(NiMnCo)O2 - NMC) cathodes are being studied mainly due to higher cycle life and higher energy density values, respectively. In the present work, 26650 Li-ion batteries with LFP and NMC cathodes were evaluated for Plug-in Hybrid Electric Vehicle (PHEV) applications, using the Federal Urban Driving Schedule (FUDS) to discharge the batteries with 20 A current in simulated Arizona, USA weather conditions (50 ⁰C & <10% RH). In addition, 18650 lithium-ion batteries (LFP cathode material) were evaluated under PHEV mode with 30 A current to accelerate the ageing process, and to monitor the capacity values and material degradation. To offset the high initial cost of the batteries used in electric vehicles, second-use of these retired batteries is gaining importance, and the possibility of second-life use of these tested batteries was also examined under constant current charge/discharge cycling at 50 ⁰C. The capacity degradation rate under the PHEV test protocol for batteries with NMC-based cathode (16% over 800 cycles) was twice the degradation compared to batteries with LFP-based cathode (8% over 800 cycles), reiterating the fact that batteries with LFP cathodes have a higher cycle life compared to other lithium battery chemistries. Also, the high frequency resistance measured by electrochemical impedance spectroscopy (EIS) was found to increase significantly with cycling, leading to power fading for both the NMC- as well as LFP-based batteries. The active materials analyzed using X-ray diffraction (XRD) showed no significant phase change in the materials after 800 PHEV cycles. For second-life tests, these batteries were subjected to a constant charge-discharge cycling procedure to analyze the capacity degradation and materials characteristics. / Dissertation/Thesis / Masters Thesis Materials Science and Engineering 2017

O presente trabalho tem por objetivo propor uma metodologia para o dimensionamento da potência tracionária em função do percurso percorrido por veículos elétricos, assim como realizar o projeto básico de uma máquina elétrica para suprir a carga tracionária exigida. Os cálculos foram realizados através de um algoritmo onde o usuário insere as variáveis mecânicas do veículo e recebe a potência e conjugado necessários, e o projeto elementar da máquina que deverá equipar o veículo. Realizou-se um estudo de caso a partir de uma scooter elétrica para validar os resultados, foi projetada uma máquina brushless dc com fluxo radial e rotor externo. Os resultados experimentais atenderam as espectativas de conjugado de 46 Nm, o máximo conjugado estático atingiu 48 Nm e a rotação a vazio obteve valor de 613 rpm à tensão nominal. Os ensaios de frenagem regenerativa com supercapacitores apresentaram resultados promissores com 50% da energia mecânica recebida durante a frenagem entregue na partida do veículo. / The present study aims to propose a methodology for the design of power traction depending on the distance traveled by electrical vehicles, and perform the basic design of an electrical machine to supply the traction load required. The calculations will be performed through an algorithm where the user enters the mechanical variables of the vehicle and receives the power and torque required and the basic machine design that should equip the vehicle. A case study was conducted for an electric scooter considering the designed dc brushless machine with radial flow and external rotor in order to validate the results. The experimental results met the target of 46 Nm of torque, the maximum static torque 48 Nm was reached, and the no-load rotation obtained was 613 rpm at nominal voltage. Regenerative braking tests with super capacitors showed a promising result: 50% of the received mechanical energy during braking was delivered to the vehicle starting.

abstract: Vehicles powered by electricity and alternative-fuels are becoming a more popular form of transportation since they have less of an environmental impact than standard gasoline vehicles. Unfortunately, their success is currently inhibited by the sparseness of locations where the vehicles can refuel as well as the fact that many of the vehicles have a range that is less than those powered by gasoline. These factors together create a "range anxiety" in drivers, which causes the drivers to worry about the utility of alternative-fuel and electric vehicles and makes them less likely to purchase these vehicles. For the new vehicle technologies to thrive it is critical that range anxiety is minimized and performance is increased as much as possible through proper routing and scheduling. In the case of long distance trips taken by individual vehicles, the routes must be chosen such that the vehicles take the shortest routes while not running out of fuel on the trip. When many vehicles are to be routed during the day, if the refueling stations have limited capacity then care must be taken to avoid having too many vehicles arrive at the stations at any time. If the vehicles that will need to be routed in the future are unknown then this problem is stochastic. For fleets of vehicles serving scheduled operations, switching to alternative-fuels requires ensuring the schedules do not cause the vehicles to run out of fuel. This is especially problematic since the locations where the vehicles may refuel are limited due to the technology being new. This dissertation covers three related optimization problems: routing a single electric or alternative-fuel vehicle on a long distance trip, routing many electric vehicles in a network where the stations have limited capacity and the arrivals into the system are stochastic, and scheduling fleets of electric or alternative-fuel vehicles with limited locations to refuel. Different algorithms are proposed to solve each of the three problems, of which some are exact and some are heuristic. The algorithms are tested on both random data and data relating to the State of Arizona. / Dissertation/Thesis / Ph.D. Industrial Engineering 2014

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / This work presents a study and design of an electronic power converter topology for on-board application in a battery charger for plug-in electric vehicles. The proposed topology is based on AC-DC converter Buck+Boost, which one is very attractive for this application due to its buck and boost characteristics in a single-stage power processing. Furthermore, this topology presents reduced weight and volume, since there is no transformer and only few components are presented in its structure. A theoretical study is performed through of qualitative and quantitative analysis, besides it is investigated the switching process and losses in the converter components. It is also performed a design example of a battery charger with rated output power of 1 kW, input voltage 220 Vac RMS and output voltage of 162 Vdc, corresponding to 12 batteries connected in series. A prototype for the indicated specifications was constructed in laboratory and tested experimentally. The simulation and experimental results obtained are used to validate the theoretical analysis and design. For rated load, it was obtained an efficiency of 96.5% and a power factor of 0.992, thus showing the effectiveness of the proposed converter. / Este trabalho apresenta o estudo e desenvolvimento de uma topologia de conversor eletrÃnico de potÃncia para a aplicaÃÃo embarcada em um carregador de baterias para veÃculos elÃtricos recarregÃveis atravÃs da rede elÃtrica. A topologia escolhida à baseada no conversor CA-CC Buck+Boost, onde a mesma torna-se bastante atrativa para este tipo de aplicaÃÃo por apresentar as caracterÃsticas elevadora e abaixadora de tensÃo em um Ãnico estÃgio de processamento de energia. AlÃm disso, esta topologia apresenta reduzido volume e peso, devido ao fato de nÃo apresentar transformador e possuir poucos componentes em sua estrutura. Um estudo teÃrico à realizado atravÃs das anÃlises qualitativa e quantitativa, alÃm das anÃlises do processo de comutaÃÃo e das perdas nos componentes do conversor. Neste trabalho à realizado um exemplo de projeto do carregador de baterias para aplicaÃÃo em veÃculos elÃtricos de 1 kW de potÃncia de saÃda, tensÃo de entrada eficaz de 220 Vca e tensÃo de saÃda de 162 Vcc, correspondente a 12 baterias conectadas em sÃrie. Um protÃtipo com as especificaÃÃes indicadas foi construÃdo e testado experimentalmente em laboratÃrio. Os resultados de simulaÃÃo e experimentais obtidos validaram a anÃlise teÃrica e o projeto realizado. Para carga nominal, foi obtido rendimento de 96,5% e fator de potÃncia de 0,992, comprovando assim o funcionamento da topologia utilizada.

Orientador: Niederauer Mastelari / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-16T18:46:49Z (GMT). No. of bitstreams: 1 CaceresDelgado_Adriana_M.pdf: 1925060 bytes, checksum: 9bc88ebf6480dc5a60e01e96de974f3d (MD5) Previous issue date: 2010 / Resumo: A proteção ambiental e o melhor uso dos recursos energéticos são áreas de pesquisa de grande atividade. Como resultado destas pesquisas o desenvolvimento de veículos elétricos (VE) e híbridos (VEH) têm se acelerado. Estes possuem problemáticas desafiadoras, como baixa autonomia, a conversão de energia, o controle do veículo, o gerenciamento e distribuição da energia dentro dele, assim como o "design" tanto estético quanto mecânico e econômico. Este conjunto de problemáticas inspirou este projeto de mestrado que tem como objetivo o estudo e elaboração de um algoritmo para frenagem regenerativa (FR) de uma máquina síncrona de imã permanente brushless (BLDC). Motivados nas características que a estratégia de FR proporciona ao VE, entre estas, o aumento na autonomia e a melhora do desempenho mecânico e eletrônico do mesmo já que quando a FR é ativada recupera-se uma parte da energia cinética durante a desaceleração através da máquina elétrica operando como gerador. Com base no anterior este trabalho foi desenvolvido em várias etapas: principalmente ao abranger os conceitos sobre frenagem regenerativa; estudar o motor BLDC desde seu modelo, acionamento e identificação das características mais relevantes com respeito a outros motores elétricos. Seguido do projeto da parte mecânica do sistema, que compreende a transmissão e a inércia, para ser envolvidos no modelo simulado. Assim como o desenvolvimento dos algoritmos para o acionamento do motor, onde serão monitoradas a velocidade e a posição do rotor, com o fim de controlar sua aceleração e desaceleração. Posteriormente um algoritmo para frenagem regenerativa, onde é monitorado o estado do motor e executam-se as decisões lógicas tanto para redirecionamento de energia, quanto para controle da frenagem. O resultado obtido foi que o algoritmo para FR regenera parte da energia cinética envolvida durante a desaceleração, além de que gerencia o funcionamento de todo o processo e subprocessos durante a aceleração, velocidade constante e desaceleração passo a passo e minimiza o consumo de energia em cada desaceleração. / Abstract: Environmental protection and optimal energy resources are great activity research areas. As a result of these researches, electric vehicles (EVs) and hybrid (HEV) developments have been accelerated. They have challenging problems such as low autonomy, power conversion, vehicle control, energy management and distribution within it, as well as the esthetic and mechanical design and also the economic issues. This set of problems inspired this master's project which is aimed to study and elaborate an algorithm for regenerative braking (RB) in a synchronous permanent magnet brushless machine (BLDC). Motivated in the RB strategy characteristics that provides to the EV, such as, autonomy increased, mechanical and electronic performance improvement just when the RB is activated and part of the kinetic energy is recovered through the electric maquine as a generator. This work was developed in several stages: mainly cover the regenerative braking concepts; study the BLDC motor from its model, driver and outstanding features identification respect others electric motors. Followed by the mechanical design of the system, which includes the transmission and inertia, to be included in the simulated model. Just as the development of the algorithms for the motor drive, where will be monitored speed and rotor position, in order to control its acceleration and deceleration. Subsequently a management regenerative braking algorithm, which monitors the engine state, and excecute the logical decisions for redirecting the energy, and for braking control. As a result it was found that when the electrical machine operates as a generator part of the kinetic energy is recovered during deceleration. And also it was able to prove that the algorithm manages the whole process operation since the acceleration, constant velocity and deceleration step by step, while minimizing energy consumption in every downturn. / Mestrado / Mecanica dos Sólidos e Projeto Mecanico / Mestre em Engenharia Mecânica