The Martin Aircraft Company Limited has been developing the Martin Jetpack for over 25 years. The recent worldwide launch of the Jetpack has enabled the company to step up its research and development programme. The goal of this project was to determine the feasibility of an electrically powered version of the Martin Jetpack. The feasibility of the Electric Jetpack was determined by researching energy storage technologies, researching power cable technologies, simulations of flight times, surveys of electric motors, and the development of a simulation program which was used to optimise some preliminary custom motor designs. The overall conclusion of this project was that the Electric Jetpack was feasible only when it was powered through a tethered power cable, and on-board energy storage was not used. An investigation into current energy storage technologies showed that the Electric Jetpack is not considered feasible when using on-board energy storage, however it is possible to obtain flight for a very short time. The energy storage technologies studied were batteries, fuel cells, and ultra-capacitors. It was found that the best performing technology was the lithium iron nano-phosphate battery. A simulation of flight time showed that this battery type would be able to provide flight for approximately 3.6 minutes. Future trends indicated that the Electric Jetpack with on-board energy storage may eventually be feasible when using a lithium-ion based battery due to improvements being made in energy density and power density. By using a tethered power cable, the weight of the on-board energy storage could be eliminated. This was shown to be a feasible method for powering the Electric Jetpack for applications where the Jetpack needs to only be operated in a small area. The best cable type to use was a multi-stranded flexible cable operating at a high DC bus voltage. The weight of a 5 meter power cable using a 1000 V bus voltage was shown to be 4.9 kg. Potential applications for this kind of Jetpack could include thrill rides and rescue operations from multi-storied buildings. A cable made from carbon nanotubes was shown to be a future technology that could offer a lighter cable. A survey of currently available electric motors showed that none met both the power density and speed required by the Electric Jetpack, even when using a tethered power cable to eliminate the energy storage weight. Because of this, a custom motor design was needed. Research into motor technologies showed that the permanent magnet brushless DC (PMBLDC) motor was the most suited type for the Electric Jetpack. The permanent magnet brushless AC (PMBLAC) motor was also suitable. A PMBLDC motor simulation program was developed using MATLAB which could be used to optimise preliminary custom designs. A characterisation of allowable motor time constants for the PMBLDC motor type was made in order to speed up the simulation time. The optimisation results showed that a power density of 5.41 kW/kg was achievable for the motor when it was located inside the ducted fan tubes, and a power density of 6.56 kW/kg was achievable when the motor was located outside the ducted fans and operated at a higher speed. The motor designs were shown to be within the expected torque per unit rotor volume (TRV) range for aerospace machines. The best power density figures would leave between 37 kg and 42 kg of weight for the motor driver/controller, cable weight, and miscellaneous motor parts. This was considered to be feasible. An FEM simulation was made on one of the optimised motor designs. The FEM results agreed with the parametric results within reasonable accuracy. The parametric back-EMF waveform over-estimated the effects of slotting.

Este estudo avaliou quantitativamente a contração de polimerização em função do aumento dos valores de densidade de potência irradiados em compósitos à base de metacrilatos e silorano, e qualitativamente a interface restauradora em relação à abertura de fendas marginais, em função da variação do tipo de substrato dentário. As resinas Filtek Z250 e Filtek P90 foram fotoativadas com 200, 400, 600, 800 e 1000 mW/cm2, em um volume constante de 12 mm3, e os valores de contração aferidos por meio da máquina de ensaios universal. Para análise qualitativa da interface restauradora, preparos cavitários classe V de 2x2x2 mm foram restaurados em incisivos bovinos, fotoativados com os mesmos valores de irradiância, e analisados em microscopia eletrônica de varredura nas interfaces da parede circundante em esmalte, parede circundante em dentina e parede axial. Os resultados quantitativos da contração de polimerização foram analisados pelo teste ANOVA a dois critérios e Tukey (p0,05), enquanto para os dados qualitativos os testes Mann-Whitney, Kruskal-Wallis e Miller foram empregados. O aumento progressivo da densidade de potência influenciou diretamente na contração de polimerização dos materiais estudados, não obstante a resina composta à base de silorano ter demonstrado valores significativamente menores. A integridade marginal sofreu influência do subtrato dentário bem como da densidade de potência utilizada, para as duas resinas estudadas. / Shrinkage is a limitation of resin composite, compromising the clinical longevity of the restorative procedure. In an attempt to reduce their harmful effects, researchers have studied monomers with lower values of contraction. As a result, low-shrinkage composites wer developed. This study evaluated quantitatively the shrinkage by a universal testing machine as a function of power density increase based on methacrylates, comparing them with silorane based resin, and qualitatively regarding gap formation between the adhesive interface as function of tooth substrate. Resin Filtek P90 and Filtek Z250 were polymerized with the device Blue Star 3 with 200, 400, 600, 800 and 1000 mW/cm2 keeping volume constant in 12 mm3. For qualitative analysis of restorative interface, class V cavity preparations in bovine incisors were restored in (2x2x2 mm), photoactivated with the same values of irradiance, and analyzed by scanning electron microscopy at the interface of the wall surrounding enamel, dentin and axial. The quantitative results of the polymerization shrinkage were analyzed by two-way ANOVA and Tukey\'s test (p0,05), while qualitative data for the Mann-Whitney, Kruskal-Wallis and Miller were employed. The progressive increase in power density directly influenced the polymerization shrinkage of the materials studied, despite the silorane based resin have demonstrated significantly lower values. The marginal integrity was influenced by the dental substrate and the power density used.

No presente estudo, avaliou-se a microdureza da resina composta Z250 (3M ESPE), quando ativada em diferentes tempos (s), diferentes densidades de potência (mW/cm²), em relação à quantidade de energia irradiada (8, 12 e 16 J/cm²), com a finalidade de estabelecer uma densidade de energia luminosa mínima capaz de polimerizar adequadamente os compósitos. Foi utilizado um aparelho com fonte de luz halógena Degulux-Degussa, com 600 mW/cm² e dois aparelhos de fonte de luz LED, Ultraled XP (Dabi-Atlante) com 150 mW/cm² e LED Ultrablue-IS (DMC) com 300 mW/cm² e 600 mW/cm². Duas matrizes bipartidas de PTFE, de 1 e de 2 mm de espessura e um orifício central de 5 mm de diâmetro, foram usadas para confeccionar 60 corpos-de-prova, 5 em cada grupo. As duas partes da matriz foram contidas em um anel metálico com as mesmas espessuras. O material foi inserido na matriz e fotoativado de acordo com os diferentes tempos e a quantidade de densidade de energia luminosa para cada fonte de luz. Para obter os valores de microdureza Knoop, os espécimes foram levados ao microdurômetro Shimadzu HMV-2, com carga estática de 300 g por 5 segundos, para aferir as superfícies exposta (topo) e oposta (base) à fonte de luz, totalizando 120 medições. Os resultados foram submetidos aos testes ANOVA e Tukey, com nível de significância de 5%. Com os dados obtidos foi possível concluir que, com valores a partir de 16 J/cm² e 12 J/cm² de densidade de energia luminosa, espessuras de 2 mm de resina composta podem ser adequadamente polimerizadas utilizando-se fonte de luz halógena (600 mW/cm²) e LED (a partir de 300 mW/cm²) respectivamente. Contudo, estudos clínicos adicionais ainda são necessários para complementar este estudo / At this study it was evaluated the microhardness of the Z250 (3M ESPE) resin composite, when light cured for different periods of time (s), with different power densities (mW/cm²), related to the irradiated luminous energy density (8 J/cm², 12 J/cm² and 16 J/cm²), in order to establish a minimal energy density capable of adequately polymerize the composites. One halogen light curing unit Degulux- Degussa, with 600 mW/cm² of power density and two light-emitting diodes curing units Ultraled XP (Dabi-Atlante) with 150 mW/cm² and LED Ultrablue-IS (DMC) with 300 mW/cm² and 600 mW/cm² were used. Two bipartite PTFE matrices, with 1 and 2 mm of depth and a central orifice of 5 mm diameter, were used to make 60 specimens, 5 per group. The halves of the matrix were positioned inside a brass ring with both depths to prepare the specimens. The resin composite was inserted and light-activated according to the different periods and energy densities of each lightcuring unit. To evaluate Knoop microhardness, specimens were taken to a microdurometer Shimadzu HMV-2 with a static load of 300 g for 5 seconds, evaluating both exposed to light (surface) and opposite to light (base) exposition surfaces, totalizing 120 measurements. Results were submitted to ANOVA and Tukeys test with 5% significance level. Based on the obtained results, it was concluded that, starting from 16 J/cm² and 12 J/cm² of energy luminous density, 2 mm depth resin composite can be adequately polymerized utilizing halogen (600 mW/cm²) and LED ( starting from 300 mW/cm²) curing-units respectively. However, additional clinical studies are necessary to complement this investigation.

This dissertation aims at developing techniques to achieve high power density in motor drives under the performance requirements for transportation system. Four main factors influencing the power density are the main objects of the dissertation: devices, passive components, pulse width modulation (PWM) methods and motor control methods. Firstly, the application of SiC devices could improve the power density of the motor drive. This dissertation developed a method of characterizing the SiC device performance in phase-leg with loss estimation, and claimed that with SiC Schottky Barrier Diode the advantage of SiC JFET could benefit the motor drive especially at high temperature. Then the design and improvement of the EMI filter in the active front-end rectifier of the motor drive was introduced in this dissertation. Besides the classical filter design method, the parasitic parameters in the passive filter could also influence the filtering performance. Random PWM could be applied to reduce the EMI noise peak value. The common-mode (CM) noise reduction by PWM methods is also studied in this dissertation. This dissertation compared the different PWM methods’ CM filtering performance. Considering the CM loop, the design of PWM methods and switching frequency should be together with the CM impedance. Variable switching frequency PWM (VSFPWM) methods are introduced in the dissertation for the motor drive’s EMI and loss improvement. The current ripple of the three-phase converter could be predicted. Then the switching frequency could be designed to adapt the current ripple requirements. Two VSFPWM methods are introduced to satisfy the ripple current peak and RMS value requirements. For motor control issue, this dissertation analyzed the principle of the start-up transient and proposed an improved start-up method. The transient was significantly reduced and the motor could push to high speed and high power with speed sensorless control. Next, the hardware development of modular motor drive was introduced. The development and modification of 10kW phase-legs and full power test of a typical 30kW modular converter is realized with modular design method. Finally, the techniques developed in this dissertation for high power density motor drive design and control are summarized and future works are proposed.

La conception des Alimentations Sans Interruption (ASI) a fait l’objet d’améliorations successives ces dernières années afin d’atteindre des niveaux de rendement avoisinant les 95% tout en minimisant leur encombrement. L’utilisation massive de l’électronique de puissance pour ces systèmes conduit à y concentrer tous les efforts de conception pour augmenter à la fois le rendement et la densité de puissance. Les développements constants en électronique de puissance offrent au concepteur des multitudes d’options, parmi elles, les topologies de puissance multi-niveaux et/ou entrelacées pour réduire le volume des composants passifs, les nouvelles technologies des matériaux semi-conducteurs avec l’introduction des composants grand gap, ainsi que l’avancée technologique sur les matériaux utilisés dans les composants passifs. Le choix entre ces options est un compromis pour atteindre les objectifs prédéfinis, particulièrement lorsque d’autres contraintes apparaissent pour limiter l’espace des solutions possibles, notamment l’aspect thermique, les limites technologiques ou les contraintes CEM. Ces travaux proposent la mise en œuvre de dimensionnements par optimisation multi-objectifs de l’ensemble du convertisseur avec toutes ses contraintes. Ceci offre un outil rapide pour comparer les différentes possibilités de conception optimale capable de quantifier le gain apporté au convertisseur par les différentes solutions. Pour ce faire, les différents choix topologiques et technologiques ont été traités par le développement de modèles multi-physiques acceptant des paramètres d’entrée discrets. Ainsi, les convertisseurs optimisés répondent naturellement aux contraintes industrielles cadrées par des catalogues de fournisseurs spécifiques. Pour ce faire, nous avons commencé par dresser les différentes contraintes énergétiques imposées sur l’ASI dans son environnement. L’identification des solutions adaptées à sa conception est réalisée à travers un état de l’art des recherches dans le domaine de l’électronique de puissance. Des modèles génériques des structures de puissance, ainsi que des modèles multi-physiques discrets des composants sont ensuite développés à la base des approches analytiques assurant le bon compromis entre précision et rapidité de calcul. Finalement, une méthodologie d’optimisation multi-objectif et multi contraintes est réalisé sur l’ensemble des solutions pour quantifier les performances atteintes par chacune d’elles. Des travaux expérimentaux nous ont été indispensables pour valider les modèles et les solutions optimales. Sur la base des résultats d’optimisation un convertisseur PFC de 4.2kW/L a été construit est ses performances ont été validées. / The design of Uninterruptible Power Supplies (UPS) has been successively improved in recent years to achieve efficiency levels of around 95% while minimizing their footprint. The massive use of power electronics for these systems is led to focus all design efforts to increase both efficiency and power density. The constant developments in power electronics provide the designer many options, among them the multi-level and/or interleaved power topologies in order to reduce passive components size, the new technologies of semiconductor materials with the introduction of grand gap components and advanced technology on passive components materials. The choice between these options is a compromise to achieve the predefined objectives, particularly when other constraints appear to limit the space of possible solutions, including thermal aspect, technological limitations or EMI constraints. This work proposes the implementation of multi-objective optimization methodology for the design of power converters with all its constraints. This offers a quick tool to compare the different possibilities of design and to quantify the improvement provided to the converter. To do this, different topological and technological choices were studied with the development of multi-physics models. These models can take discrete variables as input. So, optimized converters could meet industrial requirements covered by real components and their datasheets. To do this, we first establish the different constraints imposed on the UPS within its environment. Identifying solutions to design is carried through a state of the art research in the field of power electronics. Generic models of power structures and discrete multi-physical models of the components are then developed based on analytical approaches by ensuring a good compromise between accuracy and speed of calculation. Finally, multi-objective and multi constraints optimization methodology is performed on the set of design choices to quantify the performances achieved by each of them. Experimental work has been essential for us to validate the models and optimal solutions. Based on the optimization results PFC converter of 4.2kW/L was built is its performance has been validated.

[pt] Esta dissertação faz parte de um projeto mais abrangente que visa caracterizar os parâmetros ideais para perfuração e corte a laser em rochas, metais e cimentos tipicamente utilizados na indústria do petróleo. Este trabalho teve por objetivo de caracterizar cortes a laser em placas de aço. Procurou-se correlacionar a morfologia do corte e a formação de rebarbas com parâmetros operacionais, tais como densidade de potência e posição do ponto focal. O estudo foi desenvolvido para o aço SAE 1020 com e sem anteparo rochoso (Travertino). Foram avaliadas também as mudanças na microestrutura de regiões adjacentes do aço duplex 2205 para diferentes faixas de densidade de potência. Finalmente, avaliou-se também o uso do laser no corte do aço inox submerso em água. Conclui-se que existe uma formação de rebarba, que aumenta conforme a densidade de potência diminui. Por outro lado, quanto maior a densidade de potência, maior é a extensão da mudança na microestrutura do aço. O corte de aço com anteparo rochoso abre novas perspectivas para o desenvolvimento de uma ferramenta baseada em laser de alta potência para completação de poços na indústria do petróleo. / [en] This work is part of a larger project that aims to characterize the optimal parameters for laser cutting and drilling into rocks, metals and cement typically used in the oil industry. This study had as objective to characterize laser cuts in steel plates. An attempt to establish a correlation between the morphology of the cut and the burrs with operating parameters such as power density and position of the focal point. The study was developed for the SAE 1020 steel with and without rocky bulkhead (Travertine). Also, the changes in the microstructure of adjacent regions of duplex steel in 2205 for different ranges of power density were assessed and finally it was evaluated the use of laser cutting of stainless steel submerged in water. It follows that there is a burr formation, which increases as the power density decreases. On the other hand, the higher the power density, the greater is the extent of change in the steel microstructure. Cutting steel with rocky bulkhead opens new perspectives for the tool development with high power laser for well completion in the oil industry tool.

Made available in DSpace on 2014-10-09T12:42:06Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:05:54Z (GMT). No. of bitstreams: 0 / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Made available in DSpace on 2014-10-09T12:42:06Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:05:54Z (GMT). No. of bitstreams: 0 / As ligas à base de níquel de alta resistência são utilizadas em uma infinidade de sistemas avançados, onde baixo peso e sistemas de transmissão mecânica de alta densidade de energia são necessários. Componentes, tais como, engrenagens, rolamentos e eixos poderiam ser consideravelmente menor e mais durável se uma grande melhoria em propriedades mecânicas de ligas à base de níquel for alcançada. Um refinamento significativo no tamanho de grão (incluindo nível nano) é um método promissor para a obtenção de melhorias fundamentais nas propriedades mecânicas. O tamanho de grão é conhecido por ter um efeito significativo sobre o comportamento mecânico dos materiais. Um dos métodos mais favoráveis de alcançar refinamento de grão extremo é submetendo os materiais à deformação plástica intensa. As principais variáveis microestruturais nas superligas são a quantidade de precipitados e sua morfologia, o tamanho e a forma do grão e a distribuição de carbonetos (Cr7C3 e Cr23C6) que poderão reduzir propriedades mecânicas da liga. Neste trabalho é apresentada análise por microscopia óptica e eletrônica de transmissão e também os dados de dureza após deformação plástica intensa (tensão de cisalhamento puro) e alguns tratamentos térmicos. / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Este estudo avaliou quantitativamente a contração de polimerização em função do aumento dos valores de densidade de potência irradiados em compósitos à base de metacrilatos e silorano, e qualitativamente a interface restauradora em relação à abertura de fendas marginais, em função da variação do tipo de substrato dentário. As resinas Filtek Z250 e Filtek P90 foram fotoativadas com 200, 400, 600, 800 e 1000 mW/cm2, em um volume constante de 12 mm3, e os valores de contração aferidos por meio da máquina de ensaios universal. Para análise qualitativa da interface restauradora, preparos cavitários classe V de 2x2x2 mm foram restaurados em incisivos bovinos, fotoativados com os mesmos valores de irradiância, e analisados em microscopia eletrônica de varredura nas interfaces da parede circundante em esmalte, parede circundante em dentina e parede axial. Os resultados quantitativos da contração de polimerização foram analisados pelo teste ANOVA a dois critérios e Tukey (p0,05), enquanto para os dados qualitativos os testes Mann-Whitney, Kruskal-Wallis e Miller foram empregados. O aumento progressivo da densidade de potência influenciou diretamente na contração de polimerização dos materiais estudados, não obstante a resina composta à base de silorano ter demonstrado valores significativamente menores. A integridade marginal sofreu influência do subtrato dentário bem como da densidade de potência utilizada, para as duas resinas estudadas. / Shrinkage is a limitation of resin composite, compromising the clinical longevity of the restorative procedure. In an attempt to reduce their harmful effects, researchers have studied monomers with lower values of contraction. As a result, low-shrinkage composites wer developed. This study evaluated quantitatively the shrinkage by a universal testing machine as a function of power density increase based on methacrylates, comparing them with silorane based resin, and qualitatively regarding gap formation between the adhesive interface as function of tooth substrate. Resin Filtek P90 and Filtek Z250 were polymerized with the device Blue Star 3 with 200, 400, 600, 800 and 1000 mW/cm2 keeping volume constant in 12 mm3. For qualitative analysis of restorative interface, class V cavity preparations in bovine incisors were restored in (2x2x2 mm), photoactivated with the same values of irradiance, and analyzed by scanning electron microscopy at the interface of the wall surrounding enamel, dentin and axial. The quantitative results of the polymerization shrinkage were analyzed by two-way ANOVA and Tukey\'s test (p0,05), while qualitative data for the Mann-Whitney, Kruskal-Wallis and Miller were employed. The progressive increase in power density directly influenced the polymerization shrinkage of the materials studied, despite the silorane based resin have demonstrated significantly lower values. The marginal integrity was influenced by the dental substrate and the power density used.

No presente estudo, avaliou-se a microdureza da resina composta Z250 (3M ESPE), quando ativada em diferentes tempos (s), diferentes densidades de potência (mW/cm²), em relação à quantidade de energia irradiada (8, 12 e 16 J/cm²), com a finalidade de estabelecer uma densidade de energia luminosa mínima capaz de polimerizar adequadamente os compósitos. Foi utilizado um aparelho com fonte de luz halógena Degulux-Degussa, com 600 mW/cm² e dois aparelhos de fonte de luz LED, Ultraled XP (Dabi-Atlante) com 150 mW/cm² e LED Ultrablue-IS (DMC) com 300 mW/cm² e 600 mW/cm². Duas matrizes bipartidas de PTFE, de 1 e de 2 mm de espessura e um orifício central de 5 mm de diâmetro, foram usadas para confeccionar 60 corpos-de-prova, 5 em cada grupo. As duas partes da matriz foram contidas em um anel metálico com as mesmas espessuras. O material foi inserido na matriz e fotoativado de acordo com os diferentes tempos e a quantidade de densidade de energia luminosa para cada fonte de luz. Para obter os valores de microdureza Knoop, os espécimes foram levados ao microdurômetro Shimadzu HMV-2, com carga estática de 300 g por 5 segundos, para aferir as superfícies exposta (topo) e oposta (base) à fonte de luz, totalizando 120 medições. Os resultados foram submetidos aos testes ANOVA e Tukey, com nível de significância de 5%. Com os dados obtidos foi possível concluir que, com valores a partir de 16 J/cm² e 12 J/cm² de densidade de energia luminosa, espessuras de 2 mm de resina composta podem ser adequadamente polimerizadas utilizando-se fonte de luz halógena (600 mW/cm²) e LED (a partir de 300 mW/cm²) respectivamente. Contudo, estudos clínicos adicionais ainda são necessários para complementar este estudo / At this study it was evaluated the microhardness of the Z250 (3M ESPE) resin composite, when light cured for different periods of time (s), with different power densities (mW/cm²), related to the irradiated luminous energy density (8 J/cm², 12 J/cm² and 16 J/cm²), in order to establish a minimal energy density capable of adequately polymerize the composites. One halogen light curing unit Degulux- Degussa, with 600 mW/cm² of power density and two light-emitting diodes curing units Ultraled XP (Dabi-Atlante) with 150 mW/cm² and LED Ultrablue-IS (DMC) with 300 mW/cm² and 600 mW/cm² were used. Two bipartite PTFE matrices, with 1 and 2 mm of depth and a central orifice of 5 mm diameter, were used to make 60 specimens, 5 per group. The halves of the matrix were positioned inside a brass ring with both depths to prepare the specimens. The resin composite was inserted and light-activated according to the different periods and energy densities of each lightcuring unit. To evaluate Knoop microhardness, specimens were taken to a microdurometer Shimadzu HMV-2 with a static load of 300 g for 5 seconds, evaluating both exposed to light (surface) and opposite to light (base) exposition surfaces, totalizing 120 measurements. Results were submitted to ANOVA and Tukeys test with 5% significance level. Based on the obtained results, it was concluded that, starting from 16 J/cm² and 12 J/cm² of energy luminous density, 2 mm depth resin composite can be adequately polymerized utilizing halogen (600 mW/cm²) and LED ( starting from 300 mW/cm²) curing-units respectively. However, additional clinical studies are necessary to complement this investigation.