A modularized three-dimensional power electronics environment will become increasingly necessary as power converters are more intertwined with the dynamic desires of modern society. This is driven by ever-changing requirements, combined with the desire for quick design cycles, and then further compounded by the increased penetration of electrified technologies. The high demand for various power converters presents a design, manufacturing, and validation burden which can be lessened with a three-dimensional power electronics environment, where power converters of any arbitrary set of voltage, current, or quantity of independent input/outpt requirements can be assembled from a grouping of pre-existing converter modules. This, however, has drawbacks when compared with bespoke power converter designs. Modularization can be complex, lossy, and large, and the resulting converter's overall efficiency and power density will then suffer. To compensate for these costs of modularization, the individual modules must be first be power dense and efficient, and then the framework for grouping modules together must be simple. This dissertation first proposes a high performance Power Conversion Unit (PCU) which is achieved through a unique combination of techniques. The first of these techniques is modification to the ubiqutioius buck converter topology in a form of an adjustment to its output filter. This topological modification results in decreased current ripple handling requirements of the filter, which can be used to reduce its volume. The second topological technique is an additional capacitance placed across the drain-source terminals of each FET, which is used to reduce their turn-off switching energy at the expense of their turn-on switching energy. A variable frequency soft-switching scheme is utitlized to prevent the converter from incurring turn-on losses, and a duty cycle compensation scheme is developed to mitigate the distortions caused by this increased drain-source capacitance. Finally, a process for balancing the PCU design parameters that results in a Pareto frontier of efficiency-power density optimal points is defined, one selected, and a protoype PCU constructed and tested in a three-phase inverter configuration. A framework for the vertical stacking of PCUs is then shown. This framework, named the Manhattan Topology, is a multilevel power converter topology which is defined by a set of series stacked capacitances where there exists a method to transfer power between capacitances. This framework has linear complexity and switching device stress scaling with the number of levels, which yields a simple methodology for grouping modules together in the vertical dimension. Furthermore, it exhibits Partial Power Processing (PPP) characteristics as the power processed internally to the overall converter is less than its output power. This framework is validated for both DC/DC and AC/DC applications and control and conversion of voltages greater than the rating of any individual component within the converter is experimentally demonstrated. Lastly, another three-phase inverter is built using this topological framework and the performance of this vertically-modularized inverter is compared with the non-modularized inverter. It is shown that the three-dimensional modular power electronics environment with optimized PCUs, despite the costs of modularization, is still performance-competitive with the non-modular power electronics environment.

The Master's Thesis research focuses on analyzing the possibilities of using Direct Current distribution systems to distribute power to end users. Considering the shift in load types in the past few decades and also a growing demand of distributed generation, DC distribution can potentially offer higher efficiencies and cost savings to utilities. The incorporation of DC distribution offers the opportunity to eliminate multiple conversion stages for devices which are powered using DC electricity. The integration of power sources such as photovoltaics and fuel cells, which produce DC power, offer further incentives to consider the use of DC systems. Using DC systems can help eliminate the conversion losses associated with rectifiers and inverters which would be part of the infrastructure if AC distribution was used. In the literature, the study of DC distribution has been limited to customized systems. The objective of this research is to analyze DC distribution when applied to systems based on standard IEEE test feeder systems. The IEEE 13 node test feeder and the IEEE 37 node test feeder will be used as the basis for the analysis. Issues such as associated costs, protection and integration of appliances will also be addressed.

Made available in DSpace on 2014-06-11T19:22:34Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-12-18Bitstream added on 2014-06-13T20:29:06Z : No. of bitstreams: 1 brito_ltc_me_bauru.pdf: 1279436 bytes, checksum: d3b9eb1dc19df29b8c4458d3d793b0f3 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A transmissão em corrente contínua vem sendo muita valorizada devido a seus baixos custos em relação à transmissão em corrente alternada, principalmente para grande distâncias com o uso de menos cabos para o suprimento de energia em relação ao HVDC (High Voltage Alternating Current). Os dispositivos FACTS (Flexible Alternating Current Transmission System) foram projetados para fornecer um melhor controle de qualidade de energia transmitida, podendo ser conectados na estação geradora ou na carga. Esses dispositivos melhoraram a estabilidade e o suprimento de tensão e potência, sendo muito útil para aumentar a capacidade de transmissão de energia. O presente trabalho a tensão, corrente, potência ativa e reativa consumida pelos conversores na entrada e saída dos filtros, usando um banco de capacitores, e posteriormente, substituindo o banco de capacitores por um SVC (Static Var Compensator) em um circuito HVDC-Clássico. O circuito analisado consiste de uma geração em 60 Hz, 500k V que transmite potência para uma estação de 345K V e 50Hz. Assim, também analisa a eliminação de harmônicos de corrente, comum no conversor de 12 pulsos, e o suporte de reativos para os casos de tensão e corrente reduzidos e uma falta aplicada no lado AC do inversor / The DC transmission has been very prized due the its lower costs relative to the AC transmission, mainly for long distances and with the useful of less cables to supply energy in relation at the HVAC (High Voltage Alternating Current). The FACTS devices (Flexibe Alternating Current Transmission System) were designed to supply a better control and quality of transmitted energy, and can be connected at generator station or at generator station or at load. These devices improve the stability and the capacity to supply voltage and power, being very useful to increase the transmission capacity of energy. The present work analyses the voltage, current, active e reactive power consumed by the converters, before and after the filters, using a capacitor banks, and after that, replacing the capacitor bank by a SVC (Static Var Compensator) in a Classical HVDC circuit. The analzed circuit consists of a 60Hz, 500KV generation which transmits power for a 50Hz, 34K V station. Then, also analyses the current harmonic distortion elimination, common in the 12 pulses converter, and the reactive staff for reduced voltage and current and a 3-phase fault on the inverter AC side

Orientador: André Christóvão Pio Martins / Banca: Newton Geraldo Bretas / Banca: Pedro da Costa Junior / Resumo: A transmissão em corrente contínua vem sendo muita valorizada devido a seus baixos custos em relação à transmissão em corrente alternada, principalmente para grande distâncias com o uso de menos cabos para o suprimento de energia em relação ao HVDC (High Voltage Alternating Current). Os dispositivos FACTS (Flexible Alternating Current Transmission System) foram projetados para fornecer um melhor controle de qualidade de energia transmitida, podendo ser conectados na estação geradora ou na carga. Esses dispositivos melhoraram a estabilidade e o suprimento de tensão e potência, sendo muito útil para aumentar a capacidade de transmissão de energia. O presente trabalho a tensão, corrente, potência ativa e reativa consumida pelos conversores na entrada e saída dos filtros, usando um banco de capacitores, e posteriormente, substituindo o banco de capacitores por um SVC (Static Var Compensator) em um circuito HVDC-Clássico. O circuito analisado consiste de uma geração em 60 Hz, 500k V que transmite potência para uma estação de 345K V e 50Hz. Assim, também analisa a eliminação de harmônicos de corrente, comum no conversor de 12 pulsos, e o suporte de reativos para os casos de tensão e corrente reduzidos e uma falta aplicada no lado AC do inversor / Abstract: The DC transmission has been very prized due the its lower costs relative to the AC transmission, mainly for long distances and with the useful of less cables to supply energy in relation at the HVAC (High Voltage Alternating Current). The FACTS devices (Flexibe Alternating Current Transmission System) were designed to supply a better control and quality of transmitted energy, and can be connected at generator station or at generator station or at load. These devices improve the stability and the capacity to supply voltage and power, being very useful to increase the transmission capacity of energy. The present work analyses the voltage, current, active e reactive power consumed by the converters, before and after the filters, using a capacitor banks, and after that, replacing the capacitor bank by a SVC (Static Var Compensator) in a Classical HVDC circuit. The analzed circuit consists of a 60Hz, 500KV generation which transmits power for a 50Hz, 34K V station. Then, also analyses the current harmonic distortion elimination, common in the 12 pulses converter, and the reactive staff for reduced voltage and current and a 3-phase fault on the inverter AC side / Mestre

A eletrocirurgia é uma técnica cirúrgica que utiliza o bisturi elétrico para a realização do corte, dessecação e coagulação do tecido orgânico, diminuindo dessa forma os riscos de hemorragia. O bisturi elétrico usa o processo da faiscância para a realização do trabalho. Esse processo provoca, entre outras coisas, o aquecimento da água intracelular e, consequentemente, o rompimento da célula do tecido. Embora se saiba a quantidade de energia entregue pelo bisturi elétrico, pouco se sabe sobre as parcelas de energia envolvidas nos vários fenômenos do processo eletrocirúrgico, principalmente no corte, onde as células sofrem ablação por vaporização. Com base neste problema, foi desenvolvida esta pesquisa, que teve o objetivo de determinar a energia necessária para o corte eletrocirúrgico, através dos parâmetros elétricos envolvidos e da energia utilizada para a vaporização da água do tecido orgânico. O método desenvolvido foi testado em três experimentos, com várias séries de cortes específicos em cada. Demonstrou-se que da energia total que é entregue pelo bisturi, menos de 10% é utilizada para o corte, ou especificamente, para a vaporização da água do tecido. O restante da energia acaba sendo utilizada em outros processos que começarão a ser analisados em outros trabalhos. / Electrosurgery is a surgical technique that uses an electrosurgical device for cutting, drying (desiccation), and coagulation of organic tissue, thereby reducing the risk of bleeding. Electrosurgical device uses sparking phenomena for this purpose. This process causes heating of intracellular water and, consequently, the rupture of the cell in the organic tissue. Although the amount of energy delivered by the electrosurgical device is easy to know, little is known about the exactly amount of energy involved in the various phenomena of electrosurgical procedure, especially in cutting, where cells suffer ablation by vaporization Based on this was developed this research, which objective is to determine the energy required for the electrosurgical cutting through the electrical parameters involved and the energy used for the vaporization of water of organic tissue. The method developed was corted in three experiments, with a series of specific tests in each. It has been show that only about 10% of total energy is used for cutting, or specifically, for the vaporization of water of organic tissue. The rest of the energy is used in other processes that need more investigation to be understood.

A eletrocirurgia é uma técnica cirúrgica que utiliza o bisturi elétrico para a realização do corte, dessecação e coagulação do tecido orgânico, diminuindo dessa forma os riscos de hemorragia. O bisturi elétrico usa o processo da faiscância para a realização do trabalho. Esse processo provoca, entre outras coisas, o aquecimento da água intracelular e, consequentemente, o rompimento da célula do tecido. Embora se saiba a quantidade de energia entregue pelo bisturi elétrico, pouco se sabe sobre as parcelas de energia envolvidas nos vários fenômenos do processo eletrocirúrgico, principalmente no corte, onde as células sofrem ablação por vaporização. Com base neste problema, foi desenvolvida esta pesquisa, que teve o objetivo de determinar a energia necessária para o corte eletrocirúrgico, através dos parâmetros elétricos envolvidos e da energia utilizada para a vaporização da água do tecido orgânico. O método desenvolvido foi testado em três experimentos, com várias séries de cortes específicos em cada. Demonstrou-se que da energia total que é entregue pelo bisturi, menos de 10% é utilizada para o corte, ou especificamente, para a vaporização da água do tecido. O restante da energia acaba sendo utilizada em outros processos que começarão a ser analisados em outros trabalhos. / Electrosurgery is a surgical technique that uses an electrosurgical device for cutting, drying (desiccation), and coagulation of organic tissue, thereby reducing the risk of bleeding. Electrosurgical device uses sparking phenomena for this purpose. This process causes heating of intracellular water and, consequently, the rupture of the cell in the organic tissue. Although the amount of energy delivered by the electrosurgical device is easy to know, little is known about the exactly amount of energy involved in the various phenomena of electrosurgical procedure, especially in cutting, where cells suffer ablation by vaporization Based on this was developed this research, which objective is to determine the energy required for the electrosurgical cutting through the electrical parameters involved and the energy used for the vaporization of water of organic tissue. The method developed was corted in three experiments, with a series of specific tests in each. It has been show that only about 10% of total energy is used for cutting, or specifically, for the vaporization of water of organic tissue. The rest of the energy is used in other processes that need more investigation to be understood.