Nesta dissertação, é apresentado o projeto de uma interface que permite o controle e monitoramento de cargas de alta tensão alimentadas na faixa de 8,5V a 35V. A interface fornece duas funções básicas: a primeira é permitir que circuitos alimentados no domínio dos 5V controlem o chaveamento de transistores de potência PMOS com uma tensão de porta 5V abaixo da tensão de alimentação; a segunda é realizar o monitoramento de sobrecorrentes na carga de alta tensão, alertando, com um sinal de baixa tensão, estas ocorrências. A interface foi projetada e fabricada no processo CMOS XC06 - 0,6µm da XFAB, com a inclusão de módulos que permitem o uso de transistores de alta tensão. Como parte da solução proposta, foi analisado, implementado e caracterizado um regulador de tensão flutuante que gera uma tensão de saída 5V abaixo da tensão de alimentação. A área de silício do regulador é de 599µm x 330µm, e as medidas da tensão de saída gerada apresentam variações menores que 10%. Também foi projetado e integrado no mesmo circuito integrado um sensor para medir o nível da tensão flutuante do regulador e comunicar seu estado com um sinal de 5V, este bloco ocupa uma área de 599µm x µm. Este sensor apresentou um desvio padrão de 7% nas medidas da sua tensão limiar. A interface foi integrada em um sensor de proximidade indutivo, permitindo o chaveamento de uma carga de 430pF a 1,2kHz em toda a faixa de alimentação. / This work presents the design of an interface that allow to control and monitoring high voltage loads in the range of 8,5V to 35V. The interface provides two main features, the first one is to allow low voltage circuits supplied with 5V to control the switching of power PMOS transistors with a gate voltage 5V bellow the supply voltage. The second one is monitoring overcurrents on the high voltage load alerting with a low voltage signal these occurences. The interface was designed and fabricated on the CMOS XC06 - 0,6µm process from XFAB with the inclusion of modules that allow the use of high voltage transistors. As part of the proposed solution it was analyzed, implemented and measured a floating voltage regulator wich provides an output voltage 5V bellow the supply voltage. The area of the regulator is 599µm x 330µm and the measures of the output voltage presents variations under the 10%. Also it was designed and integrates in the same integrated circuit a sensor to measure the output level of the floating regulator and communicate the state of this output with a 5V signal, this block occupies an area of 599µm x 579µm. This sensor presented a 7% standard desviation on the measured voltage threashold. The interface was integrated on an inductive proximity sensor allowing the switching of a 430pF load at 1,2kHz for the entire all supply range.

O presente trabalho teve como objetivo estudar diferentes tecnologias na extração de óleo da semente de gergelim e de compostos fenólicos e proteínas da torta de gergelim. Este estudo está dividido em quatro partes. O objetivo da primeira parte do trabalho foi extrair compostos fenólicos de diferentes tortas de nozes e sementes nas mesmas condições e comparar o teor de tais compostos e a atividade antioxidante dos extratos. Nessa fase, foram utilizadas nos experimentos tortas das sementes de girassol, linhaça e gergelim, e das nozes amêndoa, pecã, macadâmia e avelã. O extrato da torta de noz pecã apresentou o maior teor de todos os compostos fenólicos analisados, seguido pelo extrato da torta de semente de girassol e de avelã. Essas amostras também apresentaram as maiores atividades antioxidantes. As etapas seguintes do trabalho focaram-se no gergelim. A segunda parte do trabalho teve como objetivo a otimização da extração, pela metodologia convencional, de fenólicos totais e lignanas da torta de gergelim. Inicialmente, um modelo polinomial de segunda ordem foi utilizado para predição dos resultados, mediante a variação da temperatura, concentração de etanol e razão, sólido/solvente. As variáveis de resposta foram as concentrações de fenólicos totais, de sesamina e de sesaminol triglicosídeo e a atividade antioxidante dos extratos obtidos. Entre os compostos analisados, o sesaminol triglicosídeo está presente em maior quantidade na torta de gergelim. A razão sólido/solvente e a concentração de etanol foram os fatores que mais afetaram a extração, enquanto a temperatura demonstrou uma influência reduzida. Na terceira etapa, o escopo da pesquisa foi a avaliação de metodologias alternativas na extração desses mesmos compostos e, também, de proteínas. As tecnologias usadas foram as de campo elétrico pulsado (CEP) e de descargas elétricas de alta tensão (DEAT). A análise da aplicação de CEP e de DEAT foi realizada usando essas tecnologias como pré-tratamentos ao processo de extração com solvente. Os resultados demonstraram que as técnicas foram eficazes e aumentaram os rendimentos do processo para fenólicos totais, lignanas e proteínas da torta. O uso de diferentes porcentagens de etanol também se mostrou significativo nessa etapa, entretanto, esse efeito foi reduzido quando utilizadas as tecnologias elétricas. Da mesma forma, o efeito da temperatura na etapa difusiva foi menor quando os pré-tratamento foram utilizados. Os comportamentos observados sugerem que a aplicação de CEP e DEAT aumenta a eficiência da extração de compostos de interesse. Por fim, na quarta parte do trabalho, objetivou-se melhorar a eficiência do processo de extração do óleo de gergelim aplicando as tecnologias previamente citadas. Esses experimentos demonstraram um efeito significativo dos tratamentos de CEP e DEAT e um aumento na quantidade de óleo extraído com o aumento da energia aplicada às sementes. O uso de DEAT gerou um aumento maior na quantidade de óleo extraído, se comparado à tecnologia de CEP. / The goal of the present work was to study different technologies in the extraction of oil from sesame seed and phenolic compounds and proteins from sesame cake. This study is divided in four parts. The first part aimed to extract water-soluble compounds from different seed and nut cakes under the same conditions and compare the phenolic content and antioxidant activity of the extracts. For the first portion of the study, seed cakes of sunflower, pumpkin, flaxseed and defatted sesame, and nut cakes of almond, pecan, macadamia and hazelnut were used in the experiments. The extract from pecan nut cake presented the highest amounts of all compounds analyzed, followed by sunflower seed and hazelnut cake extracts. These samples also had the highest antioxidant activities. The following steps of the work focused on sesame only. The second part of the work aimed to optimize the extraction of total phenolics and lignans from sesame seed cake. Initially, a second-order polynomial model was set up to predict the responses in different temperatures, solid/solvent ratios and ethanol concentrations. The response variables were the concentrations of total phenolics, sesamin, sesaminol triglucoside and antioxidant activity of the extracts. Among the analyzed compounds, ST is presented in the highest quantity in sesame cake. Solid to liquid ratio and ethanol concentration where the most important factors affecting extraction, whereas temperature showed reduced influence. In the third part of this work, the aim was to evaluate alternative methodologies in the extraction of phenolics and proteins. The technologies used were pulsed electric fields (PEF) and high voltage electric discharges (HVED). These methods were used as pre-treatments, prior to diffusion. Result show that PEF and HVED were efficient and increased the extraction yield for phenolic compounds, lignans and proteins from the cake. The use of different percentages of ethanol was also significant in this stage; however, the effect of this parameter was reduced when the electrical treatments were used. In the same way, temperature also showed a smaller influence on the results when the pre-treatments were used. The observed behaviors suggest that the use of PEF and HVED increases extraction efficiency. Finally, the goal of the last part of the work was to improve oil expression from sesame seeds, using the aforementioned technologies. These experiments show a significant effect of both PEF and HVED. It was observed an increase of the amount of oil extracted with the energy input applied to the seeds. When compared both technologies, HVED showed a more expressive effect then PEF.

Capillary electrophoresis laser-induced fluorescence (CE-LIF) is widely used to detect both the presence and concentration of fluorescently labeled biomolecules. In CE-LIF, a plug of sample fluid is electrophoretically driven down a microchannel using a high voltage applied between the opposite ends of the microchannel. Molecules of different sizes and charge states travel at different velocities down the channel. Laser light with a wavelength in the excitation band of the fluorophores is focused near the end of the channel. As each species of molecule passes through the laser spot, the fluorophores emit a fluorescence signal which is measured with an optical detector. Commercial CE-LIF systems are available as a complete, expensive package. Custom CE-LIF systems are a collection of commercially available components that meet the specific needs of the end user. Using the custom system in Dr. Woolley's lab as the standard, we hypothesized that 3D printed parts in conjunction with low-cost components could be used to significantly reduce costs and simplify the system, which in turn would make such systems more widely available with a lower barrier to entry. Testing this hypothesis began with five semesters of small teams of senior undergraduate students trying to design and assemble a low-cost CE-LIF system as part of their mandatory one-semester senior project. I was one of the seniors who worked on the system. Although none of the senior project teams were successful, a partially functioning system was ultimately produced. I reference this system as the starting point system throughout this thesis, which is focused on identifying and solving the system's obstacles in order to reach a working state. I re-designed and re-built each sub-system of the starting point system as needed if within the available budget to create a system that was functional. Budgetary constraints were included in evaluating potential improvements. The end goal was to compare the improved system's performance with that of an expensive conventional system (hereinafter referred to as the standard system) available in Dr. Adam Woolley's laboratory on the Brigham Young University campus. The ultimate conclusion of my masters' thesis work is that a low-cost CE-LIF system based on 3D printed and low-cost components results in a system that does not offer repeatable performance. In the course of my work, many lessons were learned as to what would reduce overall system costs while maintaining a user-friendly experience. My analysis is given on a subsystem basis to explain what limited the ability of the system to run consistently or what caused it to fail altogether. Details and methodology of my contributions including circuits designed, code written, components used, and 3D models printed in order to test the hypothesis are documented. Attribution of the work prior to mine is laid out when each subsystem is broken down in detail for the failure modes that prevented consistent operation. Future work is suggested to correct the problems encountered and provide a path forward to implement a next-generation system that can be achieved at a lower cost compared to a conventional system, and yet which does not suffer from the performance problems associated with the version explored in this thesis in which maximum cost reduction was aggressively pursued.

abstract: High Voltage Direct Current (HVDC) Technology has several features that make it particularly attractive for specific transmission applications. Recent years have witnessed an unprecedented growth in the number of the HVDC projects, which demonstrates a heightened interest in the HVDC technology. In parallel, the use of renewable energy sources has dramatically increased. For instance, Kuwait has recently announced a renewable project to be completed in 2035; this project aims to produce 15% of the countrys energy consumption from renewable sources. However, facilities that use renewable sources, such as solar and wind, to provide clean energy, are mostly placed in remote areas, as their installation requires a massive space of free land. Consequently, considerable challenges arise in terms of transmitting power generated from renewable sources of energy in remote areas to urban areas for further consumption. The present thesis investigates different transmission line systems for transmitting bulk energy from renewable sources. Specifically, two systems will be focused on: the high-voltage alternating current (HVAC) system and the high-voltage direct current (HVDC) system. In order to determine the most efficient way of transmitting bulk energy from renewable sources, different aspects of the aforementioned two types of systems are analyzed. Limitations inherent in both HVAC and HVDC systems have been discussed. At present, artificial intelligence plays an important role in power system control and monitoring. Consequently, in this thesis, the fault issue has been analyzed in transmission systems, with a specific consideration of machine learning tools that can help monitor transmission systems by detecting fault locations. These tools, called models, are used to analyze the collected data. In the present thesis, a focus on such models as linear regression (LR), K-nearest neighbors (KNN), linear support vector machine (LSVM) , and adaptive boost (AdaBoost). Finally, the accuracy of each model is evaluated and discussed. The machine learning concept introduced in the present thesis lays down the foundation for future research in this area so that to enable further research on the efficient ways to improve the performance of transmission line components and power systems. / Dissertation/Thesis / Masters Thesis Electrical Engineering 2019

This work highlights slab coupled optical sensors (SCOS) and their ability to measure high voltages. Although other high voltage measurement techniques exist, most of these techniques are electrical devices and are therefore more susceptible to stray ground currents and other electromagnetic interferences (EMI), which may cause signal distortion. Optical sensors are less susceptible to such interferences and these sensors, such as the Pockels cell, have been used in measuring high voltage. SCOS offer an alternative method of measuring high voltage optically. Consisting of an optical fiber and an electro-optic slab waveguide, SCOS have the advantage of being very small in size (0.2 mm x 0.3 mm cross-section), simpler composition, and potentially less coupling losses. Issues associated with high voltage measurements are addressed such as unwanted corona, arcing, and EMI. Solutions are also explored which include insolating materials, electrode geometries, Faraday cages, and using optical sensors such as SCOS. Although the SCOS has been traditionally used to measure electric field, the SCOS is able to measure high voltage through the use of an electrode structure. The SCOS' ability to measure high voltage is showcase through the construction and output measurements of several high voltage systems: an ignition coil-based circuit, a dual ignition coil circuit, a Marx generator, and a 200 kV generator used in a capacitor discharge configuration. These measurements show the SCOS' ability to measure at least 111 kV capacitor discharges with 6.6 ns rise times and other various high voltage waveforms.

Research Doctorate - Doctor of Philosophy (PhD) / This work reports the deposition onto high voltage insulators and correlation to atmospheric corrosivity measurement. This work includes corrosion studies at 15 sites in New Zealand (1,816 tests) for in excess of 12 months, and co-operative research in South Africa. In addition, to confirm the relevance and transportability of this proposed model, a review of the published international data on deposition rates on insulators was conducted. It was noted that the deposition rate of airborne pollutants onto a surface is dependent upon the true surface area facing the wind and the aerodynamic properties of the surface. Such is the effect that surfaces with minimal exposure to the wind such as horizontal plates, have been shown to be poor collectors of deposits while vertical plates are more efficient, followed by high voltage glass insulators, the ISO9223 salt candle, and the largest collector is the Direct Dust Deposit Gauge. This study found that the ISO9223 wet salt candle and the average annual deposition rate on the High Voltage Glass insulator bottom surface (unenergized) provided relatively similar deposition results. The deposition onto insulator surfaces may be a more relevant method as it replicates deposition on large surfaces. This Equivalent Salt Dry Deposition (ESDD) method for HV insulators is an all inclusive measure of the airborne pollutants deposition rate and converts the total deposited material into a single value equivalent to that of salt, even though the deposit may consist of sulphur, marine salts, nitrates, and other conductive pollutants. The measured deposition rate on the sheltered insulator bottoms at 85 sites around the world predicted 87% of the ISO corrosivity categories (based on zinc corrosion) for these sites. Results from equatorial Asia appear to be non-compliant and warrant further investigation. The ESDD values are now being quoted from around the world, by electrical engineers who use the recently revised CIGRE methodology, to determine the probability of arc-over (shorting to earth) of high voltage cables due to pollution build-up on insulators. The implications from this research are significant, with the cost of atmospheric corrosivity studies becoming prohibitively expensive, this method converts technically valid surface deposition results from the electrical engineers from around the world (provided at no cost), to valid empirical corrosivity rates from often remote locations.

<p>The task for this Master thesis was to evaluate different black-box arc models for circuit-breakers with the purpose of finding criteria for the breaking ability. A black-box model is a model that requires no knowledge from the user of the underlying physical processes. Black-box arc models have been used in circuit-breaker development for many years. Arc voltages from tests made in the High Power Laboratory in Ludvika were used for validation, along with the resistance calculated at current zero, R0, and 500 ns before current zero, R500. </p><p>Three different arc models were evaluated: Cassie-Mayr, KEMA and an arc model based on power calculations. The third model gave very good results and if the model is developed further, the breaking ability could easily be estimated. </p><p>The arc model based on power calculations could be improved by using better approximations of the quantities in the model, and by representing the current better. A further suggestion for the following work is to combine the second arc model tested, the KEMA model, with the model based on power calculations in order to estimate the KEMA model parameters. </p><p>The R0 and R500 values should also be calculated from more tests, in order to find a clear limit of the breaking ability.</p>

<p>Abstract In high voltage substations there is an increasing demand for computerized equipment, and automation of operation and supervision. The future primary equipment will provide the possibility to collect more information and to provide better control for improved effectiveness. </p><p>Since ABB has got a large customer target, each product must be custom made to fulfil the customers (often from different countries) demands. Later these products will be configured by engineers who may not be familiar with the tools used at ABB. This is a very expensive and time consuming. To solve the problem, ABB was looking for a low cost, easy managed and more advanced replacement. </p><p>This report includes an investigation for a function block configuration tool based on Microsoft Visio. The tool is connected to a general database using ODBC for the latest ABB Substation Automation SW platform for protection in power transmission equipment. </p><p>The thesis report mainly contains a description of the functions and features that are requested. Then methods used to build the prototype is explained and at the end the result is presented. </p><p>At the same time the possibilities and problems that will arise from using ODBC based interface for control and monitoring of real-time systems were investigated.</p>

<p>Pulsed power generators are a key component in compact systems for generation of high-power microwaves (HPM). HPM generation by virtual cathode devices such as Vircators put high demands on the source. The rise time and the pulse length of the source voltage are two key issues in the generation of HPM radiation. This thesis describes the construction and tests of several inductive high power pulse generators. The pulse generators were designed with the intent to deliver a pulse with fast rise time and rectangular voltage. Therefore, the pulse generators are all based on discharges of transmission lines. The transmission lines used in the pulse generators are modern high voltage cables normally used in power transmission. All tested pulse generators have step up transformers as intermediate magnetic energy storage. Further, the pulse generators have contributed to the knowledge of compact designs. Closing switches is another important device in pulse generator architectures. In general, high power switching involving large currents and high voltages requires the use of robust switches. The switches used in the pulse generators of this thesis are of gas and liquid type.</p>

<p>Production and consumption of electricity have grown enormously during the last century. No mater what the primary source of energy is, almost all generation of electricity comes from conversion of a rotational movement in a generator. The aim of this thesis is to see how high voltage technology influence production and storage of electricity. Power flow in the generators used to convert mechanical movement to electric energy is analyzed using Poynting‘s vector. The impact of new generator technology for efficient extraction of hydroelectric power is shown. Simulation of a large permanent magnet turbo generator is presented. A flywheel storage system for electric vehicles utilizing high voltage technology is also presented. In pulsed power applications, a cheap method for intermediate storage of energy during milliseconds, which enables an inductive primary storage is presented and experimentally tested.</p>