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21	"Analogue Network of Converters": a DfT Technique to Test a Complete Set of ADCs and DACs Embedded in a Complex SiP or SoC Kerzerho, Vincent 22 February 2008 (has links) (PDF) Une nouvelle méthode de test pour les convertisseurs ADC et DAC embarqués dans un système complexe a été développée en prenant en compte les nouvelles contraintes affectant le test. Ces contraintes, dues aux tendances de design de systèmes, sont un nombre réduit de point d'accès aux entrées/sorties des blocs analogiques du système et une augmentation galopante du nombre et des performances des convertisseurs intégrés. La méthode proposée consiste à connecter les convertisseurs DAC et ADC dans le domaine analogique pour n'avoir besoin que d'instruments de test numériques pour générer et capturer les signaux de test. Un algorithme de traitement du signal a été développé pour discriminer les erreurs des DACs et ADCs. Cet algorithme a été validé par simulation et par expérimentation sur des produits commercialisés par NXP. La dernière partie de la thèse a consisté à développer de nouvelles applications pour l'algorithme. [SPI] Engineering Sciences [SPI] Sciences de l'ingénieur Test analog to digital converter (ADC) digital to analog converter (DAC) system-inpackage (SiP) analog network of converters (ANC) dynamic parameters total harmonic distortion (THD) spurious free dynamic range ( SFDR)
22	Estudo de técnica utilizando a modulação PWM baseada em portadora aplicada ao inversores monofásicos assimétricos com diodos de grampeamento Oliveira, Francisco Hércules de 25 May 2017 (has links) Submitted by Gilvanedja Silva (gilvanedja@biblioteca.ufpb.br) on 2018-03-22T20:42:08Z No. of bitstreams: 1 arquivototal.pdf: 11929036 bytes, checksum: e796f3e04cbf0cf6da3fa9648d4f9270 (MD5) / Made available in DSpace on 2018-03-22T20:42:09Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 11929036 bytes, checksum: e796f3e04cbf0cf6da3fa9648d4f9270 (MD5) Previous issue date: 2017-05-25 / This work presents a technique using carrier-based pulse width modulation (PWM) applied to single-phase asymmetrical multilevel inverters with diodes clamped, aiming to increase the amount of output voltage levels to improve signal quality, reducing the total harmonic distortion rate (THD). The technique was used in inverters of three, four and five levels per arm, providing an output signal with seven, thirteen and nineteen levels respectively, presenting two, six and ten levels higher than the equivalent symmetrical multilevel inverters. The technique was described with a set of equations and procedures that can be generalized for inverters of any number of levels. To verify the operation, simulations were performed using the PSIM program and an experimental assembly of an asymmetrical multilevel inverter of three levels was performed, using a field programmable gate array device (FPGA) in the implementation of the PWM modulator. Finally, the simulation and experimental results that prove the effectiveness of the modulation strategy employed in this work are presented and compared / Este trabalho apresenta uma técnica utilizando a modulação por largura de pulso (PWM) baseada em portadora, aplicada aos inversores multiníveis monofásicos assimétricos com diodos de grampeamento, com o objetivo de elevar a quantidade de níveis na tensão de saída, para melhorar a qualidade do sinal, reduzindo a taxa de distorção harmônica total (THD). A técnica foi empregada em inversores de três, quatro e cinco níveis por braço, fornecendo um sinal de saída com sete, treze e dezenove níveis respectivamente, apresentando dois, seis e dez níveis a mais que os inversores multiníveis simétricos equivalentes. A técnica foi descrita com um conjunto de equações e procedimentos que pode ser generalizada para inversores de qualquer número de níveis. Para comprovar o funcionamento, foram realizadas simulações utilizando o programa PSIM e efetuada montagem experimental de uma inversor multinível assimétrico de três níveis, utilizando na implementação do modulador PWM um dispositivo em matriz de porta programável em campo (FPGA). Por fim, são apresentados e comparados os resultados de simulações e experimentais que comprovam a eficácia da estratégia de modulação empregada neste trabalho Modulação por largura de pulso Inversores multiníveis assimétricos Diodos de grampeamento Distorção harmônica total Matriz de porta programável em campo Pulse width modulation, Asymmetric multilevel inverters Diodes clamped Total harmonic distortion Field programmable gate array ENGENHARIAS::ENGENHARIA ELETRICA
23	SW nadstavba analyzátoru sítí pro automatický návrh nn kompenzační jednotky na základě měření / A power network analyzer SW upgrade implementing LV PFC capacitors bank design on the basis of measurement Bernáth, František January 2010 (has links) Thesis is devoted to a problem of Power Factor Correction on the low voltage level. It has still its own difficulties despite the fact that topic moved through long development. The main goal of this work is to offer reader variable procedure considering design process. It is based on use of measured data of network analyzer Meg30. The design algorithm has to share a maximum of eventual influencing factors. Therefore the body of master thesis goes through detailed analysis of Power Factor Correction.
24	Utvärdering av faskompenseringsmetoder för ett småskaligt vattenkraftverk : Genomgång av kondensatorbatteri, aktiv och passiv reglering, övermagnetiserad synkronmaskin, SVC och STATCOM på Fröslida kraftverk / Evaluation of power factor correction methods for a small scale hydropower plant : Review of a capacitor bank, passive and active regulation, overexcited synchronous generator, SVC, and STATCOM on Fröslida power plant Göker, Fuat, Hedberg, Christoffer January 2018 (has links) Småskalig vattenkraft är en stor användare av reaktiv effekt då de ofta har asynkrongeneratorer. Det gör att det finns ett reellt behov för faskompensering, dels för att minska distorsion i nätet samt för att förbättra deras ekonomiska ställning, då elbolag ofta tar ut en avgift för överskridande användning av reaktiv effekt. Det ligger också i allmänhetens intresse att ha en god elkvalitet och hålla störningar och avbrott nere, vilket kan erhållas med faskompensering och filtrering av övertoner. Det finns olika tekniker för faskompensering med sina respektive för- och nackdelar som specificeras efter anläggningens krav och förhållanden. Dessa tekniker är ett kondensatorbatteri, passiv och aktiv reglering, övermagnetiserad synkronmaskin, static var compensator (SVC) och static synchronous compensator (STATCOM). Med hjälp av simuleringar och ekonomisk kalkylering har deras egenskaper och investeringspotential analyserats. Det har resulterat i att ett kondensatorbatteri är en ekonomiskt god investering men med nackdelen att det blir en stor transient vid inkoppling. Aktiv reglering bistår med en snabb, kontinuerlig faskompensering men har större driftkostnader och en kortare livslängd. Övermagnetiserad synkronmaskin har en god ekonomisk framtidsutsikt men med en något långsammare reaktionstid. SVC och STATCOM är mer applicerbar på större anläggningar, eller för nät som har en större nytta av dess flexibilitet. / Small scale hydropower is a big user of reactive power, mainly because of their use of asynchrounous generators. Power companies are charging their customers a fee for an extensive use of reactive power. Which gives rise to a need of correction of the power factor as well as reduction of distorsion in the network. It is also in the interest of the general public to acquire a good electric quality in terms of keeping distorsion and interruptions in the network to a minimum. This can be achieved by using different methods for power factor correction and filtration of harmonics. These methods have their own inherent advantages and disadvantages described after the facility’s specific needs and requirements. These methods are a capacitor bank, passive and active regulation, overexcited synchronous machine, static var compensator (SVC) and static synchronous compensator (STATCOM). Simulations and economical calculations have been used to determine these properties. A capacitor bank has been proven to be a good economical investment, but it has high transients during switching conditions. Active regulation also shows a good profitability and provides a fast, continuous regulation of the reactive power, though it has higher operating costs and low life expectancy. The overexcited synchronous generator has a positive outlook in economic terms, with the drawback of a slower response time. SVC and STATCOM are more applicable to larger facilities or weak networks. Power factor correction efficiency active passive total harmonic distortion budgeting capacitor bank synchronous machine SVC STATCOM. Faskompensering effektivisering aktiv passiv distorsion kalkyl kondensatorbatteri synkronmaskin SVC STATCOM. Annan elektroteknik och elektronik
25	Evaluation of power quality and common design concept for AC-DC converters in aircraft Brolund, Andreas January 2017 (has links) This master thesis has been carried out in collaboration with Saab, Avionics Systems in Jönköping, Sweden, during the spring of 2017. The thesis investigates unidirectional rectifier topologies in aircraft and the focus has been on evaluating the power quality requirements according to the aircraft standards, in the course of the More Electric Aircraft concept. Both passive and active power factor correction topologies are considered, discussed and compared. Simulation models are designed in MATLAB/Simulink and the procedures are presented. A modular concept regarding components is discussed where different power supplies and loads are considered. The simulations present both a passive 12-pulse auto-transformer rectifier unit and an active Delta-switch rectifier fulfilling requirements for aircraft such as the total harmonic distortion of the supply current. In addition, the input power factor is close to unity and an efficiency greater than 97% is obtained. Lastly, future aspects of each topology are discussed and necessary improvements to obtain realistic simulation models are presented. AC-DC converter aircraft power electronics MOSFET MEA More electric aircraft Delta-switch ATRU Auto-transformer rectifier unit Auto-transformer Vienna rectifier passive rectifier active rectifier power factor correction APFC PFC MATLAB Simulink THD total harmonic distortion Elektroteknik och elektronik
26	Uživatelské rozhraní pro HP89410A / HP89410A User Interface Neužil, Jan January 2009 (has links) The aim of this thesis was to develop user interface in LabVIEW to make typical measurements with spectral analyzer HP89410A There is introduced the theory of operation of an analogue heterodyne and a digital FFT spectral analyzer. It is explained the background of the Fast Fourier Transform. There are discussed the key settings in measuring with FTT analyzer, like window function, bandwidth, number of frequency points, or the averaging. Further is described the program, which was developed for measuring frequency characteristic by white noise and by stepped measurement. It was also made a module for measuring Signal to Noise Ratio and module for Total Harmonic Distortion. In the last part of this thesis are shown the results of processed exemplar measurements.
27	Capacitorless Power Electronics Converters Using Integrated Planar Electro-Magnetics Haitham M Kanakri (18928150) 03 September 2024 (has links) <p dir="ltr">The short lifespan of capacitors in power electronics converters is a significant challenge. These capacitors, often electrolytic, are vital for voltage smoothing and frequency filtering. However, their susceptibility to heat, ripple current, and aging can lead to premature faults. This can cause issues like output voltage instability and short circuits, ultimately resulting in catastrophic failure and system shutdown. Capacitors are responsible for 30% of power electronics failures.</p><p dir="ltr">To tackle this challenge, scientists, researchers, and engineers are exploring various approaches detailed in technical literature. These include exploring alternative capacitor technologies, implementing active and passive cooling solutions, and developing advanced monitoring techniques to predict and prevent failures. However, these solutions often come with drawbacks such as increased complexity, reduced efficiency, or higher upfront costs. Additionally, research in material science is ongoing to develop corrosion-resistant capacitors, but such devices are not readily available.</p><p dir="ltr">This dissertation presents a capacitorless solution for dc-dc and dc-ac converters. The proposed solution involves harnessing parasitic elements and integrating them as intrinsic components in power converter technology. This approach holds the promise of enhancing power electronics reliability ratings, thereby facilitating breakthroughs in electric vehicles, compact power processing units, and renewable energy systems. The central scientific premise of this proposal is that the capacitance requirement in a power converter can be met by deliberately augmenting parasitic components.</p><p dir="ltr">Our research hypothesis that incorporating high dielectric material-based thin-films, fabricated using nanotechnology, into planar magnetics will enable the development of a family of capacitorless electronic converters that do not rely on discrete capacitors. This innovative approach represents a departure from the traditional power converter schemes employed in industry.</p><p dir="ltr">The first family of converters introduces a novel capacitorless solid-state power filter (SSPF) for single-phase dc-ac converters. The proposed configuration, comprising a planar transformer and an H-bridge converter operating at high frequency, generates sinusoidal ac voltage without relying on capacitors. Another innovative dc-ac inverter design is the twelve step six-level inverter, which does not incorporate capacitors in its structure.</p><p dir="ltr">The second family of capacitorless topologies consists of non-isolated dc-dc converters, namely the buck converter and the buck-boost converter. These converters utilize alternative materials with high dielectric constants, such as calcium copper titanate (CCTO), to intentionally enhance specific parasitic components, notably inter capacitance. This innovative approach reduces reliance on external discrete capacitors and facilitates the development of highly reliable converters.</p><p dir="ltr">The study also includes detailed discussions on the necessary design specifications for these parasitic capacitors. Furthermore, comprehensive finite element analysis solutions and detailed circuit models are provided. A design example is presented to demonstrate the practical application of the proposed concept in electric vehicle (EV) low voltage side dc-dc power converters used to supply EVs low voltage loads.</p> Circuits and systems Electrical circuits and systems Electrical machines and drives Engineering electromagnetics Solid-state power filter (SSPF) capacitorless topology active output power filter planar transformer electrolytic capacitor lifetime wear-out mechanisms notch resonant filter LLC-resonant converter calcium copper titanate (CCTO) intra capacitance Miniaturizing EV Chargers Multilevel inverters twelve-step inverter three-phase inverter six-level output voltage planar transform design Finite Element Analysis (FEA) Ansys Maxwell Ansys PEmag Ansys PExpert Ansys Simplorer Ansys Twin Builder planar electromagnetic buck-boost converter integrated magnetic hybrid LC filter high-power density converters CaCu3Ti4O12 electric vehicle chargers Nano graphene layer heat sink IGBT thermal response composite substrate planar transformer circuit models h-parameter voltage gradient dual transformer LLC resonant converter DC-DC Buck converter fundamental harmonic analysis power quality Total harmonic distortion (THD)

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