Dissertations / Theses: 'Total Harmonic Distortion Analysis'

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Tella, Pranavi Chowdari Islam Naz E. "The study of single phase diode rectifiers with high power factor and low total harmonic distortion." Diss., Columbia, Mo. : University of Missouri--Columbia, 2008. http://hdl.handle.net/10355/5677.

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The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on October 6, 2009). Thesis advisor: Dr. Naz E. Islam. Includes bibliographical references.

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West, Edward G. S. M. Massachusetts Institute of Technology. "Analysis of harmonic distortion in an Integrated Power System for naval applications." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/33594.

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Thesis (Nav. E.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering; and, (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2005. Includes bibliographical references (p. 89-91). This research quantifies the voltage distortion over the broad range of operating conditions experienced by a Naval warship. A steady state model of an Integrated Power System (IPS) was developed in a commercially available power system simulation tool. The system chosen for this study was a three-phase, 4160 VAC, 80 MW power system with a 450 VAC bus to supply traditional ship service loads. Sensitive loads, such as combat systems equipment, are isolated from the harmonic content of the 450 volt bus via solid state inverters. Power generation for this system included two 30 MW and two 10 MW generators. The sizing of these generators was based on operating configurations that would result in the best fuel efficiency under the most common loading conditions. Model components were simulated and compared to data recorded for the U.S. Navy's Full Scale Advanced Development (FSAD) test system for the IPS at the Philadelphia Land Based Engineering Site (LBES). The propulsion motor used in the simulations was developed based on the advanced induction motor installed at LBES. (cont.) Various loading conditions, including battle, cruise and anchor were simulated for both 10⁰F and 90⁰F ambient design conditions and with propulsion loads ranging from 0% to 100%. Numerous system configuration changes were implemented to determine their impact on system harmonics. These included operating the propulsion converter front end rectifiers in both controlled (varying commutation angle) and uncontrolled (diode bridge) configurations; implementation of both twelve and six pulse rectification; and installation of a tuned passive 5th harmonic filter. The simulation results are compared to both IEEE Std 519-1992 and Mil-Std 1399. by Edward G. West. S.M. Nav.E.

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Negumbo, Rosalia. "Analysis for electrical energy and overall efficiency in distribution networks with harmonic distortion." Thesis, Cape Peninsula University of Technology, 2009. http://hdl.handle.net/20.500.11838/1103.

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Thesis (MTech (Electrical Engineering))--Cape Peninsula University of Technology, 2009 Traditionally, harmonics are ignored in overall efficiency and energy usage studies. However, in the modern era, power systems contain levels of harmonics which can no longer be ignored by engineers, planners, energy conservationists and economists. The directions of power flows have to be considered when harmonics are present in the power network. A methodology and new formulae for individual and overall efficiency and energy usage is developed at each frequency (f1, h and H) and forms the main contribution to research in this field. Two case studies were conducted; a measurement based laboratory experiment set-up and a simulated case study. In the set-up, measurements of current, voltage and power at different points in the network for the 1st, 5th and 7th frequencies were taken. Current and voltage results were used for hand calculations to prove the measured power flows and directions. The measurements were taken with a Fluke 345 three-phase harmonic power quality analyzer. For the simulated case study, a network was investigated using the DIgSILENT and SuperHarm software packages. Their results were compared and it was found that DIgSILENT is the preferred package for power results. It was found that the total harmonic distortion limit for voltage in the simulated network exceeded an acceptable level. The harmonic mitigation solution chosen was to design a passive filter to decrease the distortion by shifting the resonance point of the network. The method to design the passive filter and its impact on efficiency and energy usage is included in the thesis. Unique power flow direction diagrams are developed as part of the methodology and form an essential step in the derivation of the new formulae. Efficiencies, power losses and energy usage at individual and combined frequencies were determined. Results showed the negative effects of harmonics on overall efficiency, energy usage and power losses of the system. The methodology and new formulae developed was found to be effective and their application is recommended for use by industry.

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Collins, Christopher Donald. "FACTS device modelling in the harmonic domain." Thesis, University of Canterbury. Electrical and Computer Engineering, 2006. http://hdl.handle.net/10092/1103.

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This thesis describes a novel harmonic domain approach for assessing the steady state performance of Flexible AC Transmission System (FACTS) devices. Existing harmonic analysis techniques are reviewed and used as the basis for a novel iterative harmonic domain model for PWM FACTS devices. The unified Newton formulation adopted uses a combination of positive frequency real valued harmonic and three-phase fundamental frequency power-flow mismatches to characterise a PWM converter system. A dc side mismatch formulation is employed in order to reduce the solution size, something only possible because of the hard switched nature of PWM converters. This computationally efficient formulation permits the study of generalised systems containing multiple FACTS devices. This modular PWM converter block is applied to series, shunt and multi-converter FACTS topologies, with a variety of basic control schemes. Using a three-phase power-flow initialisation and a fixed harmonic Jacobian provides robust convergence to a solution consistent with time domain simulation. By including the power-flow variables in the full harmonic solution the model avoids unnecessary assumptions regarding a fixed (or linearised) operating point, fully modelling system imbalance and the associated non-characteristic harmonics. The capability of the proposed technique is illustrated by considering a range of harmonic interaction mechanisms, both within and between FACTS devices. In particular, the impact of transmission network modelling and operating point variation is investigated with reference to ac and dc side harmonic interaction. The minor role harmonic distortion and over-modulation play in the PWM switching process is finally considered with reference to the associated reduction in system linearity.

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Ferrar, Anthony Maurice. "Measurement and Uncertainty Analysis of Transonic Fan Response to Total Pressure Inlet Distortion." Diss., Virginia Tech, 2015. http://hdl.handle.net/10919/51747.

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Distortion tolerant fans represent the enabling technology for the successful implementation of highly integrated airframe propulsion system vehicles. This investigation extends the study of fan-distortion interactions to an actual turbofan engine with a total pressure distortion profile representative of a boundary-layer ingesting (BLI) embedded engine. The goal was to make a series of flow measurements that contribute to the overall physical understanding of this complex flow situation. Proper uncertainty analysis is critical to extracting meaning from the data measured in this study. The important information in the measurements is contained in small differences that lead to large impacts on the fan performance. In some cases, these differences were measured to a useful degree of accuracy, while in others they were not. One important application of the uncertainty analysis techniques developed in this work is the identification of the dominant error sources that resulted in unacceptable uncertainties. This dissertation presents an experimental study of transonic fan response to inlet total pressure distortion. A Pratt and Whitney JT15D-1 turbofan engine was subjected to a total pressure distortion representative of a boundary layer ingesting serpentine inlet. A 5-hole probe measured the aerodynamic response of the fan rotor in terms of flow angles, total pressure, and static pressure. A thermocouple embedded in the probe measured the rotor outlet total temperature. These measurements enabled the full characterization of the flow condition at each measurement point. The results indicate that a trailing edge separation and reattachment cycle experienced by the blades caused variations in the work input to the flow and resulted in a non-uniform rotor outlet flow profile. The details of the aerodynamic process and several means for improving distortion response are presented in this context. As a second theme, the modern measurement and uncertainty analysis techniques required to obtain useful information in this situation are developed and explored. Uncertainty analysis is often treated as a less glamorous afterthought in experimental research. However, as technology develops along lines of ever increasing system-level integration, simply suggesting the solution to a single flow situation does not repre- sent closure to the larger problem. In addition to frameworks for developing distortion tolerant fans, frameworks for developing frameworks are required. Uncertainty-drivenexperimental techniques represent the enabling methodology for the discovery and un- derstanding of the subtle phenomena associated with such coupled performance. These considerations are required to extend the usefulness of the results to the overarching issue of integrating the complex performance of individual components into an overall superior system. The experimental methods and uncertainty analysis developed in this study are presented in this context. Ph. D.

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Grossman, Hy. "A NEXT GENERATION AIRCRAFT POWER MONITORING SYSTEM." International Foundation for Telemetering, 2007. http://hdl.handle.net/10150/604535.

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ITC/USA 2007 Conference Proceedings / The Forty-Third Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2007 / Riviera Hotel & Convention Center, Las Vegas, Nevada Historically, aircraft power monitoring has required the use of multiple signal conditioning functions to measure various parameters including voltage, current, frequency and phase. This information was then post processed to determine the characteristics of the 3-phase power quality on the aircraft. Recent developments in embedded DSP processors within signalconditioning systems provide the instrumentation engineer with expanded capabilities for realtime on-board power quality monitoring. Advantages include reduced space and bandwidth requirements and minimal wiring intrusion. For each phase, output data may include peak positive and negative voltages and currents, peak-to-peak, average and RMS voltages and currents, phase power (real and apparent), phase power factor, phase period (frequency), phase shift measurement from phase 1 (the reference phase) to phase 2, and from phase 1 to phase 3. In addition, a Fast Fourier Transform (FFT) is performed on each phase voltage to provide Total Harmonic Distortion measurements. This paper describes the methods employed in the implementation of these functions on a single signal-conditioning card in order to provide detailed information about the power quality of a three-phase aircraft power source.

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Kirchmann, Carl Christian. "Automatic acoustic tests of conference phones." Thesis, Uppsala universitet, Fasta tillståndets elektronik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-326253.

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This master thesis was completed at Limes Audio in Umeå. Limes Audio are specialized in speech enhancement software which is mostly used in conference phones. Their software is used to reduce noise, echo cancellation as well as reduction of distortion. When a conference phone is malfunctioning it can be troublesome to find the cause of the problem. Common issues that lead to perceived poor audio quality are rattling plastics, loose parts and an environment with demanding acoustics. There is a need for automatic tests to run on conference phone which can diagnose audio quality and the acoustics of the environment where the conference phone is located in. A previous master thesis by Wilhelmsson called "Estimating Loudspeaker Distortion and Room Reverberation Time Using a Speakerphone" focused on evaluating several tests run in MATLAB for analyzing acoustic characteristics of a room. The goal of this thesis was to continue the work of the master thesis by Wilhelmsson. Previous tests served as a basis for this thesis. The tests where modified and rewritten in C and run on a Linux computer connected to a specific conference phone model. In the extended test made in this thesis using sine sweep signals, the reverberation time as well as the distortion for the conference phone setup was determined. The calculated reverberation time was compared to the results using Room EQ Wizard and gave almost identical results. Total harmonic distortion was not easy to relate to the perceived audio quality. There is a need to further develop methods to take into account other types of distortion than the total harmonic distortion. Rub & buzz is one kind of distortion that could be of interest. To investigate pass or fail thresholds for reverberation time as well as distortion is central for further development of this test software.

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Ruckdaschel, James David. "Harmonic Analysis of a Static VAR Compensated Mixed Load System." DigitalCommons@CalPoly, 2009. https://digitalcommons.calpoly.edu/theses/82.

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As power electronic based controllers and loads become more prevalent in power systems, there is a growing concern about how the harmonics generated by these controllers and loads affect the power quality of the system. One widely used power electronic based load is the Variable Frequency Drive (VFDs) used to vary the speed of an induction motor; whereas a common example of a power electronic based controller used in power systems is the Static VAR Compensator (SVC) for improving a system’s power factor. In this thesis, the harmonic content and overall performance of a system including both a VFD and a SVC will be studied and analyzed. Specifically, the cases of no compensation, static capacitor compensation, and power electronic based static VAR compensation are examined. A small-scale model of a system for study was constructed in lab. Several cases were then performed and tested to simulate a system which contained both fixed and power electronic based harmonic generating loads. The performance of each case was determined by total harmonic current and voltage distortions, true power factor, and RMS current levels at different points in the system.

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Du, Yang. "Modeling and analysis of single-phase two-stage inverter for grid-connected photovoltaic application." Thesis, The University of Sydney, 2013. http://hdl.handle.net/2123/9334.

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In order to extract the maximum amount of power from the PV modules and convert it into an appropriate form for grid integration, a power electronics interface is needed. This thesis focuses on analysis and modeling of the single-phase two-stage inverter for grid-connected PV application with special attention given to the harmonic issues. A DC/DC battery-integrated boost converter can serve as the front end in a two-stage PV inverter configuration. A steady-state analysis for this new type of converter is carried out. An application of this converter in distributed Maximum Power Point Tracking (MPPT) architecture is proposed and compared with the conventional boost converter. By adding energy storage devices, it has the potential to compensate for the intermittent attribute of the PV generators. It also yields a more stabilized DC-link voltage in the distributed MPPT application. This thesis also analyzes the harmonic distortions generated from a PV inverter, which mainly relate to the DC/AC stage of the PV inverter. The field measurements are carried out at the CSIRO micro-grid. The high total harmonic distortion phenomenon is found when the PV inverters operate at light load condition. The conventional model of a PV inverter does not contain any harmonic information. A linear model for the PV inverter is modified to analyze the harmonic formation process. The causes of harmonics are summarized for the PV inverter operating at different power levels. The constant DC-link voltage assumption is not necessarily true for the two-stage PV inverter. The model of the grid-connected PV inverter with feedback control becomes time-varying with consideration for the DC-link voltage ripple. A series of odd harmonics is identified to be caused by this double-line frequency DC-link voltage ripple. The transfer function cannot be derived for this model. It is a challenge to calculate the exact harmonic amplitudes. The closed-form solution for this time-varying model is derived based on an idea which is similar to the harmonic balance method. A guideline is provided to select the minimum size of capacitor for the DC-link without sacrificing the power quality. Simulation and experimental results are provided to verify the aforementioned analysis results. In addition, some suggestions for future work are given.

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Souza, Wesley Angelino de [UNESP]. "Desenvolvimento de sistema de aquisição e processamento para aplicações em qualidade de energia." Universidade Estadual Paulista (UNESP), 2011. http://hdl.handle.net/11449/87201.

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Made available in DSpace on 2014-06-11T19:22:34Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-08-19Bitstream added on 2014-06-13T20:49:15Z : No. of bitstreams: 1 souza_wa_me_bauru.pdf: 3309362 bytes, checksum: a37e3a04f60e9ebbd2f490264d198dbf (MD5) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Este trabalho teve como o desenvolvimento de um sistema de aquisição e processamento de dados para aplicações em Qualidade de Energia Elétrica (QEE). Do ponto de vista dos circuitos de hardware desenvolvidos, buscou-se utilizar componentes de precisão elevada para o sensoriamento e condicionamento dos sinais de tensão e corrente. Além disso, foi implementado um algoritmo de auto calibração das medidas, em função da temperatura no medidor implementado. O processamento dos dados foi realizado através de um processador digital de sinais (DSP, Digital Sinal Processor) de 32 bits, com aritmética de ponto flutuante. Também foi agregado ao sistema um módulo de comunicação sem fio, de forma que os dados medidos pudessem ser enviados a outros dispositivos para armazenamento ou análise remota. Do ponto de vista da aplicação em Qualidade de Energia, foram implementados diversos algoritmos de indicadores de QEE, tais como o de Distorção Harmônica Total (DHT), para a validação preliminar do sistema desenvolvido. Entretanto, do ponto de vista dos estudos e pesquisas realizadas pelo Grupo de Automação e Sistemas Integráveis (GAS/UNESP), no que diz respeito à análise de circuitos elétricos sob condições de formas de onda não sensoriais e/ou desequilibradas, o sistema desenvolvido foi também utilizado para avaliar o comportamento e desempenho da Teoria de Potência Conservativa, proposta recentemente por Tenti et al. e de novos fatores de conformidade (ou desempenho) para a avaliação da QEE em sistemas polifásicos com cargas não lineares. Diversos resultados de simulação e experimentais foram apresentados e constrastados a fim de validar os algoritmos utilizados no DSP utilizado, bem como para permitir a avaliação da Teoria de Potência Conservativa para interpretação de diferentes circuitos e condições de operações This study aimed to develop a data acquisition and processing system for Power Quality applications. From the hardware point of view, high precision components have been used for the vallage and current sensing and signal conditioning. In addition, a self-calivration algorithm has been implemented in order to adjust the measured values in terms of the estimated temperature. The data processing was performed by means of 32-bit floating point digital signal processor (DSP). A wirelless communication module has also been added, so that the measured data could be sent to other storage devices or remote analyzers. From the perspective of power quality applications, several algorithms have implemented, such as the Total Harmonic Distortion (THD) for the preliminary validation of the developed system. However, considering the studies and surveys carried out by the studies and survey carried out by the Group of Automation and Integrated Systems (GASI/UNESP), especially those related to the analysis of electrical circuits under non-sinusoidal and/or unbalanced waveform conditions, the implemented system has been applied to the evaluation of the Conservative Power Theory (CPT), recently proposed by Tenti et al. Several simulation and experimental results have been depicted and compared in order to validate the practical DSP implementation of the required algorithms, as well as, for the purpose of analyzing different circuit's interpretation by means of the CPT

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Häger, Emil. "Performance Evaluation of Medium-Power Voltage Inverters." Thesis, Linköpings universitet, Elektroniska Kretsar och System, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-118568.

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Power inverters, used to convert DC power to AC, are often used in e.g. solar power applications. However, they tend to be impractically large and expensive; as such, power miniaturization is an active research area. In this thesis, several classes of modern power inverters are evaluated and compared with regards to size, efficiency and output quality in order to identify areas of potential improvement. Methods for estimation of THD, power losses and input ripple are created and verified against a simulation of a five-level neutral-point-clamped inverter with SPWM control. Finally, this design is implemented physically and is found to achieve 94.5% efficiency and 7% THD under low voltage laboratory conditions, while remaining smaller than an average textbook.

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Thunberg, Erik. "On the Benefit of Harmonic Measurements in Power Systems." Doctoral thesis, Stockholm, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3219.

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Joca, Davi Rabelo. "TÃcnica de ModulaÃÃo para ReduÃÃo de DHT em Inversor MultinÃvel com Capacitor Flutuante de TrÃs NÃveis." Universidade Federal do CearÃ, 2014. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=11222.

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CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior Diante da necessidade em aperfeiÃoar as tecnologias existentes para a conversÃo de energia elÃtrica em sistemas de alta potÃncia, este trabalho tem por finalidade projetar, analisar e implementar experimentalmente uma tÃcnica de modulaÃÃo com o intuito de reduzir o conteÃdo harmÃnico da tensÃo de saÃda em um inversor multinÃvel com capacitor flutuante de trÃs nÃveis. Algumas das diversas tÃcnicas de modulaÃÃo (PSPWM, LSPWM, HE-PWM e CSV-PWM) foram analisadas e implementadas no controlador digital FPGA a fim de comparar suas caracterÃsticas de desempenho com a tÃcnica de modulaÃÃo proposta. AlÃm disso, foi realizado o estudo de perdas da topologia de inversor multinÃvel com capacitor flutuante de trÃs nÃveis e a anÃlise teÃrica da distorÃÃo harmÃnica total da modulaÃÃo proposta. Finalmente, o desenvolvimento digital das tÃcnicas mostrou resultados coerentes, com formas de onda obtidas experimentalmente com alta qualidade de resoluÃÃo. A comparaÃÃo entre as estratÃgias de modulaÃÃo em termos de DHT resultou positivamente Ã modulaÃÃo proposta, cujos resultados experimentais de DHT nas tensÃes de linha na saÃda apresentaram o melhor desempenho para toda a faixa de Ãndices de modulaÃÃo comparadas Ãs tÃcnicas PSPWM, LSPWM-POD e CSV-PWM e uma reduÃÃo de atÃ 4,5% em relaÃÃo Ã HE-PWM. Isto comprova o estudo teÃrico realizado e sua aplicaÃÃo no inversor multinÃvel com capacitor flutuante de trÃs nÃveis. Given the need to improve the existing technologies for electrical energy conversion into high power systems, this works purpose to design, analyze and implement a modulation technique that aims to reduce the output voltage harmonic content on the three-level flying capacitor multilevel inverter. Some of the various conventional modulation techniques (PSPWM, LSPWM, HE-PWM e CSV-PWM) have been analyzed and implemented in FPGA controller in order to compare their performance features with the proposed modulation technique. Furthermore, the losses study of the three-level flying capacitor multilevel inverter topology and the total harmonic distortion theoretical analysis of the proposed modulation technique have been made. Finally, the digital implementation of the techniques showed consistent results with experimentally obtained waveforms with high quality resolution. The comparison between the modulation strategies in the THD rates resulted positively for the proposed modulation, which THD experimental results in the line output voltage showed the best performance for all range of modulation indexes compared to techniques PSPWM, LSPWM-POD and CSV-PWM and the reduction of up to 4.5% better than HE-PWM. This proved the theoretical study done and its application in three-level flying capacitor multilevel inverter.

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Aikio, J. P. (Janne P. ). "Frequency domain model fitting and Volterra analysis implemented on top of harmonic balance simulation." Doctoral thesis, University of Oulu, 2007. http://urn.fi/urn:isbn:9789514284205.

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Abstract The modern wireless communication techniques are aiming on increasing bandwidth and the number of carriers for higher data rate. This sets challenging linearity requirements for RF power amplifiers (PAs). Unfortunately, high linearity can only be obtained at the cost of efficiency. In order to improve the performance of the PA, in-depth understanding of nonlinear behaviour is mandatory. This calls for techniques that can give componentwise information of the causes of the distortion. The aim of this thesis is to develop a technique that can provide such information. This thesis proposes a detailed distortion analysis technique that is based on frequency domain fitting of polynomial models. Simulated large-signal spectra are used for fitting as these contain the necessary information about the large-signal bias point and amplitude range. Moreover, in the frequency domain the delays are easy to compensate, and detailed analysis to any fitted tone can be performed. The fitting procedure as such is simple but becomes difficult in multi-dimensional nonlinearities if the controlling voltages correlate strongly. In this thesis the solvability and reliability of the fitting procedure is increased by numerical operations, model-degree reduction and by using different excitations. A simplified Volterra method is used to calculate the distortion contributions by using the fitted model. The overall distortion is analysed by calculating the voltage response of the contributions of each nonlinearity to the terminal nodes of the device by the use of linear transfer functions of the circuit. The componentwise analysis is performed by phasor presentation enabling the cancelling mechanisms to be seen. The proposed technique is implemented on top of harmonic balance simulation in an APLAC circuit simulator in which extensive distortion simulations are performed. The technique relies on the existing device model and thus the fitted model can be only as accurate as the particular simulation model. However, two different RF PAs are analysed that show a good agreement between measurements and simulations. The proposed technique is verified with several test cases including amplitude dependent amplitude and phase distortion, intermodulation distortion sweet spots, bandwidth dependent memory effects and impedance optimization. The main finding of the detailed analysis is that the distortion is a result of several cancelling mechanisms. In general, cubic nonlinearity of transconductance is dominating the in-band distortion but is cancelled by the 2nd-degree nonlinearity that is mixed to the fundamental band from envelope and 2nd harmonic bands that is usually the main cause of memory effects.

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Musoni, Nkusi Emmanuel. "Analysis of the effect of renewable generation on the power quality of the grid, modelling and analysis of harmonic and voltage distortion." Thesis, Cape Peninsula University of Technology, 2018. http://hdl.handle.net/20.500.11838/2805.

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Thesis (Master of Engineering in Electrical Engineering)--Cape Peninsula University of Technology, 2018. As the electric energy demand grows, there is a significant increase in the penetration of renewable generation (RG) in the existing electrical grid network. Interconnecting of renewable generation technologies to an existing distribution system has proven to provide various benefits such as meeting the growing load demand and its contribution to energy system decarbonisation, long-term energy security and expansion of energy access to new energy consumers in the developing urban and rural areas. However, the aim of this thesis is to conduct a study on the impacts of renewable generation on the power quality of electrical grid. Therefore, this work aims at assessing the potential effects of Distributed Generation (DG) on the operation of electric power system by modelling of harmonics and voltage distortion. With different types of renewable generation available at present, it is believed that some designs contribute significantly to electrical network’s Power Quality (PQ). After the analysis of harmonic currents (chapter 6 and 7 of this thesis) introduced by renewable generation technologies, their negative impact on the power quality of the grid is seen to be apparent at point of connection (POC) but only within controlled limits. Analytical method for modeling of harmonic interactions between the grid and aggregated distributed generation technologies are investigated using DIgSILENT Power Factory software and the results obtained are discussed.

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Souza, Wesley Angelino de. "Desenvolvimento de sistema de aquisição e processamento para aplicações em qualidade de energia /." Bauru : [s.n.], 2011. http://hdl.handle.net/11449/87201.

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Resumo: Este trabalho teve como o desenvolvimento de um sistema de aquisição e processamento de dados para aplicações em Qualidade de Energia Elétrica (QEE). Do ponto de vista dos circuitos de hardware desenvolvidos, buscou-se utilizar componentes de precisão elevada para o sensoriamento e condicionamento dos sinais de tensão e corrente. Além disso, foi implementado um algoritmo de auto calibração das medidas, em função da temperatura no medidor implementado. O processamento dos dados foi realizado através de um processador digital de sinais (DSP, Digital Sinal Processor) de 32 bits, com aritmética de ponto flutuante. Também foi agregado ao sistema um módulo de comunicação sem fio, de forma que os dados medidos pudessem ser enviados a outros dispositivos para armazenamento ou análise remota. Do ponto de vista da aplicação em Qualidade de Energia, foram implementados diversos algoritmos de indicadores de QEE, tais como o de Distorção Harmônica Total (DHT), para a validação preliminar do sistema desenvolvido. Entretanto, do ponto de vista dos estudos e pesquisas realizadas pelo Grupo de Automação e Sistemas Integráveis (GAS/UNESP), no que diz respeito à análise de circuitos elétricos sob condições de formas de onda não sensoriais e/ou desequilibradas, o sistema desenvolvido foi também utilizado para avaliar o comportamento e desempenho da Teoria de Potência Conservativa, proposta recentemente por Tenti et al. e de novos fatores de conformidade (ou desempenho) para a avaliação da QEE em sistemas polifásicos com cargas não lineares. Diversos resultados de simulação e experimentais foram apresentados e constrastados a fim de validar os algoritmos utilizados no DSP utilizado, bem como para permitir a avaliação da Teoria de Potência Conservativa para interpretação de diferentes circuitos e condições de operações Abstract: This study aimed to develop a data acquisition and processing system for Power Quality applications. From the hardware point of view, high precision components have been used for the vallage and current sensing and signal conditioning. In addition, a self-calivration algorithm has been implemented in order to adjust the measured values in terms of the estimated temperature. The data processing was performed by means of 32-bit floating point digital signal processor (DSP). A wirelless communication module has also been added, so that the measured data could be sent to other storage devices or remote analyzers. From the perspective of power quality applications, several algorithms have implemented, such as the Total Harmonic Distortion (THD) for the preliminary validation of the developed system. However, considering the studies and surveys carried out by the studies and survey carried out by the Group of Automation and Integrated Systems (GASI/UNESP), especially those related to the analysis of electrical circuits under non-sinusoidal and/or unbalanced waveform conditions, the implemented system has been applied to the evaluation of the Conservative Power Theory (CPT), recently proposed by Tenti et al. Several simulation and experimental results have been depicted and compared in order to validate the practical DSP implementation of the required algorithms, as well as, for the purpose of analyzing different circuit's interpretation by means of the CPT Orientador: Fernando Pinhabel Marafão Coorientador: Ivando Severino Diniz Banca: Lourenço Matakas Junior Banca: Marcelo Nicoletti Franchin Mestre

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Earick, Weston R. "DESIGN OF A HIGH-POWER, HIGH-EFFICIENCY, LOW-DISTORTION DIRECT FROM DIGITAL AMPLIFIER." Wright State University / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=wright1155008919.

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Soderquist, Daniel Robert. "Analysis of Distortion Transfer and Generation through a Fan and a Compressor Using Full-annulus Unsteady RANS and Harmonic Balance Approaches." BYU ScholarsArchive, 2019. https://scholarsarchive.byu.edu/etd/7401.

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Understanding distortion transfer and generation through fan and compressor blade rows is able to assist in blade design and performance prediction. Using full annulus unsteady RANS simulations, the effects of distortion as it passes through the rotor of a transonic fan at five radial locations (10%, 30%, 50%, 70%, and 90% span) are analyzed. The inlet distortion profile is a 90-degree sector with a 15% total pressure deficit. Fourier distortion descriptors are used in this study to quantitatively describe distortion transfer and generation. Results are presented and compared for three operating points (near-stall, design, and choke). These results are used to explain the relationship between inlet total pressure distortion, pressure-induced swirl, total pressure distortion transfer, total temperature distortion generation, and circumferential rotor work variation. It is shown that very large changes in pressure-induced swirl and distortion transfer and generation occur between near-stall and design, but only small changes are seen between design and choke. The greatest changes are shown to be near the tip. Local power variations are shown to correlate with total pressure distortion transfer and total temperature distortion generation.It can be difficult to predict the transfer of distortion through a fan or compressor because traditional experimental and computational methods are very expensive and time consuming. The Harmonic Balance approach is a promising alternative which uses Fourier techniques to represent fluid flow solutions and which can provide unsteady solutions much more quickly than traditional unsteady solvers. Relatively little work has been done to assess how much Fourier information is necessary to calculate a sufficiently accurate solution with the Harmonic Balance Solver. A study is performed to analyze the effects of varying the amount of modal content that is used in Harmonic Balance simulations. Inlet distortion profiles with varying magnitudes are used in order to analyze trends and provide insight into the distortion flow physics for various inlet conditions. The geometry is a single stage axial compressor that consists of an inlet guide vane followed by the NASA Stage 37 rotor. It is shown that simulations with greater magnitudes of distortion require more modal content in order to achieve sufficiently accurate results. Harmonic Balance simulations are shown to have significantly lower computational costs than simulations with a conventional unsteady solver.

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Peterson, Marshall Warren. "Implementations of Fourier Methods in CFD to Analyze Distortion Transfer and Generation Through a Transonic Fan." BYU ScholarsArchive, 2016. https://scholarsarchive.byu.edu/etd/6384.

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Inlet flow distortion is a non-uniform total pressure, total temperature, or swirl (flow angularity) condition at an aircraft engine inlet. Inlet distortion is a critical consideration in modern fan and compressor design. This is especially true as the industry continues to increase the efficiency and operating range of air breathing gas turbine engines. The focus of this paper is to evaluate the Computational Fluid Dynamics (CFD) Harmonic Balance (HB) solver in STAR-CCM+ as a reduced order method for capturing inlet distortion as well as the associated distortion transfer and generation. New methods for quantitatively describing and analyzing distortion transfer and generation are investigated. The geometry used is the rotor 4 fan geometry, consisting of one rotor and one stator. The inlet boundary condition is a 90-degree sector total pressure distortion profile with total pressure and swirl held constant. Multiple HB simulations with varying mode combinations and distortion intensities are analyzed and compared against full annulus Unsteady Reynolds Averaged Navier-Stokes (URANS) simulations. Best practices and recommendations for the implementation of the HB solver are given. The pre-existing Society of Automotive Engineers Aerospace Recommended Practice (SAE-ARP) 1420b descriptors are demonstrated to be inadequate for the purposes of analyzing distortion transfer and generation on a stage-to-stage basis. New implementations of Fourier methods are presented as an alternative to the SAE-ARP 1420b descriptors. These Fourier descriptors are shown to describe distortion transfer and generation to a higher degree of fidelity than the SAE-ARP 1420b descriptors. These new descriptors are demonstrated on the analysis of full annulus URANS and HB simulations. The HB solver is shown to be capable of capturing distortion transfer, generation and performance degradation. Recommendations for the optimal implementation of the HB method are given.

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Bernáth, František. "SW nadstavba analyzátoru sítí pro automatický návrh nn kompenzační jednotky na základě měření." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2010. http://www.nusl.cz/ntk/nusl-218704.

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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.

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Vývoda, Marek. "Kompenzace účiníku a posouzení zpětných vlivů indučního ohřevu." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2011. http://www.nusl.cz/ntk/nusl-219077.

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This Diploma thesis deals with design of for power factor correction device for mid-frequency-range induction heating and also with assessment of correction device influence in harmonically distorted environment from the distribution net point of view. Research chapters contain of main characteristics of electrical power quality and theoretical background of reactive power, which is in our case caused by driven non-linear elements. Further, the heating power supply block is explained and simulations of power consumption in Matlab - Simulink is done, within the prove of corrective tools design. After the build of corrective tool assemblies, measurements are matched with the simulation results.

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Pelicer, Junior João Carlos. "Emprego de topologia boost semicontrolada para mitigação do conteúdo harmônico de corrente em conversores de 12 pulsos /." Ilha Solteira, 2019. http://hdl.handle.net/11449/180812.

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Orientador: Falcondes José Mendes de Seixas Resumo: Os conversores multipulsos têm sido muito utilizados para a melhoria da qualidade de energia elétrica em sistemas de retificação trifásicos. O principal motivo para tal afirmação é a robustez apresentada por esses conversores, aliada às características intrínsecas da estrutura, que resulta no cancelamento natural de certas componentes de corrente na rede, devido ao defasamento angular provocado pela ação do transformador ou autotransformador utilizado. O que se propõe nesse trabalho é a substituição de cada ponte retificadora a diodos, presente no conversor de 12 pulsos, por uma topologia retificadora trifásica semicontrolada, baseada no conversor boost operando no modo de condução descontínuo (MCD), de modo que, seja possível reduzir de maneira significativa a DHTi (Distorção Harmônica Total de corrente), bem como, incorporar os volumosos transformadores de interfase (IPTs) aos indutores boost de alta frequência, resultando na redução de peso e volume. Foram confeccionadas duas versões do conversor de 12 pulsos com retificadores semicontrolados, uma utilizando transformador isolador e a outra um autotransformador. O que se verificou para ambas as configurações é que a estrutura apresenta um reduzido conteúdo harmônico de corrente se comparado ao conversor tradicional e que, ao se operar no modo de condução descontínuo, faz-se possível o emprego de uma lógica de controle simples, possibilitando assim empregar somente uma malha de tensão, e reduzir significativamente a DHTi do... (Resumo completo, clicar acesso eletrônico abaixo) Abstract: Multipulse converters have been widely employed for electrical power quality improvement in three-phase rectifiers systems. The main reason for this statement is the robustness shown by these structures, allied to their natural characteristics, resulting in harmonic canceling at the mains, due to the phase displacement provided by the transformer/autotransformer. In this work, it is proposed the replacement of each rectifier bridge, present in the 12-pulse converter, by a three-phase half-controlled rectifier topology, based on DCM (Discontinuous Conduction Mode) boost converter, thus making it possible to significative reduce the THDi (Total Harmonic Distortion) of the current injected on the mains by the structure. It also incorporates the voluminous IPT's (Interphase Transformer) in the boost high-frequency inductor, resulting in a reduction of weight and size. Two versions of the 12-pulse converter with semicontrolled rectifiers were made, one using an isolating transformer and other using an autotransformer. It was verified that both configurations present a reduced THDi when compared to the traditional converter. So, by electing DCM, it is possible to employ a simpler control logic, employing only one voltage loop and significantly reducing the THDi. Doutor

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Nabavi, Seyed Ghavamoddin. "Statistical Analysis of Steady State Response in RF Circuits via Decoupled Generalized Polynomial Chaos." Thesis, Université d'Ottawa / University of Ottawa, 2016. http://hdl.handle.net/10393/35293.

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One of the major factors in RF circuit design is the ability to predict the performance of these circuits in the presence of uncertainty in the key design parameters. This is referred to as uncertainty quantification in the mathematical literature. Uncertainty about the key design parameters arises mainly from the difficulty of controlling the physical or geometrical features of the underlying design, especially at the nanometer level. With the constant trend to scale down the process feature size, uncertainty quantification becomes crucial in shortening the design time. This thesis presents a new approach to statistically characterize the variability of the Harmonic Balance analysis and its application to Intermodulation distortion analysis in the presence of uncertainty in the design parameters. The new approach is based on the concept of Polynomial Chaos (PC) and Stochastic Galerkin (SG) methods. However, unlike the traditional PC, the proposed approach adopts a new mathematical formulation that decouples the Polynomial Chaos problem into several problems whose sizes are equal to the size of the original Harmonic Balance problem. The proposed algorithm produces significant CPU savings with equivalent accuracy to traditional Monte Carlo and standard PC approaches.

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Tedesco, Lawrence A. Jr. "A Unified Measure of Audio System Fidelity." ScholarWorks@UNO, 2007. http://scholarworks.uno.edu/td/598.

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A new technique to qualitatively measure distortion in dynamically controlled audio systems using non-stationary noise sequences is explored and compared to traditional methods based upon stationary test signals. This technique can easily be adapted to give a qualitative measure of distortion as a function of the perceived Sound Pressure Level (SPL).

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Al-Bayaty, Hussein Kamal Anwer. "Novel methods of utilization, elimination, and description of the distortion power in electrical circuits." Thesis, University of Plymouth, 2018. http://hdl.handle.net/10026.1/10646.

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Firstly, this thesis investigates the electrical power harmonics in an attempt to utilize harmonic current and its distortion power in a novel idea to reconvert the distortion power into useful power. This is done, in order to feed different DC or AC loads in single and three-phase power system by using passive or active filters and accordingly, develop a new topology of hybrid active power filter (HAPF). In addition, this circuit can be considered as a power factor corrector (PFC) because it reduces the total harmonic distortion (THD) and improves the power factor (PF). Secondly, this thesis works on a new design of active power factor correction (APFC) circuit presenting two circuits with the same design principle: the first design consists of two active switches without an external complex control circuit, while the second design contains a single active switch with an additional control circuit. The main contribution of this circuit is 98% reduction of the inductor's value used in the newly proposed PFC circuit in comparison with the conventional boost converter which may lead to a huge reduction in size, weight and the cost of the new PFC circuit. Also, the active switches depend on a carefully designed switching pattern that results in an elimination of the third order harmonic from the input source current which decreases the value of total current harmonic distortion (THDI) to (14%) and improves the input PF to (0.99). Consequently, the simplicity of the design without requiring a complex control circuit and without a snubber circuit plus the minimum size of inductor, gives the newly proposed circuit the superiority on other PFC circuits. Thirdly, this research aims to describe the distortion power through submitting two novel power terms called effective active power (Pef ) & reactive power (Qef ) terms with a new power diagram called Right-Angled Power Triangle (RAPT) Diagram. In addition, a novel de nition of total apparent power (St) has been submitted in order to illustrate the physical meaning of (St) in non-sinusoidal systems. The new RAPT Diagram is based on the orthogonality law and depends on geometrical summation to describe the relationship between different aspects (apparent-active-reactive) of power, and different components (total-fundamental distortion), drawing a bridge to connect the time domain with the frequency domain in a two-dimensional diagram.

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Al, Shammeri Bashar Mohammed Flayyih. "A novel induction heating system using multilevel neutral point clamped inverter." Thesis, University of Plymouth, 2017. http://hdl.handle.net/10026.1/8305.

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This thesis investigates a novel DC/AC resonant inverter of Induction Heating (IH) system presenting a Multilevel Neutral Point Clamped (MNPCI) topology, as a new part of power supply design. The main function of the prototype is to provide a maximum and steady state power transfer from converter to the resonant load tank, by achieving zero current switching (ZCS) with selecting the best design of load tank topology, and utilizing the advantage aspects of both the Voltage Fed Inverter (VFI) and Current Fed Inverter (CFI) kinds, therefore it can considered as a hybrid-inverter (HVCFI) category . The new design benefits from series resonant inverter design through using two bulk voltage source capacitors to feed a constant voltage delivery to the MNPCI inverter with half the DC rail voltage to decrease the switching losses and mitigate the over voltage surge occurred in inverter switches during operation which may cause damage when dealing with high power systems. Besides, the design profits from the resonant load topology of parallel resonant inverter, through using the LLC resonant load tank. The design gives the advantage of having an output current gain value of about Quality Factor (Q) times the inverter current and absorbs the parasitic components. On the contrary, decreasing inverter current means decreasing the switching frequency and thus, decreasing the switching losses of the system. This aspect increases the output power, which increases the heating efficiency. In order for the proposed system to be more reliable and matches the characteristics of IH process , the prototype is modelled with a variable LLC topology instead of fixed load parameters with achieving soft switching mode of ZCS and zero voltage switching (ZVS) at all load conditions and a tiny phase shift angle between output current and voltage, which might be neglected. To achieve the goal of reducing harmonic distortion, a new harmonic control modulation is introduced, by controlling the ON switching time to obtain minimum Total Harmonic Distortion (THD) content accompanied with optimum power for heating energy.

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Tan, Benjamin H. "A Novel Arc Welding Power Supply with Improved Power Factor Correction." DigitalCommons@CalPoly, 2020. https://digitalcommons.calpoly.edu/theses/2199.

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This paper presents the design and development of a novel Arc Welding Power Supply utilizing a modified two-switch forward converter topology. The proposed design improves the power quality by improving power factor to near unity and reducing total harmonic distortion. State space analysis of the proposed circuit showed that the circuit followed a boost-buck input output relationship. Simulation of the circuit was first implemented in LTspice to verify the functionality of the new topology. Hardware implementation of the proposed design was built on a scaled-down prototype for a proof-of-concept of the new topology. The prototype specifications were created for a 5A, 20V output with a 20-24V, 60Hz input. This project demonstrated that the proposed new topology was successful in obtaining a near unity power factor and a total harmonic distortion of less than 2%. Additionally, the prototype followed the simulation and calculations of a boost-buck function while varying duty cycle, and the final measurements aligned well with waveforms from the simulation.

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Cordova, Vivas David Javier. "Design of CMOS active downconversion mixers for gigahertz multi-band and multiple-standard operation." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2014. http://hdl.handle.net/10183/117761.

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Os requisitos de linearidade e ruído em aplicações multi-banda e multi-protocolo fazem que o projeto de misturadores RF seja uma tarefa muito desafiadora. Nesta dissertação dois misturadores com base na topologia célula de Gilbert são propostas. Linearidade e ruído foram as principais figuras de mérito consideradas para o misturadores propostos. Para aumento linearidade, foi utilizada uma técnica de cancelamento de harmônicas pós-distorção (PDHC). E, para redução de ruído, foi utilizado um circuito de redução dinâmica de corrente combinada com um filtro LC sintonizado na frequência do LO e cancelamento de ruído térmico. A análise por séries Volterra do estágio transcondutância do misturador proposto é reportada para mostrar a eficácia da técnica de cancelamento de harmônicos com pósdistorção. O circuito de linearização adicionado não aumenta o tamanho do misturador, nem degrada ganho de conversão, figura de ruído, ou consumo de potência. Simulações elétricas foram realizadas em nível de pós-layout para a primeira topologia e nível esquemático para a segunda topologia, usando processo CMOS de 0.13 mm da IBM. As melhorias em IIP2 e IIP3 são apresentadas em comparação com o misturador do tipo célula de Gilbert convencional. Para a primeira topologia, foi obtido um ganho de conversão de 10.2 dB com uma NF de 12 dB para o misturador projetado funcionando a 2 GHz, com uma frequência intermediária de 500 kHz. E um IIP2 e IIP3 de 55 dBm e 10.9 dBm, respectivamente, consumindo apenas 5.3 mW de uma fonte de 1.2 V. Para a segunda topologia, foram obtidos um ganho de conversão de [13.8 ~11] dB, um coeficiente de reflexão na entrada (S11) de [-18 ~-9.5] dB e um NF de [8.5 ~11] dB no intervalo de 1 a 6 GHz. Para as especificações de linearidade, um valor médio de IIP3 de 0 dBm foi alcançado para toda a faixa de frequência, consumindo 19.3 mW a partir de uma fonte de 1.2 V. Especificações adequadas para operação multi-banda e multi-protocolo. The linearity and noise requirements in multi-band multi-standard applications make the design of RF CMOS mixers a very challenging task. In this dissertation two downconversion mixers based on the Gilbert-cell topology are proposed. Linearity and noise were the principal figures of merit for the proposed mixers. For linearity improvement, post distortion harmonic cancellation (PDHC) was employed. And, for noise reduction, dynamic current injection combined with an LC filter tuned at the LO frequency and thermal-noise cancellation were used. A Volterra series analysis of the transconductance stage is reported to show the effectiveness of the post-distortion harmonic cancellation technique. The added linearization circuitry does not increase the size of the mixer, nor does it degrade conversion gain, noise figure, or power consumption. Electrical simulations were performed on extracted layout level from the first topology and schematic level from the second topology. Using an IBM 0.13 mm CMOS process improvements on IIP3 and IIP2 in comparison to the conventional Gilbert-cell mixer are demonstrated. For the first topology, we achieved a conversion gain of 10.2 dB with a NF of 12 dB for the designed mixer working at 2 GHz, with a low-IF of 500 kHz and an IIP2 and IIP3 of 55 dBm and 10.9 dBm, respectively, while consuming only 5.3 mW from a 1.2 V supply. For the second topology, we achieved a conversion gain range of [13.8 ~11] dB, an input reflection coefficient (S11) of [-18 ~-9.5] dB and a NF of [8.5 ~11] dB in the frequency range of 1 to 6 GHz. For the linearity specs, an IIP3 of 0 dBm was achieved for the whole frequency range, while consuming 19.3 mW from a 1.2 V supply, making the second topology well suited for multi-band and multi-standard operation.

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Sasson, Jonathan. "Small Scale Mass Flow Plug Calibration." Case Western Reserve University School of Graduate Studies / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=case1417540797.

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Fernández, Palomeque Efrén Esteban. "Optimization of a CSI inverter and DC/DC elevator with silicon carbide devices, for applications in electric traction systems." Doctoral thesis, Universitat Politècnica de Catalunya, 2019. http://hdl.handle.net/10803/666485.

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The applications of electric traction systems currently focus on developing technologies with greater energy efficiency and lower environmental impact. Manufacturers of hybrid and electric vehicles are looking for ways to improve and optimize the efficiency of their models. Manufacturers are looking for more efficient and more compact converter topologies. The use of new band gap materials in the construction of these topologies has generated many debates and new lines of research especially in the optimization of these topologies. The silicon carbide (SiC) based switching devices provide significant performance improvements in many aspects, including lower power dissipation, higher operating temperatures, and faster switching, compared with conventional Si devices, all these features make that these devices generate interest in applications for electric traction systems. This work presents a method for improving total harmonic distortion (THD) in the currents of output and efficiency in SiC current source inverter for future application in an electric traction system. The method proposed consists in improving the coupling of a bidirectional converter topology V-I and CSI. The V-I converter serves as a current regulator for the CSI and allows the recovery of energy. The method involves an effective selection of the switching frequencies and phase angles for the carriers signals present in each converter topology. With this method, it is expected to have a reduction of the total harmonic distortion THD in the output currents. In addition, an analysis of the losses in the motor and topologies of power converters is developed considering the optimization method previously analyzed. The weighted average efficiency of the whole system (power converters + motor) in differents conditions of operations is presented. Las aplicaciones de los sistemas de tracción eléctrica actualmente se centran en el desarrollo de tecnologías con mayor eficiencia energética y menor impacto ambiental. Los fabricantes de vehículos híbridos y eléctricos están buscando formas de mejorar y optimizar la eficiencia de sus modelos. Los fabricantes buscan topologías de convertidores más eficientes y más compactas. El uso de nuevos materiales de banda prohibida en la construcción de estas topologías ha generado muchos debates y nuevas líneas de investigación, especialmente en la optimización energética de las mismas. Los dispositivos de conmutación basados en carburo de silicio (SiC) proporcionan mejoras significativas en la eficiencia en muchos aspectos, incluida una menor disipación de potencia, temperaturas de funcionamiento más altas y una conmutación más rápida, en comparación con los dispositivos de Si convencionales. Todas estas características hacen que estos dispositivos generen interés en las aplicaciones de sistemas tracción eléctrica. Este trabajo presenta un método para mejorar la distorsión armónica total (THD) en las corrientes de salida y eficiencia en el inversor de fuente de corriente SiC para aplicaciones futuras en un sistema de tracción eléctrica. El método propuesto consiste en mejorar el acoplamiento de una topología de convertidor bidireccional V-I y CSI. El convertidor V-I sirve como un regulador de corriente para el CSI y permite la recuperación de energía. El método implica una selección efectiva de las frecuencias de conmutación y los ángulos de fase para las señales portadoras presentes en cada topología del convertidor. Con este método, se espera una reducción de la distorsión armónica total THD en las corrientes de salida. Además, se desarrolla un análisis de las pérdidas en el motor y las topologías de los convertidores de potencia considerando el método de optimización analizado previamente. Se presenta la eficiencia promedio ponderada de todo el sistema (convertidores de potencia + motor) en diferentes condiciones de operación

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Філянін, Данило Володимирович. "Методи і засоби інформаційного забезпечення режимів електричних мереж в умовах низької якості електроенергії". Thesis, Національний технічний університет України "Київський політехнічний інститут імені Ігоря Сікорського", 2019. http://repository.kpi.kharkov.ua/handle/KhPI-Press/40949.

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Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.14.02 – електричні станції, мережі і системи – Національний технічний університет України "Київський політехнічний інститут імені Ігоря Сікорського", Київ, 2018. Дисертація присвячена науково-прикладній проблемі – пошуку винуватців гармонічних спотворень в електричних мережах та підвищенню якості електроенергії шляхом створення системи діагностики і контролю на базі АСКОЕ. Обґрунтовано використання технології розподілених вимірювань для пошуку винуватців спотворень. Розроблено модифікацію методу гармонічного аналізу для підвищення достовірності визначення джерел спотворення. На підставі результатів досліджень запропоновано методи розподілу компенсаційних виплат між елементами електричної мережі та абонентами, що споживають потужність вищих гармонік. Розроблено ряд рекомендацій щодо практичного застосування результатів дисертаційної роботи. Запропоновано метод непрямого контролю температури кабельних ліній. Thesis for the PhD degree in technical sciences, Specialty 05.14.02 – power plants and electric power complexes. National technical university of Ukraine "Kyiv polytechnic institute", Kyiv, 2019. The thesis is oriented to the scientific and applied problem - harmonic distortion sources detection in distribution systems (DS), improving the electromagnetic compatibility of electrical equipment, increasing the reliability of electric power supply by creating a diagnostic and control system. The use of distributed measurements to distortions source detection is justified. A modification of the method of harmonic analysis is developed to increase the reliability of distortions sources detection. Based on the study’s results, methods for distributing compensation payments between DS`s subjects that consume harmonics power are proposed. A number of recommendations on the practical application of the results of the thesis work have been developed. A method for indirect monitoring of the temperature of cable lines is proposed.

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Філянін, Данило Володимирович. "Методи і засоби інформаційного забезпечення режимів електричних мереж в умовах низької якості електроенергії". Thesis, Національний технічний університет "Харківський політехнічний інститут", 2019. http://repository.kpi.kharkov.ua/handle/KhPI-Press/40946.

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Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.14.02 – електричні станції, мережі і системи – Національний технічний університет України "Київський політехнічний інститут імені Ігоря Сікорського", Київ, 2018. Дисертація присвячена науково-прикладній проблемі – пошуку винуватців гармонічних спотворень в електричних мережах та підвищенню якості електроенергії шляхом створення системи діагностики і контролю на базі АСКОЕ. Обґрунтовано використання технології розподілених вимірювань для пошуку винуватців спотворень. Розроблено модифікацію методу гармонічного аналізу для підвищення достовірності визначення джерел спотворення. На підставі результатів досліджень запропоновано методи розподілу компенсаційних виплат між елементами електричної мережі та абонентами, що споживають потужність вищих гармонік. Розроблено ряд рекомендацій щодо практичного застосування результатів дисертаційної роботи. Запропоновано метод непрямого контролю температури кабельних ліній. Thesis for the PhD degree in technical sciences, Specialty 05.14.02 – power plants and electric power complexes. National technical university of Ukraine "Kyiv polytechnic institute", Kyiv, 2019. The thesis is oriented to the scientific and applied problem - harmonic distortion sources detection in distribution systems (DS), improving the electromagnetic compatibility of electrical equipment, increasing the reliability of electric power supply by creating a diagnostic and control system. The use of distributed measurements to distortions source detection is justified. A modification of the method of harmonic analysis is developed to increase the reliability of distortions sources detection. Based on the study’s results, methods for distributing compensation payments between DS`s subjects that consume harmonics power are proposed. A number of recommendations on the practical application of the results of the thesis work have been developed. A method for indirect monitoring of the temperature of cable lines is proposed.

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Dušek, Samuel. "Techniky slučování kanálů za účelem zvýšení dynamického rozsahu kanálu s rozsahem ±10 V." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2020. http://www.nusl.cz/ntk/nusl-413045.

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Cílem této diplomové práce je změřit a vyhodnotit parametry techniky slučování kanálů, která je momentálně implementována v součástce AD7606C firmy Analog Devices. Poté, na základě výsledků z měření, navrhnout a odsimulovat několik možností, pomocí kterých by tato technika mohla dosahovat vyšších hodnot dynamického rozsahu a celkového harmonického zkreslení. V průběhů práce bylo zjištěno, že pomocí zvýšení zesílení kanálu s nižším rozsahem společně se snížením mezní frekvence celého signálového řetězce může tato technika dosahovat až 118.6 dB dynamického rozsahu, což je o 3.6 dB více, než bylo změřeno na AD7606C. Dále také bylo zjištěno, že pomocí jednoduchého algoritmu implementovaného v logickém bloku, je možné dosáhnout imunity vůči hodnotě externího rezistoru, který zákazníci používají jako součást anti-aliasingového filtru.

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SILVA, Elson Natanael Moreira. "ESTIMAÇÃO PROBABILÍSTICA DO NÍVEL DE DISTORÇÃO HARMÔNICA TOTAL DE TENSÃO EM REDES DE DISTRIBUIÇÃO SECUNDÁRIAS COM GERAÇÃO DISTRIBUÍDA FOTOVOLTAICA." Universidade Federal do Maranhão, 2017. http://tedebc.ufma.br:8080/jspui/handle/tede/1296.

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Submitted by Maria Aparecida (cidazen@gmail.com) on 2017-04-17T13:14:17Z No. of bitstreams: 1 Elson Moreira.pdf: 7883984 bytes, checksum: cf59b3b0b24a249a7fd9e2390b7f16de (MD5) Made available in DSpace on 2017-04-17T13:14:17Z (GMT). No. of bitstreams: 1 Elson Moreira.pdf: 7883984 bytes, checksum: cf59b3b0b24a249a7fd9e2390b7f16de (MD5) Previous issue date: 2017-02-10 CNPQ A problem of electric power quality that always affects the consumers of the distribution network are the harmonic distortions. Harmonic distortions arise from the presence of socalled harmonic sources, which are nonlinear equipment, i.e., equipment in which the voltage waveform differs from the current. Such equipment injects harmonic currents in the network generating distortions in the voltage waveform. Nowadays, the number of these equipment in the electrical network has increased considerably. However, the increasing use of such equipment over the network makes systems more vulnerable and prone to quality problems in the supply of electricity to consumers. In addition, it is important to note that in the current scenario, the generation of electricity from renewable sources, connected in the secondary distribution network, is increasing rapidly. This is mainly due to shortage and high costs of fossil fuels. In this context, the Photovoltaic Distributed Generation (PVDG), that uses the sun as a primary source for electric energy generation, is the main technology of renewable generation installed in distribution network. However, the PVDG is a potential source of harmonics, because the interface of the PVDG with the CA network is carried out by a CC/CA inverter, that is a highly nonlinear equipment. Thus, the electrical power quality problems associated with harmonic distortion in distribution networks tend to increase and be very frequent. One of the main indicators of harmonic distortion is the total harmonic distortion of voltage ( ) used by distribution utilities to limit the levels of harmonic distortion present in the electrical network. In the literature there are several deterministic techniques to estimate . These techniques have the disadvantage of not considering the uncertainties present in the electric network, such as: change in the network configuration, load variation, intermittence of the power injected by renewable distributed generation. Therefore, in order to provide a more accurate assessment of the harmonic distortions, this dissertation has as main objective to develop a probabilistic methodology to estimate the level of in secondary distribution networks considering the uncertainties present in the network and PVDG connected along the network. The methodology proposed in this dissertation is based on the combination of the following techniques: three-phase harmonic power flow in phase coordinate via method sum of admittance, point estimate method and series expansion of Gram-Charlier. The validation of the methodology was performed using the Monte Carlo Simulation. The methodology was tested in European secondary distribution network with 906 nodes of 416 V. The results were obtained by performing two case studies: without the presence of PVDG and with the PVDG connection. For the case studies, the following statistics for nodal were estimated: mean value, standard deviation and the 95% percentile. The results showed that the probabilistic estimation of is more complete, since it shows the variation of due to the uncertainties associated with harmonic sources and electric network. In addition, they show that the connection of PV-DG in the electric network significantly affects the levels of of the electric network. Um problema de qualidade de energia elétrica que afeta os consumidores da rede de distribuição secundária são as distorções harmônicas. As distorções harmônicas são provenientes da presença das chamadas fontes de harmônicas que são equipamentos de características não-lineares, ou seja, equipamentos em que a forma de onda da tensão difere da de corrente. Tais equipamentos injetam correntes harmônicas na rede produzindo, portanto distorções na forma de onda da tensão. Nos dias atuais, a quantidade desses equipamentos na rede elétrica tem aumentado consideravelmente. Porém, o uso crescente desse tipo de equipamento ao longo da rede torna os sistemas mais vulneráveis e propensos a apresentarem problemas de qualidade no fornecimento de energia elétrica aos consumidores. Além disso, é importante destacar que no cenário atual, a geração de energia elétrica a partir de fontes renováveis, conectada na rede de distribuição secundária, está aumentando rapidamente. Isso se deve principalmente devido a escassez e altos custos dos combustíveis fosseis. Neste contexto, a Geração Distribuída Fotovoltaica (GDFV), que utiliza o sol como fonte primária para geração de energia elétrica, é a principal tecnologia de geração renovável instalada na rede de distribuição no Brasil. Contudo, a GDFV é uma potencial fonte de harmônica, pois a interface da GDFV com a rede CA é realizada por um inversor CC/CA, que é um equipamento altamente não-linear. Desde modo, os problemas de qualidade de energia elétrica associados à distorção harmônica nas redes de distribuição tendem a aumentar e a serem bem frequentes nos consumidores da rede de distribuição secundárias. Um dos principais indicadores de distorção harmônica é a distorção harmônica total de tensão ( do inglês “Total Harmonic Distortion of Voltage”) utilizada pelas concessionárias de energia elétrica para quantificar os níveis de distorção harmônica presentes na rede elétrica. Na literatura técnica existem várias técnicas determinísticas para estimar a . Essas técnicas possuem a desvantagem de não considerar as incertezas presentes na rede elétrica, tais como: mudança na configuração da rede, variação de carga e intermitência da potência injetada pela geração distribuída renovável. Portanto, a fim de fornecer uma avaliação mais precisa das distorções harmônicas, este trabalho tem como principal objetivo desenvolver uma metodologia probabilística para estimar o nível de em redes de distribuição secundária considerando as incertezas presentes na rede e na GDFV conectada ao longo da rede. A metodologia proposta nesta dissertação se baseia na combinação das seguintes técnicas: fluxo de potência harmônico trifásico em coordenadas de fase via método de soma de admitância, método de estimação por pontos e expansão em série de Gram-Charlier. Além disso, a validação da metodologia foi realizada utilizando a Simulação Monte Carlo. A metodologia desenvolvida foi testada na rede de distribuição secundária europeia com 906 nós de 416 V. Os resultados foram obtidos realizando dois casos de estudos: sem a presença de GDFV e com a conexão de GDFV. Para ambos os casos de estudo as seguintes estatísticas do nodal foram estimadas: valor médio, desvio padrão e o percentil de 95%. Os resultados demonstraram que a estimação probabilística da é mais completa, pois mostra a variação da devido às incertezas associadas com as fontes de harmônicas e as da rede elétrica. Os resultados também mostram que a conexão da GDFV afeta significativamente os níveis de da rede elétrica

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Hassan, Aakash. "Improving the efficiency, power quality, and cost-effectiveness of solar PV systems using intelligent techniques." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2023. https://ro.ecu.edu.au/theses/2676.

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Growing energy demand, depleting fossil fuels, and increasing environmental concerns lead to adaptation to clean and sustainable energy sources. Renewable energy sources are now believed to play a critical role in diminishing the deteriorating environment, supplying power to remote areas with no access to the grid, and overcoming the energy crisis by reducing the stress on existing power networks. Therefore, an upsurge in renewablesbased energy systems development has been observed during the previous few decades. In particular, solar PV technology has demonstrated extraordinary growth due to readily available solar energy, technological advancement, and a decline in costs. However, its low power conversion efficiency, intermittency, high capital cost, and low power quality are the major challenges in further uptake. This research intends to enhance the overall performance of PV systems by providing novel solutions at all levels of a PV system hierarchy. The first level investigated is the solar energy to PV power conversion, where an efficient maximum power point tracking (MPPT) method is developed. Secondly, the dc to ac power conversion is explored, and an optimal PV system sizing approach with abidance to power quality constraints is developed. Finally, smart power management strategies are investigated to utilise the energy produced by solar PV efficiently, such that the minimum cost of energy can be achieved while considering various technical constraints. The methods involve Genetic Algorithm (GA) for finding the optimal parameters, mathematical models, MATLAB/Simulink simulations of solar PV system (including PV arrays, dc/dc converter with MPPT, batteries, dc/ac inverter, and electric load), and experimental testing of the developed MPPT method and power management strategies at the smart energy lab, Edith Cowan University. Highly dynamic weather and electricity consumption data encompassing multiple seasons are used to test the viability of the developed methods. The results exhibit that the developed hybrid MPPT technique outperforms the conventional techniques by offering a tracking efficiency of above 99%, a tracking speed of less than 1s and almost zero steady-state oscillations under rapidly varying environmental conditions. Additionally, the developed MPPT technique can also track the global maximum power point during partial shading conditions. The analyses of power quality at the inverter’s terminal voltage and current waveforms revealed that solar PV capacity, battery size, and LC filter parameters are critical for the reliable operation of a solar PV system and may result in poor power quality leading to system failure if not selected properly. On the other hand, the optimal system parameters found through the developed methodology can design a solar PV system with minimum cost and conformance to international power quality standards. The comparison between the grid-connected and stand-alone solar PV system reveals that for the studied case, the grid-connected system is more economical than the stand-alone system but outputs higher life cycle emissions. It was also found that for grid tied PV systems, minimum cost of energy can be achieved at an optimal renewable to grid ratio. Additionally, applying a time varying tariff yields a slightly lower energy cost than the anytime flat tariff. A sensitivity analysis of the reliability index, i.e., loss of power supply probability (LPSP), demonstrates that for the stand-alone PV systems, there is an inverse relationship between LPSP and cost of energy. Contrarily, for grid-connected systems, the cost of energy does not vary significantly with the change in LPSP.

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42

Oliveira, Francisco Hércules de. "Estudo de técnica utilizando a modulação PWM baseada em portadora aplicada ao inversores monofásicos assimétricos com diodos de grampeamento." Universidade Federal da Paraíba, 2017. http://tede.biblioteca.ufpb.br:8080/handle/tede/9783.

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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

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43

Wei, Lai. "Spectral-based tests for periodicities." Columbus, Ohio : Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1201706810.

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Golfieri, Carolina Iovance. "Estudo investigativo da análise modal aplicada a sistemas de distribuição frente às distorções harmônicas." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/18/18154/tde-30102018-100229/.

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Esta pesquisa apresenta um estudo investigativo da análise modal aplicada a Sistemas de Distribuição (SDs) frente às distorções harmônicas, no contexto da Qualidade da Energia Elétrica (QEE). A partir do método de análise da ressonância modal, foi conduzido um estudo investigativo para apontar quais barramentos são mais sensíveis e permitem uma melhor observação frente às distorções harmônicas. Vale adiantar que o método de análise de ressonância modal, o qual é fundamentado na decomposição espectral da matriz de admitância do sistema elétrico, já apresenta interessantes trabalhos voltados para sistemas de transmissão. O desafio desta pesquisa foi então investigar a sua aplicação para SDs com um direcionamento às distorções harmônicas, bem como ao seu monitoramento. Dentre os resultados encontrados no desenvolvimento da pesquisa, destaca-se um melhor entendimento do problema das distorções harmônicas, o qual permitiu evidenciar a sensibilidade e a observabilidade dos SDs testes frente ao problema definido no contexto da QEE. This research presents an investigative study of the modal analysis applied to Distribution Systems (DSs) in the context of Power Quality (PQ) considering the harmonic distortions. From the modal resonance analysis, an investigative study was conducted to indicate which bus bars are more sensitive and allow better observation in face of harmonic distortions. It is worth mentioning that the method of modal resonance analysis, which is based on the spectral decomposition of the admittance matrix of the electric system, already presents interesting applications focused on transmission systems. The challenge of this research was to investigate its application to DSs focusing on harmonic distortions, as well as their monitoring. Among the observed results of the research development, a better understanding of the harmonic distortions problem was achieved, which made it possible to highlight the sensitivity and observability of the DSs tests against the problem defined in the context of the PQ.

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Moussa, Hassan. "Contribution to the Decentralized Energy Management of Autonomous AC-Microgrid." Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0161/document.

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Cette thèse porte sur des micro-réseaux AC isolées qui permettent l’intégration des ressources énergétiques distribuées (DER) pouvant fournir leur énergie d'alimentation existante de manière contrôlée pour assurer le bon fonctionnement global du système. L'interconnexion d'un DER à une micro-réseau s'effectue habituellement en utilisant un convertisseur d'interface distribué (DIC) (i.e. un bloc d'interface d'électronique de puissance générale) qui est constitué d’un module de convertisseur à l'entrée de la source, un onduleur de tension (VSI), un module d'interfaçage de sortie, et le module de commande. Dans cette thèse on réalise plusieurs lois de commande basées sur des méthodes décentralisées. L'accent principal est mis sur les fonctions "Droop" qui ont la tâche de maintenir un équilibre de distribution d'énergie entre les différentes sources énergétiques connectées à la micro-réseau. L'objectif est d'assurer la stabilité du système et d’améliorer les performances dynamiques en partageant la puissance entre les différents générateurs d’électricité distribués (DGs) en fonction de leur puissance nominale. Le développement d'une analyse de stabilité en boucle fermée s’avère utile pour étudier la dynamique du système afin d'obtenir une réponse transitoire souhaitée qui permet d'identifier les paramètres de contrôle de boucle appropriés. L'amélioration de la qualité d’énergie des micro-réseaux est également un objectif de cette thèse. La réduction des distorsions harmoniques de la tension de sortie en présence de charges linéaires et non linéaires est prise en compte dans nos travaux. D'autres aspects seront étudiés sur la façon de traiter les charges constantes connectées au réseau et les grandes perturbations qu’ils produisent. Cela donne lieu à d'autres études de recherche portant sur la stabilité grand signal des micro-réseaux This thesis deals with islanded AC microgrid that allows any integration of Distributed Energy Resources (DERs) that may provide their existing supply energy in a controlled manner to insure overall system functioning. The interconnection of a DER to a microgrid is done usually by using a Distributed Interface Converter (DIC), a general power electronics interface block, which consists of a source input converter module, a Voltage Source Inverter module (VSI), an output interface module, and the controller module. The thesis realizes several control laws based on decentralized methods. The major focus is on the Droop functions that are responsible for providing a power distribution balance between different Energy Resources connected to a microgrid. The aim is to insure system stability and better dynamic performance when sharing the power between different DGs as function to their nominal power. Developing a closed loop stability analysis is useful for studying system dynamics in order to obtain a desired transient response that allows identifying the proper loop control parameters. Power Quality enhancement in microgrids is also a purpose of this research. The reduction of harmonic distortions of the output voltage when supplying linear and non-linear loads are taken in consideration in this thesis. Further aspects will be studied about how to deal with constant power loads connected to the grid and the large perturbations exerted. This results to further research studies that deal with large-signal stability of microgrids

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Göker, Fuat, and Christoffer Hedberg. "Utvärdering av faskompenseringsmetoder för ett småskaligt vattenkraftverk : Genomgång av kondensatorbatteri, aktiv och passiv reglering, övermagnetiserad synkronmaskin, SVC och STATCOM på Fröslida kraftverk." Thesis, KTH, Hälsoinformatik och logistik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-230165.

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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.

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Passamani, Antonio. "Analysis and Design of a Transmitter for Wireless Communications in CMOS Technology." Doctoral thesis, Università degli studi di Padova, 2016. http://hdl.handle.net/11577/3424386.

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The number of wireless devices has grown tremendously over the last decade. Great technology improvements and novel transceiver architectures and circuits have enabled an astonishingly expanding set of radio-frequency applications. CMOS technology played a key role in enabling a large-scale diffusion of wireless devices due to its unique advantages in cost and integration. Novel digital-intensive transceivers have taken full advantage of CMOS technology scaling predicted by Moore's law. Die-shrinking has enabled ubiquitous diffusion of low-cost, small form factor and low power wireless devices. However, Radio Frequency (RF) Power Amplifiers (PA) transceiver functionality is historically implemented in a module which is separated from the CMOS core of the transceiver. The PA is traditionally dictating power and battery life of the transceiver, thus justifying its implementation in a tailored technology. By contrast, a fully integrated CMOS transceiver with no external PA would hugely benefit in terms of reduced area and system complexity. In this work, a fully integrated prototype of a Switched-Capacitor Power Amplifier (SCPA) has been implemented in a 28nm CMOS technology. The SCPA provides the functionalities of a PA and of a Radio-Frequency Digital-to-Analog Converter (RF-DAC) in a monolithic CMOS device. The switching output stage of the SCPA enables this circuital topology to reach high efficiencies and offers excellent power handling capabilities. In this work, the properties of the SCPA are analyzed in an extensive and detailed dissertation. Nowadays Wireless Communications operate in a very crowded spectrum, with strict coexistence requirements, thus demanding a strong linearity to the RF-DAC section of the SCPA. A great part of the work of designing a good SCPA is in fact designing a good RF-DAC. To enhance RF-DAC linearity, a precision of the timing of the elements up to the ps range is required. The use of a single core-supply voltage in the whole circuit including the CMOS inverter of the switching output stage enables the use of minimum size devices, improving accuracy and speed in the timing of the elements. The whole circuit operates therefore on low core-supply voltage. Throughout this work, a detailed analysis carefully describes the electromagnetic structures which maximize power and efficiency of low-voltage SCPAs. Due to layout issues subsequent to limited available voltages, however, there is a practical limitation in the maximum achievable power of low-voltage SCPAs. In this work, a Multi-Port Monolithic Power Combiner (PC) is introduced to overcome this limitation and further enhance total achieved system power. The PC sums the power of a collection of SCPAs to a single output, allowing higher output powers at a high efficiency. Benefits, drawbacks and design of SCPA PCs are discussed in this work. The implemented circuit features the combination of four differential SCPAs through a four-way monolithic PC and is simulated to obtain a maximum drain efficiency of 44% at a peak output power of 29dBm on 1.1V supply voltage. Extensive spectrum analysis offers full evaluation of system performances. After exploring state-of-the-art possibilities offered by an advanced 28nm CMOS technology, this work predicts through rigorous theoretical analysis the expected evolution of SCPA performances with the scaling of CMOS Technologies. The encouraging forecast further emphasizes the importance of SCPA circuits for the future of high-performance Wireless Communications. Il numero dei dispositivi senza fili è cresciuto esponenzialmente negli ultimi dieci anni. Grandi progressi tecnologici e nuove architetture di ricetrasmettitori hanno reso possibile un'impressionante insieme di applicazioni a radio-frequenza. La tecnologia CMOS ha giocato un ruolo centrale nel rendere possibile una diffusione in larga scala di dispositivi senza fili grazie ai suoi esclusivi vantaggi in termini di costo e integrazione. Nuovi ricetrasmettitori marcatamente digitali hanno preso pieno vantaggio dell'evoluzione tecnologica prevista dalla legge di Moore. La riduzione della dimensione degli integrati microelettronici ha permesso una diffusione capillare di dispositivi senza fili a basso costo, di ridotte dimensioni e dal basso consumo. D'altra parte, la funzionalità degli amplificatori di potenza (PA) per radio frequenza (RF) è storicamente implementata in un modulo che è separato dal nucleo CMOS del ricetrasmettitore. Il PA determina tradizionalmente la potenza e la durata della batteria del ricetrasmettitore, e per ciò è giustificata la sua implementazione in una tecnologia dedicata. All'opposto, un ricetrasmettitore CMOS pienamente integrato senza PA esterno beneficerebbe largamente in termini di riduzione di area e di complessità di sistema. In questo lavoro, un prototipo completamente integrato di Amplificatore di Potenza a Capacità Commutate (SCPA) è stato implementato in una tecnologia CMOS a 28nm. L'SCPA fornisce le funzionalità di un PA e di un Convertitore Digitale-Analogico in Radio Frequenza (RF-DAC) in un dispositivo CMOS monolitico. Lo stadio d'uscita commutato dell'SCPA rende questa topologia capace di raggiungere alte efficienze e offre un'eccellente capacità di generare potenza. In questo lavoro, le proprietà dell'SCPA sono analizzate in una discussione estensiva e dettagliata. Le comunicazioni senza fili di oggi operano in uno spettro molto affollato, con requisiti di coesistenza molto stretti, che quindi richiedono un'alta linearità alla sezione RF-DAC dell'SCPA. Una grande parte del lavoro di progetto di un SCPA è infatti progettare un buon RF-DAC. Per migliorare la linearità dell'RF-DAC, è richiesta una precisione della temporizzazione degli elementi fino all'ordine di grandezza dei ps. L'uso di una singola tensione di alimentazione, incluso l'invertitore CMOS dello stadio di uscita commutato, rende possibile l'uso di dispositivi di dimensione minima, migliorando l'accuratezza e la velocità della temporizzazione degli elementi. L'intero circuito opera quindi su una bassa tensione di alimentazione. Nel corso di questo lavoro, un'analisi dettagliata descrive con attenzione le strutture elettromagnetiche che massimizzano la potenza e l'efficienza degli SCPA a bassa tensione. A causa di problemi di maschere dovuti alle limitate tensioni disponibili, comunque, c'è una limitazione pratica nella massima potenza che un SCPA a bassa tensione può raggiungere. In questo lavoro, un Sommatore di Potenza Monolitico Multi-Porta (PC) è introdotto per superare questa limitazione e incrementare ulteriormente la potenza di sistema totale. Il PC somma la potenza di una collezione di SCPA in una singola uscita, rendendo possibili potenze più alte con un'alta efficienza. I benefici, i problemi e il progetto dei PC per SCPA sono discussi in questo lavoro. Il circuito progettato comprende la combinazione di quattro SCPA attraverso un Sommatore di Potenza (PC) monolitico ed è simulato ottenere un'efficienza massima di collettore del 44% con una potenza di picco di 29dBm da una tensione di alimentazione di 1.1V. Estensive analisi di spettro offrono una completa valutazione delle prestazioni di sistema. Dopo aver esplorato le prestazioni dello stato-dell'arte offerte da un'avanzata tecnologia CMOS a 28nm, questo lavoro predice attraverso un'analisi teorica rigorosa l'evoluzione attesa delle prestazioni dell'SCPA con l'evoluzione delle tecnologie CMOS. L'incoraggiante previsione enfatizza ulteriormente l'importanza dei circuiti SCPA per il futuro delle comunicazioni senza fili ad alte prestazioni.

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Kubo, Michal. "Optimalizovaný návrh sacího kanálu turbínového motoru." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2016. http://www.nusl.cz/ntk/nusl-254379.

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This master thesis deals with design of a subsonic intake which is used to supply small jet engine integrate into the fuselage of agile small unmanned aerial vehicle (UAV). Some kinds of these intakes are listed in order to inspire and introduce future designers into this part of jet plane design. This thesis contains a small amount of theory about compressible flow, and necessary knowledge which are important to know before the very first attempt to design an intake. Two models were designed in order to prove that the theory listed in this thesis is useful and can be used as a guide in design process of subsonic intakes. Both designs have the same layout. S-duct design with one intake placed on the belly of fuselage was chosen. After CFD analysis of first model it was found that there are huge area with separated flow and vortex. Separated flow leads to big total pressure loss and pressure distortion. While designing the second model the emphasis was to avoid this vortex and improve flow conditions. This optimization was success and the second design have smaller pressure loss in compare to the first design. The difference is more than 50% at fly speed M=0,8.

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Moussa, Hassan. "Contribution to the Decentralized Energy Management of Autonomous AC-Microgrid." Electronic Thesis or Diss., Université de Lorraine, 2017. http://www.theses.fr/2017LORR0161.

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Cette thèse porte sur des micro-réseaux AC isolées qui permettent l’intégration des ressources énergétiques distribuées (DER) pouvant fournir leur énergie d'alimentation existante de manière contrôlée pour assurer le bon fonctionnement global du système. L'interconnexion d'un DER à une micro-réseau s'effectue habituellement en utilisant un convertisseur d'interface distribué (DIC) (i.e. un bloc d'interface d'électronique de puissance générale) qui est constitué d’un module de convertisseur à l'entrée de la source, un onduleur de tension (VSI), un module d'interfaçage de sortie, et le module de commande. Dans cette thèse on réalise plusieurs lois de commande basées sur des méthodes décentralisées. L'accent principal est mis sur les fonctions "Droop" qui ont la tâche de maintenir un équilibre de distribution d'énergie entre les différentes sources énergétiques connectées à la micro-réseau. L'objectif est d'assurer la stabilité du système et d’améliorer les performances dynamiques en partageant la puissance entre les différents générateurs d’électricité distribués (DGs) en fonction de leur puissance nominale. Le développement d'une analyse de stabilité en boucle fermée s’avère utile pour étudier la dynamique du système afin d'obtenir une réponse transitoire souhaitée qui permet d'identifier les paramètres de contrôle de boucle appropriés. L'amélioration de la qualité d’énergie des micro-réseaux est également un objectif de cette thèse. La réduction des distorsions harmoniques de la tension de sortie en présence de charges linéaires et non linéaires est prise en compte dans nos travaux. D'autres aspects seront étudiés sur la façon de traiter les charges constantes connectées au réseau et les grandes perturbations qu’ils produisent. Cela donne lieu à d'autres études de recherche portant sur la stabilité grand signal des micro-réseaux This thesis deals with islanded AC microgrid that allows any integration of Distributed Energy Resources (DERs) that may provide their existing supply energy in a controlled manner to insure overall system functioning. The interconnection of a DER to a microgrid is done usually by using a Distributed Interface Converter (DIC), a general power electronics interface block, which consists of a source input converter module, a Voltage Source Inverter module (VSI), an output interface module, and the controller module. The thesis realizes several control laws based on decentralized methods. The major focus is on the Droop functions that are responsible for providing a power distribution balance between different Energy Resources connected to a microgrid. The aim is to insure system stability and better dynamic performance when sharing the power between different DGs as function to their nominal power. Developing a closed loop stability analysis is useful for studying system dynamics in order to obtain a desired transient response that allows identifying the proper loop control parameters. Power Quality enhancement in microgrids is also a purpose of this research. The reduction of harmonic distortions of the output voltage when supplying linear and non-linear loads are taken in consideration in this thesis. Further aspects will be studied about how to deal with constant power loads connected to the grid and the large perturbations exerted. This results to further research studies that deal with large-signal stability of microgrids

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Bissey, Sebastien. "Optimisation du coût de la consommation d'électricité dans l'habitat individuel." Thesis, Tours, 2019. http://www.theses.fr/2019TOUR4029.

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Les travaux menés durant cette thèse ont consisté à proposer des solutions pour optimiser le coût de la consommation d’électricité dans l’habitat individuel. Les outils matériels et logiciels proposés ici permettent à la fois d’estimer la rentabilité d’un système de gestion de l’électricité et l’impact des bons et simples gestes du quotidien. Dans un premier temps, des solutions permettant de faire des économies dans l’habitat individuel ont été comparées et évaluées. Le système de stockage de l’énergie électrique a été introduit. Le stockage permet entre autre de décaler la consommation d’électricité des heures pleines aux heures creuses et ainsi, de faire des économies. Dans une deuxième partie, la prédiction de la consommation d’électricité à base de logique floue a été introduite afin d’utiliser plus efficacement le système de stockage. La rentabilité des systèmes de stockage et des prises « connectées » a été étudiée. Dans un troisième et dernier temps, un convertisseur statique d’énergie à haut rendement (supérieur à 95%) a été introduit. Ce dernier est nécessairement bidirectionnel car l’énergie doit pouvoir transiter du système de stockage vers le réseau électrique de distribution et vice versa. Les taux de distorsion harmonique des signaux doivent alors être les plus petits possibles (ici, inférieurs à 8%). L’originalité du convertisseur proposé réside aussi dans la simplicité des commandes numériques nécessaires. Les composants sur substrat en SiC ont été utilisés pour atteindre les rendements souhaités. Ces composants permettent aussi d’augmenter la fréquence de découpage et ainsi, de diminuer la taille des éléments de filtrage The work carried out as part of this thesis con'sisted in proposing solutions to optimize the cost of electricity consumption in individual housing. The hardware and software tools proposed here make it possible to estimate both the profitability of an electricity management system and the impact of good and simple daily actions. First, some solutions to save money in the single-family home were compared and evaluated. The electrical energy storage system has been introduced. Storage makes it possible, among other things, to shift electricity consumption from peak to off-peak hours and thus save money. In a second part, the prediction of electricity consumption based on fuzzy logic was introduced in order to use the storage system more efficiently. The profitability of storage systems and smart plugs was studied. In a third and final part, a highly efficient energy converter (above 95%) was introduced. The latter is necessarily bidirectional because the energy must be able to pass from the storage system to the distribution network and vice versa. The harmonic distortion rates of the signals must then be as low as possible (here, less than 8%). The originality of the proposed converter also lies in the simplicity of the necessary digital control circuits. SiC power devices were used to achieve the desired energy efficiency values. These components also increase the switching frequency and thus reduce the size of the filter elements

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Dissertations / Theses on the topic 'Total Harmonic Distortion Analysis'

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