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1
Tang, Jing. "Shunt power quality compensator based on 3-leg center-split inverter". Thesis, University of Macau, 2003. http://umaclib3.umac.mo/record=b1445819.
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Haugan, Thomas Sagvold. "Smart Grid: Shunt Compensation in Non-Sinusoidal Regimes". Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for elkraftteknikk, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-20732.
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The electric power theory is of fundamental importance in most aspects of electric power engineering, enabling to analyze and control the grid based on an unambiguous physical interpretation of the power and current flow. The futuristic SmartGrid concept will include scenarios of potentially very challenging network conditions, due to large impact of non-linear loads, combined with unsymmetric and non-sinusoidal voltage regimes. New and more advanced power theories are needed, in order to maintain correct physical understanding of the power grid, independently of voltage conditions. Moreover sophisticated power theories can help identify and eliminate detrimental effects induced by loads; i.e. unsymmetry, reactive power consumption and harmonic pollution. This project has reviewed the recent and promising conservative power theory (CPT). Major part of the project was dedicated to experimental research, evaluating the CPT purely from a power theory perspective. Central part of these experiments was a real-time rapid prototyping system (RPS) and three-phase voltage source converter. Control system for the programmable voltage source, data acquisition and CPT-algorithm were implemented by the RPS. Based on extensive tests it was found that the CPT offers enhanced and physical correct interpretation of current and power flow. Obtained results from the virtual instrumentation are principally consistent with and support previous research presented in the literature. Second part evaluated the CPT in context of shunt active power filter (SAPF). Experimental implementation of SAPF failed, mainly as the RPS did not provide sufficient sampling rate. Selected cases of reactive and harmonic compensation were demonstrated, utilizing computer modeling tools (MATLAB/Simulink). The results conclude that the CPT performs excellent selective compensation, only when grid voltages are balanced sinusoidal. In scenarios of unsymmetric or distorted voltages, the compensation strategies provided by the CPT are apparently less versatile and effective, compared to the popular pq-theory. Overall this study demonstrated that optimal network operation can only be achieved, through the joint action of series and parallel compensators. Future work will amongst others include further in-depth study of the rapid prototyping system, and experimental implementation of SAPF.
3
Welgemoed, Frans Marx. "Shunt reactive compensation of voltage dips and unbalance". Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/5315.
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Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2010.ENGLISH ABSTRACT: The use of power electronic converters provides a more efficient, accurate and dynamic solution to reactive compensation. In this thesis the application of power electronic converters to shunt reactive compensation will be discussed. In particular voltage dips and voltage unbalance are considered as both can be mitigated by means of shunt reactive compensation. A pre-existing uninterruptible power supply is adapted to operate as a shunt reactive compensator. The uninterruptible power supply consists of a 250 kVA three phase voltage source inverter. The modifications are limited to software and control algorithms that do not alter the normal operation of the uninterruptible power supply. Control algorithms are designed and discussed in detail. A typical double loop control strategy is implemented on the power electronic converter. The inner loop consists of a dead-beat current controller. The outer loop consists of three proportional and integral controllers controlling the DC-bus voltage, AC voltage and voltage unbalance respectively. Voltage dips and unbalance are compensated for using only reactive power. Focus is placed on producing a result can be used easily in practice.
AFRIKAANSE OPSOMMING: Drywings elektroniese omsetters wat gebruik word vir newe reaktiewe kompensasie lewer meer effektiewe, akkurate en dinamiese resultate. In hierdie tesis word die toepassing van drywings elektroniese omsetters vir newe reaktiewe kompensasie bespreek. Daar word meer spesifiek na spannings duike en spannings wanbalans gekyk aangesien albei met newe reaktiewe kompensasie verminder kan word. ’n Bestaande nood kragbron is aangepas om as n newe reaktiewe kompenseerder te funksioneer. Die nood kragbron bestaan hoofsaaklik uit ’n 250 kVA drie fase omsetter spanningsbron. Die aanpassings is beperk tot sagteware en beheer algoritmes wat nie die oorspronklike funksionaliteit van die nood krag bron beinvloed nie. Beheer algoritmes word ontwerp en deeglik bespreek. ’n Tipiese dubbel lus beheer strategie word op die drywings elektroniese omsetter toegepas. Die binnelus bestaan uit ’n voorspellende stroom beheerder. Die buite-lus bestaan uit drie proportioneel en integraal beheerders wat onderskeidelik die GS-bus spanning, WS spanning en spanning wanbalans reguleer. Spannings duike en wanbalans is verminder deur slegs reaktiewe drywing te gebruik. Die doel was ook om ’n prakties bruikbare resultaat te lewer.
4
Siddig, Awad Ahmed. "A statistical approach to the control of shunt reactive compensators". Thesis, University of Liverpool, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.328466.
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Lenwari, Wanchak. "High performance current control for shunt active filters using resonant compensators". Thesis, University of Nottingham, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.439850.
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Gray, Matthew Alan. "A comparative analysis of proportional-integral compensated shunt active power filters". Master's thesis, Mississippi State : Mississippi State University, 2004. http://library.msstate.edu/etd/show.asp?etd=etd-11092004-083404.
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Davis, I. C. "Arc furnace and shunt reactive compensation modelling for voltage flicker reduction". Thesis, University of Liverpool, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.372680.
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Twining, Erika. "Voltage compensation in weak distribution networks using shunt connected voltage source converters". Monash University, Dept. of Electrical and Computer Systems Engineering, 2004. http://arrow.monash.edu.au/hdl/1959.1/9701.
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Zhan, Ming Hui. "Analysis and evaluation of soft-switching techniques for 3-phase 4-wire shunt power quality compensators". Thesis, University of Macau, 2006. http://umaclib3.umac.mo/record=b1678022.
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Lakkireddy, Jahnavi. "Steady State Voltage Stability Enhancement Using Shunt and Series FACTS Devices". ScholarWorks@UNO, 2014. http://scholarworks.uno.edu/td/1881.
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It is specifically important to focus on voltage stability analysis of the power system to avoid worst case scenarios such as voltage collapse. The purpose of this thesis is to identify methods for enhancing the steady-state voltage stability using FACTS devices and determining their impact on real and reactive power losses, improvement of bus voltage magnitude, and transmission line loadability. To achieve this, FACTS devices such as Static VAR Compensator (SVC), Static Synchronous Compensator (STATCOM), and Thyristor Controlled Series Capacitor (TCSC) are used in the test system as three separate test cases. The results obtained assist in drawing conclusions on the effectiveness of each FACTS devices at generator, load and swing buses, on lines between two load buses, and between a load bus and a generator bus, in terms of metrics such as voltage magnitude profile, PV curves, and active and reactive power losses.
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Arnez, Ricardo León Vasquez. "Contribuição ao estudo de aplicações do UPFC em redes elétricas". Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/3/3143/tde-19092014-153429/.
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Neste trabalho são exploradas as potencialidades e efeitos de possíveis aplicações do UPFC (Unified Power Flow Controller) em redes elétricas. Este recente equipamento da família FACTS, apesar de mais complexo, apresenta rapidez e versatilidade de respostas que podem justificar sua aplicação em redes elétricas. São apresentados modelos matemáticos deste dispositivo, para regime permanente e transitório, utilizando transformações para coordenadas ortogonais. Com base nas respostas obtidas, durante as simulações das aplicações estudadas, pode-se constatar que a tensão série e seu posicionamento angular, introduzidos pelo UPFC, desempenham um importante papel no controle rápido e eficiente do fluxo de potência. Como contribuição deste trabalho, explorou-se a conexão do conversor shunt ao enrolamento terciário de autotransformadores, demonstrando a viabilidade do controle do fluxo de potência nestes equipamentos de transformação. O esquema proposto, instalado em transformadores em paralelo, eleva a disponibilidade de operação do UPFC, aumentando a flexibilidade operativa do sistema em implementações práticas. Através da formulação apresentada, o transformador de acoplamento shunt, convencionalmente utilizado pelo UPFC, apresenta dimensões reduzidas. Foi também examinada a possibilidade de limitação de correntes de curto-circuito, equilibrados ou não, com a ação dos controles do UPFC, particularmente, aprofundando a análise do seu desempenho mais eficiente diante de curtos monofásicos. Os resultados satisfatórios obtidos permitem considerar a viabilidade de limitação destas correntes como um subproduto interessante da atuação deste dispositivo FACTS.In this thesis, the UPFC (Unified Power Flow Controller) various capabilities and effects for possible network applications, are studied. Although its structure is relatively more complex, when compared to the other FACTS controllers, its fast response and versatility can justify its application within the network. By utilising the orthogonal co-ordinates transform both the steady-state and transient mathematical models of the UPFC, are presented herein. Based on the results obtained and regarding the applications studied, it can be stated that the UPFC series voltage along with its phase angle play an important role for the fast and efficient control of the power flow. As a contribution of the present work, it has been proposed the connection of the shunt converter to the tertiary winding of autotransformers, demonstrating in this way the feasibility for controlling the power flow over such transforming assets. The proposed scheme, which regards two paralleled transformers, offers the UPFC a high operation availability increasing the system operative flexibility in actual implementations. By means of the proposed approach, the shunt coupling transformer, usually utilised in a classical UPFC configuration, presents a reduced size. Also, by utilising the UPFC control actions, it has been examined the possibility of short-circuit limitation over balanced and unbalanced circuits. Particularly, it has been analysed the UPFC most efficient performance towards line-to-ground faults. The satisfactory results obtained lead to consider the UPFC feasibility in limiting such currents; this, as an interesting by-product of this FACTS device action.
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Pahmer, Sueda Carmen M. "Contribution à l'étude de filtres actifs de puissance de type shunt : commande-simulation". Grenoble INPG, 1996. http://www.theses.fr/1996INPG0080.
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Le travail presente consiste a etudier de maniere detaillee les algorithmes de commande d'un filtre actif de puissance de type shunt realise a partir d'un onduleur de tension connecte sur un reseau triphase de puissance finie. Ces algorithmes ont ete testes en simulation a l'aide du logiciel a usage general electro-magnetic transients program (emtp). A ce propos, cinq methodes distantes pour obtenir les courants de reference pour chaque phase de l'onduleur de tension ont ete formalises. De la meme maniere, la regulation de tension aux bornes du condensateur de cet onduleur a egalement ete abordee. Dans certains cas de figure la numerisation controle-commande a ete developpe de maniere a simuler des structures les plus proches possibles de la realite. Quelques resultats experimentaux obtenus a l'aide d'un filtre actif de commande numerique permettent de valider notre methodologie
13
Horita, Marco Antonio Barbosa. "Reatores controlados por saturação para compensação de reativos". Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/3/3143/tde-23122014-143032/.
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Este trabalho tem como objetivo apresentar conceitos e prover ferramentas para estudos e análises de um equipamento ainda não explorado pelo sistema elétrico brasileiro para compensação reativa de linhas de transmissão, o Reator Controlado por Saturação. Inicialmente é apresentada a teoria necessária para o entendimento do equipamento, as aplicações e sua potencial utilidade para o Brasil. Através da concepção de um circuito equivalente e da análise de modelos adaptados para o MCSR (Magnetic Controlled Shunt Reactors) de softwares de transitórios eletromagnéticos aspectos sobre seu comportamento dinâmico e tempo de resposta são esclarecidos. Uma comparação entre o circuito equivalente com um modelo generalista de transformador ajustado às características do MCSR é realizada. A comparação serve para conferir credibilidade às suposições usadas para a elaboração do circuito equivalente e interpretações do funcionamento e dinâmica extraídas da análise deste circuito. Com uma melhor e mais clara percepção da dinâmica e efeitos do Reator Controlado por Saturação sobre a rede, realiza-se uma análise de distorção harmônica, sendo assim possível esclarecer alguns aspectos negativos do equipamento. Para o estudo da aplicabilidade e utilidade do MCSR no sistema elétrico brasileiro um modelo para transitórios eletromecânicos é proposto. Os parâmetros que determinam a dinâmica e resposta do equipamento são explorados através de suposições razoáveis e das características do equipamento. O modelo é primeiramente testado e analisado em um sistema simples composto por uma geração representada como fonte ideal, um circuito equivalente PI de uma linha de transmissão, uma carga e o MCSR realizando a compensação reativa. O trabalho segue para a escolha de uma rede brasileira em que o MCSR seria uma opção viável. Uma rede no norte do Brasil é escolhida para a análise e, após estudos de fluxo de potência, propõe-se a troca de um CER (Compensador Estático de Reativos) e quatro reatores shunt fixos por quatro Reatores Controlados por Saturação. A rede é então modelada no PSCAD e realizam-se estudos de distorção harmônica e estabilidade eletromecânica. Por fim realiza-se uma comparação econômica entre três alternativas de compensação reativa para o sistema escolhido incluindo a opção adotada e a opção sugerida com MCSRs. O trabalho conclui que reatores controlados por saturação são, em muitos casos, uma alternativa mais barata ao CER e, portanto deve ser estudado no planejamento e expansão do sistema elétrico.This work aims to present concepts and provide tools for research and analysis of an equipment not yet explored by the Brazilian power system for reactive compensation of AC transmission lines, the Magnetic Controlled Shunt Reactor (MCSR). Initially, the theory used for the understanding of the equipment, its applications and usefulness for the Brazilian network, is presented. By the analysis of an equivalent circuit and a model implemented in software for electromagnetic transient simulation adapted to the MCSR (Magnetic Controlled Shunt Reactors) some aspects of its dynamic behaviour and response time are clarified. A comparison between the equivalent circuit and an electromagnetic transformer model adapted to the characteristics of the MCSR (implemented in the PSCAD software) is performed. The comparison serves to grant credibility to the assumptions used for the preparation of the equivalent circuit and interpretations of the function and dynamics drawn from the analysis of this circuit. With a better and clearer understanding of the dynamics and effects of the MCSR on the network a simplified analysis of harmonic distortion is performed allowing to clarify some negative aspects of the equipment. To study the applicability and usefulness of the equipment in the Brazilian electrical system a model for electromechanical transients is proposed. The parameters that determine the dynamics and response of equipment are explored using reasonable assumptions and the characteristics of the equipment. The model is first tested and analyzed in a simplified system consisting of a generation represented as ideal source, an equivalent PI circuit representing a transmission line, a load and the MCSR performing the reactive compensation. The work follows to the choice of a Brazilian network on which the MCSR would be a viable option. A network in northern Brazil is chosen for analysis. Further studies of power flow reveals the possibility to exchange the SVS (Static Var System ) and four shunt reactors for four MCSRs. The network is then modelled in PSCAD and studies of harmonic distortion and electromechanical stability are conducted. Finally we make an economic comparison between three alternatives of reactive compensation for the chosen system including the originally adopted and the suggested solutions. The study concludes that magnetic controlled reactor are, in many cases, a cheaper alternative to the SVS and therefore should be studied in the planning and expansion of the power system.
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Schröter, Thorsten. "Shun the Pun, Rescue the Rhyme? : The Dubbing and Subtitling of Language Play in Film". Doctoral thesis, Karlstad University, Faculty of Arts and Education, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-704.
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Language-play can briefly be described as the wilful manipulation of the peculiarities of a linguistic system in a way that draws attention to these peculiarities themselves, thereby causing a communicative and cognitive effect that goes beyond the conveyance of propositional meaning. Among the various phenomena answering this description are the different kinds of puns, but also more strictly form-based manipulations such as rhymes and alliteration, in addition to a host of other, sometimes even fuzzier, subcategories.
Due to its unusual nature, and especially its frequently strong dependence on the idiosyncrasies of a particular language, language-play can generally be assumed to constitute a significant challenge in a translation context. Furthermore, given its non-negligible effects, the translator is not free to simply ignore the language-play (provided it has been recognized as such in the first place) without having taken an active stance on its treatment. However, the difficulties in finding a suitable target-language solution are possibly exacerbated if the source text is a complex multimedia product such as a film, the translation of which, normally in the form of dubbing or subtitling, is subject to additional constraints.
In view of these intricacies, it has been the aim of this study to analyze and measure how language-play in film has actually been treated in authentic dubbing and subtitle versions. As a prerequisite, the concept of language-play has been elaborated on, and more than a dozen subcategories have been described, developed, and employed. For the purpose of carrying out a meaningful analysis of the dubbing and subtitling of language-play, a corpus has been compiled, comprising 18 family films and 99 of their various target versions, most on DVD, and yielding nearly 800 source-text instances of language-play and thousands of translation solutions.
The results indicate that especially two sets of factors, among the many that are likely to influence a translation, play a prominent role: the type of the language-play, and the identity and working conditions of the translator. By contrast, the mode of translation (dubbing vs. subtitling), the target language, or the general properties of the films, could not be shown to have a sizeable impact.
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Zevallos, Alcahuaman Milton Elvis 1974. "Analise de sensibilidade da corrente de arco secundario para diferentes linhas de transmissão". [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/259605.
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Orientador: Maria Cristina Dias TavaresDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação
Made available in DSpace on 2018-08-10T09:15:34Z (GMT). No. of bitstreams: 1 ZevallosAlcahuaman_MiltonElvis_M.pdf: 2029693 bytes, checksum: 59155e98cbc8a1da85069d7cec8f451e (MD5) Previous issue date: 2007
Resumo: O arco secundário surge na manobra de abertura monofásica durante a eliminação de faltas monofásicas não permanentes para terra. O problema se apresenta especialmente nas linhas de EAT, no isolamento aéreo, em faltas que têm características não permanentes. Neste trabalho analisamos diferentes linhas de transmissão com níveis de tensão de 345 kV até 765 kV e com comprimentos de 150 km até 900 km, variando seu nível de compensação reativa em derivação de 40 % até 100 % e para as linhas mais longas compensando também 50 % da sua impedância longitudinal. Em linhas de EAT com compensação reativa em derivação é possível aproveitar a associação dos reatores adicionando um reator de neutro para minimizar o acoplamento mútuo entre as fases das linhas de transmissão, sendo este acoplamento a causa principal da manutenção da corrente de arco secundário. Com valores de reatores de neutro ótimos minimizamos a corrente de arco secundário e avaliamos a viabilidade da aplicação do religamento monofásico nos sistemas em estudo, aumentando o desempenho e confiabilidade dos sistemas elétricos
Abstract: The secondary arc appears in single-phase switching during clearing of non-permanent ground single-phase to ground faults. The problem happens especially on EHV lines, on aerial isolation, in faults with non permanent characteristics. In this work different transmission lines with voltage levels of 345 kV up to 765 kV and with 150 km up to 900 km length are analyzed, varying its level of reactive shunt compensation from 40 % up to 100 % and for the longest lines compensating 50 % of its longitudinal impedance. In EHV lines with have reactive shunt compensation, it is possible to add a neutral reactor in order to minimize the phase coupling of the transmission lines, being this coupling the main cause for the maintenance of the secondary arc current. With optimal values of neutral reactors it was possible to minimize the secondary arc current and evaluate the viability of the application of the single-phase reclosure in the systems under study, increasing the performance and reliability of the electrical systems
Mestrado
Energia Eletrica
Mestre em Engenharia Elétrica
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CHITTORA, PRAKASH. "ANALYSIS AND CONTROL OF SHUNT COMPENSATOR IN DISTRIBUTION SYSTEM". Thesis, 2018. http://dspace.dtu.ac.in:8080/jspui/handle/repository/16436.
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Electrical Power distribution systems suffer from power quality (PQ) problems such as poor
power factor, load unbalancing, harmonics, distortion in voltage etc. The contribution of non
linear loads incorporating power electronics devices viz. switch mode power supply, variable
frequency drive (VFD), lighting loads (CFL, LED) etc. in power distribution systems is high.
This leads to higher PQ problems into the system such as harmonics injection in voltage and
current, high neutral current etc. Since the continued presence of PQ problems deteriorates the
quality of power at the end user level, hence it becomes important to find solutions to overcome
power quality problems.
Conventional methods to improve PQ in distribution system include the installation of
capacitors, tap changing transformers, reactors, capacitor banks etc. However, these are slow
compensation techniques and do not provide active load compensation, so new custom power
devices have been designed. Shunt Active Power Filter (SAPF) is one such solution aimed to
provide load compensation. The SAPF can mitigate several PQ problems such as load
unbalancing, current harmonics, poor power factor of load etc. A SAPF can be realized using
Voltage Source Converter (VSC) with a DC link capacitor. Three leg VSC for three-phase, three
wire (TPTW) and four leg VSC for three-phase, four wire (TPFW) configuration are
conventionally used VSC configurations.
TPFW systems may have additional requirement of neutral current compensation due to the
presence of unbalanced loads. The SAPF with four legs can be realized for TPFW system,
however, the system cost increases. A low cost solution is to use zigzag transformer
configuration to mitigate excess neutral current and the conventional TPTW SAPF configuration.
v
The proposed work has been divided into four parts and deals with compensation in TPTW and
TPFW distribution systems, distorted three-phase grid systems and single –phase systems
without/ with PV integration. Detailed system design, development and analysis of new control
algorithms have been investigated. Simulation as well as experimental results have been
analyzed and tabulated with linear as well as non-linear loads. Conventional control techniques
viz Synchronous Reference frame Theory (SRFT), Power Balance Theory (PBT) and
Instantaneous Reactive Power Theory (IRPT) have been initially tested on the prototype system
developed in the laboratory.
Three new control algorithms have been developed on TPTW distribution system which include
Notch Filter, Kalman-LMS and Hopfield neural network based algorithm. These have been
developed and implemented using dSPACE 1104 as Digital Signal Processor (DSP). Various PQ
issues such as load unbalancing, current harmonics and supply current power factor have been
considered. Detailed simulation results are recorded and verification of these results on the
experimental setup is performed. Simulation has been performed in MATLAB/SIMULINK
environment.
PQ problems in TPFW distribution system have been studied. The control algorithms developed
for this system are Self Tuning Filter (STF), Modified Recursive Gauss Newton (MRGN) and
Chebyshev polynomial based algorithms. A conventional three leg configuration of VSC has
been used as SAPF; however zigzag transformer has been designed and used for neutral current
compensation. The experimental setup has been controlled using dSPACE 1104. PQ issues such
as load unbalancing, current harmonics, supply current power factor and neutral current
compensation have been considered with different loads. Experimental results of all techniques
have been analyzed in details.
vi
In electrical power distribution system, the presence of distortion in the grid voltages is also a
major PQ problem. The supply voltages may have high distortion due to presence of large source
impedance. The TPFW experimental setup with distorted grid and unbalanced linear and non
linear loads has been investigated. PQ issues such as load unbalancing, current harmonics,
supply current power factor and neutral current compensation have been mitigated successfully
for distorted Point of Common Connection (PCC) voltages. Both simulation and hardware
results using Multiple Complex Coefficient Filter (MCCF) and Second Order Generalized
Integrator (SOGI) control algorithms have been analyzed and compared.
Next, PQ problems in a single phase grid connected system have been analyzed and the system
has been developed in the laboratory. Two aspects discussed in this chapter are the integration of
PV and mitigation of PQ problems. Three control algorithms viz SRFT, Notch Filter and second
order generalized integrator (SOGI) based algorithm have been developed to mitigate PQ
problems.
Solution of PQ problems in single-phase, TPTW, TPFW distribution systems using different
SAPF configurations and new control techniques is the highlight of this thesis work.
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Wang, Sheng-Kuan, i 王勝寬. "Effect of Series and Shunt Compensation on Subsynchronous Resonance". Thesis, 1998. http://ndltd.ncl.edu.tw/handle/82695503848771362667.
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碩士國立臺灣大學
電機工程學系研究所
86
For the power system of Taiwan Power Company (TPC) during the peak loadper iod in 2000 AD, two problems have been observed. One is the phenomenon ofunequ al sharing of power flows over the EHV transmission lines connectingthe northe rn and central areas; the other is the bus voltage of OMEIsubstation being too low in some outage cases. Although series compensationmay be applied to contr ol the power flows over transmission lines, the dampingof subsynchronous reson ance (SSR) may be adversely affected. The effect of series capacitors with various compensation ratios andinstallation locations on the damping of SSR mo des in Taiwan power system is evaluated in this thesis. It is found that by co mbining a fixed capacitor (FC)and a static VAR compensator (SVC) into a shunt compensator, we can not only improve the dynamic response of OMEI bus voltage but also increase the dampingof SSR modes over series capacitor compensated sy stem.
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Hong, Yi-Jun, i 洪憶鈞. "2.4 GHz SiGe HBT High Linearity Power Amplifiers with an Analog Gain Compensation Predistorter and Two-Stage Gain Compensation Shunt-Shunt Feedback FET LNAs". Thesis, 2018. http://ndltd.ncl.edu.tw/handle/3tjn2a.
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碩士國立交通大學
電信工程研究所
107
This thesis consists of two parts, the first part is the introduction of nonlinear system and power amplifiers with an analog predistorter, and the second part is the analysis of shunt-shunt feedback LNAs. In the first part, we introduce the nonlinear system and nonlinear HBT Volterra analysis. Then, the analog predistortion design principle and these architectures are studied. Furthermore, we discuss the relationship between different bias points, different architectures, and their gain deviation through ADS Harmonic Balance simulations. Finally, we implemented two power amplifiers with an analog predistorter using TSMC 0.18 μm SiGe BiCMOS process . In the second part, the input matching and gain analysis of the resistive shunt-shunt feedback amplifiers are discussed. Then, noise parameters of the source degeneration FET device with resistive shunt-shunt feedback is derived utilizing noise transformation matrix. Finally, three broadband shunt-shunt feedback LNAs are implemented to compare with other LNAs with different input match networks.
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Chang, Yu-Hsin, i 張玉欣. "Compensation Policy Research of An-Shun Case". Thesis, 2009. http://ndltd.ncl.edu.tw/handle/01051437529914549900.
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碩士國立成功大學
政治經濟學研究所
97
This thesis includes both "policy identify" and "social justice" to evaluate the effect of compensation policy in the An-Shun Plant pollution case. The author explores that the community has the positive impression for the policy-making of compensation. They expected, however, the government should offer an apology for the pollution. The compensation policy was not recognized by the community citizens although there was a high expectation before policy implementation. The community citizens didn't believe the "short-term" "sympathy-subsidy" had much effect. The threshold of dioxin-in-blood for medical allowances was high. But other measure in practice such as the supplement of medical resource and the establishment of new health institution did have a lot of effect. There were the other problems with the community, for instance, the conflict of identification between policy-makers and the residents, and the discredit concerned to the community from mass media. The policy-making of compensation concerned to the responsibility of pollution- actors has based on the justice. To compare other pollution cases, however, there was little process justice and "the principles of fairness". There were two reasons for this case. First, the threshold of compensation should include different indicators instead of using just one standard based on the meanings of medicine. Second, the information of policy-making was not informed to all community citizens. Main problems of the community may be its low literacy rate, much portion of elders and children in population, and the unworkable self-help institution.
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Yeh, Chia-Ming, i 葉家銘. "Optimization-Based Reference Compensation Current Strategies for Shunt Active Power Filter Control". Thesis, 2004. http://ndltd.ncl.edu.tw/handle/86757520007496567750.
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碩士國立中正大學
電機工程研究所
92
A new theory and a conceptual design for the three-phase shunt active power filter (APF) control strategy under imbalanced and distorted supply voltages are present in the thesis. Conventionally, the compensation currents injected by the APF are determined according to reference frame transformation-based approaches, where the load instantaneous real and reactive powers are calculated in the new reference frame. The APF injection currents are then computed to maintain the balanced and sinusoidal source currents, as well as the least active power consumption by the APF. However, if current harmonics set by harmonic standards or other constraints are considered, the load harmonic currents after APF compensation can be controlled to meet the requirement. Therefore, the APF may have an adjustable performance. This thesis proposes an optimal algorithm for the APF control in steady state, where the individual and total harmonic current distortion limits, the minimum load power factor, levels of current imbalance, and the size of the APF can be taken into account. The planned APF does not consume or produce the active power and only the passive energy-storage elements are required in the new APF design. Results obtained by simulations with Matlab and Simulink show that the proposed approach is more flexible than the conventional approaches on compensating reactive power and harmonic/neutral currents of the load, even if the source voltages are severely distorted and imbalanced. The new control strategy is very suitable for planning the APF when several alternate objectives and constraints that are under considerations.
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Shih, Cheng-Hsiao, i 石晟孝. "Selective Compensation Strategy Applied in Shunt Active Power Filter Based on IEEE Std. 1459". Thesis, 2017. http://ndltd.ncl.edu.tw/handle/gawm24.
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碩士國立中央大學
電機工程學系
105
This thesis is aimed to achieve the simulation of control harmonic current compensation by shunt active power filter(SAPF). Analyzing harmonic signal through synchronous reference frame (SRF), and estimating the non-efficient powers with IEEE Std.1459-2010.When reference compensating current exceeds the maximum output of SAPF,a selective compensation strategy is applied to eliminate or proportionally reduce the non-efficient powers to improve the efficiency of the SAPF. In the aspect of power system design, this thesis applies three-phase four-wire system. Through Simulink to simulate nonlinear loads and inter-harmonic load in balanced and unbalanced situations, the signals of voltage and current are extracted at point of common coupling (PCC). With the control strategy proposed in this thesis, the compensation of nonlinear harmonic currents is completed. Finally, the total harmonic current distortion after compensation is analyzed to verify if it is complied with harmonic limitations presented by IEEE Std. 519-2014 and TPC harmonic regulation standards at present. In the aspect of shunt active power filter design, the eight power switches and one DC storage capacitors are used as the main structure. And hysteresis current control is used to realize the harmonic current compensation.
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"Temperature Compensated, High Common Mode Range, Cu-Trace Based Current Shunt Monitors Design and Analysis". Doctoral diss., 2011. http://hdl.handle.net/2286/R.I.9189.
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abstract: Sensing and controlling current flow is a fundamental requirement for many electronic systems, including power management (DC-DC converters and LDOs), battery chargers, electric vehicles, solenoid positioning, motor control, and power monitoring. Current Shunt Monitor (CSM) systems have various applications for precise current monitoring of those aforementioned applications. CSMs enable current measurement across an external sense resistor (RS) in series to current flow. Two different types of CSMs designed and characterized in this paper. First design used direct current reading method and the other design used indirect current reading method. Proposed CSM systems can sense power supply current ranging from 1mA to 200mA for the direct current reading topology and from 1mA to 500mA for the indirect current reading topology across a typical board Cu-trace resistance of 1 ohm with less than 10 µV input-referred offset, 0.3 µV/°C offset drift and 0.1% accuracy for both topologies. Proposed systems avoid using a costly zero-temperature coefficient (TC) sense resistor that is normally used in typical CSM systems. Instead, both of the designs used existing Cu-trace on the printed circuit board (PCB) in place of the costly resistor. The systems use chopper stabilization at the front-end amplifier signal path to suppress input-referred offset down to less than 10 µV. Switching current-mode (SI) FIR filtering technique is used at the instrumentation amplifier output to filter out the chopping ripple caused by input offset and flicker noise by averaging half of the phase 1 signal and the other half of the phase 2 signal. In addition, residual offset mainly caused by clock feed-through and charge injection of the chopper switches at the chopping frequency and its multiple frequencies notched out by the since response of the SI-FIR filter. A frequency domain Sigma Delta ADC which is used for the indirect current reading type design enables a digital interface to processor applications with minimally added circuitries to build a simple 1st order Sigma Delta ADC. The CSMs are fabricated on a 0.7µm CMOS process with 3 levels of metal, with maximum Vds tolerance of 8V and operates across a common mode range of 0 to 26V for the direct current reading type and of 0 to 30V for the indirect current reading type achieving less than 10nV/sqrtHz of flicker noise at 100 Hz for both approaches. By using a semi-digital SI-FIR filter, residual chopper offset is suppressed down to 0.5mVpp from a baseline of 8mVpp, which is equivalent to 25dB suppression.Dissertation/Thesis
Ph.D. Electrical Engineering 2011
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"Improvement of power transfer in an existing power system by means of series and shunt compensation". Thesis, 2010. http://hdl.handle.net/10210/3068.
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M.Phil.The Motraco transmission system is a classical case illustrating the increase in power transfer of a network considering the possibility of a voltage collapse. This case study was used in the dissertation to find a techno-economical solution for the Motraco system to increase the power transfer to satisfy an additional load. The Motraco power system is operating close to a voltage collapse at present. A voltage collapse will be experienced if additional load is added at the Maputo substation. The possibility of a voltage collapse can be reduced if the power transfer capability of the Motraco power system is increased. Various technologies can be used to increase the power transfer of the Motraco power system. The technologies used in this study to increase the power transfer were limited to the following: • Adding shunt capacitor banks at critical locations in the network • Adding a series capacitor bank on an existing 400 kV transmission line • Adding an additional 400 kV transmission line • Adding a series capacitor bank on the new 400 kV transmission line The correct use of the combination of the shunt capacitor banks, series capacitor bank and the new transmission line contributes to: • support voltages in the network; • reduce the transmission losses; and • increase the fault levels at the receiving end. The principles used in this dissertation can be used to increase the power transfer limit of any power system with the same characteristics.
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Shee, T. C., i 施泰彰. "A Study on Reference Compensation Current Strategies for Three-Phase Four-Wire Shunt Active Power Filters". Thesis, 2002. http://ndltd.ncl.edu.tw/handle/58215613068166539976.
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碩士國立中正大學
電機工程研究所
90
This thesis proposes a new reference compensation current strategy of shunt active power filters used in a three-phase, three-wire or four-wire distribution system with unbalanced, ideal or non-ideal source voltages supplying balanced or unbalanced nonlinear loads. Firstly, a comparative study of the effectiveness for six conventional approaches for determining reference compensation currents of shunt active power filters is present. Then, a novel reference compensation currents approach is described. The proposed compensation strategy makes implementation of the compensator of the active power filter simpler than those conventional approaches. Moreover, the proposed compensation strategy is verified with an virtual implementation of controller with using MATLAB/Simulink. It is shown that even the source is non-ideal, when supplying a nonlinear load, the source current is maintained sinusoidal and in phase with the positive-sequence source voltage. Therefore, the active power filter effectively controls the source power factor and harmonic currents generated by the nonlinear load. In addition, it does not require any active elements in the implementation of the active power filter.
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Ciou, Yan-Bin, i 邱彥斌. "Neural Network-based Approach for Calculation of Optimal Reference Compensation Current Generated by Shunt Active Power Filter". Thesis, 2010. http://ndltd.ncl.edu.tw/handle/91473373289645776213.
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碩士國立中正大學
電機工程所
98
Due to the increasing use of non-linear loads, the harmonic problems have become of great concerns. Not only do harmonics increase the extra losses in the transmission process, but they also pollute the source side of distribution system which would make the original three-phase sinewaves voltage become three-phase imbalance or generate harmonic distortion. One of the solutions to harmonics is the use of active power filter (APF) for nonlinear loads. The APF reference compensation strategy proposed in this thesis is to improve previously developed optimal control strategy. The proposed method adopts backpropagation neural network to prevent the drawback of the previous optimal control strategy. Although optimal control algorithm can perform compensation and tackles different constraints, it cannot consider the case of load variations. On the other hand, the backpropagation neural network can train the control part and calculate the amount of compensation with the trained neural network under the suddenly changing loads. Simulations by using MATLAB/Simulink for verification of the proposed method are then presented to show its usefulness.
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Ramaite, Mbuso Fikile. "Study of the effects of harmonics in the design of transmission network shunt compensators : network simulation and analysis methods". Thesis, 2013. http://hdl.handle.net/10413/9232.
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The management of parallel and series resonance conditions is important for ensuring that
harmonic levels are managed on utility networks, and that shunt compensators are able to operate
without constraints for various network conditions (states). For these and similar problems,
harmonic impedance assessment of the ac network is required for the design of ac filter or shunt
capacitor bank installations. This is particularly important for large installations connected to HV
or EHV systems, because resonances at these voltage levels tend to be highly un-damped
resulting in potentially damaging voltage and current amplification.
The objective of this dissertation was to develop and demonstrate a design methodology which
makes use of network impedance assessment methods to provide robust harmonic integration of
large shunt compensators into a transmission and HVDC systems.
The design methodology has two aspects. The first part considers network modeling, evaluation
of different models and simulation of harmonic impedance. In the second part, methods of
analyzing and assessing the simulated harmonic impedance are developed.
A detailed step-by-step approach was taken in the development of the design methodology. The
methodology was documented as a guideline and accompanied by the development of an Excel
tool that can be used to assess the simulated harmonic impedance. The Excel tool permits a
systematic assessment of the simulated network impedance where shunt compensators are
integrated into transmission systems. The tool also ensures that the design of transmission and
HVDC ac shunt compensation is optimally robust in terms of harmonic resonances.
The theoretical and computational review has been tested and demonstrated on the existing
Eskom Transmission system through several case studies. The results have shown the merits of
the design methodology.Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2013.
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Hong, Rong-Chin, i 洪榮欽. "IEEE Standard 1459-based Reference Compensation Current Strategy of Three-phase Shunt Active Power Filter Implemented with Processor-in-the-loop". Thesis, 2014. http://ndltd.ncl.edu.tw/handle/12614956158646798307.
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博士國立中正大學
電機工程研究所
103
This thesis proposes an efficient method to obtain the equivalent fundamental positive-sequence voltage for determining the shunt active power filter (APF) reference compensation currents, where the source voltage magnitude and phase angle at the fundamental frequency are detected by a simplified adaptive linear combiner (ADAptive LINear Element ADALINE) neural network. The APF reference current calculator is developed and is realized on the DSP (Digital Signal Processor) board through processor-in-the-loop (PIL) simulation for validating the effectiveness of the proposed APF control strategy, where the source voltages and the load currents are both distorted and unbalanced. In addition, results obtained based on the true positive-sequence fundamental source current after APF compensation and another classic approach are included for comparison. It is shown that results obtained by the PIL simulations with the proposed and compared methods agree very well. The proposed APF reference compensation current strategy is simple and practical, which provides a cost-effective and computationally efficient manner for the APF controller implementation with PIL simulations.
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Koenig-Barron, Matthew. "The Emergence and Compensation of Reactive Power in the North Western Province of Zambia". Thesis, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-331765.
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The design of a transmission project is as varied in the factors that affect it as the people to which the project supplies electricity. This thesis focuses on the theoretical considerations in the design process that affect the emergence of reactive power in a system and how reactive compensation is achieved. It examines the place of theoretical concepts in reality by expounding on a field study on the construction of a new transmission power system connecting the North Western Province (NWP) of Zambia to the national grid. The thesis provides colour to these grey theoretical concepts in the form of conductor specifications, geometrical transmission tower relationships, load characteristics, population traits, transformer interactions and recommendations for improvements to the constructed grids using the analytic tools provided by the theoretical background. There is also provided some theoretical description of three recommendations made by this thesis to improve the power quality and general efficiency of the NWP. Along the way the thesis confirms the analytic calculations with reference to field documentation and programming tools such as MATLAB and Power World. It is the uniqueness of the system in terms of load demand and geography that allows for an analysis and comparison of the reactive power in the transmission network. These challenges and the possible solutions to them form the focus of the thesis.
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Deekshit, Ravishankar. "Techniques For Planning And Operation Of Distribution Systems". Thesis, 2005. https://etd.iisc.ac.in/handle/2005/1507.
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Deekshit, Ravishankar. "Techniques For Planning And Operation Of Distribution Systems". Thesis, 2005. http://etd.iisc.ernet.in/handle/2005/1507.
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Almeida, Raul Fernando Silva. "Desenvolvimento de um filtro ativo paralelo monofásico compacto e didático utilizando MOSFETs". Master's thesis, 2013. http://hdl.handle.net/1822/39846.
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Dissertação de mestrado integrado em Engenharia Eletrónica Industrial e ComputadoresA crescente modernização dos setores económicos e sociais, a par do aumento da qualidade de vida das pessoas, deve-se em larga escala à crescente utilização de equipamentos eletrónicos, capazes de realizar as mais variadas e complexas tarefas. Estes equipamentos absorvem correntes distorcidas, provocando efeitos prejudiciais à qualidade da energia no sistema elétrico, manifestando-se numa sequela de consequências, como aumento das perdas em diferentes dispositivos ou mesmo o mau funcionamento de determinados equipamentos. No sector industrial podem causar uma diminuição da eficiência na produção, e consequentemente reverter em perdas económicas elevadas. No seguimento dos trabalhos de investigação na área da Qualidade de Energia Elétrica desenvolvidos pelo Grupo de Eletrónica de Potência e Energia (GEPE) da Universidade do Minho, esta dissertação descreve o desenvolvimento de um Filtro Ativo Paralelo monofásico, utilizado para mitigar harmónicas na corrente e o baixo fator de potência. Pretende-se que o equipamento desenvolvido seja o mais eficiente e compacto possível, sendo a utilização de MOSFETs no inversor de potência um dos pontos fulcrais para conquistar esse objetivo. Através da utilização de frequências de comutação elevadas é conseguida a diminuição dos componentes constituintes do mesmo, tornando-o mais compacto e leve. Um dos desígnios deste equipamento é a sua utilização em demostrações públicas da tecnologia, para tal foi desenvolvida uma interface gráfica com o utilizador, onde é possível visualizar formas de onda do sistema, bem como outras variáveis importantes para o entendimento do funcionamento do equipamento e da tecnologia envolvida. Ao longo deste documento é realizado um levantamento dos vários componentes constituintes do Filtro Ativo Paralelo, por forma a perceber o seu funcionamento, bem como as diversas topologias de hardware e teorias de controlo exequíveis de implementar. De forma a avaliar o funcionamento do Filtro Ativo Paralelo monofásico, são realizadas simulações computacionais, analisando a sua operação para diferentes condições de carga. Por fim, é apresentada toda a implementação prática deste equipamento, terminando com os resultados experimentais.
The growing modernization of economic and social sectors, along with the increase of quality of life, is due in large measure to the growing use of electronics equipment, capable of performing the most varied and complex tasks. These devices absorb distorted currents, causing pernicious effects to the power quality of the electrical system, manifesting itself in several consequences, such as, increased losses on different devices, or even malfunctioning of some equipment. In the industrial sector it may cause a decrease in production efficiency, and consequently revert to high economic losses. Following the research in the area of Power Quality developed by the Group of Energy and Power Electronics (GEPE), of the University of Minho, this dissertation describes the development of a single-phase Shunt Active Power Filter, used to mitigate current harmonics and low power factor. The main goal is that the developed equipment is as efficient and compact as possible, and for that, the use of MOSFETs in the power inverter is of crucial importance in order to achieve this purpose. Through the use of high switching frequencies is achieved a reduction in the size of the components, making it more compact and lightweight. One of the purposes of this equipment is its use in public technology demonstrations, and in this way, an graphical user interface was developed, where is possible to view the waveforms of the system, as well as other important variables, in order to understand the operation of the equipment and the technology involved. Throughout this document the various constituent components of the Shunt Active Power Filter are presented, in order to understand its operation, as well as the various hardware topologies and control theories feasible to be implemented. In order to evaluate the performance of the single-phase Shunt Active Power Filter, computational simulations are performed, and its operation is analyzed for different load conditions. Finally, every practical implementation of this equipment is presented, and this dissertation ends with the experimental results.