Dissertations / Theses on the topic 'Chopper'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Chopper.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
Carrión, O. Paola, E. Edith Ibacache, R. Rafael Guillier, R. Rodrigo Cariceo, and Juan José Kwasigroch. "Club Chopper." Tesis, Universidad de Chile, 2008. http://www.repositorio.uchile.cl/handle/2250/111575.
Full textNo disponible a texto completo
Club Chopper nace de la experiencia de vivir el mundo de las motocicletas Harley Davidson y de la observación de las conductas y actividades predominantes en los fanáticos de esta actividad. Efectivamente, al conocer a fondo este particular y específico mundo, se detectó la necesidad de contar con un lugar físico único, característico, que fuera capaz de acoger al mundo de las motocicletas de alta cilindrada de Santiago, ofreciéndole un conjunto de productos y servicios de una manera tal, que de inmediato los miembros de este grupo se hicieran parte de este concepto y lo adoptaran como su lugar, propio, personal, a su medida y deseo. Lo anterior sumado a la expansión del mercado de las motocicletas, donde se ha incrementado tres veces en volumen, entre 2005 y 2006, y con un aumento relevante para 2007 en la marca Harley Davidson, genera las condiciones óptimas para el desarrollo de este proyecto. La característica predominante de este mercado es la pertenencia, ser parte del mundo Harley. Éste además, es un referente y una aspiración para la mayor parte de los poseedores de motocicletas de otras marcas, siempre en el segmento “custom”, “chopper” o “bobber”. Esto lleva a detectar la necesidad de crear un lugar donde los “Harlistas” y otros motociclistas puedan reunirse frecuentemente, a diario muchos de ellos y donde además puedan satisfacer todas sus necesidades al respecto, desde la adquisición de una motocicleta nueva o usada, hasta la obtención de servicios para sus motocicletas, vestimenta, accesorios, repuestos y encuentro con amigos. Con lo anterior, ‘Club Chopper’ es un conglomerado comercial que consta de tres áreas básicas: a) Tienda de motos, vestimenta, accesorios y repuestos de la marca Harley Davidson, más venta y consignación de motocicletas usadas. b) Taller de mantención, servicios y transformaciones de motocicletas. c) Un pub – restaurant temático. Las tres áreas configuradas en una conformación física tal que se genere un espacio cálido, específico y único donde se pueda practicar y disfrutar de este “estilo de vida”. El negocio base es la venta de motocicletas marca Harley Davidson, para lo cual, en un inicio, se importarán las unidades desde un dealer de Estados Unidos, para, posteriormente, trabajar en la obtención de un contrato con Harley Davidson para transformarnos en dealer autorizado e importar las unidades directamente desde la matriz. Asimismo, los demás productos para la venta (vestimenta, accesorios y repuestos) también seguirán este modelo de desarrollo. El taller se desarrollará sobre la base de uno de los actuales talleres no oficiales de la marca en Chile, el cual es propiedad de uno de los personajes líderes en este ambiente y quien se incorporará a Club Chopper, aportando su conocimiento técnico, experiencia, cartera de clientes y su imagen, característica altamente relevante para el éxito del proyecto. Finalmente, se creará un pub restaurant, con ambientación ad-hoc, una carta sencilla y espacios adecuados para las reuniones periódicas de diferentes grupos de motociclistas. La particularidad es la unidad, la que dará sinergia a las tres áreas, potenciará la actividad individual y generará la característica distintiva y única del proyecto. Club Chopper se ubicará en la comuna de Las Condes, en un local arrendado, el cual se deberá remodelar para albergar la configuración adecuada de las tres actividades. Hemos estimado la inversión inicial en un monto de MM$ 270, donde la mayor parte se dedica a la remodelación del local, más la importación de un stock de motocicletas y demás ítems tanto en artículos personales como repuestos y accesorios para las motos y la implementación del restaurant. Pese a las conservadoras proyecciones de ventas, el proyecto tiene la capacidad de recuperar la inversión inicial al cuarto trimestre del segundo año de operaciones. La competencia directa que enfrentará Club Chopper será la del actual distribuidor para Chile de la marca e indirectamente, los importadores de otras marcas de motos de este segmento como Yamaha, Honda y Suzuki. Estimamos que el distribuidor H-D, por lejos el líder en el segmento, como las demás marcas, no han explotado adecuadamente los conceptos subyacentes en este mercado, por lo que Club Chopper ingresará al mercado con claras ventajas competitivas y, dada la estructura de nicho, con un rápido posicionamiento como “el lugar propio de los Harlistas” y otros motociclistas, imagen que claramente será atractiva también para un público general.
Hadiashar, Ali. "Chopper stabilization in analog multipliers." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/35604.
Full textIncludes bibliographical references (p. 57-58).
The multiplier is a fundamental analog building block. Analog multipliers are used in many systems such as filters, neural networks, automatic gain control circuits, and phase alignment systems. As with any circuit, analog multipliers are plagued by DC offsets. When considering techniques for removing this offset, the question of continuous regulation versus calibration arises. We can easily implement a calibration method, however, how often one must calibrate becomes an issue. Additionally, calibration typically forces the multiplier to suspend normal operation while the offsets are being measured. In this thesis, a technique for continuously regulating offset in multipliers is studied in isolation. Chopper stabilization, a technique long used in DC amplifiers, is applied to analog multipliers to achieve the lowest offset reported.
by Ali Hadiashar.
S.M.
Allen, Kirk D. "Practical implementation of the hard switched buck chopper." Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1997. http://handle.dtic.mil/100.2/ADA331788.
Full textMurad, Thamir Faraj. "Digital control of chopper-fed DC motor drive." Thesis, Loughborough University, 1985. https://dspace.lboro.ac.uk/2134/10836.
Full textChang, Kee Anselmo Marco Antonio. "Diseño de un amplificador chopper de señales neuronales." Bachelor's thesis, Pontificia Universidad Católica del Perú, 2016. http://tesis.pucp.edu.pe/repositorio/handle/123456789/8877.
Full textTesis
Godoy, Philip (Philip Andrew). "Nested chopper stabilization in analog multipliers and mixers." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/44379.
Full textIncludes bibliographical references (p. 97-99).
We describe a general offset-cancelling architecture for analog multiplication using chopper stabilization. Chopping is used to modulate the offset away the output signal where it can be easily filtered out, providing continuous offset reduction which is insensitive to drift. Both square wave chopping and chopping with orthogonal spreading codes are tested and shown to reduce the offset down to the microvolt level. In addition, we apply the nested chopping technique to an analog multiplier which employs two levels of chopping to reduce the offset even further. We discuss the limits on the performance of the various chopping methods in detail, and present a detailed analysis of the residual offset due to charge injection spikes. An illustrative CMOS prototype of a chopper-stabilized general-purpose multiplier in a 0.18/pm process is presented which achieves a worst-case offset of 1.5/tV. This is the lowest measured offset reported in the DC analog multiplier literature by a margin of two orders of magnitude. The prototype multiplier is also tested with AC inputs as a squarer, variable gain amplifier, and direct-conversion mixer, demonstrating that chopper stabilization is effective for both DC and AC multiplication. The AC measurements show that chopping removes not only offset, but also 1/f noise and 2nd-order harmonic distortion. The specific application of chopper stabilization to RF direct-conversion mixers is also discussed in detail, showing how it can be used to improve the sensitivity of direct-conversion receivers by reducing the mixer's offset, 1/f noise, and even-order distortion. A prototype IC of a chopper-stabilized RF mixer in a 0.18pm CMOS process is presented, along with measured results.
by Philip Godoy.
S.M.
Menolfi, Christian Ivo. "Low noise CMOS chopper instrumentation amplifiers for thermoelectric microsensors /." Zürich, 2000. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=13583.
Full textCox, Graeme J. "A yield mapping system for sugar cane chopper harvesters." University of Southern Queensland, Faculty of Engineering and Surveying, 2002. http://eprints.usq.edu.au/archive/00004617/.
Full textSloboda, Alex R. "AC coupled ripple reduction method for chopper-stabilized amplifiers." Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/119772.
Full textCataloged from PDF version of thesis.
Includes bibliographical references (page 44).
There exists a variety of applications where precision voltage amplifiers are required to faithfully sense and properly filter signals. While methods have been developed to create such precision amplifiers, these methods typically suffer from increased output noise. In the case of chopper amplifiers, this increased output noise comes in the form of narrow bandwidth, high frequency noise referred to as ripple noise. To reduce this ripple noise many topologies and techniques have been created and put into practice. However all of these topologies and techniques come at some cost in larger circuit area, higher power consumption, or increased noise. An AC coupled ripple reduction filter for chopper-stabilized precision amplifiers has been developed to reduce the cost of filtering out ripple noise. What follows is an explanation of ripple noise, an examination of existing ripple reduction methods, the presentation of the AC coupled ripple reduction filter, and simulated evidence of improved performance with this new method over existing methods in terms of smaller area, lower power consumption, and reduced noise.
by Alex R. Sloboda.
M. Eng.
Said, Waleed M. "Microprocessor based speed control of a chopper-fed d.c. drive." Thesis, Loughborough University, 1985. https://dspace.lboro.ac.uk/2134/14140.
Full textRefoufi, L. "Steady state analysis of the chopper controlled static Kramer drive." Thesis, University of Newcastle Upon Tyne, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239814.
Full textFairley, Peter Douglas. "Novel solid state modulator for the infrared : the germanium chopper." Thesis, University of Southampton, 2000. https://eprints.soton.ac.uk/15503/.
Full textTomm, Fabio Luis. "Projeto de reatores eletronicos para hid baseado no conversor chopper AC." Universidade Federal de Santa Maria, 2007. http://repositorio.ufsm.br/handle/1/8437.
Full textThis thesis proposes a design of a power supply for high-pressure discharge lamps based on a high efficiency and high power factor electronic ballast, without exciting the intrinsic acoustic resonance. The ballast consists on a bipolar buck chopper operating in continuous conduction mode (CCM), with an input filter, and an igniter circuit. It works with a switching frequency of 33 kHz and supplies the lamp in the mains frequency. The igniter circuit provides the necessary high voltage for the lamp's startup initial procedure. It is controlled by an 8 bits microcontroller, thus contributing to reduction in the number of parts and the ballast final cost, without compromising its reliability. Two possible solutions for an igniter circuit are proposed, the first based on a igniter device, and the second on a LC resonant circuit. A study on the ignition process and the required circuits to guarantee it, and a brief review on the electrical characteristics of electromagnetic ballasts are also included as secondary contributions. Experimental results with a 70W HPS lamp supplied by a 220V±20% and 60 Hz mains, are presented to validate the proposed ballast. The behavior of the experimental ballast shows that it is a good choice in avoiding unstable effects provoked by acoustic resonance phenomenon.
Esta dissertação apresenta o projeto de uma fonte de alimentação para lâmpadas de descarga em alta pressão baseada em um reator eletrônico com alto rendimento e ótimo fator de potência que não excita de forma destrutiva a ressonância acústica (AR). O reator consiste de um conversor buck bipolar operando em modo continuo (CCM), com filtro de entrada acoplado e com um circuito de ignição. O conversor opera em 33 kHz e alimenta a lâmpada em freqüência de rede. O circuito de ignição fornece a alta tensão para a formação inicial do arco elétrico. O controle do reator é implementado em um microcontrolador de 8 bits, o que contribui com a redução do número de componentes e do custo final do sistema, sem prejudicar a confiabilidade do mesmo. Duas propostas de circuito de ignição são apresentadas, uma baseada em um dispositivo ignitor, e a segunda em um circuito LC ressonante. Uma breve revisão e avaliação das características elétricas do reator eletromagnético é também apresentada a título de comparação. Um estudo do processo de ignição e os circuitos necessários a formação do arco é também incluído. Resultados experimentais para uma lâmpada HPS de 70W alimentada a partir de uma rede de 220V±20% e 60Hz são apresentados para validar o reator proposto e demonstram que este é uma boa escolha para evitar os efeitos danosos do fenômeno da ressonância acústica.
Balasingham, Karunananthan. "A single-phase fully-regenerative converter for chopper controlled DC drives /." Thesis, McGill University, 1990. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=59821.
Full textIn the proposed scheme the energy produced during regeneration is re-injected into the ac mains supply. The scheme consists of adding to each diode of the front end rectifier a transistor capable of conducting the reverse current, and suppressing the dc link capacitor.
The performance of the complete converter with a single phase ac mains is analysed in terms of operation in both motoring and braking modes. The advantages of the scheme are presented and its characteristics are compared to the standard chopper configuration and to the conventional phase-controlled converter systems. It is shown that the system exhibits high power factor and efficiency and is very compact.
Jordy, Keith (Keith M. ). "Low-power amplifier chopper stabilization for a digital-to-analog converter." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/46167.
Full textThesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2008.
Modern portable media devices demand low-power and low-noise performance from the internal digital-to-analog converter. CMOS design has allowed for oversampling sigma-delta modulation to achieve these goals. However, noise is typically limited by the kT/C noise in the switched capacitor filter following the digital modulation. These filters also require a large amount of on-chip capacitance. The goal of this project is to design a continuous-time output stage for a DAC. A continuous-time output requires much less capacitance than the SC filter. Chopper stabilization is applied to the amplifier to reduce the low-frequency noise. The challenge of this architecture is maintaining amplifier harmonic performance and transient performance. In simulations, chopper stabilization improved signal-to-noise ratio by 11dB while maintaining system level harmonic distortion performance.
by Keith Jordy.
M.Eng.
Bryant, Angus Toby. "Simulation and optimisation of diode and IGBT interaction in a chopper cell." Thesis, University of Cambridge, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.597041.
Full textPIPINO, ALESSANDRA. "Design of Analog Circuits in 28nm CMOS Technology for Physics Applications." Doctoral thesis, Università degli Studi di Milano-Bicocca, 2017. http://hdl.handle.net/10281/158126.
Full textThe exponential trend of the complementary metal-oxide-semiconductor (CMOS) technologies predicted by Moores law has been successfully demonstrated over the last three decades. A constant downscaling of CMOS technologies with smaller and smaller device size has been developed, in order to comply with requirements on speed, complexity, circuit density and power consumption of advanced high performance digital applications. The minimum reachable length, which corresponds to the half the length of the channel of the smallest transistor that can be manufactured, represents every following technological node. With the arrival of nanoscale (sub-100nm) CMOS technologies, digital performance improve further, but many new challenges have been introduced for analog designers. In fact, for the digital circuits CMOS scaling-down leads to several benefits: speed improvement, reduced power consumption, high integration and complexity level. The analog circuits, instead, strongly suffers from the ScalTech trend, because the MOS behavior dramatically changes through the different technological nodes and especially for the ultra-scaled ones, where second order effects, previously negligible, become very important and start to be dominant, affecting its performance. For instance, lower intrinsic DC-gain, reduced dynamic range, operating point issues and larger parameter variability are some of the problems due to scaling-down. Analog designers must face this problems at different phases of the design, circuital and layout. Despite that, the design of analog circuit in sub-nm technologies is mandatory in some cases or can be even helpful in others. For example, in mainly mixed-signal systems, the read-out electronic requires high frequency performance, so the choice of deep submicron technology is mandatory, also for the analog part. Other types of applications where using scaled technology is even strategical are the high-energy physics experiments, where read-out circuits are exposed to very high radiation levels with consequent performance degradation and breakdown events. Since radiation damage is proportional to gate oxide volume, smaller devices exhibit lower radiation detriment. It has been demonstrated in fact, that 28nm CMOS technology devices are capable to sustain 1Grad-TID exposure, not possible with previous technologies. In this thesis, the main key challenges in ultra-scaled technologies are analyzed in the first chapter, and then integrated circuits designed in 28nm CMOS technology are presented. The first circuit design, presented in the second chapter and integrated in 28nm CMOS technology, is a Fast-Tracker front-end (FTfe) for charge detection. The read-out system has been developed starting from the main specifications and circuital solutions already adopted for muon detection in ATLAS experiment. The proposed front-end is able to detect an event and soon after to reset the system in order to make the FTfe already available for the following event, avoiding long dead times. The architecture is analyzed in detail, followed by the layout choices and the performance results. The second circuit design presented in the third chapter and always integrated in 28nm CMOS technology, is a Chopper instrumentation amplifier. Instrumentation amplifiers are the key building blocks in sensor and monitoring applications, where they are used to sense and amplify usually very small (sub-mV) and low frequency signals. For this reason it is important to reduce or eliminate the input offset and flicker noise, which cover and disturb the main signal to be detected. The proposed amplifier use a modulation technique, called chopper, in order to meet the low offset and low flicker noise requirements. Moreover it has been modeled to operate in sub-threshold region, in order to address the scaling problems. After the architecture description, layout and results of the integrated prototype are shown.
Spro, Ole Christian B. "Reactive Power Compensation and Active Filtering Capabilities of the Step-down AC Chopper." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for elkraftteknikk, 2013. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-23617.
Full textRaimondo, Giuliano. "Power quality improvements in 25kV 50 Hz railway substation based on chopper controlled impedances." Thesis, Toulouse, INPT, 2012. http://www.theses.fr/2012INPT0004/document.
Full textThis work is the result of collaboration between the LAPLACE laboratory, the “Seconda Università degli Studi di Napoli” (SUN) and the French national railways operator SNCF. The research topic treated herein concerns the use of power electronic devices in 25kV/50Hz railways substations to achieve power quality improvements. In railway transportation, single-phase 25kV-50Hz electrification system is widely diffused especially for high-speed railway applications. Although electrified DC systems are still widely applied, the adoption of AC single-phase system offers economical advantages for the infrastructures of about 30% in terms of investment, exploitation and maintenance. In early ages, due to its very simple diagram, there was no necessity to integrate power electronics in substations. However, for the last decade, the interest in power electronic equipments raised since they can provide the solution for network optimization when traffic increases or when a difficulty is foreseen for a substation implementation. Two types of devices are implemented today on the French Railway Network: Reactive Power compensators and Voltage Unbalance compensators. This thesis presents an investigation into new topologies based on the concept of “Chopper Controlled Impedances”(CCI). Compared to existing solutions, the new topologies show interesting features in terms of semi-conductor losses reduction and volume of reactive components. The manuscript is developed through three main parts: Firstly, the French railways system is introduced and the interest in installing power electronic compensators in substations is highlighted. After a brief description of currently used solutions, the CCI concept is presented: the use of Pulse Width Modulated AC Choppers allows achieving structures which behave as variable impedances. In the second part, the use of CCI structures in reactive power compensation is investigated. The SNCF substation of Revest is under study. It is equipped by a 60MVA single phase transformer with the primary side connected to a 225kV transmission line. Based on the step-down or step-up functioning mode of CCIs, two topologies of reactive power compensator are presented. The converter design is developed on the base of a measurement campaign carried out at the substation. Numerical simulations using real current and voltage waveforms are presented. Finally, experimental results carried out at the SNCF test platform on a 1.2MVAR prototype are shown. In the last part, the problem of voltage unbalance is treated. Using the concept of CCI, the feasibility of an active Steinmetz circuit based on AC choppers is explored. As a case study, the substation of Evron is considered. It is a 32MVA substation connected to a 90kV transmission line. Measurements carried out on the substation site allow the compensator design and the possibility to consider real waveforms for current and voltage in numerical simulations. A comparison with classical solution based on two levels VSI and three levels NPC-VSI highlights the advantages of the proposed solution. Calculation and simulation results show that the stored energy in reactive elements is reduced by a factor six whereas the semiconductor losses are 40% lower. Experimental results obtained on a scaled demonstrator (1.5 kVA) validate the principle of the active Steinmetz circuit
Raimondo, Giuliano. "Power quality improvements in 25 kV 50 Hz railways substation based on chopper controlled impedances." Phd thesis, Institut National Polytechnique de Toulouse - INPT, 2012. http://tel.archives-ouvertes.fr/tel-00682719.
Full textTurner, Clifton C. "Design and implementation of a zero-voltage-switching, pulse-width-modulated, high-frequency, resonant buck chopper." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1999. http://handle.dtic.mil/100.2/ADA371024.
Full text"September 1999". Thesis advisor(s): Robert W. Ashton, John G. Ciezki. Includes bibliographical references (p. 137-138). Also Available online.
Benmessaoud, Messaouda. "Recherches sur l'Acheuléen et l'Ahaggar : les matières premières lithiques ; L'outillage lithique, rapport éclats/outils ; Le cadre statigraphique et chronologique : (Exemple du site Téhéntawek-Idelès)." Thesis, Paris 1, 2014. http://www.theses.fr/2014PA010575/document.
Full textThe thesis presented here updates the old data on the Acheulian of the Ahaggar, although these date are few in number and all dated 20th century. But it is obvious to mention them to borrow a new er of research on the subject. Despite the fruitful discoveries in many lower Palaeolithic sites in the Ahaggar, no scientific interest have been provided to many lithic collections interposed in several laboratories for scientific research. The new site “Téhéntawek” Acheulean discovered in the region of Idelès in the central Sahara of the Ahaggar and excavated with new pedagogical methods introduced in the present prehistory, has delivered in 2008 and 2010 an interesting lithic materials representative of the Acheulian industry. These approaches are considered renovative of the Saharan prehistory. The appropriate and adequate environmental of exploration, the adaptation of work to the rocky terrain of the Ahaggar region, have allowed us to reconsider the Saharan terrain. The study of lithic technology has provided a variety of tools and coexisted chopper, biface and cleaver, many raw chips, very consistent with the nucleus. Lithic raw materials used for shaping are local. The results of analyses on the sediments provided new data, including an opening on the paleoenvironment of the Ahaggar. Thus Téhéntawek site offered us with relevant information on the mastery of man in this currently Saharan environment
Bělíček, David. "Řízení krokového motoru mikrokontrolérem." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2009. http://www.nusl.cz/ntk/nusl-218073.
Full textSuperczynski, Matthew J. "Analysis of the Power Conditioning System for a Superconducting Magnetic Energy Storage Unit." Thesis, Virginia Tech, 2000. http://hdl.handle.net/10919/34860.
Full textMaster of Science
Sámelová, Vendula. "Technologické parametry elektrojiskrového řezání drátovou elektrodou." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2009. http://www.nusl.cz/ntk/nusl-228642.
Full textAmghar, Bilal. "Modélisation, observabilité et commande de convertisseurs multicellulaires parallèles dans un environnement dédié." Phd thesis, Université de Cergy Pontoise, 2013. http://tel.archives-ouvertes.fr/tel-00880757.
Full textArsoy, Aysen. "Electromagnetic Transient and Dynamic Modeling and Simulation of a StatCom-SMES Compensator in Power Systems." Diss., Virginia Tech, 2000. http://hdl.handle.net/10919/27225.
Full textPh. D.
Duan, Hongxu. "Generation and printing of strictly monodisperse droplets." Master's thesis, University of Central Florida, 2013. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5931.
Full textM.S.M.E.
Masters
Mechanical and Aerospace Engineering
Engineering and Computer Science
Mechanical Engineering; Miniature Engineering Systems
Lowinsky, Luc Anthony. "Nouvelle topologie de Compensateur de Puissance Réactive pour les Réseaux Ferrés 25 kV / 50 Hz." Thesis, Toulouse, INPT, 2010. http://www.theses.fr/2010INPT0036/document.
Full textThe work presented in this thesis is the result of collaboration between the Static Converters research group of LAPLACE Laboratory and the department "Installations Fixes de Traction Electrique" of the Engineering Division of the French Railways company, SNCF. Nowadays, most of the traffic in 25 kV – 50 Hz lines is achieved by old locomotives equipped with thyristor rectifiers. As traffic and load increase, reactive power compensation devices are required to keep the overhead line voltage at acceptable level and to reduce the spending for reactive power. The basic power factor correction is completed by fixed compensation banks. But the difficulty of such configuration is the no-load operation of overhead lines. The voltage can increase out of the 29 kV standard limit and to avoid this problem, variable reactive power compensator is often added to the fixed compensation banks. Nowadays, SNCF is equipped with thyristor based static VAR compensators (SVC). The main drawback of this topology is the requirement of a large LC shunt filter tuned for the third harmonic. The goal of this thesis is to find a new high-efficiency topology of STATic COMpensator (STATCOM) using PWM control to minimize the filtering components. The first part of this thesis focuses on a comparative study of different topologies in terms of semiconductor losses and filter elements size. The results of this study show that the topologies based on PWM AC Chopper are the most interesting solutions to achieve the compensator. The second part of the work concerns the influence of the connection of a STATCOM to a substation and focuses on the harmonic interactions with locomotives. The study case concerns a high traffic substation where a 3 MVAR STATCOM should be installed. Substation output current measurement was carried out in order to analyze its harmonic content. Models of the substation and the STATCOM are then proposed and simulations using real current waveforms are performed. Finally, this simulation study helps to refine the features of the AC Chopper topology and its filter elements. It highlights the advantage of a solution, with boost AC Choppers which operate without transformer and reuse the fixed compensation banks already installed in the substation as voltage divider and filter. To validate the principle of this new topology of STATCOM, a 1.2 MVAR prototype is built in LAPLACE laboratory and tested on a SNCF test platform
Schmakat, Philipp [Verfasser], PETER [Akademischer Betreuer] [Gutachter] BOENI, and Winfried [Gutachter] Petry. "Neutron Depolarisation Measurements of Ferromagnetic Quantum Phase Transitions : Wavelength-Frame Multiplication Chopper System for the Imaging Instrument ODIN at the ESS / Philipp Schmakat ; Gutachter: Peter Böni, Winfried Petry ; Betreuer: Peter Böni." München : Universitätsbibliothek der TU München, 2016. http://d-nb.info/1115332848/34.
Full textPlogmaker, Stefan. "Techniques and Application of Electron Spectroscopy Based on Novel X-ray Sources." Doctoral thesis, Uppsala universitet, Yt- och gränsskiktsvetenskap, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-168799.
Full textPierleoni, Enrico. "Analisi e progetto del Z-Source Buck Converter." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2018. http://amslaurea.unibo.it/16305/.
Full textNøland, Jonas Kristiansen. "A New Paradigm for Large Brushless Hydrogenerators : Advantages Beyond the Static System." Doctoral thesis, Uppsala universitet, Elektricitetslära, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-317780.
Full textPavlík, Ondřej. "Měnič pro malý 3f asynchronní motor." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2013. http://www.nusl.cz/ntk/nusl-219915.
Full textBalasubramanian, Sidharth. "Low-voltage and low-power libraries for Medical SoCs." The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1259776639.
Full textGomes, Evandro de Carvalho. "PROJETO DE CONTROLADORES PARA CONVERSORES CC-CC PELA ABORDAGEM DO DESACOPLAMENTO DE ESTADOS." Universidade Federal do Maranhão, 2009. http://tedebc.ufma.br:8080/jspui/handle/tede/422.
Full textIn this work, we propose to analyze the controller design of a classical dc-dc converter in a different manner. Instead of the traditional mathematics transfer function analysis, we will describe the block diagram of the plant to be controlled using Space-State Averaging, decoupling the states effects one acts each other and designing the controllers individually. With this technique, we can obtain first order transfer function allowing easier synthesis and design of the involved controllers. Outcomes are compared to controllers based on K-factor approach which are entirely applicable in academy and industry environment.
Neste trabalho propomos analisar o projeto de controladores para conversores cc-cc clássicos de uma forma diferente da tradicional análise matemática da função de transferência, descrevendo o diagrama de blocos da planta a ser controlada, desacoplando os efeitos que um estado exerce sobre o outro e projetando os controladores individualmente. Com essa técnica, obtêm-se funções de transferências de primeira ordem o que permite um projeto e síntese mais fácil dos controladores envolvidos. Os resultados são comparados com os controladores baseados na abordagem do fator K, por se tratar de uma abordagem amplamente aplicada no meio acadêmico e industrial.
Kauffmann, Claude. "Conception et optimisation d'une alimentation de puissance pour fauteuil roulant électrique : un microcontrôleur régit la commande optimale qui s'adapte au handicap." Vandoeuvre-les-Nancy, INPL, 1993. http://www.theses.fr/1993INPL021N.
Full textKristiansson, Fredric. "Torn, Spun and Chopped : Various Limits of String Theory." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-3930.
Full textKlauss, Catherine Ellen. "Measuring Velocities in an Atom Interferometer Using Chopped Electric Fields." Thesis, The University of Arizona, 2011. http://hdl.handle.net/10150/144542.
Full textBöhnke, Dietmar. "Liz Lochhead, 'Mary Queen of Scots Got Her Head Chopped Off' (1987)." Wissenschaftlicher Verlag, 2006. https://ul.qucosa.de/id/qucosa%3A32035.
Full textWinsryg, Margaret Diggles 1952. "UTILIZATION OF CHOPPED WHEAT STRAW IN COMPLETE RATIONS FOR LACTATING DAIRY COWS." Thesis, The University of Arizona, 1987. http://hdl.handle.net/10150/276446.
Full textMansouri, Abdelkader. "Le moteur asynchrone monophase à vitesse variable : modélisation et alimentation par convertisseurs statiques." Vandoeuvre-les-Nancy, INPL, 1995. http://www.theses.fr/1995INPL096N.
Full textKuzdas, Jan. "Pomocné měniče v systémech elektrické trakce." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2009. http://www.nusl.cz/ntk/nusl-217888.
Full textFazio, James A. "Durability of Chopped FiberReinforced Polymeric Composites for use in Experimental Automotive Fuel Cells." Thesis, Virginia Tech, 2003. http://hdl.handle.net/10919/46070.
Full text
A chopped carbon fiber epoxy composite (Material A) and a chopped glass fiber epoxy composite (Material B) were exposed at 85°C to air, water, and a 50/50 water/antifreeze mixture, and periodically examined for tensile, compression, and flexural strengths at various temperatures. Following 2000 hours (83 days) of exposure, Materials A & B did not reach full saturation. Fatigue tests were conducted at various load levels and temperatures to determine their effect on cycles to failure, and carpet plots were generated. Blister formation in aged composites led to reductions in material properties as great as 25% to 75%. A mechanistic explanation was developed for the formation of blisters in the epoxy composite. Recommendations for material improvement and feasibility of material use for fuel cell manifolds and pressure plates were made.
Master of Science
Heil, Joshua W. "Methods of Processing Kenaf Chopped Strand Mats for Manufacturing Test Specimens and Composite Structures." DigitalCommons@USU, 2015. https://digitalcommons.usu.edu/etd/4376.
Full textZein, El Din Ashraf. "Comparaison d'architecture pour la commande des machines électriques." Vandoeuvre-les-Nancy, INPL, 1993. http://www.theses.fr/1993INPL034N.
Full textBahmer, Andreas. "Computer simulation of chopper neurons." Phd thesis, 2007. https://tuprints.ulb.tu-darmstadt.de/817/1/Promotion_bahmer.pdf.
Full textFaizy, A., and S. Kumar. "DC Motor Control using Chopper." Thesis, 2010. http://ethesis.nitrkl.ac.in/1677/2/amir_final_project_report.pdf.
Full textCheng, Lan-Shan, and 鄭嵐瑄. "Design of CMOS Chopper Temperature Sensor." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/61364617988166674644.
Full text國立清華大學
電子工程研究所
92
A CMOS chopper temperature sensor is present. Accurate bandgap reference and PTAT voltage are designed. The circuit uses substrate bipolar transistors as a temperature sensing element. In order to reduce the effect of the offset voltage of the operational amplifier in the circuit, we use the chopper stabilization technique to eliminate the offset voltage. The complete system is realized in a double metal 0.6�慆 CMOS process, and the chip size is 1.3mm2. In the temperature range from -55 to 125�aC, the total inaccuracy of bandgap reference and PTAT voltage is 3.5�aC without calibration. The circuit operates at a typical supply voltage, 3.3V, and its supply current is 150�嫀. Experiment results of the bandgap reference and PTAT voltage and simulated design of the circuit are discussed in this thesis.
Deepak, M. L., and A. Mishra. "Speed control of DC motorusing chopper." Thesis, 2014. http://ethesis.nitrkl.ac.in/5954/1/E-121.pdf.
Full text