Tesis sobre el tema "Active compensation"
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Müller, Jonas [Verfasser]. "Active Toe-Angle Compensation / Jonas Müller". München : Verlag Dr. Hut, 2013. http://d-nb.info/1035049937/34.
Texto completoBush, Robert Walton. "Design of an active acceleration compensation robot". Thesis, Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/19314.
Texto completoAnwar, Saeed. "Active Power Compensation of Microgrid Connected Systems". University of Akron / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=akron1406653103.
Texto completoCarpenter, Paul Andrew. "Active filter current compensation for transmission optimisation". Master's thesis, University of Cape Town, 2015. http://hdl.handle.net/11427/24291.
Texto completoDecker, Michael Wilhelm. "Active acceleration compensation for transport of delicate objects". Thesis, Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/21258.
Texto completoPinfold, W. R. "An active motion compensation system using multiple bodies". Thesis, University of Strathclyde, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.381330.
Texto completoPomierski, Wojciech. "Position signal filtering for hydraulic active heave compensation system". Technische Universität Dresden, 2020. https://tud.qucosa.de/id/qucosa%3A71095.
Texto completoGranjon, Pierre. "Contribution à la compensation active des vibrations des machines électriques". Phd thesis, Grenoble INPG, 2000. http://tel.archives-ouvertes.fr/tel-00101286.
Texto completodes courants de commande additionnels afin d'engendrer des forces radiales sur le stator. Celui-ci répond alors par des vibrations additionnelles qui interagissent avec les vibrations naturelles de la machine. Le but de ce
système de contrôle actif est donc de calculer la valeur ”optimale” de ces courants, permettant de minimiser la puissance des signaux vibratoires au niveau de capteurs accéléromètriques fixés à la périphérie du stator.
Dans un premier temps, la modélisation du transfert situé entre les commandes et les contre-vibrations engendrées conduit à un système linéaire et variant périodiquement dans le temps (LVPT). La fréquence fondamentale de ses variations est alors proportionnelle à la fréquence de rotation de la machine.
Après avoir montré l'insuffisance des méthodes classiques de contrôle actif pour cette application, une étude théorique détaillée des systèmes LVPT est réalisée. Elle conduit à la définition d'une matrice de transfert, jouant le même rôle que la fonction de transfert classique employée pour les systèmes linéaires et invariants dans le temps. Cette matrice permet d'écrire simplement la relation entre les entrées et les sorties du système
considéré dans le domaine fréquentiel.
Finalement, les résultats précédents sont utilisés afin de déterminer l'expression optimale des courants de commande minimisant la puissance des signaux de vibrations mesurés. Un algorithme récursif permet également de converger vers cet optimum, et de prendre en compte d'éventuelles variations des perturbations vibratoires à éliminer. Divers résultats, obtenus sur des signaux synthétiques puis sur des signaux vibratoires réels, illustrent les performances obtenues par ce système de contrôle actif. Il permet une réduction significative des vibrations
synchrones au phénomène de rotation, sans pour autant modifier les caractéristiques des autres. Enfin, son implantation en temps-réel dans un processeur numérique de traitement de signal est discutée et réalisée.
Argillander, Joakim. "Active Phase Compensation in a Fiber-Optical Mach-Zehnder Interferometer". Thesis, Linköpings universitet, Informationskodning, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-166419.
Texto completoDet här examensarbetet undersöker fenomenet fasstabilitet i en fiber-optisk MZI (Mach-Zehnder-Interferometer). MZI:n är en viktig byggsten i optiska system som används till experiment med både kontinuerligt emitterande lasrar och med enskilda fotoner. Genom att dela upp inkommande ljus i två strålar och låta det interferera med sig själv så bildas ett interferensmöster vid utgången vilket kan användas för att koda information. Det här är huvudprincipen bakom, till exempel, experiment inom QKD (kvantnyckeldistribution, eng: Quantum Key Distribution). Denna interferens förutsätter en koherens (högre än längdskillnaden mellan strålarna) mellan strålarna som det inkommande ljuset är uppdelat i. Särskilt måste fasen hos de bägge strålarna vara lika för att åstadkomma fullständig konstruktiv intereferens. Om en stråle är fasförskjuten (i förhållande till den andra) på grund av att ljuset har färdats en längre sträcka så uppnås endast delvis konstruktiv interferens. Om fasförskjutningen även varierar med tiden så leder det till ett system där experiment inte längre kan pålitligt utföras. Sådana fluktuationer är orsakade av termiskt, akustiskt samt mekaniskt varierande effekter. Fiberoptiska interferometrar är särskilt känsliga mot förändringar i vågledarnas längd. Detta på grund av att det fiberoptiska mediet dras ihop respektive sträcks ut med temperaturen, samt att fibern har en större ytarea som cirkulerande luft kan påverka mekaniskt jämfört med interferometrar konstruerade av bulkoptik. I det här examensarbetet presenteras en lösning på problemet med miljöinducerad fasskift genom att utvärdera reglertekniska återkopplande algoritmer. Algoritmerna PID (Proportionell-, Integrerande-, Deriverande regulator) samt ICA (Inkrementell Regleralgoritm, eng: Incremental Control Algorithm) har undersökts och deras prestanda har jämförts med samt utan avskärmning. Algoritmerna har implementerats i en FPGA (fältprogrammerbar grindmatris, eng: Field-Programmable Gate Array) och regulatorn styr en elektrooptisk fasmodulator som kan addera en fasförskjutning till en av ljusstrålarna i MZI:n. Resultat visar att passiv avskärmning inte är tillräckligt utan behöver användas tillsammans med aktiv reglering för att uppnå stabilitet över en längre tidsperiod. Detta examensarbete visar på att en signifikant förbättring i den optiska stabiliteten kan uppnås med aktiv reglering jämfört med en interferometer utan aktiv fasreglering.
Raju, N. Ravisekhar. "A decoupled converter topology for active compensation of power systems /". Thesis, Connect to this title online; UW restricted, 1996. http://hdl.handle.net/1773/5847.
Texto completoPaschal, Matthew James 1964. "Compensation techniques for gain-bandwidth effects of active RC filters". Thesis, The University of Arizona, 1992. http://hdl.handle.net/10150/278081.
Texto completoTowliat, Abolhassani Mehdi. "Integrated electric alternators/active filters". Diss., Texas A&M University, 2004. http://hdl.handle.net/1969.1/268.
Texto completoAbolhassani, Mehdi Towliat. "Integrated electric alternators/active filters". Texas A&M University, 2004. http://hdl.handle.net/1969.1/268.
Texto completoStöppler, Guido [Verfasser]. "Active compensation of structural oscillations on high dynamic gantry machines / Guido Stöppler". Aachen : Shaker, 2005. http://d-nb.info/1186588349/34.
Texto completoBach, Susan Elizabeth. "Chirp compensation in active mode-locked semiconductor diode laser using a DFB". Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/36504.
Texto completoNdiaye, Abdoul Ousmane. "Compensation active des ondulations de couple d'un moteur synchrone à aimants permanents". Besançon, 2002. http://www.theses.fr/2002BESA2038.
Texto completoThe work carried out in this thesis presents a method of torque ripple compensation in permanent magnets synchronous motor without polar parts. The aim is the improvement of the electromechanical conversion quality by minimizing the torque ripple and the vibrations. The thesis starts with a presentation of the torque characteristics of the studied synchronous motor and the different causes of its torque ripples. In the second chapter, a computation method of optimal current harmonics is developed : starting from the back electromotive force harmonics of a magnet synchronous motor without polar parts, a minimal number of current harmonics are calculated to cancel the torque ripple while optimizing the efficiency. The third and fourth chapters present the test bench and the experimental study of the vibrations. The bench makes it possible one the one hand to fed synchronous motor with various current waveforms using a control system realized with the dSPACE tool and on the other hand to measure the vibrations of the system (bench-motor)
da, Silva Neddef N. (Nedio). "Active phased array transceiver:an operational compensation for a multiple phase shifter system". Master's thesis, University of Oulu, 2018. http://jultika.oulu.fi/Record/nbnfioulu-201805151790.
Texto completoSverdrup-Thygeson, Jørgen. "Modeling and Simulation of an Active Hydraulic Heave Compensation System for Offshore Cranes". Thesis, Norwegian University of Science and Technology, Department of Engineering Cybernetics, 2007. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-9531.
Texto completoThis thesis deals with the mathematical modeling of hydraulic heave compensation systems. When performing operations such as launch and recovery of remote operated vehicles and lowering subsea installation parts to the sea floor, it is important to attenuate unwanted load motion caused by elongation of the cable and heave motion of the vessel. Quite often, such operations must be put off while waiting for the weather to calm down. Extending the window of operations by developing equipment that can handle varying sea states can result in significant cost savings. There exist both electric and hydraulic heave compensation devices, but the main focus of this thesis is on the hydraulic configurations. A mathematical model is developed in Simulink, and simulations are performed for long-crested seas with values corresponding to the average sea conditions in the North Sea.
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.
Texto completoDavies, David Bradley. "Analysis of active compensation for shock, vibration, and wind-up in disk drives". Thesis, Massachusetts Institute of Technology, 1991. http://hdl.handle.net/1721.1/13301.
Texto completoSoares, Guilherme Márcio. "Capacitance reduction in off-line led drivers by using active ripple compensation techniques". Universidade Federal de Juiz de Fora (UFJF), 2017. https://repositorio.ufjf.br/jspui/handle/ufjf/6044.
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CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Este documento apresenta uma nova técnica para a minimização da ondulação de baixa frequência, típica de conversores para o acionamento de LEDs alimentados a partir da rede elétrica. Esta estratégia baseia-se na modulação em baixa frequência da razão cíclica do conversor de modo que a ondulação de corrente possa ser reduzida e, consequentemente, as capacitâncias de filtragem do conversor possam ser minimizadas. Esta técnica foi desenvolvida para a aplicação em conversores de malha única, como é o caso de conversores de estágio único ou mesmo dois estágios integrados. A modulação da razão cíclica é projetada de maneira que o comportamento de baixa frequência das principais variáveis do conversor seja alterado, permitindo uma redução da ondulação da corrente de saída ao custo de um incremento cotrolado no conteúdo harmônico da corrente de entrada. Duas possíveis metodologias para a implementação da técnica proposta são discutidas ao longo do trabalho. A primeira envolve a injeção de harmônicas específicas no sinal da razão cíclica do conversor através de ramos adicionais na estrutura de controle. Esta abordagem foi aplicada para projetar um controlador de LEDs baseado em um conversor flyback e também em uma topologia integrada baseada na conexão cascata de dois conversores Buck-boost. Este estudo inicial foi expandido para outros conversores e uma análise generalizada acerca da influência da modulação da razão cíclica no comportamento de controladores de LED alimentados a partir da rede elétrica é apresentada. A segunda metodologia para a implementação da compensação ativa da ondulação de baixa frequência do conversor é baseada na otimização de um controlador proporcional-integral a fim de que tal elemento influencie não só no comportamento dinâmico do circuito, mas também na característica de baixa frequência do conversor. Por fim são discutidas as principais contribuições da tese e algumas propostas para trabalhos futuros são apresentadas
This document presents a novel approach for low-frequency output current ripple minimization in off-line light-emitting diode (LED) drivers. This strategy is based on the large-signal modulation of the duty-cycle so that the output ripple can be reduced and, consequently, the required filtering capacitances of the converter can be somehow decreased. This technique is devised to be used on converters in which a single control loop is employed, such as off-line single-stage or integrated converters. The duty-cycle modulation is used to change the shape of the main waveforms of the converter, especially the input and output currents. This allows for a reduction of the output current peak-to-peak ripple while the harmonic content of the input current is increased but kept within the limits imposed by the IEC standard. Two methodologies for implementing the proposed technique are discussed along the text. The first one is related to the injection of harmonic components to the duty cycle signal by means of additional branches inserted in the conventional control structure. This approach was applied to design an off-line flyback-based LED driver and also a circuit based on the Integrated Double Buck-boost converter. This first study was expanded to other topologies and a generalized analysis regarding the impact of the duty cycle modulation on off-line converters is then presented. The second methodology for implementing the ripple compensation is based on the optimization of a proportional-integral controller so that this element is designed to influence not only in the dynamic behavior of the circuit, but also in its low-frequency characteristic. Finally, the main contributions of this work are discussed and the proposals for future works are presented.
Reyes-Moraga, Eduardo Felipe. "Predictive control of a direct series resonant converter with active output voltage compensation". Thesis, University of Nottingham, 2015. http://eprints.nottingham.ac.uk/31263/.
Texto completoBó, Antônio Padilha Lanari. "Compensation Active de Tremblements Pathologiques des Membres Supérieurs via la Stimulation Electrique Fonctionnelle". Thesis, Montpellier 2, 2010. http://www.theses.fr/2010MON20162/document.
Texto completoTremor, defined as an involuntary, approximately rhythmic and roughly sinusoidal movement, is one of the most common movement disorders. It is not a life-threatening pathology, but it often decreases significantly the person's quality of life. Today, effective treatments for pathological tremor are not yet available, since current pharmacological and surgical alternatives still present limitations with respect to effectiveness, risks, and costs. A different approach is the use of assistive technologies, such as upper limb exoskeletons or Functional Electrical Stimulation (FES).Nevertheless, the design of active tremor compensation systems based on these technologies presents several challenges. Such a system must be able, for instance, to attenuate tremor while minimizing the induced fatigue, pain, and discomfort. Also, it must be able to distinguish between pathological tremor and voluntary motion, in order to reduce interference on intentional movements.This thesis is focused then in evaluating the use of FES to attenuate the effects of tremor. A first contribution concerns the use of neuromusculoskeletal models to study the effects reflex pathways may produce on tremor dynamics, as well as how FES-induced co-contraction may modulate joint impedance. Also, an online algorithm to estimate tremor and its features while simultaneously filtering voluntary motion has been proposed and validated with tremor patients. Finally, a FES system to attenuate tremor based on impedance control has been designed and evaluated on tremor patients, while a second strategy using closed-loop FES control has been tested on healthy subjects
Chen, Weiqun. "A Microcontroller Configured Active Analog Phase Shifter at 1.96GHz". University of Cincinnati / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1273841250.
Texto completoReader, Daniel Martin. "Nonlinear Mr Model Inversion for Semi-Active Control Enhancement With Open-Loop Force Compensation". Thesis, Virginia Tech, 2009. http://hdl.handle.net/10919/32660.
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For simplicity, MR dampers are often assumed to have a linear relationship between the current input and the force output at a given relative velocity. Often this assumption is made implicitly and without knowledge of the underlying nonlinearity. This thesis shows that the overall performance of a semi-active Skyhook control system can be improved by explicitly inverting the nonlinear relationship between input current and output force. The proposed modification will work with any semi-active control algorithm, such as Skyhook, to insure that the controller performance is at least as good as the performance without the proposed modification. This technique is demonstrated through simulation on a quarter-vehicle system.
Hysteretic damping effects are incorporated into the modification by application of simple open loop force compensation. Laboratory testing of the hysteretic inversion process was performed with the goal of emulating an ideal linear damper without hysteresis. These results are compared with the implicit assumption thus providing a basis for validating the benefits of the improved methodology.
Master of Science
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.
Texto completoThe 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
Humphreys, Heather Celeste. "Modeling and compensation for biodynamic feedthrough in backhoe operation". Thesis, Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/37254.
Texto completoPrasai, Anish. "Direct dynamic control of impedance for VAR and harmonic compensation". Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/42816.
Texto completoKhalsa, Harnaak Singh. "Generalised power components definitions for single and three-phase electrical power systems under non-sinusoidal and nonlinear conditions". Monash University. Faculty of Engineering. Department of Electrical and Computer Systems Engineering, 2008. http://arrow.monash.edu.au/hdl/1959.1/42420.
Texto completoLee, Bong-ha. "Active power system compensator with fuzzy vector controller". Thesis, Queensland University of Technology, 2002. https://eprints.qut.edu.au/36152/1/36152_Lee_2002.pdf.
Texto completoDang, Anh X. H. "Theoretical and experimental development of an active acceleration compensation platform manipulator for transport of delicate objects". Diss., Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/17277.
Texto completoIngram, David. "An Evaluation of Harmonic Isolation Techniques for Three Phase Active Filtering". Thesis, University of Canterbury. Electrical and Computer Engineering, 1998. http://hdl.handle.net/10092/1260.
Texto completoWang, Lei. "Design and implementation of a three-phase three-wire thyristor controlled LC-coupling hybrid active power filter with low dc-link voltage and wide compensation range". Thesis, University of Macau, 2017. http://umaclib3.umac.mo/record=b3691876.
Texto completoSchneider, Jason C. y Neil L. Ebuen. "The potential effects of the Defense Business Board military compensation task groups 2011 recommendations on active-duty service member retirement". Thesis, Monterey, California. Naval Postgraduate School, 2012. http://hdl.handle.net/10945/27899.
Texto completoApproved for public release; distribution is unlimited
In July 2011, the Defense Business Board (DBB) made recommendations to the Secretary of Defense for modernizing the military retirement system. If implemented, the plan would significantly modify military retirement as it has existed since its inception, shifting it from a defined benefit plan to a defined contribution plan. In this study, we compared the current defined benefit retirement plan to a hypothetical, retrospective defined contribution plan using the constraints proposed by the Defense Business Board Military Compensation Task Group. We also gathered service members sentiments about the current military retirement system and proposed changes. This is an important topic because it revealed the potential financial effects on service members retirement savings, and government and departmental challenges should a new retirement system be implemented. In this study, we created a mathematical model to simulate accumulated savings under the proposed defined contribution (DC) plan, and then compared it to the lump-sum equivalent of the existing defined benefit (DB) plan. Our model considered three investment strategies for asset allocation for active-duty personnel (i.e., officer and enlisted) spanning a 20-year career beginning in January 1, 1991, and ending in December 31, 2010. Additionally, our study surveyed active-duty service members assigned to the Naval Postgraduate School and personnel assigned to the II Marines Expeditionary Force. Through the survey, we gathered feedback on service members attitudes toward military retirement, in general, and proposed changes to the military retirement system. For an officer, the model showed that under a DC plan, accumulated savings were only 37.5% of the lump-sum equivalent of total annuities received under the current DB plan. Likewise, for an enlisted service member, this value was 31.9%. The survey showed that an overwhelming majority of service members are in favor of retaining the current DB retirement system, or, if the retirement system must be replaced, doing so gradually.
Zafeiropoluos, Andreas. "An MMC-based topology with Dual-Active-Bridge power channels for load balancing in 50 Hz-railway applications". Thesis, KTH, Skolan för elektro- och systemteknik (EES), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-201656.
Texto completoSyftet med detta examensarbete är att studera de svårigheter som elektrifierade järnvägar står inför.När systemet utgörs av växelström kan tågen ses som en enfas last, vilket kan skapa avsevärdaobalanser i nätet då det matas från två intilliggande faser. En alternativ systemdesign för att uppnåen god effekt leverans uppnås då effekten är matad till kontaktledningen genom statiska frekvensomräknare (SFCs), detta kan dock vara en kostsam lösning. Ett annat alternativ är att användastatisk shunt kompensation (STATCOMs) som selektivt kan hantera den obalanserade effekten föratt uppnå symmetri och balans i järnvägslasten, sett från nätets sida.Modulära multiomriktare (MMCs) är en ledande teknik för omriktare till applikationer på mellanochhögspännings nivå, till exempel för lastbalans och reaktiv kompensering. Detta projektanalyserar modulära multiomriktare för lastbalansering i järnvägssystem. Kraven för dennaapplikation leder till en potentiell svaghet i MMCs där den asymmetriska karaktären på lastenkräver högre märkeffekt jämfört med konventionella omriktare. Detta på grund av de komponentersom återskapar symmetri och balans i kondensator spänningarna i submodulerna.Här analyseras en reducerad variant av MMC-baserad topologi med enbart två grenar för att mötakraven på järnvägens lastbalans. Denna kedjelänk-kompensator använder dc-dc omriktare för attstyra effektflödet till lasten vid obalanserad effekt, utan att för den skull överdimensionerahalvledarna i den ordinarie strömvägen.
Xue, Kai. "Modal filtering for active control of floor vibration under impact loading". Kyoto University, 2018. http://hdl.handle.net/2433/232024.
Texto completoMérad, Manelle. "Investigations on upper limb prosthesis control with an active elbow". Thesis, Paris 6, 2017. http://www.theses.fr/2017PA066615/document.
Texto completoProgress in mechatronics has enabled the improvement of upper limb prosthetics increasing the grasps catalog. However, a gap has been growing between the prosthesis technological possibilities and the methods to control it. Indeed, common myoelectric control strategy remains complex, especially for transhumeral amputees who can have an active elbow in addition to a prosthetic wrist and hand. Since most transhumeral amputees have a mobile residual limb, an interesting approach aims at utilizing this mobility to control intermediate prosthetic joints, like the elbow, based on the shoulder/elbow coordination observed in healthy movements. This thesis investigates the possibility of controlling an active prosthetic elbow using the residual limb motion, measured with inertial measurement units, and knowledge of the human motor control. A primary focus has been targeting the reaching movement for which a model has been built using regression tools and kinematic data from several healthy individuals. The model, implemented on a prosthesis prototype, has been tested with 10 healthy participants wearing the prototype to validate the concept, and with 6 amputated individuals. These participants also performed the task with a conventional myoelectric control strategy for comparison purpose. The results show that the inter-joint coordination-based control strategy is satisfying in terms of intuitiveness and reduction of the compensatory strategies
Wang, Yu. "Tunable C Band Coupled-C BPF with Resonators Using Active Capacitor and Inductor". Wright State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=wright1472479817.
Texto completoBarka, Noureddine. "Développement d'un système de mesure en temps réel des erreurs dans les machines-outils à axes multiples pour une compensation active". Thèse, [Rimouski, Québec] : Université du Québec à Rimouski, 2005.
Buscar texto completoTitre de lʹécran-titre (visionné le 31 août 2006). Mémoire présenté à l'Université du Québec à Rimouski comme exigence partielle du programme de maîtrise en ingénierie. Comprend un résumé. CaQRU CaQRU CaQRU Bibliogr.: f. 97-99. Paraît aussi en éd. imprimée. CaQRU
Zhang, Yigong. "ACTIVE CURRENT INJECTION METHOD FOR LIMITING GROUND FAULT CURRENT HARMONICS IN UNDERGROUND COAL MINES". UKnowledge, 2014. http://uknowledge.uky.edu/mng_etds/15.
Texto completoRaimondo, 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.
Texto completoThis 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
Besset, Pierre. "Automatic control of a marine loading arm for offshore LNG offloading offloading". Thesis, Paris, ENSAM, 2017. http://www.theses.fr/2017ENAM0011/document.
Texto completoMarine loading arms are articulated structures that transfer liquefied gas between two vessels. The flanging operation of the loading arm to the receiving tanker is very sensitive. This thesis aims to robotize a loading arm so it can flange automatically. The required accuracy for the connection is very high. A calibration procedure is thus proposed to increase the accuracy of loading arms. Moreover a jerk-limited trajectory generator is developed to smoothly drive the arm without inducing oscillation. This element is important because the structures of loading arms have a very low stiffness and easily oscillate, as highlighted by modal analyses.A predictive active compensation algorithm is developed to track without delay the relative motion between the two vessels. This algorithm relies on an artificial neural network able to predict the evolution of this relative motion. Finally this thesis presents the first automatic connection of an offshore loading arm. The success of the final tests validate the feasibility the automatic connection and the validity of this approach
Nascimento, Bruno Moreira. "Implementação de um controle digital para o compensador regenerativo de potência ativa /". Ilha Solteira : [s.n.], 2009. http://hdl.handle.net/11449/87086.
Texto completoBanca: Falcondes Jose Mendes de Seixas
Banca: Hari Bruno Mohr
Resumo: A tendência dos sistemas de energia elétrica é uma operação cada vez mais próxima de seus limites operacionais. A presença de equipamentos que utilizam a eletrônica de potência, no controle e condicionamento da energia, é cada vez mais freqüente. A utilização de conversores como fonte de tensão, associados a elementos armazenadores de energia como, por exemplo, a bateria de sódio-enxofre, com alta densidade de energia, alta eficiência na carga e descarga e ainda um longo ciclo de vida, é a configuração básica de um Compensador Regenerativo de Potência Ativa. Compensação regenerativa de potência é um conceito que permite o armazenamento de energia em períodos favoráveis sob o ponto de vista dos custos da energia elétrica. Este conceito de compensação baseia-se no armazenamento da energia excedente ao longo do dia, nos períodos de menor tarifação, para utilizá-la nos horários de ponta (sobre-tarifa), aproveitando-se as vantagens contratuais de consumo de energia fora de ponta e promovendo-se uma melhor equalização de consumo, permitindo uma redução no contrato de demanda. Portanto, na compensação regenerativa de potência ativa, os períodos de consumo de energia são deslocados, com o objetivo de se obter redução na tarifa. Este conceito mostra-se interessante em sistemas com tarifação do tipo horo-sazonal, como é o caso brasileiro. Com o objetivo de se verificar tal troca de potência ativa, um modelo trifásico foi implementado e simulado. Os controles da potência ativa trocada entre o compensador e o sistema e da tensão na barra na qual o mesmo está instalado são realizados independentes e por controladores do tipo PID. Os sinais de controle dos interruptores semicondutores que compõe o conversor como fonte de tensão são gerados a partir do DSP TMS320F2808 da Texas Instruments, o que está embarcado no módulo didático eZdsp F2808 da Spectrum Digital
Abstract: Nowadays, electric power systems are expected to work closer to their operating limits. Power electronics based controllers, such as voltage sourced converters, are increasingly present in power systems. Electronic devices are often used to energy controlling and conditioning. The use of voltage sourced converters, associated to high-density storage elements, is the basic configuration of a Regenerative Active Power Compensator. Regenerative Active Power Compensator is a concept which proposes the energy storage as a possibility for revaluation of electrical energy cost with demand contracts. This concept is based on storing energy surplus during off peak periods, when the energy cost is cheaper, and injecting it back to the system during the overpriced peak periods. This procedure allows a better equalization of energy consumption and a reduction in electric power demand contracts. Therefore, using regenerative active power compensation, the consumption is dislocated from peak periods, resulting in a reduction of energy costs for the consumer. This concept is especially attractive for countries that use hour-seasonal fees police, as in the Brazilian case. This work proposes a three-phase model simulation with digital signal processor controller to investigate the active power flow control between the power system and the compensator, using a proportional-integral-derivative control strategy. The control signals are generate using the Texas Instruments DSP TMS320F2808, witch is embedded into the eZdsp F2808 didactic module, from Spectrum Digital
Mestre
Black, Ross Arthur Graduate School of Biomedical Engineering Faculty of Engineering UNSW. "Compensatory strategies in humans performing active and passive gaze fixation and re-fixation tasks after unilateral vestibular deafferentation". Publisher:University of New South Wales. Graduate School of Biomedical Engineering, 2009. http://handle.unsw.edu.au/1959.4/43541.
Texto completoMasuda, Mario. "Aplicação do dispositivo FACTS (Flexible AC Transmission Systems) em sistema de distribuição -simulação de desempenho". Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/3/3143/tde-08122006-161400/.
Texto completoThe new FACTS technologies applied to the transmission system, based on power electronics, can also be useful to the distribution. For that, it is necessary to drive a procedure to consolidate the use and the performance for their application without risks. In this work two aspects will be approached. The first refers to the application of a FACTS device acting as series compensator. This device will be able to control the voltage in module and phase in order to act as a voltage drop in a serie reactance with capacitive or inductive features. The control of this series reactance (increasing/ decreasing) will allow the application of series compensation concept to any point of the distribution system, providing the benefits of continuous control of the voltage added to the load flow control in the system independent of the current. The second aspect refers to its use in the connection of two feeders controlling the active power between them. For this operation other device, UPFC, with similar concept as described previously, acts mainly in the phase of the injected voltage in the line, performing as a phase-shift with continuous taps variation and is able to control the active power flow between feeders. The application of this technology will provide several benefits for the distribution expansion, such as, a greater flexibility in the use of the network, connection of feeders without load flow interruption, continuous adjust of reactive power during the operation and dynamic control of power flow. The purpose of this work is to study the applicability of the FACTS technology, to extend this concept for the application in the distribution system by using digital simulations in distribution network up to 15kV identifying the performance and the reached benefits.
Gasc, Laurent. "Conception d'un actionneur à aimants permanents à faibles ondulations de couple pour assistance de direction automobile : approches par la structure et par la commande". Phd thesis, Toulouse, INPT, 2004. http://oatao.univ-toulouse.fr/7375/1/gasc.pdf.
Texto completoFelicetti, Roberto. "Field Current Control for the Damping of Rotor Oscillations and for the Alternative Start of Synchronous Machines : Further Innovative Applications of Field Current Active Control besides UMP-Compensation". Thesis, Uppsala universitet, Institutionen för teknikvetenskaper, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-353669.
Texto completoAliouane, Kamel. "Contribution à l'étude du filtrage d'harmoniques des réseaux de distribution à l'aide de l'association de filtres actif et passif parallèle". Vandoeuvre-les-Nancy, INPL, 1995. http://www.theses.fr/1995INPL012N.
Texto completoWang, Xuan. "Contrôle de forme d'un miroir spatial par actionneurs piézoélectriques". Thesis, Toulouse, ISAE, 2013. http://www.theses.fr/2013ESAE0043/document.
Texto completoThe next generation of space-based observation systems will make use of larger primary mirrors to achieve higher image resolution. Large primary mirrors lead to the increase of structural flexibility and are more susceptible to distortions. Thus maintaining optical tolerances across the mirror surface becomes increasingly difficult. The techniques of active shape control may be required for spatial mirror surfaces in future space observation systems. Piezoelectric actuators are often studied as embedded elements for the active control of mirror structures due to their excellent properties. However, unwanted nonlinear effects in piezoelectric actuators, i.e., hysteresis and creep, severely limit the service performance. This thesis aims at developing openloopcontrol laws to compensate hysteresis and creep effects in piezoelectric actuators. The studies led during this thesis are applied to the shape control of spatial mirror surfaces. An experimental setup with a small-scale mirror test structure involving multiple piezoelectric actuators is first developed and is used as support for all the measurements conducted during this thesis. Then the open-loop control methodologies of creep compensation, hysteresis compensation, and simultaneous compensation of both the nonlinear effects in a single piezoelectric actuator are respectively developed. To compensate creep, a nonlinear viscoelastic model is used to portray creep, and a new inverse model of creep based on the concept of “voltage relaxation” is proposedRegarding the hysteresis compensation, the classical Preisach model is modified by adding a derivative term in parallel to describe hysteresis more accurately with relatively few measurements, and the new inverse model is constructed in the similar way. For the simultaneous compensation of the two nonlinear effects, the hysteresis is first compensated and then, the creepof the hysteresis-compensated piezoelectric actuator is attenuated by open-loop control. The methodology is first developed for a single actuator. Finally, the shape control of a mirror surface with several piezoelectric actuators is achieved by actuating the points on the mirror surface in such a way as to reach the required displacements. The mirror test structure involving multiplepiezoelectric actuators compensated in hysteresis and creep is considered as a linear system on which the superposition principle can be applied. The influence coefficients characterizing the coupling effect between the piezoelectric actuators are determined by measurements. The influence coefficient matrix is first constructed using the superposition principle, and is then inverted. By insertion of the inverse matrix in cascade with multiple piezoelectric actuators with hysteresis and creep compensation, a feed-forward control approach to actuate the multiple interesting points of the mirror surface is developed. A number of experimental results demonstrate that the developed control methodologies are effective and feasible in practice
Castellanos, Silva Abraham. "Compensation adaptative par feedback pour le contrôle actif de vibrations en présence d’incertitudes sur les paramètres du procédé". Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENT050/document.
Texto completoIn this thesis, solutions for the design of robust Active Vibration Control (AVC) systems are presented. The thesis report is composed of two main parts.In the first part of the thesis uncertainties issues in Active Vibration Control systems are examined. In addition of the uncertainties on the frequency of the disturbances it has been found that the presence of low damped complex zeros raise difficult design problems even if plant and models are perfectly known. Solutions for the linear control in this context have been proposed. In order to reduce the uncertainties in the identification of low complex zeros and improved closed loop identification procedure has been developed. To handle the uncertainties on the disturbance frequency adaptation has any way to be used.The second part is concerned with the further development and/or the improvement of the now classical direct adaptive feedback compensation algorithms using Youla Kucera controller parametrization. Two new solutions have been proposed in this context. The first one results from the improvement of a previous work (Landau et al., 2005). The contributions are a new robust central controller design to the optional use of over parameterization of the Q-FIR filter which aims to ensure a small waterbed effect for the output sensitivity function and therefore reducing the unwanted amplification. The second algorithm presents a mixed direct/indirect structure which uses a Q-IIR filter. The improvements are mainly the effect of the Q filter denominator, which is obtained from a disturbance identification. This solution in addition drastically simplifies the design of the central controller.The algorithms have been tested, compared and validated on an international benchmark setup available at the Control System Department of GIPSA-Lab, Grenoble, France