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Moussi, A. "The microprocessor control of a DC machine." Thesis, University of Nottingham, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.334974.
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ACAR, DELAL, and KARIN SVENSSON. "The Claw Machine Tivoliautomaten." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-279813.
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Claw machines have been around for about a century spreading joy and entertainment to people of all ages. They are usually seen in amusement parks and malls. In this Bachelors Thesis, one version of a claw machine will be constructed. Different constructing solutions and motors will be discussed for an easy and optimal claw machine that meet all the requirements given in the project. This report is divided into four parts, consisting of introduction, theory, construction of the machine and results. The first part is an introduction where some background information and delimitations of the project are presented. The second part of the report deals with the theory behind various selectable motors for this project as well as solutions for the design itself. The third part of the dissertation gives a detailed overview of how this particular Claw Machine was designed. Selection of materials, motors and how everything is connected and how the various parts harmonize with each other are also presented in this part. In the fourth and final part, the results are presented and a discussion of future improvements is provided.Tivoliautomater har snart funnits i ett århundrade och har under flera årtionden varit en stor nöjesattraktion för såväl gammal som ung. De är vanligt förekommande i nöjesparker och köpcentrum. I detta kandidatexamensarbete kommer en sådan tivoliautomat att konstrueras. Diskussioner kring olika motorer och konstruktionslösningar kommer att föras, för att slutligen uppnå en konstruktion som uppfyller de givna direktiven för projektet. Denna rapport är uppdelad i fyra delar, bestående av introduktion, teori, byggandet av maskinen och resultat. Första delen är en introduktion där grundläggande fakta samt avgränsningar för projektet presenteras. Andra delen av rapporten behandlar teorin bakom olika valbara motorer för detta projekt samt lösningar för själva konstruktionen. I avhandlingens tredje del ges en detaljerad genomgång av hur just denna tivoliautomat konstruerats. Val av material, motorer samt hur allt är sammankopplat och hur de olika delarna harmoniserar med varandra presenteras även i denna del. I den fjärde och sista delen presenteras resultatet och en diskussion kring framtida förbättringar tillhandahålls.
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Sauthier, François. "Nouvelle topologie de commande d'une machine brushless DC (BLDC) /." Sion, 2008. http://doc.rero.ch/record/12809?ln=fr.
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Swint, Ethan Baggett. "DC Reluctance Machine — A Doubly-Salient Reluctance Machine with Controlled Electrical and Mechanical Power Ripple." Diss., Virginia Tech, 2012. http://hdl.handle.net/10919/27717.
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Doubly-Salient Reluctance Machines (DSRMs) sidestep many of the issues with permanent
magnet and induction machines and embody the lowest cost and simplest manufacturing of the
motor technologies. Major drawbacks to RMs have been (1) the need for failure-prone
electrolytic capacitors, (2) large torque ripple, and (3) acoustic noise. Conventionally, these
drawbacks have been addressed independently either through (1) excitation control or (2)
machine design, but not as a holistic system or solution. This disseratation presents a design for
high-efficiency low-cost RM while producing smooth output torque and avoiding pulsating
inverter input current and the associated electrolytic capacitor. We propose a method for shaping
the machine reluctance profile to reduce machine torque ripple to a desired level (here, <5%)
without compromising on machine efficiency or power density, a Shaped Reluctance Machine
(ShRM). Furthermore, a comprehensive approach which combines both phase excitation control
and machine design to cooperatively address the excursions of input and output powers from
their average values which results in less than 5% ripple for both electrical and mechanical net
power â essentially a DC Reluctance Machine (DCRM). Compared to conventional practice in
DSRMs, electrical power ripple is reduced by 85 times and torque ripple is reduced by almost 20
times, while overall efficiency, torque density, and power density are maintained.Ph. D.
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Kou, Martin. "Energy Harvesting from Elliptical Machines: DC-DC Converter Design Using SEPIC Topology." DigitalCommons@CalPoly, 2012. https://digitalcommons.calpoly.edu/theses/753.
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Cal Poly’s ongoing Energy Harvesting from Exercise Machines (EHFEM) project is a very convenient and cost-effective way for generating DC power from physical exercise and sending it back to the electrical grid as AC power, providing a renewable energy source for the future. The EHFEM project consists of numerous subprojects involving converting different types of exercise machines for power generation. This project is a continuation of one of the previous subprojects, specifically involving an elliptical machine, and focuses on improving system functionality at different machine settings without altering the elliptical user’s experience by selecting a new DC-DC converter design, while keeping the other system components intact. The new proposed DC-DC converter design is based on a non-isolated, PWM-switching single-ended primary inductor converter (SEPIC) topology, as opposed to the resonant zero-current switching/zero-voltage switching (ZCS/ZVS) topology-based off-the-shelf DC-DC converter that the previous project utilized, which had poor system functionality at high physical input levels (greater than 30V input) from the elliptical trainer. This project proves that a PWM-switching SEPIC topology provides a functional DC-DC converter design for DC power generation and inverter interfacing from a dynamic input voltage generator because of its wide input voltage range, high power driving capability and inherent voltage step-up and step-down functions. The proposed DC-DC converter supplies up to 288 watts of power and outputs 36 volts, and simultaneously takes 5-65 volts from its input depending on the elliptical user’s physical input level. This project details the new DC-DC converter’s design and construction processes, compares its topology to other existing DC-DC converter topologies and analyzes unfeasible designs as well as the overall system’s performance when converting the generated DC power to AC power, and documents any potential problems when used for this specific application.
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Liu, Yu. "SLOTLESS SIX-PHASE BRUSHLESS DC MACHINE DESIGN AND STEPPING VECTOR CONTROL." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1440086585.
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Hines, Jonathan T. "Emulation of Wind Power with a DC Machine to Provide Input to a Doubly-Fed Induction Machine." Thesis, Monterey, California. Naval Postgraduate School, 2012. http://hdl.handle.net/10945/6808.
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The behavioral modeling of a separately excited direct current (DC) motor as a prime mover for a doubly-fed induction machine (DFIM) is studied in this thesis. The output torque of the DC motor is computed in the simulation under controlled parameters. The input to the DFIM, used as a doubly-fed induction generator (DFIG), is taken from the DC motor. In theory, the combination of the two machines can be used to emulate various wind patterns and their expected electrical returns for a given DFIM-based wind turbine. A Simulink model was created to appropriately emulate the operation of the DC machine. That model was then incorporated into an existing model of a DFIM. The resulting simulations are compared to system operating data to determine if machine speed is being correctly modeled. The speeds determined by the simulator accurately track those that are gathered from lab data. Operating speeds of the system were mapped to historical wind speeds in a geographical area. Output power of the DC motor for the different operating speeds was calculated and plotted. The data confirmed the theory of the proportionality of the rotational output power of a DC motor.
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Mohler, Michael Augustine Gaylord Mihalcea Rada F. "The enhancement of machine translation for low-density languages using web-gathered parallel texts." [Denton, Tex.] : University of North Texas, 2007. http://digital.library.unt.edu/permalink/meta-dc-5140.
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Al-Aubidy, Kasim Mousa A. "Rotor position sensing and microprocessor control of a permanent magnet machine." Thesis, University of Liverpool, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.257508.
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Fares, Adnan. "Development of advanced architectures of power controllers dedicated to Ultra High Switching Frequency DC to DC converters." Thesis, Montpellier, 2015. http://www.theses.fr/2015MONTS195.
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La sophistication grandissante des dispositifs intelligents ultra-portatifs, tels que les smartphones ou les tablettes,crée un besoin d'amélioration des performances des organes de conversion de puissance.La tendance des technologies d'acheminement de puissance évolue progressivement vers une fréquence plus élevée, une meilleure densité d'intégration et une plus grande flexibilité dans les schémas d'asservissement. La modulation dynamique de tension est utilisée dans les circuits intégrés de gestion de puissances(DVS PMICs)des transmetteurs RF alors que la modulation DVFS est utilisée dans les PMICs dédiées au CPUs et GPUs. Des DCDC flexibles et fonctionnant à haute fréquence constituent aujourd'hui la solution principale en conjonction avec des régulateurs à faible marge de tension (LDO).L'évolution vers des solutions à base de HFDCDC de faibles dimensions pose un défi sérieux en matière de 1)stabilité des boucles d'asservissement,2)de complexité des architectures de contrôle imbriquant des machines d'état asynchrones pour gérer une large dynamique de puissance de sortie et 3)de portabilité de la solutions d'une technologie à une autre.Les solutions les plus courantes atteignent aujourd'hui une gamme de 2 à 6 Mhz de fréquence de découpage grâce à l'usage de contrôleurs à hystérésis qui souffrent de la difficulté à contenir la fréquence de découpage lors des variations de la tension ou du courant en charge.Nous avons voulu dans ce travail étendre l'usage des méthodes de conception et de modélisation conventionnelles comme le modèle petit signal moyen, dans une perspective de simplification et de création de modèles paramétriques. L'objectif étant de rendre la technique de compensation flexible et robuste aux variations de procédés de fabrication ou bien aux signaux parasités inhérents à la commutation de puissance.Certes, le modèle moyen petit signal, au demeurant bien traité dans la littérature, réponds amplement à la problématique de compensation des DCDCs notamment quand la stabilité s'appuie sur le zéro naturel à haute fréquence inhérent à la résistance série ESR de la capacité de sortie, mais les HFDCDC actuels utilisent des capacités MLCC ayant une très faible ESR et font appel à des techniques de compensation paramétriques imbriquant le schéma de compensation dans la génération même du rapport cyclique. La littérature existante sur le fonctionnement de la machine d'état, se contente d'une description simpliste de convertisseurs PWM/PFM mais ne donne que très peu d'éléments sur la gestion des opérations synchrones/asynchrones alternant PWM,PFM,écrêtage de courant, démarrage ou détection de défaillance. Dans ce travail, notre études est axée sur les deux aspects suivants:1)La modélisation paramétrique et la compensation de la boucle d'asservissement de HFDCDC et 2)la portabilité de la conception de la machine d'états du contrôleur notamment lorsqu'elle intègre des transitions complexes entre les modes.Dans la première section, nous avons développé un modèle petit signal moyen d'un convertisseur Buck asservi en mode courant-tension et nous l'avons analysé pour faire apparaitre les contributions proportionnelle, intégrale et dérivé dans la boucle. Nous avons démontré la possibilité d'utiliser le retour en courant pour assurer l'amortissement nécessaire et la stabilité de la boucle pour une large dynamique de variations des conditions de charge.Dans la seconde section, nous avons développé une architecture de machine d'états sophistiquée basé sur la méthode d'Huffman avec un effort substantiel d'abstraction que nous a permis de la concevoir en description RTL pour une gestion fiable du fonctionnement asynchrone et temps réel.Notre contribution théorique a fait l'objet d'une réalisation d'un PMIC de test comportant deux convertisseurs Buck cadencés à 12MHz en technologie BiCMOS 0.5um/0.18um. Les performances clefs obtenues sont:une surtension de 50mV pendant 2us suite à l'application d'un échelon de courant de 300mAThe continuous sophistication of smart handheld devices such as smartphones and tablets creates an incremental need for improving the performances of the power conversion devices. The trend in power delivery migrates progressively to higher frequency, higher density of integration and flexibility of the control scheme. Dynamic Voltage Scaling Power Management ICs (DVS PMIC) are now systematically used for powering RF Transmitters and DVFS PMICS using Voltage and Frequency scaling are used for CPUs and GPUs. Flexible High frequency (HF) DC/DC converters in conjunction with low dropout LDOs constitute the main solution largely employed for such purposes. The migration toward high frequency/small size DCDC solutions creates serious challenges which are: 1) the stability of the feedback loop across a wide range of loading voltage and current conditions 2) The complexity of the control and often-non-synchronous state machine managing ultra large dynamics and bridging low power and high power operating modes, 3) The portability of the proposed solution across technology processes.The main stream solutions have so far reached the range of 2 to 6 MHz operation by employing systematically sliding mode or hysteretic converters that suffer from their variable operating frequency which creates EMI interferences and lead to integration problems relative to on-chip cross-talk between converters.In this work we aim at extend the use of traditional design and modeling techniques of power converters especially the average modeling technique by putting a particular care on the simplification of the theory and adjunction of flexible compensation techniques that don't require external components and that are less sensitive to process spread, or to high frequency substrate and supply noise conditions.The Small Signal Average Models, widely treated in the existing literature, might address most needs for system modeling and external compensation snubber design, especially when aiming on the high frequency natural zero of the output capacitor. However, HFDCDC converters today use small size MLCC capacitors with a very low ESR which require using alternative techniques mixing the compensation scheme with the duty cycle generation itself. The literature often provides a simplistic state machine description such as PWM/PFM operations but doesn't cover combined architectures of synchronous / non synchronous mode operations such as PWM, PFM, Current Limit, Boundary Clamp, Start, Transitional and finally Fault or Protection modes.In our work, we have focused our study on two main axes: 1) The parametric modeling and the loop compensation of HFDCDC and 2) the scalability of the control state machine and mode inter-operation. In the first part, we provided a detailed small signal averaged model of the “voltage and current mode buck converter” and we depicted it to emphasize and optimize the contributions of the Proportional, Integral and Derivative feedback loops. We demonstrated the ability to use the current feedback to damp and stabilize the converter with a wide variety of loading conditions (resistive or capacitive). In the second part, we provided architecture of the mode control state machine with different modes like the PWM, PFM, soft-start, current limit,… .The technique we have used is inspired by Huffman machine with a significant effort to make it abstract and scalable. The state machine is implemented using RTL coding based on a generic and scalable approach.The theoretical effort has been implemented inside a real PMIC test-chip carrying two 12MHz buck converters, each employing a voltage and current mode feedback loop. The chip has been realized in a 0.5um / 0.18um BiCMOS technology and tested through a dedicate Silicon validation platform able to test the analog, digital and power sections. The key performance obtained is a 50mV load transient undershoot / overshoot during 2us following a load step of 300mA (slope 0.3A/ns)
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Karim, A. H. M. "Gate-Turn-Off thyristor commutation of DC machines : the development of a rotating DC machine with static commutation of armature coil current using Gate-Turn-Off thyristor devices." Thesis, University of Bradford, 1986. http://hdl.handle.net/10454/3371.
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The thesis Is concerned with the development of a separately excited DC machine In which gate turn-off thyristor devices with their associated firing and protective circuits are used to provide the static commutation of armature coil current. The developed machine has Its armature winding with 24 tapping points located on the stator and Interconnected In "Lop" configuration. The Initiation of the conduction periods of armature switching devices Is defined by a digital control logic circuit. In conjunction with an Incremental rotary encoder which provides the necessary feedback Information relating to shaft speed and shaft angular position. This Is arranged such that, under normal running conditions of the machine, the axis of the radial field of the armature winding maintains the normal space-quadrature relationship with that of the main field winding, giving the optimal torque angle of 000. Provision Is made, however, within the digital control circuit for controlled departure of the armature switch tapping points from the quadrature axis positions, and the effect of this, In Improving commutation Is Investigated. The effect of Interpoles Is also explored. On the basis of the analysis carried out, a proposal Is made for the future development of the machine employing a reduced number of armature switching devices without the need for Interpole windings.
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Ganesan, Rajesh. "Process monitoring and feedback control using multiresolution analysis and machine learning." [Tampa, Fla] : University of South Florida, 2005. http://purl.fcla.edu/usf/dc/et/SFE0001248.
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Gule, Nkosinathi. "Analysis and evaluation of brush-DC equivalent controlled multiphase cage induction machine drive." Thesis, Stellenbosch : University of Stellenbosch, 2011. http://hdl.handle.net/10019.1/6489.
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Thesis (PhD (Electrical and Electronic Engineering))--University of Stellenbosch, 2011.ENGLISH ABSTRACT: The multiphase induction machine drive has been under investigation for the last half century. Although it offers several attractive advantages over the conventional three-phase induction machine drive, it is restricted to highly specialised applications. One aspect of the multiphase induction machine drive is the complexity of the control algorithm for decoupled flux and torque control. The complexity, arising from the required coordinate transformations, increases with increase in the number of phases of the machine. Recently, a method that allows the control of a six-phase induction machine drive without any coordinate transformations was developed and tested. This new control technique allows the control of the machine to be similar to that of dc machines through the use of special trapezoidal-shaped stator current waveforms. These stator phase current waveforms consist of field (flux) and torque current components, with flat-topped amplitudes allowing a stator phase to act alternately in time as either a flux or a torque producing phase. The idea is to have a number of stator phases acting as flux producing phases, whilst the remaining phases act as torque producing phases at each time instance. This dissertation takes a further step in the research on this particular control technique. As the control method relates directly to the brush-dc machine operation, in this dissertation, the control method is defined as a “brush-dc equivalent” (BDCE) control method. First, in this dissertation, a simple analytical method is developed to determine a defined optimal ratio of the number of field to the number of torque phases of a multiphase induction machine that utilises trapezoidal stator current waveforms. The method is applied to induction machines with up to fifteen stator phases. Finite element analysis is used to verify the validity of the developed criterion and to verify the square-like air gap flux density. Secondly, in this dissertation, an analytical method for predicting and evaluating the rotor bar current waveform of a cage multiphase induction machine is proposed. The method is based on the Fourier transform and the winding function theory under linear condition assumptions. The method also allows for the calculation of the electromagnetic torque and rotor bar losses. Skin effect is considered in the calculation of the rotor bar resistance of the machine. Again, finite element analysis is used to verify the analytically calculated results. The developed method can be expanded and used to evaluate the rotor current waveform of any multiphase induction machine supplied with any stator current waveforms. The BDCE control method is implemented on a prototype nine-phase cage-rotor induction machine drive. A nine-phase inverter and control system are developed for supplying the nine-phase induction machine with the trapezoidal stator current waveforms. Rotor current waveform measurements are taken on a specially designed rotor to verify the analytically predicted waveform. The linear relationship of the developed torque and torque current of the proposed BDCE control method is verified through measurements. Through the comparison of analytical calculated results with finite element calculated and measured results, it is shown in this dissertation that the developed analytical techniques can be used in the design and performance analysis of multiphase induction machines. Also, from the results, it is clear that the new control technique works remarkably well even in the flux weakening region. However, outstanding aspects, such as efficiency and generated torque quality of the proposed drive still need to be investigated further.
AFRIKAANSE OPSOMMING: Die multifase induksiemasjien aandryfstelsel word in die laaste halwe eeu al in navorsing ondersoek. Alhoewel dit verskeie aantreklike voordele bied bo die konvensionele driefase induksiemasjien aandryfstelsel, is dit beperk tot hoogs gespesialiseerde aanwendings. Een aspek van die multifase induksiemasjien aandryfstelsel is die kompleksiteit van die beheer algoritme vir ontkoppelde vloed en draaimoment beheer. Die kompleksiteit, wat voortspruit uit die vereiste koördinaat transformasies, neem toe met toename in die aantal fases van die masjien. Onlangs is 'n metode wat die beheer van ’n sesfase induksiemasjien sonder enige koördinaat transformasies doen, ontwikkel en getoets. Hierdie nuwe beheertegniek maak die beheer van die masjien soortgelyk aan dié van GS masjiene deur die gebruik van spesiale trapezium-vormige statorstroom golfvorms. Hierdie stator fasestroom golfvorms bestaan uit veld- (vloed-) en draaimoment-stroom komponente met plat amplitudes, sodat 'n statorfase om die beurt in tyd optree as óf' ’n vloed of 'n draaimoment genereerde fase. Die idee is om 'n aantal statorfases te hê wat as vloed genereerde fases dien, terwyl die oorblywende fases as draaimoment genereerde fases optree op enige tydstip. Hierdie tesis neem 'n verdere stap in die navorsing op hierdie spesifieke beheertegniek. Met die beheermetode wat direk verband hou met borsel-GS masjien werking, word in hierdie proefskrif die beheermetode as 'n "borsel-GS ekwivalente" ["brush-DC equivalent" (BDCE)] beheermetode gedefinieer. In die eerste plek word in hierdie proefskrif 'n eenvoudige analitiese metode ontwikkel om ’n gedefinieerde optimale verhouding van die aantal veld tot die aantal draaimoment fases van 'n multifase induksiemasjien te bepaal, wat van trapesoïdale statorstroom golfvorms gebruik maak. Die metode word toegepas op induksiemasjiene met tot vyftien statorfases. Eindige element analise is gebruik om die geldigheid van die ontwikkelde kriterium te verifieer en om die vierkantvormige luggaping vloeddigtheid te verifieer. In die tweede plek word in hierdie proefskrif 'n analitiese metode vir die voorspelling en evaluering van die rotorstaafstroom golfvorm van 'n kourotor multifase induksiemasjien voorgestel. Die metode is gebaseer op die Fourier transform en die wikkelingsfunksie teorie onder lineêre-toestand aannames. Die metode wend hom ook daartoe tot die berekening van die elektromagnetiese draaimoment en rotorstaafverliese. Die huideffek word in ag geneem in die berekening van die rotorstaafweerstand van die masjien. Weereens is eindige element analise gebruik om die analitiese berekende resultate te verifieer. Die ontwikkelde metode kan uitgebrei en gebruik word om die rotorstroom golfvorm van van enige multifase induksiemasjien te evalueer wat gevoer word met enige statorstroom golfvorms. Die BDCE beheermetode is toegepas op 'n prototipe negefase kourotor induksiemasjien. 'n Negefase omsetter en beheerstelsel is ontwikkel vir die toevoer van die trapesoïdale statorstroom golfvorms aan die negefase induksiemasjien. Die rotorstroomgolfvorm metings is geneem op 'n spesiaal ontwerpte rotor om die analitiese voorspelde golfvorm te verifieer. Die lineêre verwantskap tussen die ontwikkelde draaimoment en draaimomentstroom van die voorgestelde BDCE beheermetode is geverifieer deur metings. Deur die analitiese berekende resultate met die eindige element berekende en gemete resultate te vergelyk, wys hierdie proefskrif dat die ontwikkelde analitiese tegnieke gebruik kan word in die ontwerp en werkverrigting analise van ’n multifase induksiemasjien. Vanuit die resultate is dit ook duidelik dat die nuwe beheertegniek besonder goed werk, selfs in die vloedverswakking spoedgebied. Egter, uitstaande aspekte soos effektiwiteit en genereerde draaimoment kwaliteit van die voorgestelde aandryfstelsel moet nog verder ondersoek word.
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Sysoeva, Viktoriia. "Hidden Markov Model-Supported Machine Learning for Condition Monitoring of DC-Link Capacitors." Miami University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=miami1595978044573618.
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Lerch, Christopher Allen. "Non-invasive recovery of gear rotation from machine vibration dc by Christopher Allen Lerch." Thesis, Massachusetts Institute of Technology, 1995. http://hdl.handle.net/1721.1/35019.
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Salgues, Christophe Xavier. "Torque Control of a Permanent Magnet Brushless DC Machine for a Hybrid Electric Vehicle." University of Akron / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=akron1216920443.
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Coxson, David Rittenhouse. "The District of Columbia Waterfront Atelier (DCWA): A Machine for the Arts." Thesis, Virginia Tech, 2007. http://hdl.handle.net/10919/33818.
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In an attempt to address the accessibility of the arts in Washington, D.C. and also to engage the underutilized waterfront, this thesis proposes a cultural center for the arts that at once links the building with the water, but which also becomes a source of excitement for the city. The arts center will act as an atelier that mixes education, production and exhibition of fine arts, theater, dance and music, with the goal being to achieve a space alive with activity and shared energy.
Typically, buildings for art education have followed a model that emphasizes interaction by forcing artists of different media to share the same space in a classroom environment. Those same rooms may appear no different than, say, a room intended for an English class or science lab. The District of Columbia Waterfront Atelier (DCWA) aims to offer spaces that are designed for the specific medium and nothing else, thus, elevating the importance of the craft. By separating the arts into singular units, one may wonder if interaction between artists is lost. Interaction, however, may be achieved through different methods rather than, simply, by programmatic ones and the DCWA has become an exploration to discover alternatives to maintain and heighten the universal goal of an art atelier: to become engulfed and energized by the arts in an interactive setting.Master of Architecture
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Pobi, Shibendra. "A study of machine learning performance in the prediction of juvenile diabetes from clinical test results." [Tampa, Fla] : University of South Florida, 2006. http://purl.fcla.edu/usf/dc/et/SFE0001671.
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Suppharangsan, Wisaruda. "A new switching technique for minimisation of DC-link capacitance in switched reluctance machine drives." Thesis, University of Sheffield, 2013. http://etheses.whiterose.ac.uk/14610/.
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In a switched reluctance (SR) drive, the transfer of the de-fluxing energy in stator windings back to the dc-link results in a large dc-link capacitance. This limits its applications where weight and size of the drive are restricted. This thesis describes a control technique for the dc-link capacitance minimisation in an SR drive. The proposed control technique maintains the constant power transfer between the de supply and the H-bridge converter. The average dc-link current over a switching period is kept constant. When the output of the integrator, i.e., the average dc-link current, reaches a predefined value proportional to the torque demand, appropriate switching takes place. This is achieved by integrating the dc-link current in each switching period. This technique is called dc-link current integration control (DLCIC). The de-fluxing current from the outgoing phase is not fed back to the dc-link capacitor. Instead, it is transferred to the incoming phase to prevent a negative dc-link current, which causes a fluctuation in the capacitor voltage. Extensive simulation studies of the DLCIC and other techniques reported in literature have been performed and the simulation results from DLCIC are compared with those from other techniques such as Hysteresis Current Control (HCC) and Pulse Width Modulation Current Control (PWMCC). It has been shown that the peak-to-peak voltages across the dc-link capacitor from DLCIC are the lowest amongst other techniques. The operational speed range of the DLCIC is determined and the optimal turn-on and turn-off angles are proposed. Filter components under the DLCIC operation has been designed and compared with the filter for HCC. It is shown that the weight of the filter for DLCIC is far lower than that for HCC. The proposed control technique have been validated by experiments. The experimental results show that at the dc-link voltage ripple which results from DLCIC is much lower than that from HCC. This demonstrates that DLCIC can minimise the dc-link capacitance in an SR machine drive.
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Gambetta, Daniele Morco. "Sensorless technique for BLDC motors." University of Southern Queensland, Faculty of Engineering and Surveying, 2006. http://eprints.usq.edu.au/archive/00001427/.
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Commutation is a fundamental feature of all DC machines. In conventional DC machines the commutation function is performed by the commutator and brushes. These act as both position sensors and switches. The mechanical commutator has obvious disadvantages. Overcoming those disadvantages has been a major reason behind the development of brushless DC (BLDC) machines. In brushless DC machines commutation is performed by power electronic devices forming part of an inverter bridge. However, switching of the power electronic devices has to be synchronised with rotor position. Position sensing is therefore an essential requirement. This can be done by using sensors such as Hall Effect devices or a sensorless approach may be adopted. Advantages of sensorless techniques include reduced cost and wiring. The most common sensorless method is based on detection of the zero crossing of back EMF signals. But this technique works only above a certain speed since back EMF is directly proportional to speed. As a result BLDC systems which rely solely on back EMF signals for commutation suffer from relatively poor starting performance characterised by back rotation of up to one hundred and eigthty electrical degrees and large fluctuations in electromagnetic torque resulting from non-ideal commutation instants. This may not be acceptable for some applications and many researchers have attempted to overcome those problems. The aim of this project has been to investigate the possibility of a sensorless technique which does not cost more than the back EMF method but with a performance at start-up comparable with that obtained when Hall sensors are used. Initial investigations led to a saliency based method. Detailed theoretical analysis is presented which shows that the method is insensitive to variations in operational parameters such as load current and circuit parameters such as power device voltage drops and winding resistances. There is a close parallel between it and the back EMF method and this makes it easy to swap to the latter method at high speed if necessary. A starting strategy, relying on saliency related measurements, is proposed which offers starting performance much better than the back EMF method and almost as good as Hall sensor based techniques. Experimental evidence is provided to confirm that commutation instants determined by the proposed method are practically coincident with those obtained when Hall sensors are used.
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Noon, John Patrick. "Development of a Power Hardware-in-the-Loop Test Bench for Electric Machine and Drive Emulation." Thesis, Virginia Tech, 2020. http://hdl.handle.net/10919/101498.
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This work demonstrates the capability of a power electronic based power hardware-inthe-
loop (PHIL) platform to emulate electric machines for the purpose of a motor drive
testbench with a particular focus on induction machine emulation. PHIL presents advantages
over full-hardware testing of motor drives as the PHIL platform can save space and
cost that comes from the physical construction of multiple electric machine test configurations.
This thesis presents real-time models that were developed for the purpose of PHIL
emulation. Additionally, real-time modeling considerations are presented as well as the modeling
considerations that stem from implementing the model in a PHIL testbench. Next, the
design and implementation of the PHIL testbench is detailed. This thesis describes the
design of the interface inductor between the motor drive and the emulation platform. Additionally,
practical implementation challenges such as common mode and ground loop noise
are discussed and solutions are presented. Finally, experimental validation of the modeling
and emulation of the induction machine is presented and the performance of the machine
emulation testbench is discussed.Master of Science
According to the International Energy Agency (IEA), electric power usage is increasing across all sectors, and particularly in the transportation sector [1]. This increase is apparent in one's daily life through the increase of electric vehicles on the road. Power electronics convert electricity in one form to electricity in another form. This conversion of power is playing an increasingly important role in society because examples of this conversion include converting the dc voltage of a battery to ac voltage in an electric car or the conversion of the ac power grid to dc to power a laptop. Additionally, even within an electric car, power converters transform the battery's electric power from a higher dc voltage into lower voltage dc power to supply the entertainment system and into ac power to drive the car's motor. The electrification of the transportation sector is leading to an increase in the amount of electric energy that is being consumed and processed through power electronics. As was illustrated in the previous examples of electric cars, the application of power electronics is very wide and thus requires different testbenches for the many different applications. While some industries are used to power electronics and testing converters, transportation electrification is increasing the number of companies and industries that are using power electronics and electric machines. As industry is shifting towards these new technologies, it is a prime opportunity to change the way that high power testing is done for electric machines and power converters. Traditional testing methods are potentially dangerous and lack the flexibility that is required to test a wide variety of machines and drives. Power hardware-in-the-loop (PHIL) testing presents a safe and adaptable solution to high power testing of electric machines. Traditionally, electric machines were primarily used in heavy industry such as milling, processing, and pumping applications. These applications, and other applications such as an electric motor in a car or plane are called motor drive systems. Regardless of the particular application of the motor drive system, there are generally three parts: a dc source, an inverter, and the electric machine. In most applications, other than cars which have a dc battery, the dc source is a power electronic converter called a rectifier which converts ac electricity from the grid to dc for the motor drive. Next, the motor drive converts the dc electricity from the first stage to a controlled ac output to drive the electric machine. Finally, the electric machine itself is the final piece of the electrical system and converts the electrical energy to mechanical energy which can drive a fan, belt, or axle. The fact that this motor drive system can be generalized and applied to a wide range of applications makes its study particularly interesting. PHIL simplifies testing of these motor drive systems by allowing the inverter to connect directly to a machine emulator which is able to replicate a variety of loads. Furthermore, this work demonstrates the capability of PHIL to emulate both the induction machine load as well as the dc source by considering several rectifier topologies without any significant adjustments from the machine emulation platform. This thesis demonstrates the capabilities of the EGSTON Power Electronics GmbH COMPISO System Unit to emulate motor drive systems to allow for safer, more flexible motor drive system testing. The main goal of this thesis is to demonstrate an accurate PHIL emulation of a induction machine and to provide validation of the emulation results through comparison with an induction machine.
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Tarasso, Markus, and Daniele Usai. "Utveckling av kontrollrumsstyrning : För DC-generator genom PLC och HMI." Thesis, Högskolan i Borås, Akademin för textil, teknik och ekonomi, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-22104.
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Projektet går ut på att ersätta den befintliga styrningen av en DC-generator för 1200 kV med en fjärrstyrning från kontrollrummet via optolänk. Den nya styrningen ska utgöras av ett PLC-system (Programmable Logic Controller) som manövreras med hjälp av ett HMI – Human Machine Interface. Bakgrunden till projektet härrör från att den befintliga styrutrustningen är opålitlig samt styrs i en farlig miljö. Rapporten går igenom hur befintlig styrutrustning fungerar samt dess ingående komponenter, hur ett PLC-system fungerar med dess bakgrund och olika programmeringsspråk. Även programmeringen och byggnationen av det nya systemet avhandlas. I slutet av rapporten ges en genomgång av de provkörningar som utförts för att säkerställa att alla funktioner fungerar som tänkt. Resultat av provkörningarna ges och diskussion förs kring projektet. Projektet är utfört åt högspänningsgruppen på RISE i Borås som använder generatorn bland annat vid kalibrering av spänningsdelare. Det nya styrsystemet innefattar alla av den tidigare styrutrustningens funktioner och några nya funktioner så som överströms- och överspänningsskydd vilka slår från spänningsmatningen om dessa begränsningar överskrids. Att styrutrustningen nu är placerad i kontrollrumsmiljö gör att operatören kan hantera utrustningen utan att vara i närheten av farlig spänning.The report aims to replace the current control equipment for a DC-generator for 1200 kV by remote control from control room through optical fibre link. The new control will be a PLC system controlled by a HMI – Human Machine Interface. The background to the project is that the existing control equipment is unreliable and controlled in a dangerous environment. The report shows how the current control equipment works and its constituent components, how a PLC-system works with its background and different programming languages. This report will also describe how the programming and building of the hardware are done. In the end of this report are going through a test run to confirm that the system is working properly. Result of the test run are given and some discussion. The project is initiated by the high voltage group at RISE in Borås, who are using the DC-generator for instance while calibrating voltage dividers. The new control system contains all of the functions from the earlier control system but also some new functions such as overcurrent and overvoltage protection who turns off power supply if the limits are exceeded. The control system is now located in the control room so that the operator can use the system without being close to high voltage.
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Godoi, Dias Milena Sabrina [Verfasser]. "Discrete time sliding mode control strategies applied to a multiphase brushless DC machine / Milena Sabrina Godoi Dias." Kassel : Kassel University Press, 2017. http://d-nb.info/1138291099/34.
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Remsen, Andrew Walker. "Evolution and field application of a plankton imaging system." [Tampa, Fla] : University of South Florida, 2008. http://purl.fcla.edu/usf/dc/et/SFE0002429.
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Banfield, Robert E. "Learning on complex simulations." [Tampa, Fla.] : University of South Florida, 2007. http://purl.fcla.edu/usf/dc/et/SFE0002112.
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Perols, Johan L. "Detecting Financial Statement Fraud: Three Essays on Fraud Predictors, Multi-Classifier Combination and Fraud Detection Using Data Mining." [Tampa, Fla] : University of South Florida, 2008. http://purl.fcla.edu/usf/dc/et/SFE0002486.
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Petruška, Ľubomír. "Simulace řídicích struktur elektromechanických systémů." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2010. http://www.nusl.cz/ntk/nusl-218310.
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Construction of motor models is the main topic of this project. Mathematical characterization of AC machine, permanent magnet synchronous motor, separately-excited DC motor, series-wound DC motor, permanent magnet DC motor, switched reluctance motor is also described. Design of models is based on mathematical description of particular motors. Models are created in Matlab Simulink. Each model is implemented in continuous and also in discrete time variant. Selected models are implemented also on processor from Freescale 56F800E Hybrid Controller family. Each model has individual graphic user interface. Besides motor models, there is description and easy algorithm of Space Vector Modulation. Model of this method is also created. Models are build-up into a library, which can be used for simulations and tests of control structures. Results of models simulations are presented at the end of this project. Simulation of models that are implemented on processor is also made in Matlab Simulink environment and is compared to simulation of models that are implemented directly in Matlab Simulink.
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Lovgren, Nicholas Keith. "Energy Harvesting From Exercise Machines: Forward Converters with a Central Inverter." DigitalCommons@CalPoly, 2011. https://digitalcommons.calpoly.edu/theses/520.
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This thesis presents an active clamp forward converter for use in the Energy Harvesting From Exercise Machines project. Ideally, this converter will find use as the centerpiece in a process that links elliptical trainers to the California grid. This active clamp forward converter boasts a 14V-60V input voltage range and 150W power rating, which closely match the output voltage and power levels from the elliptical trainer. The isolated topology outputs 51V, higher than previous, non-isolated attempts, which allows the elliptical trainers to interact with a central grid-tied inverter instead of many small ones. The final converter operated at greater than 86% efficiency over most of the elliptical trainer’s input range, and produced very little noise, making it a solid choice for this implementation.
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Ho, Vinh Thanh. "Techniques avancées d'apprentissage automatique basées sur la programmation DC et DCA." Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0289/document.
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Dans cette thèse, nous développons certaines techniques avancées d'apprentissage automatique dans le cadre de l'apprentissage en ligne et de l'apprentissage par renforcement (« reinforcement learning » en anglais -- RL). L'épine dorsale de nos approches est la programmation DC (Difference of Convex functions) et DCA (DC Algorithm), et leur version en ligne, qui sont reconnues comme de outils puissants d'optimisation non convexe, non différentiable. Cette thèse se compose de deux parties : la première partie étudie certaines techniques d'apprentissage automatique en mode en ligne et la deuxième partie concerne le RL en mode batch et mode en ligne. La première partie comprend deux chapitres correspondant à la classification en ligne (chapitre 2) et la prédiction avec des conseils d'experts (chapitre 3). Ces deux chapitres mentionnent une approche unifiée d'approximation DC pour différents problèmes d'optimisation en ligne dont les fonctions objectives sont des fonctions de perte 0-1. Nous étudions comment développer des algorithmes DCA en ligne efficaces en termes d'aspects théoriques et computationnels. La deuxième partie se compose de quatre chapitres (chapitres 4, 5, 6, 7). Après une brève introduction du RL et ses travaux connexes au chapitre 4, le chapitre 5 vise à fournir des techniques efficaces du RL en mode batch basées sur la programmation DC et DCA. Nous considérons quatre différentes formulations d'optimisation DC en RL pour lesquelles des algorithmes correspondants basés sur DCA sont développés. Nous traitons les problèmes clés de DCA et montrons l'efficacité de ces algorithmes au moyen de diverses expériences. En poursuivant cette étude, au chapitre 6, nous développons les techniques du RL basées sur DCA en mode en ligne et proposons leurs versions alternatives. Comme application, nous abordons le problème du plus court chemin stochastique (« stochastic shortest path » en anglais -- SSP) au chapitre 7. Nous étudions une classe particulière de problèmes de SSP qui peut être reformulée comme une formulation de minimisation de cardinalité et une formulation du RL. La première formulation implique la norme zéro et les variables binaires. Nous proposons un algorithme basé sur DCA en exploitant une approche d'approximation DC de la norme zéro et une technique de pénalité exacte pour les variables binaires. Pour la deuxième formulation, nous utilisons un algorithme batch RL basé sur DCA. Tous les algorithmes proposés sont testés sur des réseaux routiers artificielsIn this dissertation, we develop some advanced machine learning techniques in the framework of online learning and reinforcement learning (RL). The backbones of our approaches are DC (Difference of Convex functions) programming and DCA (DC Algorithm), and their online version that are best known as powerful nonsmooth, nonconvex optimization tools. This dissertation is composed of two parts: the first part studies some online machine learning techniques and the second part concerns RL in both batch and online modes. The first part includes two chapters corresponding to online classification (Chapter 2) and prediction with expert advice (Chapter 3). These two chapters mention a unified DC approximation approach to different online learning algorithms where the observed objective functions are 0-1 loss functions. We thoroughly study how to develop efficient online DCA algorithms in terms of theoretical and computational aspects. The second part consists of four chapters (Chapters 4, 5, 6, 7). After a brief introduction of RL and its related works in Chapter 4, Chapter 5 aims to provide effective RL techniques in batch mode based on DC programming and DCA. In particular, we first consider four different DC optimization formulations for which corresponding attractive DCA-based algorithms are developed, then carefully address the key issues of DCA, and finally, show the computational efficiency of these algorithms through various experiments. Continuing this study, in Chapter 6 we develop DCA-based RL techniques in online mode and propose their alternating versions. As an application, we tackle the stochastic shortest path (SSP) problem in Chapter 7. Especially, a particular class of SSP problems can be reformulated in two directions as a cardinality minimization formulation and an RL formulation. Firstly, the cardinality formulation involves the zero-norm in objective and the binary variables. We propose a DCA-based algorithm by exploiting a DC approximation approach for the zero-norm and an exact penalty technique for the binary variables. Secondly, we make use of the aforementioned DCA-based batch RL algorithm. All proposed algorithms are tested on some artificial road networks
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Fefilatyev, Sergiy. "Detection of marine vehicles in images and video of open sea." [Tampa, Fla] : University of South Florida, 2008. http://purl.fcla.edu/usf/dc/et/SFE0002609.
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Kachlík, Jan. "Model elektrického vozidla v programu SIMULINK/SIMSCAPE." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2011. http://www.nusl.cz/ntk/nusl-219034.
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The topic of this diploma thesis is mathematical model of electric vehicle. The traction drive consists of Li-Ion battery, free-phase DC/AC converter and permanent magnet synchronous machine. The main goal of the thesis is development of function model and making simulations in SIMULINK/SIMSCAPE program. Work is divided into three main parts. The first part is dedicated to the theoretical description of the main drive components. The second part describes partial subsystems of the model. In the last part is build a complete model of electric vehicle and simulated different driving mode.
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Melo, Bruno Mattos Souza de Souza. "Modelagem e simulação de uma máquina elétrica de corrente contínua levando-se em consideração os efeitos de reação de armadura." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/3/3139/tde-27042007-094259/.
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Acionamentos elétricos em corrente contínua ainda são largamente empregados em plantas industriais. Os modelos usualmente adotados para os motores envolvem diversas simplificações, desprezando os efeitos da reação de armadura. Neste trabalho, foi realizada uma pesquisa bibliográfica a fim de se encontrar modelos matemáticos que contemplassem os efeitos da reação de armadura em máquinas CC. Devido à escassez de material encontrado, optou-se por desenvolver um modelo próprio com base em dados obtidos experimentalmente em ensaios de laboratório. Tal modelo, o qual foi validado através da comparação com os dados experimentais, visa a contemplação dos principais efeitos da reação de armadura tanto no circuito de campo como também no circuito de armadura.DC motor drives are still extensively used in industrial plants. The motor models usually adopted involve several simplifications, neglecting armature reaction effects. In this work, an extensive bibliographical survey was carried on so that references of mathematical models that account for the armature reaction effects on DC machines could be found. The lack published material on the subject led us to undertake laboratory experiments on a DC machine in order to evaluate the effects of the armature current on the field circuit and on the armature circuit as well. Finally, a mathematical model was derived and validated by the comparison of simulated results with real data.
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Kukuczka, Adam. "Využití Bondových grafů pro modelování elektrických strojů." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2008. http://www.nusl.cz/ntk/nusl-217638.
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Tato diplomová práce pojednává o možnostech simulace a modelování elektrických pohonů na základě Bondových grafů. Je zde uvedena základní teorie k problematice. V práci jsou představeny modely stejnosměrného a synchronního stroje sestavené touto technikou. Dále je zde seznámení s Freeware knihovnou Bondových grafů BG V2.1 k programu MATLABSimulink. Za pomocí této knihovny byly sestaveny oba modely strojů. V poslední kapitole je uvedeno srovnání modelování na základě teorie Bondových grafů s modelováním v blokových diagramech.
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Monteiro, José Roberto Boffino de Almeida. "Transformação dq não senoidal para máquinas síncronas com imã permanente no rotor." Universidade de São Paulo, 2002. http://www.teses.usp.br/teses/disponiveis/18/18133/tde-24092015-135013/.
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O presente trabalho apresenta uma transformação dq não senoidal e sua aplicação em máquinas síncronas com ímã permanente na superfície do rotor (MSIP) e forma de onda de FEM não senoidal. O modelo resultante da aplicação dessa transformação permite o controle direto do torque eletromagnético, permitindo reduzir as ondulações do torque produzido nesse tipo de máquina. A redução dessas ondulações em MSIPs não senoidais possibilita que esse tipo de máquina seja empregado em aplicações onde somente MSIPs senoidais, que possuem custo mais elevado, poderiam ser usadas. Simulações e resultados práticos, obtidos pela implementação do sistema de controle vetorial não senoidal desenvolvido, são apresentados no trabalho. Pelos resultados obtidos, pode-se verificar que o método proposto é eficaz na redução das ondulações do torque eletromagnético em MSIPs não senoidais.This work presents a non-sinusoidal dq transformation and its application in permanent- magnet synchronous machines (PMSM) with a non-sinusoidal back-EMF waveform. The resulting model of the application of such transformation permits direct control of machine electromagnetic torque, which achieves the reduction of torque ripple. The reduction of torque ripple in non-sinusoidal PMSMs makes possible the use of this kind of PMSM instead of sinusoidal PMSMs, which are more expensive. Simulation and practical results, obtained by the implementation of such non-sinusoidal vectorial control system, are shown in this work. Those results show that the method presented is efficacious in the torque ripple reduction in non-sinusoidal PM synchronous machines.
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Bazhar, Sara. "Modélisation, optimisation en vue du dimensionnement d’une nouvelle structure de démarreurs à griffes pour les véhicules « micro-hybrides »." Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0131/document.
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Cette thèse propose une nouvelle structure de machine à courant continu pouvant être utilisée dans une application démarreur Stop-Start automobile. Une structure tridimensionnelle à griffes est proposée pour remplacer le stator à plots actuel dans le but de réduire son coût de fabrication. La structure de la machine à griffes est modélisée par un réseau de réluctances permettant la prise en compte de la saturation et de la réaction magnétique d'induit. Grâce à sa rapidité et précision, ce modèle est ensuite intégré dans un processus d’optimisation afin d'obtenir rapidement une machine optimale. Enfin, un prototype de machine à courant continu à griffes est réalisé, montrant ainsi la faisabilité de cette topologie. Par ailleurs, un modèle original combinant réseaux de réluctances et résolution de l'équation de Laplace a été développé pour lever certaines difficultés liées à la modélisation par réseau de réluctances des machines électriques tout en prenant en compte la rotationThis thesis deals with a new DC machine structure that can be used in an automotive Stop-Start starter application. A three-dimensional claw pole stator is proposed to replace the current stator in order to reduce its manufacturing cost. The claw pole machine topology is modeled by a reluctance network to take into account the saturation and the magnetic armature reaction. Thanks to its speed and precision, this model is then integrated in an optimization process to obtain an optimal machine. Finally, a prototype of a machine with DC claws is manufactured to show the feasibility of this topology. Moreover, an original model combining reluctance networks and solving the Laplace equation has been developed to overtake some difficulties related to modeling by reluctance network of electrical machines while taking into account the rotation
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Lin, Qing. "Small-Signal Modeling and Stability Specification of a Hybrid Propulsion System for Aircrafts." Thesis, Virginia Tech, 2021. http://hdl.handle.net/10919/103515.
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This work utilizes the small-signal impedance-based stability analysis method to develop stability assessment criteria for a single-aisle turboelectric aircraft with aft boundary-layer propulsion (STARC-ABL) system. The impedance-based stability analysis method outperforms other stability analysis methods because it does not require detailed information of individual components for system integration, therefore, a system integrator can just require the vendors to make the individual components meet the impedance specifications to ensure whole system stability. This thesis presents models of a generator, motor, housekeeping loads, and battery all with power electronics interface which form an onboard electrical system and analyzes the relationship between the impedance shape of each component and their physical design and control loop design. Based on the developed small-signal model of the turbine-generator-rectifier subsystem and load subsystem, this thesis analyzes the impact of electromechanical dynamics of the turbofan passed through the generator on the dc distribution system, concluding that the rectifier can mitigate the impact. Finally, to ensure the studied system stable operation during the whole flying profile, the thesis provides impedance specifications of the dc distribution system and verifies the specifications with several cases in time-domain simulations.M.S.
Electric aircraft propulsion (EAP) technologies have been a trend in the aviation industry for their potential to reduce environmental emissions, increase fuel efficiency and reduce noise for commercial airplanes. Achieving these benefits would be a vital step towards environmental sustainability. However, the development of all-electric aircraft is still limited by the current battery technologies and maintenance systems. The single-aisle turboelectric aircraft with aft boundary-layer (STARC-ABL) propulsion concept is therefore developed by NASA aiming to bridge the gap between the current jet fuel-powered aircraft and future all-electric vehicles. The plane uses electric motors powered by onboard gas turbines and transfers the generated power to other locations of the airplane like the tail fan motor to provide distributed propulsion. Power electronics-based converter converts electricity in one form of electricity to another form, for example, from ac voltage to dc voltage. This conversion of power is very important in the whole society, from small onboard chips to Mega Watts level electrical power system. In the aircraft electrical power system context, power electronics converter plays an important role in the power transfer process especially with the recent trend of using high voltage dc (HVDC) distribution instead of conventional ac distribution for the advantage of increased efficiency and better voltage regulation. The power generated by the electric motors is in ac form. Power electronics converter is used to convert the ac power into dc power and transfer it to the dc bus. Because the power to drive the electric motor to provide distributed propulsion is also in ac form, the dc power needs to be converted back into ac power still through a power electronics converter. With a high penetration of power electronics into the onboard electrical power system and the increase of electrical power level, potential stability issues resulted from the interactions of each subsystem need to be paid attention to. There are mainly two stability-related studies conducted in this work. One is the potential cross-domain dynamic interaction between the mechanical system and the electrical system. The other is a design-oriented study to provide sufficient stability margin in the design process to ensure the electrical system’s stable operation during the whole flying profile. The methodology used in this thesis is the impedance-based stability analysis. The main analyzing process is to find an interface of interest first, then grouped each subsystem into a source subsystem and load subsystem, then extract the source impedance and load impedance respectively, and eventually using the Nyquist Criterion (or in bode plot form) to assess the stability with the impedance modeling results. The two stability-related issues mentioned above are then studied by performing impedance analysis of the system. For the electromechanical dynamics interaction study, this thesis mainly studies the rotor dynamics’ impact on the output impedance of the turbine-generator-rectifier system to assess the mechanical dynamics’ impact on the stability condition of the electrical system. It is found that the rotor dynamics of the turbine is masked by the rectifier; therefore, it does not cause stability problem to the pre-tuned system. For the design-oriented study, this thesis mainly explores and provides the impedance shaping guidelines of each subsystem to ensure the whole system's stable operation. It is found that the stability boundary case is at rated power level, the generator voltage loop bandwidth is expected to be higher than 300Hz, 60˚ to achieve a 6dB, 45˚ stability margin, and load impedance mainly depends on the motor-converter impedance.
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Liu, Hongliang. "Contribution for integrating urban wind turbine into electrical microgrid : modeling and control." Thesis, Compiègne, 2017. http://www.theses.fr/2017COMP2331/document.
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L’intégration de l’énergie éolienne, qui est une ressource renouvelable très utilisée, n’est pas toujours facile pour le micro-réseau urbain. Dans cette thèse, une éolienne urbaine basée sur une machine synchrone à aimants permanents (MSAP) est étudiée pour être intégrée dans un micro-réseau urbain à courant continu. Un état de l'art concernant les énergies renouvelables, les micro-réseaux à courant continu et les stratégies de contrôle de la production d'énergie éolienne, est réalisée. Basé sur un modèle d’éolienne urbaine répondant à la demande du système électrique, qui se compose d’un émulateur de vent et de pales, un MSAP et un convertisseur DC/DC, cette thèse propose des méthodes de poursuite du point de puissance maximale satisfaisant à l’obligation de produire de l’énergie dans la mesure du possible. Une stratégie de contrôle à puissance limitée répond correctement. De simples à complexes, quatre algorithmes MPPT, P&O à pas fixe, P&O à pas variable avec la méthode Newton-Raphson améliorée, P&O à pas variable à base de logique floue et une méthode indirecte de type lookup table, sont étudiés et implémentés pour être comparés à l’aide de trois profils de vitesse du vent. Par expérimentation, les algorithmes MPPT et PLC sont comparés, analysés et discutés. Résumant tous les résultats expérimentaux, la méthode lookup table peut gérer toutes les exigences du mode de fonctionnement MPPT en présentant la meilleure performance, mais, dans le mode de fonctionnement PLC, la P&O à base de logique floue présente les meilleures performancesThe integration of the wind power, which is one mostly used renewable resource, is always one challenger for urban microgrid. In this thesis, one urban wind turbine based on a permanent magnet synchronous machine (PMSM) is studied in order to be integrated into a DC urban microgrid. A state of the art concerning the renewable energies, DC microgrid, and control strategies of wind power generation is done. Based on a model of urban wind turbine fitting the demand of urban electric system, which consists of an emulator of wind speed and blades, a PMSM and a DC/DC converter, this thesis proposes the maximum power point tracking (MPPT) methods satisfying the requirement of producing energy as much as possible, and power limited control (PLC) strategies answering the demand of flexible energy production. From simple to complex, four MPPT algorithms including Perturbation and Observation (P&O) fixed step-size method, P&O with improved Newton-Raphson method, P&O with fuzzy logic method and lookup table method are studied and implemented to be compared with each other using three wind velocity profiles. According to the experience about MPPT subject, four PLC algorithms are introduced and implemented to be analyzed and compared with each other with one power demand profile calculated randomly. Summarizing all experimental results, the lookup table method can handle all requirement of MPPT operating mode supplying the best performance, however, in the condition of more flexible power demand operating mode, the combination of P&O and fuzzy logic method presents the best performance and potential which can be achieved in future works
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Janeček, Jan. "Řízení pohybů dvouramenného žonglovacího stroje." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2012. http://www.nusl.cz/ntk/nusl-230105.
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The diploma thesis is a part of the project Intelligent double arm juggling machine. The project is divided into two diploma thesis. This thesis deals with the motion control of juggling arms. Information about hardware and software resources used in this project is in the first part of thesis. There is explanation of the control loop, explanation of used communication protocols and implementation of program proceeding in the second part of thesis.
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Zhu, Zongfan. "An intelligent CAD system for DC machines /." Thesis, McGill University, 1991. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=60491.
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This thesis presents the development of an intelligent CAD system (ICADS) for DC machines. This system was implemented on a PC using Common Lisp provided by Gold Works II and connected with a Sun Workstation working under the Unix system for file transfer.Both frame-based and rule-based knowledge representation techniques have been used to capture the knowledge about the design of electric machines. The system has its own inference engine specially designed to handle both decision making and numerical computation. Forward-chain reasoning and procedural attachment were used to construct this inference engine. The knowledge base management system provides a user interface for knowledge acquisition, knowledge representation, man-machine communication, design document preparation, etc. The design results are translated to a finite element analysis file and sent to MagNet2D, a powerful electromagnetic field analysis package for design checking and refinement.
The system provides different levels of design automation to suit the needs of the system user. As examples the design results of a series of universal motors and a small DC motor are provided in the thesis.
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Sireci, Alexander. "DC-DC Converter Control System for the Energy Harvesting from Exercise Machines System." DigitalCommons@CalPoly, 2017. https://digitalcommons.calpoly.edu/theses/1747.
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Current exercise machines create resistance to motion and dissipate energy as heat. Some companies create ways to harness this energy, but not cost-effectively. The Energy Harvesting from Exercise Machines (EHFEM) project reduces the cost of harnessing the renewable energy. The system architecture includes the elliptical exercise machines outputting power to DC-DC converters, which then connects to the microinverters. All microinverter outputs tie together and then connect to the grid. The control system, placed around the DC-DC converters, quickly detects changes in current, and limits the current to prevent the DC-DC converters and microinverters from entering failure states.
An artificial neural network learns to mitigate incohesive microinverter and DC-DC converter actions. The DC-DC converter outputs 36 V DC operating within its specifications, but the microinverter drops input resistance looking for the sharp decrease in power that a solar panel exhibits. Since the DC-DC converter behaves according to Ohm’s Law, the inverter sees no decrease in power until the voltage drops below the microinverter’s minimum input voltage. Once the microinverter turns off, the converter regulates as intended and turns the microinverter back on only to repeat this detrimental cycle. Training the neural network with the back propagation algorithm outputs a value corresponding to the feedback voltage, which increases or decreases the voltage applied from the resistive feedback in the DC-DC converter.
In order for the system to react well to changes on the order of tens of microseconds, it must read ADC values and compute the output neuron value quicker than previous control attempts. Measured voltages and currents entering and leaving the DC-DC converter constitute the neural network’s input neurons. Current and voltage sensing circuit designs include low-pass filtering to reduce software noise filtering in the interest of speed. The complete solution slightly reduces the efficiency of the system under a constant load due to additional component power dissipation, while actually increasing it under the expected varying loads.
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Bach, Tran. "Algorithmes avancés de DCA pour certaines classes de problèmes en apprentissage automatique du Big Data." Electronic Thesis or Diss., Université de Lorraine, 2019. http://www.theses.fr/2019LORR0255.
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De nos jours, le Big Data est devenu essentiel et omniprésent dans tous les domaines. Par conséquence, il est nécessaire de développer des techniques innovantes et efficaces pour traiter la croissance rapide du volume des masses de données. Nous considérons les problèmes suivants dans le contexte de Big Data : la sélection de groupes de variables pour la régression logistique multi-classes, la réduction de dimension par t-SNE (« t-distributed Stochastic Neighbor Embedding « en anglais) et l'apprentissage en profondeur pour la classification non-supervisée (« Deep Clustering « en anglais). Nous développons des algorithmes DC (Difference of Convex functions) avancés pour ces problèmes, qui sont basés sur la programmation DC et DCA (DC Algorithm) -- des outils puissants pour les problèmes d'optimisation non-convexes non-différentiables. Dans la première partie, nous étudions le problème de la sélection de groupes de variables pour la régression logistique multi-classes. Nous résolvons ce problème en utilisant des DCAs avancés – Stochastic DCA et DCA-Like. Plus précisément, Stochastic DCA se spécialise dans le problème de la minimisation de la grande somme des fonctions DC, et ne nécessite qu'un sous-ensemble de fonctions DC à chaque itération. DCA-Like relaxe la condition de convexité de la deuxième composante DC en assurant la convergence. Accelerated DCA-Like intègre la technique d'accélération de Nesterov dans DCA-Like pour améliorer sa performance. Les expériences numériques sur plusieurs jeux de données benchmark de grande taille montrent l'efficacité de tous les algorithmes proposés en termes de temps d'exécution et de qualité de la solution. La deuxième partie concerne t-SNE, une technique efficace de réduction de dimension non linéaire. t-SNE est modélisé sous forme d'un problème d'optimisation non-convexe. Motivés par le caractère novateur de DCA-Like et Accelerated DCA-Like, nous développons ces deux algorithmes pour résoudre le problème t-SNE. La supériorité de nos algorithmes, appliqués à la visualisation de données, par rapport aux méthodes existantes est illustrée via des expériences numériques réalisées sur les jeux de données de très grande taille. La troisième partie est consacrée à la classification non-supervisée par l'apprentissage en profondeur. Dans la première application, nous proposons deux algorithmes basés sur DCA pour combiner t-SNE avec MSSC (Minimum Sum-of-Squares Clustering) par ces deux approches : « tandem analysis » et joint-clustering. La deuxième application considère le clustering en utilisant l'auto-encodeur. Nous avons proposé une extension d'une classe d'algorithmes de joint-clustering pour résoudre le problème de mise à l'échelle de données (« scaling problem » en anglais), et appliqué pour un cas spécifique de joint-clustering avec MSSC. Les résultats numériques sur plusieurs jeux de données benchmark montre l'efficacité de notre algorithme comparé aux méthodes existantesBig Data has become gradually essential and ubiquitous in all aspects nowadays. Therefore, there is an urge to develop innovative and efficient techniques to deal with the rapid growth in the volume of data. This dissertation considers the following problems in Big Data: group variable selection in multi-class logistic regression, dimension reduction by t-SNE (t-distributed Stochastic Neighbor Embedding), and deep clustering. We develop advanced DCAs (Difference of Convex functions Algorithms) for these problems, which are based on DC Programming and DCA – the powerful tools for non-smooth non-convex optimization problems. Firstly, we consider the problem of group variable selection in multi-class logistic regression. We tackle this problem by using recently advanced DCAs -- Stochastic DCA and DCA-Like. Specifically, Stochastic DCA specializes in the large sum of DC functions minimization problem, which only requires a subset of DC functions at each iteration. DCA-Like relaxes the convexity condition of the second DC component while guaranteeing the convergence. Accelerated DCA-Like incorporates the Nesterov's acceleration technique into DCA-Like to improve its performance. The numerical experiments in benchmark high-dimensional datasets show the effectiveness of proposed algorithms in terms of running time and solution quality. The second part studies the t-SNE problem, an effective non-linear dimensional reduction technique. Motivated by the novelty of DCA-Like and Accelerated DCA-Like, we develop two algorithms for the t-SNE problem. The superiority of proposed algorithms in comparison with existing methods is illustrated through numerical experiments for visualization application. Finally, the third part considers the problem of deep clustering. In the first application, we propose two algorithms based on DCA to combine t-SNE with MSSC (Minimum Sum-of-Squares Clustering) by following two approaches: “tandem analysis” and joint-clustering. The second application considers clustering with auto-encoder (a well-known type of neural network). We propose an extension to a class of joint-clustering algorithms to overcome the scaling problem and applied for a specific case of joint-clustering with MSSC. Numerical experiments on several real-world datasets show the effectiveness of our methods in rapidity and clustering quality, compared to the state-of-the-art methods
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Michelle, Lum Yuen Jonathan. "Energy harvesting from elliptical machines DC converter troubleshooting /." Click here to view, 2009. http://digitalcommons.calpoly.edu/eesp/12/.
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Thesis (B.S.)--California Polytechnic State University, 2009.Project advisor: David Braun. Title from PDF title page; viewed on Feb. 4, 2010. Includes bibliographical references. Also available on microfiche.
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Atallah, Kais. "Iron losses in brushless permanent magnet DC machines." Thesis, University of Sheffield, 1993. http://etheses.whiterose.ac.uk/14941/.
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A closed-loop computer-controlled single-sheet test system has been developed to characterise lamination materials and to measure, the iron loss density under any specified flux density waveform. The system has been 'used to validate predictions from a recently developed theoretical model, for the calculation of the excess loss component associated with domaiQ wall movement, under flux density waveforms typical of those encountered in the stator core of brushless permanent magnet dc motors. In addition, an improved expression for the calculation of the iron loss density component, from measured 71 and 7!vectors, due to rotatio~ in non-purely rotating flux conditions, has been derived. A simple analytical model from which the airgap flux density and spread of magnet working points can be determined and which accounts for the effects of curvature for radial-field permanent magnet machines has been developed and validated. The model has been coupled to an analytical technique for the prediction of the open-circuit flux density waveforms in different regions of the stator core, and has subsequently been employed for the prediction of the open-circuit iron loss. In order to predict the iron loss under any specified load condition, a technique which couples a brushless dc drive system simulation to a series of magnetostatic finite element analyses corresponding to discrete instants in a commutation cycle has been developed. It enables the prediction of the local flux density waveforms throughout the stator core under any operating condition, and has been employed to predict the local iron loss density distribution 'and the total iron loss and their variation with both the load and the commutation strategy, Finally, the theoretical findings have been validated against measurements on a representative low power brushless drive system.
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Pokálený, Jan. "Trakční pohon elektromobilu napájený vodíkovým palivovým článkem." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2008. http://www.nusl.cz/ntk/nusl-217584.
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The topic of this diploma thesis is a traction drive of electrocar with fuel cell. The drive is supplied with hydrogen fuel cell with power of 2 kW. The traction drive consists of the three-phase DC/AC converter and the asynchronous machine. The main part of this work is a creation of the mathematical model of the traction drive in program Matlab–Simulink.
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Lacroix, Samantha. "Modélisation et commande d’une chaine de conversion pour véhicule électrique intégrant la fonction de charge des batteries." Thesis, Paris 11, 2013. http://www.theses.fr/2013PA112074/document.
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Le développement des véhicules hybrides et électriques s’est intensifié ces dernières années, face aux problématiques environnementales et économiques. Afin que les performances de ces derniers soient comparables à celle d’un véhicule à moteur thermique, de nombreuses avancées technologiques sont indispensables. Le déploiement de véhicule entièrement à traction électrique, ne serait être réalisable, sans des infrastructures de recharge adaptées. Cette thèse constitue une contribution à l’étude d’un chargeur de batteries intégré au véhicule électrique, dans le cadre du projet SOFRACI.L'architecture de ce chargeur entièrement réversible sert également pour la traction du véhicule. L’utilisation de tous les éléments y compris le moteur de traction pour les deux fonctions, réduit l’encombrement et le coût de la structure. L’objectif principal consiste à modéliser le système de conversion alternatif-continu du chargeur et à établir les lois de commandes.Lors de la première phase de l’étude, une attention particulière a été portée à l’utilisation des enroulements de la machine en tant qu’inductance de filtrage du convertisseur. Un modèle correspondant à ce fonctionnement a été obtenu et a permis de mettre en évidence un couplage magnétique existant entre les diverses phases.En s’appuyant sur les modèles obtenues, la seconde étape a consisté à définir les stratégies de commande. Deux méthodes ont été employées. La première, par le biais d’une transformation a permis de se ramener dans un repère, où la majorité des termes de couplage ont été éliminés. Pour l’autre méthode, tous les éléments du couplage ont été considérés. Pour chacune de ces stratégies, des correcteurs PI et RST fondés sur le placement de pôles robustes ont été dimensionnés pour garantir la stabilité du système.Une part importante du travail a été consacrée à la réalisation d’un banc d’essai expérimental reconstituant la conversion alternative-continue. Compte tenu des différences de dynamiques des grandeurs asservies, une carte FPGA et un processeur ont été utilisés. L’exploitation de ce moyen d’essai a permis de comparer et de valider les lois de commande développéesEnvironmental constraints and reduction of fossil fuels resources have led industrials and laboratories to search for alternative solutions in the transportation domain. For the last few years, several vehicles or planes functions have been gradually electrified, up to their complete electrification. This thesis presents an AC/DC converter integrated in an Electric Vehicle (EV) for the charger application. The conversion is realized by using the electric traction powertrain, in order to reduce the global cost and increase compactness where a specific motor has been design.During the first phase of the study, a model of the motor used as filtering inductances has been obtained and allowed to highlight an existing magnetic coupling between the motor’s phases.The second step was to define control strategies. Two methods were used. The first one, by a transformation allowed eliminating the majority of the coupling term. In the other method, all coupling elements have been considered. For each strategies, IP and RST controllers based on robust pole placement were designed to ensure system stability.An important part of the work was devoted to the realization of an experimental test bench for AC-DC conversion. A FPGA and a processor were used for control implementation. The control laws has been compared and validated thanks to the experimental platform
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Forster, Andrew E. "Energy Harvesting From Exercise Machines: Buck-Boost Converter Design." DigitalCommons@CalPoly, 2017. https://digitalcommons.calpoly.edu/theses/1702.
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This report details the design and implementation of a switching DC-DC converter for use in the Energy Harvesting From Exercise Machines (EHFEM) project. It uses a four-switch, buck-boost topology to regulate the wide, 5-60 V output of an elliptical machine to 36 V, suitable as input for a microinverter to reclaim the energy for the electrical grid. Successful implementation reduces heat emissions from electrical energy originally wasted as heat, and facilitates a financial and environmental benefit from reduced net energy consumption.
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Kimball, Karen Yeager Lain Brian. "Milk machines exploring the breastfeeding apparatus /." [Denton, Tex.] : University of North Texas, 2008. http://digital.library.unt.edu/permalink/meta-dc-6088.
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Lacroix, Samantha. "Modélisation et commande d'une chaine de conversion pour véhicule électrique intégrant la fonction de charge des batteries." Phd thesis, Université Paris Sud - Paris XI, 2013. http://tel.archives-ouvertes.fr/tel-00836751.
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Le développement des véhicules hybrides et électriques s'est intensifié ces dernières années, face aux problématiques environnementales et économiques. Afin que les performances de ces derniers soient comparables à celle d'un véhicule à moteur thermique, de nombreuses avancées technologiques sont indispensables. Le déploiement de véhicule entièrement à traction électrique, ne serait être réalisable, sans des infrastructures de recharge adaptées. Cette thèse constitue une contribution à l'étude d'un chargeur de batteries intégré au véhicule électrique, dans le cadre du projet SOFRACI.L'architecture de ce chargeur entièrement réversible sert également pour la traction du véhicule. L'utilisation de tous les éléments y compris le moteur de traction pour les deux fonctions, réduit l'encombrement et le coût de la structure. L'objectif principal consiste à modéliser le système de conversion alternatif-continu du chargeur et à établir les lois de commandes.Lors de la première phase de l'étude, une attention particulière a été portée à l'utilisation des enroulements de la machine en tant qu'inductance de filtrage du convertisseur. Un modèle correspondant à ce fonctionnement a été obtenu et a permis de mettre en évidence un couplage magnétique existant entre les diverses phases.En s'appuyant sur les modèles obtenues, la seconde étape a consisté à définir les stratégies de commande. Deux méthodes ont été employées. La première, par le biais d'une transformation a permis de se ramener dans un repère, où la majorité des termes de couplage ont été éliminés. Pour l'autre méthode, tous les éléments du couplage ont été considérés. Pour chacune de ces stratégies, des correcteurs PI et RST fondés sur le placement de pôles robustes ont été dimensionnés pour garantir la stabilité du système.Une part importante du travail a été consacrée à la réalisation d'un banc d'essai expérimental reconstituant la conversion alternative-continue. Compte tenu des différences de dynamiques des grandeurs asservies, une carte FPGA et un processeur ont été utilisés. L'exploitation de ce moyen d'essai a permis de comparer et de valider les lois de commande développées.
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Rakgati, Edward Tshitshiri. "Torque Performance of Optimally Designed Multi-Phase Reluctance DC Machines." Thesis, Link to the online version, 2006. http://hdl.handle.net/10019/1174.
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Shi, Juntao. "Novel stator permanent magnet and DC field excited synchronous machines." Thesis, University of Sheffield, 2016. http://etheses.whiterose.ac.uk/12351/.
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