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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Modeling and Analysis of Four Quadrant Sensorless Control of a Switched Reluctance Machine Over the Entire Speed Range

Khalil, Ahmed 23 September 2005 (has links)
No description available.
2

A permanent magnet synchronous motor for an electric vehicle - design analysis

Chin, Yung-Kang January 2004 (has links)
<p>This thesis presents the study and the design analysis of apermanent magnet synchronous motor (PMSM) for the tractionapplication of an electric vehicle. An existing inductiontraction motor for an electric forklift benchmarks the expectedperformances of the proposed PMSM design. Further, thepossibility of using the identical stator as the one used inthe induction motor is explored for the fast prototyping. Theprototype motor is expected to be field-weakened and to have aconstant power speed range (CPSR) of 2.5 to 3.</p><p>A design approach based on the CPSR contour plot in aninterior permanent magnet (IPM) parameter plane is derived toobtain the possible designs that meet all the designspecifications and the targeted CPSR. This study provides thepossible alternative designs for the subsequent futureprototype motors.</p><p>An analytical approach to estimate the iron loss in PMsynchronous machines is developed and included in the designprocedure. The proposed technique is based on predicting theflux density waveforms in the various regions of the machine.The model can be applied at any specified load condition,including the field-weakening operation region. This model canbe ultimately embedded in the design process for a routine usein loss estimations.</p><p>The first prototype motor with an inset permanent magnetrotor has been built and the available measurements are used tovalidate the design performance. In particular, the thermalanalyses based both on the lumped-circuit approach and thenumerical method are compared with the measured results. Asecond and possibly a third prototype motor targeting a widerand higher performance will be carried out in the continuingphase of the project.</p><p><b>Keywords:</b>Constant Power Speed Range, Electric Vehicles,Field-weakening, Reference Flux Linkage, Iron Loss, PermanentMagnet Synchronous Motor, Thermal Analysis</p>
3

A permanent magnet synchronous motor for an electric vehicle - design analysis

Chin, Yung-Kang January 2004 (has links)
This thesis presents the study and the design analysis of apermanent magnet synchronous motor (PMSM) for the tractionapplication of an electric vehicle. An existing inductiontraction motor for an electric forklift benchmarks the expectedperformances of the proposed PMSM design. Further, thepossibility of using the identical stator as the one used inthe induction motor is explored for the fast prototyping. Theprototype motor is expected to be field-weakened and to have aconstant power speed range (CPSR) of 2.5 to 3. A design approach based on the CPSR contour plot in aninterior permanent magnet (IPM) parameter plane is derived toobtain the possible designs that meet all the designspecifications and the targeted CPSR. This study provides thepossible alternative designs for the subsequent futureprototype motors. An analytical approach to estimate the iron loss in PMsynchronous machines is developed and included in the designprocedure. The proposed technique is based on predicting theflux density waveforms in the various regions of the machine.The model can be applied at any specified load condition,including the field-weakening operation region. This model canbe ultimately embedded in the design process for a routine usein loss estimations. The first prototype motor with an inset permanent magnetrotor has been built and the available measurements are used tovalidate the design performance. In particular, the thermalanalyses based both on the lumped-circuit approach and thenumerical method are compared with the measured results. Asecond and possibly a third prototype motor targeting a widerand higher performance will be carried out in the continuingphase of the project. Keywords:Constant Power Speed Range, Electric Vehicles,Field-weakening, Reference Flux Linkage, Iron Loss, PermanentMagnet Synchronous Motor, Thermal Analysis / <p>QCR 20161026</p>
4

Position-sensorless control of permanent magnet synchronous machines over wide speed range

Chi, Song 30 August 2007 (has links)
No description available.
5

Voltage Stabilization Control of Wide-Speed-Range Permanent-Magnet Synchronous Generator Systems

Miao, Dongmin 14 December 2016 (has links)
DC power systems have a constant DC-link voltage, as well as the advantages such as high stability, high efficiency, small size and light weight; therefore, they are widely used in stand-alone power systems, e.g. the power systems in aircrafts and automobiles, isolated wind power generation systems, etc. Permanent-Magnet Synchronous Generators (PMSGs) possess the advantages including high power density, high efficiency, and high control precision, and have obtained great attention and have been widely used in military, inductry, and daily life. Pulse Width Modulation (PWM) rectifier has been one of the main power conversion topologies thanks to its full controllability. The key point in the dissertation is to study the DC power system consisting of a PMSG to be the main power input device and a PWM rectifier to be the main power conversion topology. The objective of control is to output a constant DC-link voltage in a wide PMSG speed range. Since the PM-excited flux linkage is constant, when the PMSG is working at a high speed, field-weakening is needed to stabilize the stator voltage, further to stabilize the DC-link voltage. Hybrid excitation may be used to realize the field-weakening, but it has complex structure; no auxiliary devices are needed in the field regulation with the armature current, and can be easily realized with the PWM recifier and field-regulation control strategies. In this dissertation, the typical applications of the DC power systems are first introduced, with a comprehensive analysis and elaboration on the relevant research throughout the world. The research work is focused on the DC power system and its stabilization control, which is composed of a PMSG and a PWM rectifier. The involved research content in this dissertation includes the following aspects: 1. DC power system design with a wide-speed-range PMSGAs for the common DC power systems, PMSG with high power density, high efficiency is selected to the system power input device, usually with a variable-speed prime mover. The PWM rectifier with fully controlled switches is chosen to be the power conversion topology, which converts the AC power generated by PMSG into DC power, and supplies the DC load after the DC filter. The matching between the system requirements and the generator parameters are determined. Through finite-element analysis (FEA), a PMSG with strong field-weakening ability and suitable for wide-speed-range operation has been designed and manufactured, and the system test bench has been built based on dSPACE. 2. Study, analysis, optimization and experimental verification of the traditional control strategiesAccording to the PMSG designed in part 1, the DC-link model has been built, as well as the control model of the traditional control strategies, e.g. field-oriented control (FOC), direct torque control (DTC), and the effectiveness of the DC-link voltage stabilization control has been verified in a wide speed range. The theory of active damping has been proposed and analyzed, and has been utilized in the DC-link voltage control. When the load on the DC-link changes, the dynamic response of the DC-link voltage has been greatly accelerated, and it recovers quickly to its reference value. In the meantime, the performance influence of the prime mover speed on the actual system test bench should be considered. Finally, the performance of FOC and DTC has been compared and analyzed. 3. Analysis and experimental verification of the direct voltage control (DVC), and the comparative study of all the studied control strategiesThe derivation process of DVC has been theoretically analyzed: the inner current loops in FOC have been eliminated to obtain the direct voltage field-oriented control (DVFOC); the reference value of d-axis voltage in DVFOC has been replaced by the product of the stator voltage calculated by the speed and the load condition, and the sine value of load angle generated by the DC-link voltage PI controller, in order to form the DVC-1. Further, the DC-link voltage PI controller directly outputs the reference value of load angle and it becomes DVC-2. Finally, the comparative study has been carried out among all the studied control strategies. / Doctorat en Sciences de l'ingénieur et technologie / info:eu-repo/semantics/nonPublished
6

Contributions à l’étude de machines multi-enroulements pour l’aéronautique : machine synchrone à aimants permanents pour la tolérance aux défauts : machine asynchrone pour la traction / Contributions to the study of multi-winding machines for aeronautic : Permanent Magnet synchronous Motor for fault tolerant applications : Asynchronous motor for Taxiing

Velly, Nicolas 06 April 2011 (has links)
Le projet d'avion électrique vise à remplacer les vecteurs énergétiques que sont les fluides hydrauliques et l'air comprimé par le courant électrique et d'obtenir en conséquence une diminution significative de la consommation en carburant Dans cette thèse, nous proposons deux solutions : la première dans un souci d'accroitre la disponibilités des actionneurs électriques et la seconde pour la traction au sol (taxiage d'avion). Dans la première étude, nous nous plaçons dans le cadre d'un actionneur pour lequel il est demandé une redondance électrique. Ceci peut être le cas d'un actionneur de mode « normal », redondé par un actionneur de type secours, mais où les fiabilités cumulées ne sont pas suffisantes, et où la partie électrique et la commande du système dit normal est redondé. Nous proposons une topologie de moteur synchrone à aimants permanents à bobinage à plots à deux étoiles découplées magnétiquement et à courant de court-circuit limité. Pour les machines à plots, nous avons établi un modèle semi analytique dans le but de prédire l'amplitude de la résultante des forces radiales agissant sur le rotor de cette machine en cas de fonctionnement en modes sain et dégradé. Nous avons établi le modèle de cette machine en vue de la commande et nous avons validé expérimentalement ce principe de conception sur un prototype dimensionné au laboratoire et réalisé par une société du groupe SAFRAN. Dans la seconde étude, nous avons investigué sur l'utilisation de moteurs multi-enroulements permettant de répondre au mieux à un cahier des charges exigeant pour une application de traction d'aéronefs: le « green taxiing ». Le principe est de permettre de faire varier le coefficient de couple d'un moteur de manière à optimiser la masse du moteur mais aussi les contraintes sur le convertisseur qui l'alimente permettant d'atteindre de larges plages de vitesse. Le modèle en vue de l'alimentation a été développé et validé par une comparaison à une résolution par éléments finis en magnétodynamique / The more electrical aircraft project aims at replacing most of current power generation sources by electrical ones. Consequently this replacement might generate a significant decrease of the fuel consumption. Through this thesis we determine two electrical solutions allowing on the one hand the increase of disponibility level of the actuators and on the other handthe aircraft taxiing by electrical means. We firstly focused on electrical actuators that require electrical redundancy. A first mean to achieve this redundancy is to use two actuators. Nevertheless this solution is not relevant under the reliability constraint because the global failure rate is increased. A double star permanent magnet synchronous motor with concentrated winding is proposed in which a special care was taken to the short circuit current limitation and the magnetic decoupling between the two star winding. We established a semi-analytic model for this kind of motors to predict the amplitude of the resultant of the radial forces acting on the rotor of the machine when operating under normal and faulty operation. We established the model of the machine in order to determine the command strategy. We experimentally validated all of the design principles mentioned above through a prototype designed in the laboratory and built by one of the SAFRAN group company. We secondly investigated on the way to apply the multi winding principles to a brand new project linked to the aircraft taxiing called “green taxiing”. The goal is to obtain a motor topology that allows operating on a wide speed range thanks to the command strategy and the change of its torque coefficient. We established the model of the machine and we compared the results given by this ingenious model to the results given by a finite element resolution using a transient magnetic application
7

Contribution to the Synchronous Reluctance Machine Performance Improvement by Design Optimization and Current Harmonics Injection / Contribution à l'amélioration des performances d'une machine synchrone à réluctance variable synchrone par optimisation de la conception et injection d'harmoniques de courant

Yammine, Samer 06 November 2015 (has links)
Cette thèse est consacré à l’évaluation et l’amélioration de la performance de la machine synchrone à réluctance variable pour des applications à vitesse variable en général et pour les applications automobiles en particulier. Les deux axes de développement sont la conception de la machine et l’injection des harmoniques de courants de phase. Le rotor est un élément important dans la conception de la machine, et un intérêt particulier est dédié à la conception et l’évaluation du rotor pour améliorer la performance de la machine. Une méthode analytique est proposée dans la thèse pour concevoir le rotor. Plusieurs éléments tels que les ponts qui maintiennent le rotor mécaniquement résistant, ainsi que le rapport d’isolation d’axe q (rapport air-acier) sont étudiés. Une étude de conception assistée par ordinateur basé sur un problème d’optimisation paramétrique est présentée aussi. Les trois familles des algorithmes d’optimisation sont évaluées pour la procédure d’optimisation: un algorithme à base de gradient (algorithme de Newton Quasi), un algorithme non-évolutionnaire sur la base de non-gradient (Nelder Mead Simplex) et un algorithme évolutif sur la base non-gradient (algorithme génétique). Les designs de machines basées sur la procédure analytique et la procédure d’optimisation sont testés sur un banc d’essai. Le deuxième axe d’études de la thèse est l’injection d’harmoniques dans les courants de phase de la machine à réluctance variable synchrone. L’interaction des harmoniques de courant avec les harmoniques spatiales des inductances est étudiée et formalisée pour une machine à m-phases. Ensuite, le concept d’injection d’harmoniques est évalué dans le cas particulier d’une machine à deux phases. Cette étude montre l’avantage de l’injection d’harmoniques dans la réduction de l’ondulation de couple de la machine. Un design d’une machine est finalement développé pour une application automobile sur la base de l’optimisation paramétrique du stator et du rotor. Cette conception est évaluée pour les spécifications imposées électromagnétiques par une application de traction à puissance moyenne / This thesis is dedicated to the evaluation and the improvement of the synchronous reluctance machine’s performance for variable speed drive applications in general and for automotive applications in particular. The two axes of development are machine design and phase current harmonics injection. The rotor is an important element in the machine design and particular emphasis is placed to the design and evaluation of the rotor for enhancing the machine performance. An analytical procedure is proposed for the rotor design. The rotor elements like the ribs and the bridges that maintain the rotor mechanically strong as well as the q-axis insulation ratio (air-to-steel ratio) are studied. A computer-aided design study based on a parametric optimization problem is presented as well. The main three families of the optimization algorithms are evaluated for the optimization procedure: a gradient-based algorithm (Quasi Newton Algorithm), a non-gradient based non-evolutionary algorithm (Nelder Mead Simplex) and a non-gradient based evolutionary algorithm (Genetic Algorithm). The machine designs based on the analytical procedure and the optimization procedure are both manufactured and tested on a bench. The second axis of study of the thesis is the injection of harmonics in the phase currents of the synchronous reluctance machine. The interaction of current harmonics with the spatial inductance harmonics is studied and formalized for an m-phase machine. Then, the harmonics injection concept is evaluated in the particular case of a 2-phase machine. This study shows the benefi t of harmonics injection in the reduction of the machine torque ripple. A synchronous reluctance machine design is fi nally developed for an automotive application based on parametric optimization of the stator and rotor. This design is evaluated for the electromagnetic specifi cations imposed by a mid-power electric vehicle traction application

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