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1
Xie, Lihan. "Suivi numérique des bifurcations pour l'analyse paramétrique de la dynamique non-linéaire des rotors." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSEI018/document.
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Au cœur des moyens de transport, de transformation d'énergie, et de biens d'équipements, les machines tournantes peuvent avoir des comportements dynamiques complexes dus à de multiples sources de non linéarités liées aux paliers hydrodynamiques, à la présence de fissures, aux touches rotor-stator, ... Des phénomènes comme les décalages fréquentiels et donc de vitesses critiques, les cycles d'hystérésis avec sauts d'amplitudes, le changement brutal du contenu fréquentiel des réponses, sont des expressions de ces comportements. Résoudre les équations du mouvement induites par des modélisations avec des éléments finis de type poutre ou volumique, pour calculer les réponses à des sollicitations diverses (comme le balourd ou le poids propre), est réalisable avec des méthodes d'intégration pas à pas dans le temps mais au prix de temps de calcul prohibitifs. Cela devient particulièrement préjudiciable au stade du pré-dimensionnement où il est nécessaire de réaliser rapidement des études paramétriques. Aussi une alternative intéressante est de mettre en {\oe}uvre une méthode numérique, à la fois générale et efficace pour analyser la réponse non linéaire des rotors en régime stationnaire. La démarche proposée combine, dans un premier temps, la méthode de la balance harmonique (HBM) et la technique de bascule Temps-Fréquence (AFT) afin d'obtenir rapidement dans le domaine fréquentiel les réponses périodiques des rotors à grand nombre de degrés de liberté apportés par les éléments finis volumiques. Puis, l'association à la méthode de continuation par pseudo-longueur d'arc aboutit à établir continûment l'ensemble des solutions d'équilibre dynamique sur la plage de vitesse de rotation. Enfin la stabilité dynamique locale de la solution périodique est analysée grâce à des indicateurs de bifurcation basés sur l'évolution des exposants de Floquet. Ainsi sont détectées les bifurcations de branches de solutions périodiques de type point limite, point de branchement et notamment Neimark-Sacker. Leur localisation est déterminée précisément en résolvant un système augmenté constitué de l'équation du mouvement et d'une équation supplémentaire caractérisant le type de bifurcation considéré. En déclarant un paramètre du système (coefficient de frottement, jeu rotor/stator, amplitude de l'excitation,...) comme nouvelle variable, l'utilisation de la technique de continuation conjointement avec le système augmenté détermine directement le cheminement des bifurcations en fonction de ce paramètre sur la nappe des réponses non linéaires. Les suivis de bifurcations délimitent les zones de fonctionnement spécifiques, extraient efficacement l'essentiel du comportement dynamique et offrent ainsi une nouvelle approche pour dimensionner de façon efficace les systèmes notamment en rotation. Nombre des développements réalisés sont implantés dans le code de calcul Cast3M<br>Generally speaking, the rotating systems utilized in the energy production have a small rotor-stator gap, are able to run during long periods, and are mounted on hydrodynamic bearings. Rotor-stator interactions in case of blade loss, crack propagation due to fatigue, and a variable stiffness due to the nonlinear restoring forces of the bearings can make the rotordynamics nonlinear and the responses complicated: significant amplitude and frequency shifts are introduced, sub- and super-harmonics appear, and hysteresis occurs. It is of great importance to understand, predict and control this complicated dynamics. Due to the large number of DOFs and the broad range of study frequency, the computation time for solving the equations of motion by a temporal integration method can be quite prohibitive. It becomes particularly disadvantageous at the design stage where a parametrical study need to be quickly performed. An alternative numerical method, which is general and effective at the same time, is proposed in order to analyse the nonlinear response of the rotors at steady state. Firstly, the periodic responses of nonlinear rotors are calculated in the frequency domain by combining harmonic balance method (HBM) and alternating frequency-time (AFT). With the help of continuation method, all dynamic equilibrium solutions of nonlinear systems are determined for the range of study frequency. Then, Floquet exponents which are the eigenvalues of Jacobian are sought for stability analysis of periodic solutions. Then the local stability of the periodic solution is analysed through the bifurcation indicators which are based on the evolution of Floquet exponents. The bifurcations of periodic solution branch, such as limit point, branch point, and Neimark-Sacker bifurcation, are thus detected. By declaring a system parameter (friction coefficient, rotor / stator gap, excitation amplitude, ...) as a new variable, applying once again the continuation method to the augmented system determines directly the bifurcation's evolution as a function of this parameter. Thus, parametric analysis of the nonlinear dynamic behaviour is achieved, the stability boundary or the regime change boundary is directly determined. Numerous developments are implemented in the calculation code Cast3M
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SEGAYER, AHMED MOHAMMED. "ROTOR STATOR CONTACT IN A ROTATING MACHINE." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2000. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=34202@1.
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COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR<br>O crescente avanço da tecnologia de equipamentos rotativos tem exigido dos projetistas de máquinas adapta-los às condições de operação mais rigorosas e, consequentemente, projetos mais sofisticados. O aumento da eficiência é frequentemente realizado por operações de minimização de folga entre os elementos rotativos e estacionários e/ou aumento da velocidade de rotação do rotor. A natureza das funções e o custo elevado dos equipamentos rotativos de alta velocidade exigem precisão e segurança no projeto para evitar riscos de operação. Quando o rotor entra em contato com o estator, este pode exibir um
comportamento dinâmico fascinante cujo movimento depende de impacto, atrito, e efeitos giroscópicos. Grande parte das preocupações dos engenheiros com relação a vibrações em máquinas rotativas leves e de alta velocidade deve-se aos seus efeitos destrutivos sobre o sistema do estator. Interação devido ao efeito do rubbing entre o conjunto do rotor e sua respectiva carcaça um dos principais causadores de falhas em máquinas rotativas. As forças e tensões desenvolvidas como resultado de pequenas folgas podem resultar em desgaste, perda de desempenho, redução de estabilidade, ruído, calor e vibrações. Obter maior conhecimento sobre este fenômeno torna-se extremamente importante para melhorar a capacidade de
proteger o sistema de possíveis danos. O fator chave para almejar este objetivo é continuamente aumentar a habilidade de prever a resposta dinâmica com precisão para então garantir a estabilidade do sistema do rotor. Neste âmbito, o presente trabalho apresenta um estudo teórico, com simulação numérica e validação experimental como objetivo de melhorar nosso conhecimentos sobre o fenômeno.<br>Increasing demands for high performance, yet reliable operation of rotating machinery continues to increase and have placed stringent requirements on designers and developers to produce efficient, trouble-free rotating machinery. The performance of high-performance turbomachinery can be enhanced by decreasing clearance between rotating parts and housing and/or by increasing the rotor velocity. When a rotor touches upon a boundary, it can exhibit a quite fascinating dynamical behavior and its motion depends on impact, friction, and gyroscopic effects. A large portion of the engineering concern with vibration in high speed rotating machinery results from its destructive effects on the stator system. Rub
interactions between a rotor assembly and its corresponding casing structure has been one of the major causes for machine failure. The forces and tensions developed as a result of such clearances can result in wear, loss of performance, reduction of the stability, noise, heat and vibration. Gaining increased knowledge about rnb-related phenomena is important for improving the ability to protect a machine from damage. A key factor in achieving this objective continues to be the ability to accurately predict the dynamic response and stability of a rotor system. This work presents theoretical study, with numerical simulation and
experimental validation to improve our knowledge about this phenomena.
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Sparv, Lisa. "Cooling simulation of a BEV electrical machine rotor." Thesis, KTH, Fordonsdynamik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-302143.
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The thesis work described in this report is about simulation of the cooling of an electrical machine rotor. Limitations and simplifications were made on the CAD model of the rotor with the purpose of reducing the simulation time, for it to then be used for CFD-simulations using STAR-CCM+. This was done to see the temperature, as well as its distribution, in the model. By changing various parameters, one at the time whilst the rest were kept at their assigned standard values, the changes could be analysed and thereafter compared. The tests include smaller geometry changes, parameters of the coolant and its flow, parameters for the airgap and the materials in the laminates and the material around the magnets, as well as changes in loss values. The simulations for geometry changes involving the magnets and their surrounding material resulted in minor temperature increases. An inner rotor radius increase gave a relatively large temperature decrease (although this change would be more difficult to make in practice). Most of the mean values of the temperature changes in the regions of the model were within 10% from the standard simulation used. Increased thermal contact resistance between the Bakelite and the laminates, and increased losses had the worst impact on the cooling. Meanwhile the changes in coolant parameters (as well as the its inlet temperature and mass flow) and reduced losses had the best impact on the cooling. Generally, the temperature distributions looked similar for the different simulations. There were more differences in the distributions for the simulations with changed material properties or thermal contact resistance.<br>Examensarbetet som beskrivs i denna rapport handlar om simulering av kylningen av en elmaskinsrotor. Avgränsningar och vissa förenklingar gjordes på en CAD modell av rotorn för att reducera simuleringstiden. Sedan användes CFD-simuleringsprogrammet STAR-CCM+ för att simulera temperaturfördelningen i modellen. Genom att ändra olika parametrar, en åt gången medan resten hölls vid sina bestämda standardvärden, kunde förändringarna undersökas och sedan jämföras. Det som testades inkluderar bland annat mindre geometriförändringar, parametrar för kyloljan och dess flöde, parametrar för luftgapet och materialen i laminaten och runt permanentmagneterna, samt förlustförändringar. Geometriförändringarna som gjordes för magneterna och det omgivande materialet gav små temperaturökningar. En ökad inre radie på rotorn gav relativt stor temperaturminskning (men denna ändring vore svårare att genomföra på rotorn i praktiken). Majoriteten av medelvärdena av modellregionernas temperaturförändringar var inom 10% från standardsimuleringen som användes. Ökat termiskt kontaktmotstånd mellan Bakeliten och laminaten samt ökade förluster hade sämst påverkan för kylningen, medan förändring i kylvätskans egenskaperna (samt inflödestemperaturen och massflödet) samt minskade förluster hade bäst inverkan. Generellt så såg temperaturfördelningarna lika ut för de olika simuleringarna. Det var främst när materialegenskaperna eller det termiska kontaktmotståndet ändrades som fördelningen såg annorlunda ut.
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Wills, Dominic. "Methods to quantify and reduce rotor losses in a solid rotor yoke permanent magnet machine." Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/4014.
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Thesis (PhD (Electrical and Electronic Engineering))--University of Stellenbosch, 2010.<br>ENGLISH ABSTRACT: Certain types of electric machines are particularly susceptible to the proliferation of eddy
currents flowing within the solid conducting regions in the rotor. Single-layer, non-overlapping
windings within uneven open slots are some stator properties that can produce damaging,
asynchronous magnetic field harmonics which manifest in the rotor as eddy currents. The
ohmic losses caused by these eddy currents are a source of inefficiency and can cause a marked
increase in the temperature of the rotor. This temperature rise can be dangerous for the
magnets, which have to be kept within temperature limits to avoid partial or full
demagnetization.
The research work presented here is concerned with reducing the effect of eddy currents in the
rotor magnets and solid rotor yoke of an electric machine. The work presents analytical
methods to calculate the magnetic fields, eddy currents and solid loss in an electric machine due
to current in the winding and due to the interaction of the permeance variation in the stator
with the magnets in the rotor. A method is also suggested where the analytical theory can be
used with a magnetostatic finite element solution to produce a transient solid loss result. The
research work also investigates a method for optimal segmentation in both level and
penetration, and provides some design suggestions.
The work presents the method of partial magnet segmentation, which is a technique whereby
thin incisions are made into the magnet material from one or both sides. Another method of
partial rotor segmentation is also presented where the incisions are made into a portion of the
magnet-facing solid yoke. These methods attempt to interrupt the flow of eddy currents and
increase the resistance ‘seen’ by the eddy currents, while also keeping construction difficulty
and cost to a minimum. The methods are verified using finite element calculations which are
compared to measured results.
The result is that partial magnet segmentation is a very useful, effective and practical method of
segmenting magnets. The loss reduction profile can be similar to that of traditional full
segmentation. The method of partial rotor segmentation also shows a large reduction in rotor
power loss. With implementation of these methods on a test machine, one can expect an
efficiency increase of more than 4 %<br>AFRIKAANSE OPSOMMING: Sekere tipes van elektriese masjiene is veral sensitief vir die vloei van werwelstrome in solied
geleidende gebiede in die rotor. Enkellaag, nie-oorvleuelende wikkelings in oneweredige oop
gleuwe is enkele stator eienskappe wat skadelike, asinchrone magneetveld harmonieke tot
gevolg kan hê, wat as werwelstrome in die rotor manifesteer. Die ohmiese verliese wat deur
hierdie werwelstrome teweeg gebring word is 'n bron van ondoeltreffendheid en kan lei tot 'n
merkbare toename in die temperatuur van die rotor. Hierdie temperatuur styging hou gevaar in
vir die magnete en moet binne temperatuur limiete gehou word om gedeeltlike of self volle
demagnetisering te vermy.
Die navorsing vervat in hierdie document is gemoeid met die vermindering van die effek van
werwelstrome in die rotor magnete en in die soliede rotor juk van 'n elektriese masjien. Die
werk bied analitiese metodes aan vir die berekening van die magneetvelde, werwelstrome en
soliede verliese in ’n elektriese masjien as gevolg van strome in die wikkelings en die interaksie
van die permeansie variasie van die stator met die magnete in die rotor. ’n Metode word ook
voorgestel waar die analitiese teorie saam met ’n magnetostatiese eindige element oplossing
gebruik word om ’n resultaat vir die oorgang soliede verliese te verkry. Die
navorsingswerk ondersoek ook ’n metode vir die optimale segmentering in beide vlak sowel as
penetrasie, en verskaf sekere ontwerp voorstelle.
Die werk bied die metode aan van gedeeltelike magneet segmentering, wat 'n tegniek is
waarvolgens dun insnydings gemaak word aan een of beide kante van die magneet materiaal.
Nog ’n metode van gedeeltelike rotor segmentering word beskou waar die insnydings in in ’n
gedeelte aan die magneetkant van die soliede rotor juk gemaak word. Hierdie metodes poog om
die vloei van werwelstrome te onderbreek en die weerstand soos "gesien" deur die
werwelstrome te verhoog, terwyl konstruksie kompleksiteit en koste tot ’n minimum beperk
word. Die metodes word bevestig deur eindige element berekeninge wat met gemete resultate
vergelyk word.
Die gevolg is dat gedeeltelike magneet segmentering 'n baie nuttige, doeltreffende en praktiese
metode van die segmentering van magnete is. Die verliesverminderingsprofiel van gedeeltelike
segmentering kan soortgelyk wees aan dit van tradisionele volle segmentering. Die metode van
gedeeltelike rotor segmentering toon ook 'n groot afname in rotor drywingsverlies. Met die
implementering van hierdie metodes op ’n toetsmasjien, kan ’n mens ’n verhoging in
benuttingsgraad verwag van meer as 4 %
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Masoud, Mahmoud Ibrahim. "Decoupled control of rotor torque and rotor electric power in a salient pole, synchronous machine." Thesis, Heriot-Watt University, 2003. http://hdl.handle.net/10399/389.
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Drennan, Duncan Scott. "Design of a passive rotor transverse flux rotating machine." Thesis, Stellenbosch : Stellenbosch University, 2005. http://hdl.handle.net/10019.1/50313.
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Pages 6-12 missing.<br>Thesis (MScEng)--University of Stellenbosch, 2005.<br>ENGLISH ABSTRACT: The transverse flux machine (TFM) offers the opportunity of high torque to volume ratios which makes
it an excellent candidate for direct wheel drives and low speed generator applications. TFMs have a
three dimensional flux path which eliminates iron laminates as a viable core material. Soft magnetic
composites have been adopted in these machines due to their isotropic nature. There are three main
variants of TFMs, namely, active rotor (with magnets on the rotor), passive rotor (with magnets on the
stator), and reluctance (with no magnets). As a relatively recent development in electrical machines, the
TFM still has many hurdles facing its adoption in industry. Some of these hurdles are high cogging torque,
a difficult construction, and expensive materials.
This thesis focuses on the design of a three phase 50 kW passive rotor machine. Finite element
simulation is used to determine the optimal configuration, and the final machine is analysed in detail. The
construction process and associated problems are also detailed. The completed machine did not perform
to the desired specification, but much knowledge was gleaned about the TFM, the construction caveats,
and future potential directions.<br>AFRIKAANSE OPSOMMING: Die transversale-vloed masjien (TFM) met sy hoe draaimoment tot volume verhouding, is 'n uitstekende
kandidaat vir direkte wiel aandrywing en lae spoed generator toepassings. Die vioed pad van die masjiene
is drie-dimensioneel, wat yster laminasies as kern materiaal elimineer. "Soft magnetic composites" kan
gebruik word vir hierdie masjiene as gevolg van hulle isotropiese eienskappe. Daar bestaan drie hoof
variante van die TFM, naamlik, die aktiewe rotor (met magnete op die rotor), passiewe rotor (met magnete
op to stator), en reluktansie (sonder magnete). Die TFM is 'n redelike nuwe tipe masjien en daar is nog
probleme wat opgelos moet word voordat die industrie sal begin om dit te gebruik. Van hierdie probleme
is "cogging" draaimoment, 'n moeilike konstruksie en duur materiale.
Die fokus van hierie tesis is op die ontwerp van 'n 50 kW drie-fase passiewe rotor masjien. Eindige
element simulasie is gebruik om die optimale konfigurasie te kry, en 'n analise is gedoen op die finale
masjien. Die konstruksie proses en die probleme wat daarmeer saam gaan is ook beskryf. Die prototipe
masjien wat gebou is het nie aan sy oorspronklike spesifikasie voldoen nie, maar baie kennis is opgedoen
oor die TFM, die konstruksie proses, en potensiele toekomende toepassings.
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Al-Amer, Itihad Abd Al-Hameed Abd. "A stable doubly-fed machine with novel rotor design." Thesis, Queen's University Belfast, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.335349.
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Papini, Luca. "Performance calculation of high speed solid rotor induction machine." Thesis, University of Nottingham, 2018. http://eprints.nottingham.ac.uk/52180/.
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Solid rotor induction machines are suitable for applications which require robustness, reliability and high rotational speed. A literature review of high speed technologies is initially presented. The current limitation and challenges are detailed based on a wide collection of data. The multi-physics aspect related with electrical machines for high speed applications are discussed providing a summary of the current state of the art. The main aim of the research was to develop a multi-physic computational environment for the design and analysis of solid rotor induction machines. The electromagnetic, thermal, structural and rotor dynamics models have been developed targeting reduced computational time and accurate predictions. Numerical techniques are proposed based on the discretisation of the computational domain. The different disciplines are linked together providing a flexible and powerful tool for the characterisation of solid rotor induction machine. Another objective was to investigate the impact of the rotor material on the electromagnetic performances of the machine. Finite Element simulation are used to account for the non linear magnetic properties. The impact on the equivalent circuit parameter is discussed and general criteria for material selection presented. Three dimensional finite element calculation are p erformed targeting the validation of the end region correction factor and select the rotor length. The performances of a 120 [kW]−25000 [rpm] solid rotor machine are compared with a caged rotor induction machine for waste heat recovery application.
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Delport, Jacques. "Synchronized Measurement of Machine Rotor Angle and Its Application." Thesis, Virginia Tech, 2015. http://hdl.handle.net/10919/51242.
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The internal voltage angle of a generator is an important parameter that indicates the stability, both transient and steady-state, of the generator. This paper proposes a method of measuring and synchronizing the internal angle using a microprocessor and an optical encoder installed on the shaft of a generator. With a synchronized angle measurement, accurate stability studies and wide-area controls can be implemented. The experimental setup for measuring the rotor angle of a generator is explained in this work.
A wide-area power system stabilizer implementing the synchronized angle measurement is then investigated using a four machine, two-area system. A synchronized remote feedback rotor angle signal is included in a traditional stabilizer design. It is shown that this remote signal helps increase the stability of the system while also having the benefit of being able to be predicted accurately. This capability makes bad data detection and communication delay compensation possible.<br>Master of Science
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Wang, Hong. "MACHINE HEALTH MONITORING OF ROTOR-BEARING-GEAR TRANSMISSION SYSTEM." University of Akron / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=akron1133281063.
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Mercier, Jean-Charles. "Contribution à l'étude par éléments finis du comportement électromagnétique des machines asynchrones rapides." Vandoeuvre-les-Nancy, INPL, 1993. http://www.theses.fr/1993INPL085N.
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Dans un but d'augmenter la puissance volumique des machines électriques, et grâce au développement de l'électronique de puissance, les industriels cherchent à construire des machines à grande vitesse de rotation. Un tour d'horizon des différentes technologies envisageables pour de telles applications est présenté. Pour des raisons autant économiques que pratiques, notre choix s'est porté sur la machine asynchrone à rotor massif. L'inexistence de schéma équivalent classique et la volonté d'optimiser les paramètres géométriques du rotor imposent l'utilisation de méthodes numériques. Le calcul par éléments finis du comportement électromagnétique d'une machine asynchrone (classique ou rapide) au régime établi est très consommateur de temps et de mémoire. En effet, les simulations pas à pas dans le temps peuvent durer jusqu'a 200 heures suivant le matériel informatique utilisé. Une nouvelle modélisation est proposée, fondée sur la séparation du domaine d'étude en deux (rotor+entrefer et stator+entrefer) et sur un couplage de ces derniers par le premier harmonique d'espace de la représentation complexe du potentiel vecteur magnétique dans l'entrefer. Le calcul est réalisé en trois étapes successives pour un temps de une à cinq minutes suivant le nombre de nœuds des maillages rotor et stator. Cette méthode de calcul est validée par la comparaison de ses résultats (couple, puissance, courant, tension, glissement) avec les mesures expérimentales effectuées sur une machine réelle. Enfin, des études de machines asynchrones à rotor massif sont présentées
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Sá, Luís Fernando Nogueira de. "Topology optimization method applied to laminar flow machine rotor design." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/3/3152/tde-16032017-103709/.
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Flow machines are very important to industry, being widely used on various processes. Performance improvements are relevant factors and can be achieved by using optimization methods, such as topology optimization. Thus, this work aims to develop a method to design radial flow machine rotors operating on laminar regime, by implementing a topology optimization formulation based on density model. The design of a rotor involves firstly modelling the fluid flow by using the Navier-Stokes equations on a rotating reference frame and using the Finite Element Method for solving the differential equations. To determine the material distribution on the domain, a porous flow model based on the Darcy equation is employed by using an inverse permeability that interpolates between fluid and solid. In the optimization phase, it is defined a multi-objective function that aims to minimize the viscous energy dissipation, vorticity and power. The optimization problem is implemented using the FEniCS environment and the libraries dolfin-adjoint and pyIpopt. The optimized topologies are verified with the ANSYS software. The resulting topologies are post-processed and a CAD model is created. The rotors are manufactured by using a 3D printer, the complete prototype is built by coupling an electric brushless motor and an experimental characterization is performed by measuring fluid flow and pressure head given by the pumps. Experimental and computational results are compared and the improvement is verified.<br>Máquinas de fluxo são muito importantes para a indústria, sendo utilizadas em diversos processos. Assim, melhorias de desempenho são fatores relevantes e podem ser alcançadas com a utilização de métodos de otimização, como a otimização topológica. Este trabalho visa desenvolver uma metodologia para projetar rotores de máquinas de fluxo radiais que operam em escoamento laminar implementando-se a formulação de otimização topológica baseada no modelo de densidades. O projeto de rotores envolve, primeiramente, a modelagem do escoamento utilizando-se as equações de Navier-Stokes em um referencial rotativo e a utilização do Método de Elementos Finitos para a resolução das equações diferenciais. A distribuição de material no domínio é feita empregando-se um modelo de escoamento em meio poroso baseado nas equações de Darcy, utilizando-se a permeabilidade inversa que interpola o elemento entre sólido e fluido. Na fase de otimização é definida uma função multi-objetivo, que visa minimizar dissipação de energia viscosa, a vorticidade e a potência. O problema de otimização é implementado utilizando-se o ambiente FEniCS para a resolução do sistema de elementos finitos e as bibliotecas dolfin-adjoint e pyIpopt para o algorithmo de otimização. As topologias otimizadas são verificadas com o software ANSYS. As topologias resultantes são pós-processadas para a criação de um modelo CAD dos rotores. Os rotores são construídos utilizando-se a impressão 3D, o protótipo completo é montado acoplando-se um motor elétrico sem escovas e a caracterização experimental é feita medindo-se a vazão e o ganho de pressão dados pelas bombas. Por fim, os resultados experimentais e computacionais são comparados e uma melhoria de desempenho é observada.
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Higgs, John. "The dynamical behaviour of damped, rotor assembly systems." Thesis, University of Wolverhampton, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.371858.
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Guettafi, Amor. "Modelisation d'une generatrice asynchrone impulsionnelle a rotor discoide en acier." Paris 6, 1987. http://www.theses.fr/1987PA066072.
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Mazur, David Christopher. "Synchronized Rotor Angle Measurement of Synchronous Machines." Thesis, Virginia Tech, 2012. http://hdl.handle.net/10919/31813.
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A key input parameter to governor feedback control and stability protection of generators is the angle of the induced voltage internal to the generator. Current practice is to estimate this value using measurements from the terminals of the generator and mathematical models. This project aims to develop a system that would directly measure the internal angle of the generator using a rotary encoder on the shaft of the machine. This document describes the theory and experimental setup of this proposed system and outlines the test procedure of experimentation.<br>Master of Science
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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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Geoffriault, Maud. "Réduction active des vibrations et des bruits d'une machine électrique par la stratégie de commande." Thesis, CentraleSupélec, 2015. http://www.theses.fr/2015SUPL0003/document.
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Les travaux de cette thèse s’inscrivent dans le contexte du développement de groupes motopropulseurs électriques pour véhicules automobiles. Ces développements ont mis en lumière les problématiques liées aux phénomènes acoustiques et vibratoires des machines électriques, spécifiques à l'application automobile. L'objectif de ces travaux est la mise en place de lois de commande dédiées à la réduction d'harmoniques de courant à l'origine d'harmoniques vibratoires.Pour cela, les différents éléments du système ont été modélisés, puis les paramètres du modèle électrique de la machine ont été identifiés au moyen de mesures expérimentales.Deux stratégies de commande ont ensuite été développées puis mises en place. D'une part, un régulateur dédié à l'harmonique de courant visé a été synthétisé par optimisation H-infini. D'autre part, la modélisation de l'origine de cet harmonique comme provenant d'un signal perturbateur externe a permis la compensation de celui-ci au moyen d'un observateur.L'efficacité de ces deux stratégies sur la réduction des harmoniques de courant visés et des harmoniques vibratoires correspondants a été validée expérimentalement sur banc d'essai vibratoire<br>This work takes place in the context of the development of powertrains for electric vehicles. Those developments have raised new issues such as noise and vibrations of electrical machines, which are important issues in automotive applications. The aim of this thesis is to develop control laws dedicated to the reduction of currents harmonics that are responsible for vibration harmonics.In that purpose, different parts of the system have been modelled. Parameters of the electrical model of the studied machine have then been identified thanks to experimental measurements.Two different control laws are proposed and developed. One the one hand, a controller is synthetized thanks to H-infinity optimization. On the other hand, the studied current harmonic is modelled as coming from an external disturbance. This virtual disturbance is estimated thanks to an observer and compensated
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Bomela, Xola B. "Some design aspects of the multi flux barrier rotor reluctance synchronous machine." Thesis, Stellenbosch : Stellenbosch University, 2000. http://hdl.handle.net/10019.1/51912.
Full textAbstract:
Thesis (MEng)--University of Stellenbosch, 2000.<br>ENGLISH ABSTRACT: This thesis deals with different design aspects of the multi-flux barrier rotor of the reluctance synchronous
machine (RSM). The effect of the different designs on the performance of the RSM is
investigated by means of two-dimensional finite element analysis. The finite element analysis is also
directly used in the optimum design of the rotor of the RSM. The importance of the use of the finite
element analysis in the design and performance calculations of the RSM is illustrated in this thesis.
The design aspects of the RSM which are focussed on in this thesis are, amongst other things,
the chording of the stator winding, the skewing of the rotor and the ratio of the number of rotor flux
barriers to the number of stator slots of the RSM. The effects of these design aspects on the average
torque and torque ripple of the RSM are investigated and general design directives are given. The
occurrence of flux pulsations in the stator teeth and rotor iron segments of the RSM are also studied
to some extent.
The finite element optimum design of a4-pole RSM-rotor with a high number of flux barriers is
described in the thesis. This optimum designed rotor is built and the RSM with this rotor is tested
in the laboratory. Its calculated and measured performances are studied and compared with a conventional,
low number rotor flux barrier RSM. It is found, amongst other things, that the RSM with
the high number of rotor flux barriers has a slightly higher average torque with a significantly lower
torque ripple.<br>AFRIKAANSE OPSOMMING: Hierdie tesis handeloor verskillende ontwerp-aspekte van die reluktansie sinchroonmasjien (RSM)
met 'n multi-vloedversperringsrotor. Die effek van die verskillende ontwerpe op die vermoë van die
RSM is met behulp van twee-dimensionele eindige element analise ondersoek. Die eindige element
analise is ook direk in die optimum ontwerp van die rotor van die RSM gebruik. Die belangrikheid
van die gebruik van die eindige element analise in die ontwerp en vermoë-berekening van die RSM
word in die tesis geïllustreer.
Die ontwerp-aspekte van die RSM waarop in hierdie tesis gefokus word, is onder andere die spoelsteekverkorting
van die statorwikkeling, die skuinsing van die rotor en die verhouding van die
getal rotor-vloedverperrings tot die getal statorgIeuwe van die RSM. Die effek van hierdie ontwerpaspekte
op die gemiddelde draaimoment en draaimoment-rimpel van die RSM word ondersoek en
algemene riglyne vir die ontwerp van die RSM word gegee. Die voorkoms van vloedpulsasies in die
statortande en rotor yster segmente van die RSM word ook deels ondersoek.
Die eindige element optimum ontwerp van 'n 4-pool RSM-rotor met 'n hoe getal vloedversperrings
word in die tesis beskryf. Hierdie optimum ontwerpte rotor is gebou en die RSM met hierdie rotor is
in die laboratorium getoets. Die berekende en gemete vermoë is bestudeer en vergelyk met die vermoë
van 'n RSM met 'n konvensionele, lae getal vloedversperrings rotor. Dit is onder andere gevind
dat die RSM met die hoë getal rotor-vloedversperrings 'n effens hoër gemiddelde draaimoment het
met 'n behuidende laer draaimoment-rimpel.
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Kremer, Mickaël. "Electromagnetic design of a disc rotor electric machine as integrated motor-generator for hybrid vehicles." Thesis, Mulhouse, 2016. http://www.theses.fr/2016MULH8792/document.
Full textAbstract:
Cette thèse présente le dimensionnement d’une machine électrique à rotor disque pour la traction de véhicules hybrides. Un état de l’art complet sur les machines électriques à rotor disque permet de montrer que la machine à flux axial à rotor central est la plus adaptée. Différentes géométries du circuit magnétique sont successivement étudiées et comparées par simulations par éléments finis. Pour maximiser le rendement de la machine, les pertes d’origine électromagnétique sont étudiées. Un modèle analytique des pertes par effet de peau dans les conducteurs de cuivre est proposé et validé par éléments finis. Un second modèle analytique estime les pertes par courant induits dans les aimants permanents pour tous les points de travail de la machine se basant sur uniquement trois simulations par éléments finis permettant ainsi un gain de temps important lors du dimensionnement. Deux méthodes de dimensionnement sont comparées : le dimensionnement manuel par essais/erreurs et l’optimisation multi-objectifs. Cette dernière méthode automatise le dimensionnement et permet une optimisation plus pointue et une forte amélioration des performances. Dans ce cas, la densité de couple a par exemple été augmentée de 29%. La machine à flux axial dimensionnée est comparée avec une machine à flux radial pour véhicules hybrides. Cette comparaison révèle le potentiel de la machine à flux axial avec notamment une densité de couple augmentée de plus de 20%. Enfin, deux prototypes ont été construits et mesurés pour valider les simulations<br>This PhD presents the design of a disc rotor electric machine for the traction of hybrid vehicles. A complete state of the art enables the selection of the internal rotor axial flux machine which is the most suited to this application. Different geometries of the magnetic circuit are successively studied and compared with finite elements simulations. To maximize the efficiency of the machine losses generated in the magnetic circuit are studied. An analytic model on the skin effect in the copper conductors is proposed and validated with finite elements simulations. A second analytic model estimates the eddy current losses in the permanent magnets for every operating point of the machine based on only three finite element simulations enabling an important time-saving. Two dimensioning methods are compared: the manual dimensioning based on a tries/errors method and the multi-objectives optimization. This last method automates the dimensioning and enables a more refined optimization and a strong improvement of the performances. For example, the torque density has been improved by 29% in that case. The designed axial flux machine is compared to a state of the art radial flux machine for hybrid vehicle. This comparison shows the potential of the axial flux machine with an improvement of the torque density by more than 20%. Finally two prototypes have been built and measured to validate the simulations
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Pellé, Julien. "Etude expérimentale des échanges convectifs sur le rotor d'une machine discoïde : influence d'un jet impactant." Valenciennes, 2006. https://ged.uphf.fr/nuxeo/site/esupversions/7cba07cb-e44b-4272-bc7b-ca5e2a2a403d.
Full textAbstract:
La nécessité de produire plus d’énergie électrique à un côut moindre entraîne la nécessité de produire mieux, à un rendement meilleur. Ce constat pose de multiples problèmes de refroidissement des machines électriques, notamment celles utilisées au sein des éoliennes. La méconnaissance des phénomènes qui s’y produisent et la recherche de solutions de refroidissement ont motivé cette étude. Le travail consiste en la détermination expérimentale des échanges convectifs à la surface d’un disque en rotation en régime permanent, dans trois configurations : rotor seul et système rotor-stator avec et sans jet. Un banc expérimental a été mis au point pour mesurer localement l’énergie prélevée au disque en rotation en utilisant une technique de « couche épaisse » et la thermographie infrarouge. Le disque est mis en rotation dans de l’air au repos. Cela crée un écoulement d’air à sa surface et un échange de chaleur convectif. L’étude du rotor seul a permis la validation du banc expérimental en comparaison aux données bibliographiques, très complètes sur cette configuration. Les configurations rotor-stator avec et sans jet ont permis de mettre en évidence l’influence des différents paramètres sur le refroidissement du système. Les données bibliographiques sur les écoulements et les visualisations effectuées permettent de faire une analyse des phénomènes mis en jeu. Les transferts de chaleur locaux et moyens à la surface du disque en rotation sont ensuite corrélés par des lois faisant intervenir les paramètres géométriques et dynamiques de l’étude<br>The need for producing more electric power at a less cost involves the need for better producing, at a higher efficiency. This report poses multiple problems as far as the cooling of electrical machines is concerned, particularly those used within the wind turbines. The ignorance of the phenomena which occur there and the search of cooling improvement justified this study. Work consists of the experimental determination of the convective heat transfer on the surface of a rotating disk, when the steady-state regime is reached: single rotating disk and rotor-stator system with and without impinging jet. An experimental apparatus was developed to locally measure the dissipated energy over the rotating disk surface by using a technique of “thick layer” and infrared thermography. When the disk is rotating, an air flow is created and so a convective heat transfer. The apparatus was validated in a single disk configuration, which is very detailed in literature. The both rotor-stator configurations (with and without jet) let to highlight the influence of the different parameters on the system cooling. As far as the flow structure is concerned, literature data and visualization using a laser technique make possible the analysis of phenomena inside the air gap. Local and mean heat transfer are then correlated
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Sibande, Sguda Enock. "Rotor design and performance evaluation of a PM-assisted reluctance synchronous traction machine." Thesis, Stellenbosch : Stellenbosch University, 2005. http://hdl.handle.net/10019.1/50444.
Full textAbstract:
Thesis (MScEng)--University of Stellenbosch, 2005.<br>ENGLISH ABSTRACT: The thesis describes the optimum rotor design and performance of a 110kW
Permanent-Magnet assisted (PM-assisted) Reluctance Synchronous traction Machine
(RSM) using bonded permanent magnet sheets. Particular attention is given to the
performance of the machine drive in the flux-weakening speed region. A detail
explanation is given of the finite-element design optimisation, the basic principles of
operation and the control-design of the PM-assisted RSM drive. A theoretical torque
comparison of the PM-assisted RSM, the standard RSM and the induction machine is
also done. The measured and calculated results of the different drives are presented
and analysed in detail. It is concluded that the performance of the PM-assisted RSM
in terms of torque, voltage and power factor compares favourably well with that of the
induction machine in both the constant torque and flux-weakening speed regions.
Furthermore, it is shown that the temperature rise of the stator winding of the PMassisted
RSM is lower than that of the RSM with both machines at the same load.<br>AFRIKAANSE OPSOMMING: Die tesis beskryf die optimum rotor ontwerp en vermoë van 'n 110 kW Permanent-
Pagnet-ondersteunde (PM-ondersteunde) Reluktansie Sinchroon Masjien (RSM)
trekkrag aandryfstelsel. Spesifieke aandag word gegee aan die vermoë van die
aandryfstelsel in die vloedverswakking spoedgebied. 'n Volledige verduideliking
word gegee van die eindige-element ontwerp optimering, die basiese beginses van
werking en die beheer-ontwerp van die PM-ondersteunde RSM aandryfstelsel. 'n
Teoretiese vergelyking van die draaiumoment-vergelyking van die PM-ondersteunde
RSM, die standard RSM en die induksmasjien word gedoen. Die berekende en gemete
resultate van die verskillende aandryfstelsels word in detail aangebied en ge-analiseer.
Dit is gevind dat die vermoë van die PM-ondersteunde RSM in terne van
draairnoment, spanning en arbeidsfaktor gunstig vergelyk met dit van die
induksiemasjien in beide die konstante draairnoment en vloedverswakking
spoedgebiede. Verder word getoon dat die temperatuur-styging van die statorwinding
van die PM-ondersteunde RSM laer is as die van die RSM, met deide masjiene by die
selfde las
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Ranft, Cornelius Jacobus Gerhardus. "Mechanical design and manufacturing of a high speed induction machine rotor / Cornelius Ranft." Thesis, North-West University, 2010. http://hdl.handle.net/10394/4940.
Full textAbstract:
The McTronX research group at the North–West University designs and develops Active Magnetic
Bearings (AMBs). The group’s focus shifted to the design and development of AMB supported drive
systems. This includes the electromagnetic and mechanical design of the electric machine, AMBs,
auxiliary bearings as well as the development of the control system.
The research group is currently developing an AMB supported high speed Induction Machine (IM) drive
system that will facilitate tests in order to verify the design capability of the group. The research
presented in this thesis describes the mechanical design and manufacturing of a high speed IM rotor
section. The design includes; selecting the IM rotor topology, material selection, detail stress analysis
and selecting appropriate manufacturing and assembly procedures.
A comprehensive literature study identifies six main design considerations during the mechanical design
of a high speed IM rotor section. These considerations include; magnetic core selection, rotor cage
design, shaft design, shaft/magnetic core connection, stress due to operation at elevated temperatures
and design for manufacture and assemble (DFMA). A critical overview of the literature leads to some
design decisions being made and is used as a starting point for the detail design. The design choices
include using a laminated cage rotor with a shrink fit for the shaft/magnetic core connection.
Throughout the detail design an iterative process was followed incorporating both electromagnetic and
mechanical considerations to deliver a good design solution. The first step of the iterative design process
was, roughly calculating the material strengths required for first iteration material selection followed by
more detailed interference fit calculations. From the detail stress analysis it became apparent that the
stress in the IM rotor section cannot be calculated accurately using analytical methods. Consequently, a
systematically verified and validated Finite Element Analysis (FEA) model was used to calculate the
interferences required for each component. The detail stress analysis of the assembly also determined
the allowable manufacturing dimensional tolerances. From the detail stress analysis it was found that
the available lamination and squirrel cage material strengths were inadequate for the design speed
specification of 27,000 r/min. The analysis showed that a maximum operating speed of 19,000 r/min can
be achieved while complying with the minimum factor of safety (FOS) of 2.
Each component was manufactured to the prescribed dimensional tolerances and the IM rotor section
was assembled. With the failure of the first assembly process, machine experts were consulted and a
revised process was implemented. The revised process entailed manufacturing five small lamination
stacks and assembling the stack and squirrel cage afterwards. The end ring/conductive bar connection
utilises interference fits due to the fact that the materials could not be welded. The process was
successful and the IM rotor section was shrink fitted onto the shaft.
However, after final machining of the rotor’s outer diameter (OD), inspections revealed axial
displacement of the end rings and a revised FEA was implemented to simulate the effect. The results
indicated a minimum FOS 0.6 at very small sections and with further analytical investigation it was
shown that the minimum FOS was reduced to only 1.34. Although the calculations indicated the FOS was below the minimum prescribed FOS ? 2, the rotor spin
tests were scheduled to continue as planned. The main reasons being that the lowest FOS is at very
small areas and is located at non critical structural positions. The fact that the rotor speed was
incrementally increased and multiple parameters were monitored, which could detect early signs of
failure, further supported the decision.
In testing the rotor was successfully spun up to 19,000 r/min and 27 rotor delevitation test were
conducted at speeds of up to 10,000 r/min. After continuous testing a secondary rotor inspection was
conducted and no visible changes could be detected.
The lessons learnt leads to mechanical design and manufacturing recommendations and the research
required to realise a 27,000 r/min rotor design.<br>Thesis (M.Ing. (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2011.
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Orciari, Luca. "Rotor position estimation of a bearingless permanent magnet synchronus motor by machine learning techniques." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019.
Find full textAbstract:
In this testis project, developed at the university of Bologna at LAR (Laboratory of Automation and Robotics), is studied the reconstruction of the rotor attitude of Bearingless Permanent Magnet Synchronous Motor (BPMSM), by processing the output of six hall effect sensor using a neural network to improve an already existing model-based reconstruction algorithm.
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Ullah, Sana. "A magnet assisted segmental rotor switched reluctance machine suitable for fault tolerant aerospace applications." Thesis, University of Newcastle upon Tyne, 2016. http://hdl.handle.net/10443/3368.
Full textAbstract:
The aerospace industry is moving towards more-electric aircraft. These electrical systems are lighter, more efficient and smaller compared to present hydraulic system. The permanent magnet electrical machine is an obvious choice to replace these hydraulic systems because of its high torque density. However for low speed applications, there are significant drag torque issues which negate some of the machine’s advantages. This thesis introduces a new permanent magnet assisted segmental rotor switched reluctance machine. This machine was first designed by using finite element software and then compared with a conventional segmental rotor switched reluctance machine, showing an increase in torque by increasing non saturation region of the stator lamination. On this basis, a fault-tolerant permanent magnet assisted segmental rotor switched reluctance machine was designed to replace the permanent magnet machine used in the nose wheel of the aeroplane. Both two-dimensional and three-dimensional finite element analyses were conducted to analyse the dominant end winding effect. Fault-tolerant segmental rotor switched reluctance machine was then built and tested. Static analysis was conducted to determine current-flux linkage and torque values at different rotor angles. The machine was analysed both with and without magnets to assess the effect of reverse magnetization with magnets at the stator tooth tip. Mutual inductance was also found using the same test rig. Dynamic testing of the machine was done to determine open circuit voltage and short-circuit current. A novel pot core permanent magnet assisted inductor was also designed and compared with the conventional E-E core inductor. The magnet was used to hold the inductance of the inductor constant for high current values and the inductor was then tested to determine magnet’s effect. A dominant inner loop effect was found which was proved by doing several tests. Various recommendations were made to further improve overall performance of the machine and the inductor.
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Gazdac, Ana Maria. "Design and control of the dual rotor permanent magnet induction machine for electric traction." Amiens, 2013. http://www.theses.fr/2013AMIE0109.
Full textAbstract:
Cette thèse propose un nouveau concept de machine électrique, la Machine Asynchrone à Aimants Permanents à double rotor dite machine hybride (MASH) comme une alternative aux machines existantes pour les applications de traction électrique. Le concept de la MASH, son principe de fonctionnement, ses avantages et inconvénients par rapport aux machines classiques ainsi que la démarche méthodologique de conception et dimensionnement sont étudiés. Deux méthodes analytiques de dimensionnement sont ainsi proposées soit pour la première basée sur la géométrie du stator (encombrement donné) soit pour la seconde basée sur la puissance nominale (imposée). L'approche analytique est complétée par une étude par la méthode des éléments finis qui permet de comparer la MASH à la MSAP et à la MAS d'après le rendement, le couple électromagnétique, les pertes ainsi que la puissance fournie. Une analyse de l'influence des différents types de matériaux magnétiques et conducteurs sur les performances est aussi effectuée de même qu'une analyse du comportement thermique. La dernière partie de la thèse concerne la commande de la MASH qui nécessite au préalable d'identifier les paramètres électriques des schémas équivalents. La stratégie de contrôle basée sur l'orientation du flux statorique comprenant deux boucles, une boucle asynchrone pour le rotor à cage et une boucle synchrone pour le rotor à aimants permanents, est alors proposée pour valider le comportement dynamique de la MASH. Cette validation est faite par comparaison des résultats obtenus par co-simulation (FEM & commande externe) et par le modèle de Park. L'ensemble des résultats obtenus permettent de construire un prototype de la MASH<br>The present thesis proposes a new concept of electrical machine, the dual-rotor Permanent Magnet Induction Machine, as an alternative to existing electrical machines for electric traction applications. The concept of dual-rotor Permanent Magnet Induction Machine (PMIM), its operating principle, advantages and disadvantages compared to classical machines as well as design and sizing methodologies are studied. Two analytical pre-sizing methods are thus proposed in this thesis: Stator Geometry Based Method (SGBM) where the sizing algorithm begins from a given stator geometry and Output Power Based Method (OPBM) where the sizing algorithm starts from an imposed output power. The analytical approach is complemented by a study using the Finite Element Method for comparing the PMIM with the IM (Induction Machine) and the PMSM (Permanent Magnet Synchronous Machine) based on their performance, electromagnetic torque, losses and output power. Analysis of the influence of different types of magnetic and conductive materials on the performance of the PMIM is also performed, as well as an investigation on its thermal behavior. The last part of the thesis focuses on the control of the PMIM which required a prior identification of parameters of the equivalent electric circuit. The control strategy, which is based on the Field Oriented Control and is composed of two loops, one asynchronous loop for the cage rotor and one synchronous loop for the PM rotor, is then proposed to validate the dynamic behavior of the PMIM. The validation is done by comparing the results obtained by co-simulation (FEM and External control) and Park model. All obtained results allow building a prototype of the PMIM
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Le, Luong Huong Thao. "Optimal Design of Modular High Performance Brushless Wound Rotor Synchronous Machine for embedded systems." Thesis, Toulouse, INPT, 2018. http://www.theses.fr/2018INPT0111/document.
Full textAbstract:
Cette thèse est dédiée à la conception optimale de la machine synchrone à rotor bobiné modulaire sans balais pour les systèmes embarqués. Cette machine est basée sur une structure POKIPOKITM développée par Mitsubishi Electric Coopération avec les convertisseurs de puissance intégrée pour augmenter la capacité de tolérance aux défauts. L'analyse électromagnétique est utilisée pour étudier les différentes machines synchrones à rotor bobiné et donc, pour sélectionner la structure qui offre la meilleure tolérance aux défauts et les performances les plus élevées. D’abord, le choix des nombres de phases, d’encoches et de pôles est un point critique. Ensuite, quelques machines sont analysées et comparées selon les critères tels que la densité de couple, le rendement, l'ondulation de couple. La machine avec 7 phases, 7 encoches et 6 pôles est alors choisie. Cette machine est ensuite comparée à la machine synchrone à aimant permanent monté en surface. Le résultat démontre que la machine synchrone à rotor bobiné modulaire sans balais possède le potentiel de remplacer la machine synchrone à aimant permanent dans notre application parce qu’elle présente des performances similaires avec une capacité de tolérance aux défauts élevée. Dans un second temps, une fois la structure 7phases/7encoches/6pôles choisie, cette machine est optimisée en utilisant NOMAD (qui est un logiciel d'optimisation de boîte noire) afin de minimiser le volume externe sous les contraintes électromagnétiques, thermiques et mécaniques. Comme ce problème d'optimisation est extrêmement difficile à résoudre, quelques relaxations ont été effectuées pour tester les différents algorithmes d'optimisation : fmincon (de Matlab) et NOMAD. Nous remarquons que NOMAD est plus efficace que fmincon pour trouver des solutions à ce problème de conception où certaines contraintes sont calculées par des simulations numériques (ANSYS Maxwell ; code éléments finis). En utilisant la méthode NOMAD basée sur l’algorithme Mesh Adaptive Direct Search, nous obtenons des résultats optimaux qui satisfont toutes les contraintes proposées. Il est nécessaire de valider ce design optimisé en vérifiant toutes les contraintes par des simulations électromagnétiques et thermiques en 3D. Les résultats montrent que le couple moyen obtenu par la simulation en 3D est inférieur à la valeur souhaitée. Par conséquent, en augmentant la longueur de la machine, une nouvelle machine corrigée est ainsi obtenue. Nous observons que les pertes de fer obtenues en 3D sont plus élevées qu'en 2D en raison du flux de fuite dans la tête de bobinage. En prenant les valeurs des pertes analysées par la simulation en 3D, la température de surface de la nouvelle machine analysée par la méthode Computational Fluid Dynamics est plus élevée que celle calculée dans l’optimisation. Enfin, un prototype de machine est construit et quelques tests expérimentaux est réalisés. Le résultat montre que la force électromotrice à vide a une forme d'onde similaire par rapport à la prédiction numérique en 3D et la différence de couple statique maximum entre les tests expérimentaux et les simulations par éléments finis en 3D est faible<br>This thesis is dedicated to the design and the optimization of modular brushless wound rotor synchronous machine for embedded systems. This machine is constructed based on POKIPOKITM structure with integrated drive electronics. Finite element analysis based optimization becomes more popular in the field of electrical machine design because analytical equations are not easily formalized for the machines which have complicate structures. Using electromagnetic analysis to comparatively study different modular brushless wound rotor synchronous machines and therefore, to select the structure which offers the best fault tolerant capability and the highest output performances. Firstly, the fundamental winding factor calculated by using the method based on voltage phasors is considered as a significant criterion in order to select the numbers of phases, stator slots and poles. After that, 2D finite element numerical simulations are carried out for a set of 15 machines to analyze their performances. The simulation results are then compared to find an appropriate machine according to torque density, torque ripple and machine efficiency. The 7phase/7-slot/6-pole machine is chosen and compared with a reference design surfacemounted permanent magnet synchronous machine in order to evaluate the interesting performance features of the wound rotor synchronous machine. In the second design stage, this machine is optimized by using derivative-free optimization. The objective is to minimize external volume under electromagnetic, thermal and mechanical constraints. Given that an accurate finite element analysis for machine performance takes a long time. Moreover, considering that the average torque can be obtained by simulating the model with only four rotor positions instead of one electric period, optimization strategy is proposed to reduce computational time and therefore, obtain a fast convergence ability by defining relaxed problems which enable minimizing the external volume of the machine under only several constraints such as average torque, torque ripple and copper losses. By testing relaxed problems, two different optimization methods (NOMAD and fmincon) are compared in order to select an appropriate method for our optimization problem. Using NOMAD method based on Mesh Adaptive Direct Search, we achieve optimal results which satisfy all of the constraints proposed. In the third design stage, all constraints are validated by 3D electromagnetic and thermal simulations using finite element and computational fluid dynamics methods. The 3D results show that the average torque obtained is lower than the desired value. By increasing the length of the machine, a new corrected machine is thus obtained. It can be observed that the iron losses obtained in 3D are higher than that in 2D due to the leakage flux in the end-winding. Then, the machine temperature is analyzed by using ANSYS Fluent. Note that the surface temperature is higher than that calculated in the optimization and the coil temperature is 8.48°C higher than the desired value (105°C). However, some dissipation by the shaft and the bearings of the machine are expected to reduce the machine temperature. Finally, a machine prototype is built and some experimental tests are carried out. The results show that the electromotive force has a similar waveform compared to 3D prediction and the difference of the measured and predicted maximum static torques is small
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Dakel, Zaki. "Stabilité et dynamique non linéaire de rotors embarqués." Thesis, Lyon, INSA, 2014. http://www.theses.fr/2014ISAL0087/document.
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Les rotors sont excités non seulement par le balourd tournant mais aussi par les différents mouvements de leur support : turbocompresseurs de véhicules, turbomoteurs aéronautiques, pompes à vide portées en sont des exemples industriels. Ainsi la conception de rotors robustes capables de bien fonctionner sous de telles conditions (excitations extrêmes) est nécessaire pour éviter des instabilités, source de défaillance catastrophique. Le présent travail a pour objectif de prévoir le comportement dynamique d’un rotor embarqué monté sur des paliers rigides ou élastiques hydrodynamiques et soumis à des excitations du support rigide. Les énergies cinétiques et de déformation ainsi que le travail virtuel des composants d’un rotor flexible tournant sont calculés. Le modèle proposé de rotor embarqué est basé sur les éléments finis de poutre de TIMOSHENKO. Il contient les effets relatifs à l’inertie de rotation des sections droites, à l’inertie gyroscopique, à la déformation de cisaillement d’arbre et à la dissymétrie géométrique de l’arbre et/ou du disque rigide et considère six types de mouvements déterministes (rotations et translations) du support. Suivant le type d’analyse utilisé pour le palier, les forces de rappel hydrodynamiques agissant sur l’arbre et calculées avec l’équation de REYNOLDS sont linéaires/non linéaires. L’utilisation des équations de LAGRANGE fournit les équations différentielles linéaires/non linéaires du mouvement du rotor embarqué en flexion par rapport au support mobile supposé rigide, qui représente un système de coordonnées non inertiel. Les équations du mouvement contiennent des termes paramétriques périodiques en raison de la dissymétrie géométrique du rotor et des termes paramétrique variables dans le temps en raison des rotations du support. Ces termes paramétriques sont considérés comme des sources d’excitation intérieure et conduisent à une instabilité dynamique latérale. Dans les applications numériques proposées, trois configurations de rotor embarqué sont analysées. Tout d’abord, un rotor symétrique monté sur des paliers rigides est soumis à un balourd combiné avec des mouvements de rotation constante et de translation sinusoïdale du support. Ensuite, un rotor avec une dissymétrie géométrique du disque monté sur des paliers rigides est excité par l’effet de balourd et par des mouvements combinés de rotation constante et de translation sinusoïdale du support. Enfin, un rotor symétrique monté sur des paliers hydrodynamiques est soumis au balourd et aux excitations sinusoïdales de rotation ou de translation du support<br>Rotors are excited not only by the rotating mass unbalance but also by the different motions of their support: vehicle turbochargers, aircraft turbo-engines, carried vacuum pumps, are different industrial applications. Thus the design of robust rotors able to run well under such conditions (extreme excitations) and to avoid catastrophic failure is required. The present work aims to predict the dynamic behavior of an on-board rotor mounted on rigid or elastic hydrodynamic journal bearings and subjected to rigid support excitations. The kinetic and strain energies as well as the virtual work of the rotating flexible rotor components are computed. The proposed on-board rotor model is based on TIMOSHENKO beam finite elements. It includes the effects relative to the rotating inertia, the gyroscopic inertia, the shear deformation of shaft as well as the geometric asymmetry of shaft and/or rigid disk and considers six types of deterministic motions (rotations and translations) of the support. Depending on the type of analysis used for the bearing, the restoring fluid film forces acting on the shaft and computed with the REYNOLDS equation are linear/non-linear. The use of LAGRANGE’s equations yields the linear/non-linear differential equations of vibratory motion of the on-board rotor in bending with respect to the moving rigid support which represents a non-inertial reference frame. The equations of motion contain periodic parametric coefficients because of the geometric asymmetry of the rotor and time-varying parametric coefficients because of the support rotations. These parametric coefficients are considered as sources of internal excitation and can lead to lateral dynamic instability. In the proposed numerical application examples, three rotor configurations are studied. Firstly, a symmetric rotor mounted on rigid bearings is subjected to rotating mass unbalance combined with constant rotation and sinusoidal translation of the support. Secondly, a rotor with geometric asymmetry due to the disk mounted on rigid bearings is excited by the mass unbalance effect and by the combination of a constant rotation and a sinusoidal translation of the support. Thirdly, a symmetric rotor mounted on linearized/non-linear hydrodynamic bearings is subjected to the excitation due to the mass unbalance and to the sinusoidal rotational or translational excitations of the support
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Rabbi, Ata-E. "Detection of stator interturn fault of synchronous machine by rotor current analysis : A SIMULATION APPROACH." Thesis, KTH, Skolan för elektro- och systemteknik (EES), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-187654.
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One of the major electrical faults of synchronous machines is an interturn short circuit in the stator winding, due to winding insulation failure. A synchronous machine is designed to have electrical and mechanical symmetry in the stator and rotor. An interturn fault in a synchronous machine damages the symmetrical property, thereby inducing abnormal symptoms like varying torque, mechanical vibration, and deviation of stator and rotor terminal currents from their usual waveform. This last symptom is what is studied in this thesis, as an indicator of the presence of an interturn fault. An interturn fault during machine operation can lead to a catastrophic machine failure and consequent long outage, unless it is rapidly detected and the machine shut down. Prevention of such outages is an important concern for machine owners and power system operators. That is why early detection of interturn faults is desirable to prevent such machine failure. Several external sensors can be implemented to detect such interturn fault, which is costly. That is why it is desirable if the interturn fault can be detected by analyzing the measured currents that already are available to a protective relay. In this thesis a simulation approach is presented to observe the pattern and frequency spectrum of rotor field current in presence of a stator inter turn fault. All simulations have been performed using Matlab-based programs written during this thesis work in the Electromagnetic department (ETK) in KTH. The outcome of the thesis is that in the presence of an interturn fault in the stator, several even harmonic components are found in the frequency spectrum of the rotor field current. The presence of these harmonics is not a definitive sign of an interturn fault, as almost the same even harmonics are found in the rotor field current if the stator winding asymmetry is taken into account.<br>En av de största elektriska felen i synkronmaskiner är en kortslutning mellan varv i statorlindningen, på grund av skadad lindningsisolering. En synkronmaskins konstruktion ger elektrisk och mekanisk symmetri i statorn och rotorn vilket ger en hög effektivitet. Ett varvfel i statorn skadar symmetrin och inducerar onormalt stora strömmarvilket leder till ett tidsvarierande vridmoment, mekanisk vibration, och onormala vågformer av strömmarna vid statorns och rotorns poler. Varvfel under maskinens drift kan snabbt orsaka stora skador, med följd av långa avbrottstider. Förebyggande av sådana avbrott är viktig hos maskinägare och systemansvariga. Därför är snabb detektering av sådana fel, och urdrifttagning av maskinen önskvärd för att minska skadan. Däremot ska detekteringen ha låg sannolikhet att lösa ut i onödan, av annat skäl. Externa sensorer kan användas för att upptäcka sådana fel, men det är tydligt önskvärt om detekteringen kan göras genom att analysera strömmarna som redan mäts av skyddsreläer för synkronmaskiner. I denna avhandling presenteras en metod för att simulera och observera mönster och frekvensspektrum av rotors magnetiseringsström i fall där statorn har varvfel, samt i andra fall som måste kunna skiljas från varvfel. Alla simuleringar har utförts med Matlab hos avdelningen för Elektroteknisk teori och konstruktion (ETK) i Skolan för Elektro- och systemteknik (EES) på KTH.
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Staněk, Michal. "Dynamická vyvažovačka malých rotorů." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2014. http://www.nusl.cz/ntk/nusl-221148.
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Balancing of rotors is used to remove unwanted vibrations caused by uneven distribution of mass around the axis of rotation of the rotor. Operation of an unbalanced rotor may causes shortening of bearing life, fatigue of materials and deformation of shafts. This work deals with construction of a balancing machine (balancer). Because of its good properties, a soft bearing type balancer was chosen for construction. This type of balancer achieves higher sensitivity at the cost of calibration required for each type of rotor. To capture the magnitude of vibration electrodynamics sensors were chosen. To enter data and display results a microprocessor is used.
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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.<br>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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Ghosn, Ragi. "Contrôle vectoriel de la machine asynchrone à rotor bobiné à double alimentation : optimisation des ondulateurs des puissances des onduleurs au stator et au rotor : régulation des courants au stator et au rotor : fonctionnement sans capteur de vitesse ni de position." Toulouse, INPT, 2001. http://www.theses.fr/2001INPT023H.
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Cette étude traite la machine asynchrone à double alimentation (MADA) où le stator et le stator sont alimentés chacun par un onduleur de tension. Une nouvelle stratégie de commande basée sur l'orientation du flux statorique est developpée. Les fréquences sont choisies au stator et au rotor de façon à répartir les puissances des deux côtés. Il en résulte que la puissance totale des deux convertisseurs est de l'ordre de grandeur de la puissance mécanique nominale de la machine. Cette solution est intéressante comparée aux méthodes de commande actuellement utilisée dans lesquelles cette puissance est pratiquement le double de la puissance mécanique nominale de la machine. Il est aussi possible de faire fonctionner la machine à une vitesse allant jusqu'au double de sa vitesse nominale sans démagnétisation. Les équations de la machine sont écrites dans un repère lié au flux statorique. Une étude théorique en régime permanent, suivie d'une étude en régime transitoire nous ont permis de trouver une loi de commande qui assure un meilleur découplage entre les axes d et q. Il en résulte de meilleures performances [. . . ]. Les résultats de simulation montrent d'excellentes performances [. . . ]. Ces performances sont maintenues lors du fonctionnement à très faibles vitesses ou à vitesses élevées. Cette méthode est pratiquement insensible aux variations des paramètres de la machine lors du fonctionnement avec capteur de position ou de vitesse. L'étude du fonctionnement sans capteurs mécaniques nous a permis de trouver une méthode d'estimation de la position et de la vitesse basée sur la technique du MRAS associée à un observateur de Luenberger. Les résultats des simulations sont satisfaisants, cependant nous avons remarqué que cette méthode est sensible aux variations des paramètres de la machine. Les principales lois de commandes étudiées ont été validées expérimentalement.
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Anghel, Cristian. "Sensorless Flux Vector Control for a Permanent Magnet Synchronous Machine with cylindrical rotor under severe starting conditions." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0023/MQ51613.pdf.
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Chabour, Ferhat. "Commande sans capteur de position d'une machine synchrone à rotor bobiné : application à l'alterno-démarreur séparé StARS." Compiègne, 2007. http://www.theses.fr/2007COMP1705.
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La société Valeo produit pour l'industrie automobile plusieurs machines synchrones destinées à fonctionner en mode démarreur et en mode alternateur. L'une, la StARS, est un alterno-démarreur séparé (ADS) à rotor bobiné et son alimentation est de type pleine onde pilotée par un capteur de position mécanique intégré. La suppression de ce capteur, si rudimentaire soit-il, est un passage très prometteur. Outre la suppression du coût du capteur lui-même et de sa mise en place, la disparition de la connectique qui lui est associée améliore la fiabilité et la robustesse du système. L'objet de cette thèse est la réalisation du contrôle sans capteur de position de l'ADS StARS. A l'arrêt, à partir d'une modélisation simplifiée de la machine, une procédure de détection de la position du rotor et une identification paramétrique de l'induit sont proposées. En marche, lorsque la vitesse de rotation est importante, l'autopilotage sans capteur est réalisé à partir de l'estimation des forces électromotrices de rotation. A faible vitesse, la position de l'axe polaire est reconstituée par observation des flux de la machine. La méthode sans capteur proposée a une simple structure et fait appel à deux capteurs de courant. Elle permet de contrôler la StARS depuis l'arrêt jusqu'à sa pleine vitesse de rotation en mode démarreur. L'entraînement sans i capteur de l'ADS est enfin validé par des résultats expérimentaux<br>Valeo Company produces for the automotive industry several synchronous machines intended to operate either in starter mode or in alternator mode. One of the manufactured machines is the Starter-Alternator Reversible System (StARS) that is a wound rotor belt-driven machine. Actually, StARS is supplied by a full-wave voltage inverter and its self-commutation is controlled by an integrated shaft-mounted position sensor. The removal of the latter is a very promising passage. In addition to the suppression of the costs due to the sensor and its installation, the elimination of the sensor's wiring improves the reliability and the robustness of the system. The main purpose of this thesis is to investigate the StARS sensorless control. At zero speed, initial rotor position detection and motor parameter identification are presented. In medium and high speed range, the sensorless operation of the StARS is based on the estimation of the machine rotational electromotive forces. At low speed, the rotor position is detected by estimating the stator flux which is obtained by integration of the measured back electromotive force. The proposed sensorless control can perform a switchover from starting to sensorless open-loop operation. It has a simple structure and uses two current sensors. Experimental results are presented to demonstrate the successful operation of the investigated sensorless method
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Juliani, Aline Durrer Patelli. "Análise do campo magnético de um motor de ímã permanente no rotor utilizando o método dos elementos finitos." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/18/18133/tde-23042007-173344/.
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Neste trabalho é estudado um motor trifásico de ímã permanente no rotor, com fluxo não senoidal, através da análise do campo magnético. Essa máquina foi projetada utilizando-se a estrutura ferromagnética do estator de um motor de indução monofásico de 24 ranhuras o qual recebeu um novo enrolamento trifásico, e foi construído o rotor que é constituído de ímãs permanentes em sua superfície. Ela é aplicada em compressores herméticos de refrigeração, possibilitando o controle de velocidade e a melhoria da eficiência, quando comparada às demais máquinas utilizadas para a mesma aplicação. O estudo é realizado através da análise dos resultados obtidos utilizando-se um programa computacional baseado no método dos elementos finitos, aplicado em grandezas como: tensão induzida, densidade de fluxo magnético, torque eletromagnético e perdas. São apresentados resultados numéricos comparativos para a máquina existente (protótipo) com as seguintes alterações: diminuição do tamanho do entreferro, troca dos ímãs de ferrita pelos de NdFeB (Bonded) e, juntamente com essas mudanças, o recálculo do número de espiras e do diâmetro do enrolamento do estator.<br>In this work is studied a three-phase permanent-magnet motor, with nonsinusoidal flux, through the analysis of magnetic field. This machine was designed to use the same stator of a 24 slots single-phase induction motor that received a new three-phase winding. The rotor consists of permanent-magnet on its surface. The main application of this machine is in hermetic compressor household refrigeration systems. It has speed control and better efficiency than other machines used for the same application. The study is made through the analysis of numerical results, obtained by a software joint in the finite element method. The results consist in electromagnetic quantity like, back-emf, magnetic flux density, electromagnetic torque and losses. Comparisons between the prototype with these changes are presented: fall in the size of airgap, exchange of ferrite magnets for NdFeB (Bonded) magnets and, together with these changes, the number of turns in each winding and the wire diameter are recalculated.
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Tekgun, Didem. "Acoustic Noise and Vibration Reduction on Switched Reluctance Machines through Hole Placement in Stator/Rotor Laminations." University of Akron / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=akron1491678743829375.
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Lefevre, Daniel. "Contribution à la modélisation et à l'asservissement de position d'un actionneur tournant-linéaire." Compiègne, 1991. http://www.theses.fr/1991COMPD414.
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L'actionneur asynchrone à deux degrés de liberté offre une alternative précise et performante pour la génération simultanée de mouvements de translation et de rotation. La simplicité mécanique, que cette solution apporte, est contrebalancée par la complexité du contrôle de la machine, puisque le rotor est massif. Une méthode permettant d'établir un schéma équivalent en régime harmonique est présentée. La déduction d'une loi de contrôle scalaire a permis de réaliser un asservissement de position, offrant une grande précision et des temps de réponse pratiquement optimaux.
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Nilsen, Åsmund Kleiva. "Design of a Permanently Magnetized Hypocycloidal Reluctance Machine : Adapting the rolling rotor concept to generator and converter operation." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for elkraftteknikk, 2011. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-14761.
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Investigations into the nature of the HRM in general, and a PMHRM-design in particular, were undertaken. Two separate simulation models, based on a magnetic equivalent circuit and FEM-model of the machine were built and used to find inductances, induced voltages and torque potential. The process of building a prototype was started and ran parallell to the theoretical studies. A CAD-model of the machine and it's parts was built up, and stator laminations and magnets were ordered. Plans for the assembly were made, and the assembly work started. Some main conclusions are:The PMHRM has a very high torque potential. Individual control of the coils increases makes it higher than for the traditional HRM-design. PM magnetizing of the proposed HRM-machine is most sensible for generator operation, since the actuator approach in combination with individual control removes the need for DC-magnetization.Ratio of rotor to stator radius should be close to unity to achieve a high torque densityCog wheels are not ideal mechanical bearings, as interlocking restricts the rotor ratio
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Paula, Geyverson Teixeira de. "Influência da saturação no torque da máquina síncrona de ímã permanente no rotor." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/18/18153/tde-26082013-105401/.
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O presente trabalho trata do estudo e análise da influência da saturação magnética no torque de uma máquina síncrona com ímã permanente no rotor. A máquina síncrona em es-tudo trata-se de uma máquina cuja forma de onda de força contra eletromotriz é trapezoidal. Inicialmente é feito um estudo sobre os efeitos da saturação magnética nos três principais parâmetros da máquina, indutância de fase, relutância (vista pelo circuito que tem como fonte de fluxo magnético os ímãs permanentes) e a força contra eletromotriz. Em seguida, realiza-se um estudo sobre o torque eletromagnético para a máquina e a importância dos parâmetros estudados, demonstrando a forte dependência da qualidade do torque com estes parâmetros. Com base nos estudos sobre saturação e torque, objetiva-se, portanto, descrever o comportamento de cada um dos parâmetros quando da saturação da máquina e quanto/como cada um deles afeta o torque eletromagnético da máquina. A fim de se estudar cada componente do torque separadamente, avalia-se a máquina por meio do Método da Permeabilidade Fixa. Por fim, faz-se simulações em elementos finitos empregando o método apresentado e os resultados são analisados.<br>This work deals with the influence of magnetic saturation on torque of permanent mag-net synchronous machine. At first, a study of magnetic saturation is carried out in order to understand its influence on three main machines parameters, phase inductance, magnet re-luctance and back electromotive force. A study describing the electric torque and its compo-nents is carried out. This study explain the importance of each machines parameter on electric torques smoothness and amplitude. In order to investigate and describe each torques com-ponent, a review on Frozen Permeability Method is developed. At last, some simulation by means of finite element method with Frozen Permeability Method are carried out. The results are shown and analyzed.
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Král, Radek. "Vysokootáčkový synchronní stroj s vnějším rotorem." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2021. http://www.nusl.cz/ntk/nusl-442788.
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The master thesis deals with the construction and design of a high-speed synchronous machine with an outer rotor. The thesis is organised into three main chapters. The first chapter deals with machine design theory as well as mechanical limits, which are significant for high speed machines. This chapter also provides examples of applications of these electrical machines. In the second chapter, the initial design of the machine is calculated analytically. This machine design is optimised and the third chapter of this work shows the results of simulations using the finite elements method, including the evaluation of these results.
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Chauvicourt, Fabien. "Vibro-acoustics of rotating electric machines: Prediction, Validation and Solution." Doctoral thesis, Universite Libre de Bruxelles, 2018. https://dipot.ulb.ac.be/dspace/bitstream/2013/271049/4/thesis.pdf.
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The increase of greenhouse gas emission is commonly accepted to largely contribute to global warming, in part due to the massive use of non-renewable fossil energy sources. It is a reason why recently, beside other industrial sectors, electric mobility has been considered as the next generation for transportation systems. But the electrification of a vehicle introduces new challenges in its design since it involves different domains of expertise than the ones from Internal Combustion Engine (ICE) vehicles. In particular, Noise, Vibration and Harshness (NVH) comfort is significantly affected by powertrain changes, i.e. from ICE to electric machine. High and unpleasant acoustic noise from resonances may occur but can be addressed numerically to support decision making processes early enough in the design stages. The accurate prediction of its radiated acoustic noise then requires a thorough multi-physical understanding, from the system-level (electric machine) to the component-level (stator and rotor cores).First from a system-level point of view, two multi-physical modeling frameworks that use different model simplifications were implemented. By comparing simulated results to experimental measurements at each physical step of the modeling flow (electromagnetic, vibration, acoustic), it was shown that both models are accurate enough for pre-designing phases. It was also shown that considering only the stator core to contribute to the vibro-acoustic behavior of electric machines is a valid assumption.Second from a component-level point of view, the rotor and the stator core were investigated. The rotor influence on the complete machine structural dynamics was assessed. Beside the validated effects of different rotor topologies on the radiated noise, an analytical model was successfully developed to explain the occurrence of a particular vibration mode; whose explanation was still not offered in literature. In parallel, the stator core was studied, essentially because it is composed of hundreds of thin laminations stacked together which introduce difficulties in understanding its structural behavior. The effects of the laminations on the structural behavior of the stator core were studied numerically and experimentally as well. Two modeling guidelines were thus provided depending on the mode shape of interest and the computational resources available. The experimental studies comforted these two modeling approaches, and also permitted to highlight the importance of looking at the damping properties. Therefore it was shown that different lamination stacking techniques could affect significantly this damping.Finally the influence of the stacking technique (gluing, welding) on the structural behavior of the laminated compound motivated the implementation of an alternative solution to the mitigation of resonance phenomenon responsible for large acoustic noise. By using a skewed distribution of welding or glue lines, the technique aims at forcing laminations to vibrate with different phases which generates friction between them. The induced damping increases and then depends on the introduced asymmetry and on the mode shape considered. This innovative technique was validated experimentally and showed up to 7 times higher structural damping and 10 dB reduction in structural transfer function amplitudes.<br>Doctorat en Sciences de l'ingénieur et technologie<br>info:eu-repo/semantics/nonPublished
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Rajabi, Moghaddam Reza. "Synchronous Reluctance Machine (SynRM) Design." Thesis, KTH, Elektrisk energiomvandling, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-153663.
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The Synchronous Reluctance Motor (SynRM) has been studied. A suitable machine vector modelhas been derived. The influence of the major parameters on the motor performance has beentheoretically determined.Due to the complex rotor geometry in the SynRM, a suitable and simple combined theoretical(analytical) and finite element method has been developed to overcome the high number ofinvolved parameters by identifying some classified, meaningful, macroscopic parameters.Reducing the number of parameters effectively was one of the main goals. For this purpose,attempt has been made to find and classify different parameters and variables, based on availableliteratures and studies. Thus a literature study has been conducted to find all useful ideas andconcepts regarding the SynRM. The findings have been used to develop a simple, general, finiteelement aided and fast rotor design procedure. By this method rotor design can be suitablyachieved by related and simplified finite element sensitivity analysis.The procedure have been tested and confirmed. Then it is used to optimize a special rotor for aparticular induction machine (IM) stator. This optimization is mainly focused on the torquemaximization for a certain current. Torque ripple is also minimized to a practically acceptablevalue. The procedure can also be used to optimize the rotor geometry by considering the othermachine performance parameters as constrains.Finally full geometrical parameter sensitivity analysis is also done to investigate the influence ofthe main involved design parameters on the machine performance.Some main characteristics like magnetization inductances, power factor, efficiency, overloadcapacity, iron losses, torque and torque ripple are calculated for the final designs and in differentmachine load conditions.Effects of ribs, air gap length and number of barriers have been investigated by means of suitableFEM based method sensitivity analysis.
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Logan, Thomas George. "Harmonic analysis of the brushless doubly-fed machine including single-phase operation." Thesis, University of Cambridge, 2012. https://www.repository.cam.ac.uk/handle/1810/252277.
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Frias, Anthony. "Minimisation des pertes fer des machines électriques de traction par la modélisation et l'optimisation." Thesis, Université Grenoble Alpes (ComUE), 2015. http://www.theses.fr/2015GREAT028/document.
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Le coût, l'autonomie et la durée de vie sont les principaux aspects qui freine le public dans l'achat d'une voiture électrique. Tous ces aspects sont liés à la batterie qui ne permet de stocker qu'une quantité limitée d'énergie. Dans ces conditions, il est indispensable de maîtriser les pertes d'énergie de la chaîne de traction. La machine électrique étant le principal consommateur d'énergie, elle joue un rôle important dans l'efficacité énergétique globale. Dans ce contexte, comment réduire les pertes de la machine électrique pour la rendre plus efficace ? Pour répondre à cette question, l'objectif de ce travail est de modéliser (avec une précision suffisante) et réduire les pertes fer dans notre application machine électrique de traction afin de les maîtriser. On comblera ainsi le manque de confiance en les modèles de pertes fer que peut avoir le concepteur de machine du concepteur de machine en lui permettant de réaliser des optimisations fines jusque dans les dernières phases de développement. Dans la première partie de ce manuscrit, le lecteur découvrira alors une machine synchrone à rotor bobiné du point de vue du matériau magnétique doux. Les premières conclusions montrent qu'une modélisation fine est nécessaire pour bien prendre en compte les phénomènes générateurs de pertes. On s'intéresse également à la mesure des matériaux magnétiques doux afin de comprendre de manière générale et tangible les pertes dans le matériau. On prend également conscience de la toute première source d'incertitude des modèles, la mesure du matériau. Enfin, nous présentons les démarches couramment rencontrées dans la littérature pour la modélisation des pertes fer. Face aux limitations des modèles couramment rencontrés, le modèle LS (un modèle d'hystérésis scalaire qui décompose les pertes en une contribution statique et une contribution dynamique) est redéveloppé afin qu'il réponde encore mieux aux exigences de l'industrie automobile. Il est précis et facilement identifiable à partir de mesures faciles à réaliser. La contribution statique reprend le modèle de Preisach formulé à l'aide des fonctions d'Everett dont l'identification à partir des caractéristiques mesurées est directe. La contribution dynamique quant à elle est dorénavant identifiable à partir de caractérisations en induction sinusoïdales. La précision du modèle ainsi améliorée est ensuite validée sur 63 cas tests exigeants dont la forme de l'induction est à fort contenus harmoniques. Le modèle développé est ensuite couplé avec un modèle électromagnétique élément finis de la machine électrique et validé par l'expérience. Les mesures faites sur le matériau étant l'un des points faibles des modèles, une méthodologie permettant d'évaluer la pertinence de la plage des mesures est proposée. On dresse également un état de l'art de l'impact du process (découpage, empilement et assemblage des tôles) sur les pertes fer afin d'aider le concepteur à mettre en balance les impacts liés au process qui n'ont pu être modélisés. Enfin des méthodologies parmi lesquels, les méthodologies des plans d'expériences sont mises en place afin d'optimiser les cartographies de commandes en des temps de calcul raisonnables. On montre des gains allant jusqu'à 50% de réduction des pertes totales de la machine dans certaines zones de fonctionnement par rapport à une optimisation dont l'objectif serait de minimiser uniquement les pertes dans les conducteurs de la machine. Ces résultats montrent l'intérêt d'utiliser un modèle de pertes fer précis afin de réduire les pertes totales de la machine<br>Cost, range and lifetime are the main aspects that hold back the consumer to buy electric cars. These three aspects are all related to the battery which stores a limited amount of energy. Under such condition energy consumption is a major concern in electric cars. As the major electricity consumer, electrical machines play a key role for global energy savings. In this context how the electric machine can be made more energy efficient? To answer this question this thesis aim to model (accurately enough) and reduce the iron losses in traction electrical machine for electrical car. Indeed iron loss model suffer from a lack of confidence when it comes to fine optimization during the late phase of development. This thesis answers this question and takes into account the development criteria of the car industry and the constraints of the electric car. The first part of the thesis gives an overview of the application by taking a wounded rotor synchronous machine as a case study. The reader will discover the electrical machine with a soft magnetic material perspective. First, conclusion show that fine modelling of the electric machine is necessary to achieve desired accuracy. An overview on soft magnetic material behavior and measurements is then given. The reader will then acquire a broad feeling on soft magnetic material behavior and understands the first source of inaccuracy of the models (the measurements). Then, the typical models for predicting iron losses in magnetic materials are presented in a literature review. The second part of this study focus on iron loss modelling aspect. The loss surface model (a scalar hysteresis model made of a static and dynamic contribution) is used as the base of this modelling work. The static contribution is re-developed using Everett function formulation of the Preisach model is used to allow easy identification of the model directly from measurements. The identification of the dynamic contribution is re-worked to allow identification from sine-wave measurements (triangular wave measurement previously required). The model accuracy is improved and validated on 63 test cases with high harmonic distortion wave forms. The iron loss model is then coupled to finite element model of the electric machine and the limits of the model are investigated. One of the limits coming from measurement limitation, a methodology to evaluate the relevance of the measurement range is proposed. A literature review of the main impact of the process including cutting, stacking and assembling effects on electrical steel magnetic characteristics is intended to complement the modelling work to help the decision making of the designer on aspects that cannot be modeled. Finally methodologies playing with the modelling hypothesis and involving design of experiment and response surface are presented to reduce computational time and allow the optimization of the control of the machine. The optimizations carried out show total machine loss reduction up to 50% for some working point of the machine compared to an optimization dedicated to minimize only Joule's losses. This results show the interest of using a reliable iron loss model to reduce the total loss of the machine
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Randewijk, Peter-Jan. "Analysis of a radial flux-air-cored permanent magnet machine with a double-sided rotor and non overlapping windings." Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/20246.
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Thesis (PhD)--Stellenbosch University, 2012.<br>ENGLISH ABSTRACT: In this dissertation a new type of electrical machine, a Radial Flux Air-Cored Permanent Magnet
machine with a Double-sided Rotor and utilising concentrated, non-overlapping windings,
is proposed. The concept of the Double-sided Rotor Radial Flux Air-Cored Permanent Magnet
machine, or RFAPM machine for short, was derived from the Double-sided Rotor Axial Flux
Air-Cored Permanent Magnet (AFAPM) machine. One of the problems that AFAPM machines
experience, is the deflection of the rotor discs due to the strong magnetic pull of the permanent
magnets, especially with double-sided rotor machines. The main advantage of a RFAPM machine
over a AFAPM machine is that the rotor back-iron is cylindrically shaped instead of disk
shaped. Due to the structural integrity of a cylinder, the attraction force between the two rotors
does not come into play any more.
The focus of this dissertation is on a thorough analytical analysis of the Double-Sided Rotor
RFAPM machine. With the RFAPM being an air-cored machine, the feasibility to develop a
linear, analytical model, to accurately predict the radial flux-density and hence the induced
EMF in the stator windings, as well as the accurate calculation of the developed torque of the
machine, needed to be investigated. The need for a thorough analytical examination of the
Double-Sided Rotor RFAPM machine stemmed from the need to reduce the blind reliance on
Finite Element Modelling (FEM) software to calculate the back-EMF and torque produced by
these machines.
Another problem experienced with the FEM software was to obtain accurate torque results.
Excessive ripple torque oscillations were sometimes experienced which took a considerable
amount of time to minimise with constant refinement to the meshing of the machine parts.
Reduction in the mesh element size unfortunately also added to the simulation time. The requirement
for an accurate analytical model of the RFAPM machine was also necessary in order to reduce the amount of time spent on successive FEM simulation to obtain the optimum pole
arc width of the permanent magnet in order to minimise the harmonic content of the radial
flux-density distribution in the the stator windings.
In this dissertation, the use of single-layer and double-layer, non-overlapping, concentrated
winding for the RFAPM machine is also investigated. It was decided to include a comparison of
these two non-overlapping winding configurations with a “hypothetical” concentrated, overlapping
winding configuration. This would allow us to gauge the effectiveness of using nonoverlapping
winding with respect to the reduction in copper losses as well as in the reduction
in copper volume. It would also allow us to investigate the extent of how much the developed
torque is affected by using non-overlapping windings instead of overlapping windings.<br>AFRIKAANSE OPSOMMING: In hierdie proefskrif word ’n nuwe tipe elektriese masjien, ’n Radiale-vloed Lugkern Permanent
Magneet Masjien met ’n dubbelkantige rotor en nie-oorvleuelende Windings voorgestel.
Die konsep vir die Radiale-vloed Lugkern Permanent Magneet Masjien, of RVLPM vir kort,
is afgelei vanaf die Dubbelkantige Rotor, Aksiale-vloed Lugkern (AVLPM) masjien. Een van
die probleme wat met AVLPM masjiene ondervind word, is die defleksie van die rotorjukke as
gevolg van die sterk aantrekkingskragte van die permanente magnete, veral in dubbelkantige
rotor masjiene. Die hoof voordeel wat die RVLPM masjien inhou bo die AVLPM masjien, is
die feit dat die RVLPM se rotorjukke silindries is in plaas van ronde skywe. As gevolg van die
strukturele integriteit van ’n silinders, speel die aantrekkingskrag van die permanente magnete
nie meer ’n rol nie.
Die fokus van die proefskrif gaan oor die deeglike analitiese analise van die dubbelkantige
RVLPM masjien. Weens die feit dat die RVLPM masjien ’n lugkern masjien is, is daar besluit
om ondersoek in te stel na die moontlikheid om ’n lineêre, analitiese model vir die masjien
op te stel waarmee die radiale-vloeddigtheid, teen-EMK asook die ontwikkelde draaimoment
vir die masjien akkuraat bereken kan word. Die behoefde aan ’n akkurate analitiese model
vir die dubbelkantige rotor RVLPM masjien is om die blinde vertroue te elimineer wat daar in
Eindige-Element Modellering (EEM) sagteware gestel word om die teen-EMK en ontwikkelde
draaimoment van die RVLPM masjien uit te werk.
’n Verdere probleem wat daar met EEM sagteware ondervind is, is die akkurate berekening
van die ontwikkelde draaimoment. Oormatige rimpel draaimoment ossillasies is soms
ondervind wat heelwat tyd geverg het om te minimeer, deur voortdurende verfyning van die
EEM maas in die verskillende dele van die masjien. Soos die maas egter kleiner word, verleng
dit die simulasie tyd van die EEM aansienlik. Nog ’n rede vir ’n akkurate analitiese model van die RVLPM masjien, is om vinnige metode te verkry om die optimale permanente magneet
pool hoekwydte te verkry, wat die minste Totale Harmoniese Vervorming (THV) in die
radiale-vloeddigtheidsdistribusie in die statorgebied sal veroorsaak, sonder om herhaaldelike
EEM simulasies te loop.
In die proefskrif word die gebruik van enkellaag en dubbellaag, nie- oorvleuelende, gekonsentreerde
wikkelings vir die RVLPM masjien ook ondersoek. Daar is besluit om hierdie
twee nie-oorvleuelende windingskonfigurasies met ’n “hipotetiese” gekonsentreerde, oorvleuelende
windingskonfigurasie te vergelyk. Dit behoort ons in staat te stel om die doeltreffendheid
van nie-oorvleuelende windings te bepaal, met betrekking tot die afname in koperverliese
asook die afname in kopervolume. Verder sal dit ons in staat stel om ook mate waartoe die ontwikkelde
draaimoment deur nie-oorvleuelende windings beïnvloed word, te ondersoek.
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Wang, Zhu-Yun. "Analyse et mesure de pertes dans le rotor d'une machine synchrone à aimants permanents pour en optimiser la structure." Paris 11, 2005. http://www.theses.fr/2005PA112226.
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"Cette thèse a pour l'objectif l'estimation et la réduction des pertes dans les aimants par le choix des dimensions et du nombre d'aimants dans un pôle. Pour déterminer les pertes totales par courants de Foucault dans les aimants, nous avons appliqué une triple approche : par éléments finis, par modélisation analytique et par mesures sur un montage de type éprouvette. Le modèle analytique de pertes dans le rotor permet une évaluation simple des pertes en fonction de la fréquence. Ce modèle porte le nom de " modèle parallèle ". La méthode numérique d'analyse par éléments finis est la plus précise pour le calcul des pertes par courants de Foucault. Elle permet de calculer l'énergie totale stockée dans la machine et les pertes dans le rotor. Nous avons identifié les paramètres du modèle parallèle par calculs en éléments finis. Les pertes peuvent alors être calculées et comparées avec les essais pour différentes formes d'onde. Cette double évaluation par éléments finis et par modèle analytique nous a permis de comparer différentes structures du rotor et de proposer une structure optimisée, en tenant compte des contraintes industrielles. Un banc d'essai pour les mesures des pertes dans un échantillon d'aimant par un montage en U fermé était aussi réalisé pour paramétrer le modèle des pertes en éléments finis ainsi que le modèle analytique. Un bon accord a été trouvé entre la comparaison des pertes calculées et mesurées sauf pour certaines premières harmoniques. Une analyse a été faite pour expliquer les écarts entre les mesures et le calcul. "<br>This thesis is focused on the estimation and the reduction of losses in magnets by choosing the dimensions and the number of the magnets in the pole of synchronous machine. In order to determine the total eddy current losses in the magnets, we have applied a triple approach: by finites elements model, by analytic model and by measurements. The analytic model helps us to evaluate the losses in function of frequency. This model is named the “parallel model”. The finites element method is the most precise to calculate the eddy current losses. It permits to calculate the total energy stored in the machine and the rotor losses. We have identified the parameters of the parallel model using the finites element model. The losses are calculated and compared with measurements. This double evaluation by the finites elements model and by analytic model helps us to compare different structures of the rotor and to propose an optimized structure considering industrial constraints. Measurements on samples of magnet on a closed “U” have been realized to parameterize the finites element model and also the analytic model. A good agreement has been found between the comparisons between the calculated losses and the measured ones except for some certain first harmonics. An analysis of the discrepancies has been tried
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Alrifai, Fayez. "Control of a brushless permanent magnet machine using an integrated torque sensor in place of a rotor position sensor." Thesis, University of Manchester, 2011. https://www.research.manchester.ac.uk/portal/en/theses/control-of-a-brushless-permanent-magnet-machine-using-an-integrated-torque-sensor-in-place-of-a-rotor-position-sensor(33c96f6b-f8d6-4bab-9e79-d96b975e9fa3).html.
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The work presented in this thesis proposes the use of measured torque feedback from an integrated, low cost surface acoustic wave (SAW) torque transducer in place of a position sensor to control brushless permanent magnet (BLPM) machines. The BLPM machine closed loop control requires knowledge of the rotor position to control stator current and maximum torque per ampere. The electrical position feedback to control the phase current requires a position sensor or position sensorless technique. Position sensors such as absolute encoder or resolver are needed for position information, in the absolute encoder, an accurately patterned disk rotates between a light source and a detector giving a unique digital output signal for every shaft position. However, each bit in the digital world represents an independent track on the encoder disk, resulting in a complex and costly sensors. Brushless resolvers operation is based on inductive coupling between stator and rotor winding. The resolver with its resolver to digital converter also gives precise absolute position information, but again the cost is often prohibitive. So the disadvantages of the position sensors are the added cost and size to the machine. The position sensorless techniques for the BLPM machine are based on obtaining position from the terminal voltages and currents based on estimating the back electro-magnetic force (EMF), flux-linkage or inductance which from position can be estimated. The disadvantages of the back-EMF and flux-linkage techniques are (1) that they behave poorly at zero and low speed (2) behave poorly for load disturbances since load torque is estimated from machine parameters which can change. The inductance techniques work at zero and low speed, however the disadvantages are (1) in a surface mounted machine there is no saliency so any variation of winding inductances with rotor position arises from magnetic saturation; (2) the back-EMF dominates the rate-of-change in the current; (3) the variation of incremental inductances with rotor position undergoes two cycles per single electrical cycle of the brushless pm machine causing an ambiguity in sensed position; (4) the distortion due to the nonlinearities in the inverter; (5) the load offsets and the noise caused by signal injection. This thesis develops a start-up routine and operation algorithms that enhance the performance of position sensorless control of brushless permanent magnet machines at all speeds, including zero speed, and loads by using a machine integrated, low-cost, SAW torque transducer in place of the rotor position sensor.
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Lu, Fei [Verfasser]. "Induction Machine Control: State Observation, Electromagnetic Analysis, Modeling for Control, Finite Element Simulation, and Rotor Temperature Estimation / Fei Lu." Düren : Shaker, 2021. http://d-nb.info/1240853866/34.
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Jha, Amit Kumar. "Conception d'une machine à rotor externe de type Halbach pour l'électromobilité considérant la réutilisation et le recyclage des aimants permanents." Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAT014/document.
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Les véhicules électriques (VE) ou les véhicules électriques hybrides (VEH) offrent de nombreux avantages par rapport aux véhicules à moteur à combustion interne classiques. Selon les tendances récentes, la demande en VE(H) efficaces devrait augmenter considérablement. Pour une gamme haute puissance, la technologie des moteurs à aimants permanents a été le choix privilégié dans les véhicules électriques hybrides. La demande croissante de moteurs à haut rendement est en corrélation directe avec la demande d'aimants puissants (NdFeB ou SmCo) utilisant des terres rares. La disponibilité et la production des terres rares sont très critiques particulièrement pour les terres rares lourdes. L'objectif de cette thèse de doctorat est donc de concevoir un moteur Halbach à rotor extérieur pour une application VE(H) avec recyclage et réutilisation faciles des aimants. En outre, le projet vise à étudier et à proposer la fabrication d'un aimant Halbach utilisé dans les moteurs de forte puissance pour application VE.Tout d'abord, la fabrication d'un aimant Halbach utilisant un aimant NdFeB fritté avec et sans liant a été étudiée. L'étude montre que la fabrication d'une configuration de Halbach à l'aide d'un aimant collé est beaucoup plus facile et plus rentable que la fabrication d'un aimant fritté. La caractérisation d'un aimant NdFeB lié utilisé pour fabriquer un aimant Halbach a également été réalisée. Diverses voies de recyclage des aimants frittés et liés ont été analysées; on peut en déduire que les aimants collés sont beaucoup plus faciles à recycler, de manière rentable et respectueuse de l'environnement. La thèse propose également un moyen de recyclage pour l'aimant collé utilisé dans le moteur.Deuxièmement, un moteur à aimant Halbach collé a été conçu en modélisation éléments finis 2D et 3D. Pour obtenir un moteur très efficace et compact, on a utilisé un bobinage à pas fractionnaire. Les propriétés de l'aimant Halbach ont été calculées à l'aide du modèle éléments finis et comparées au modèle analytique. Les résultats obtenus par les deux approches étaient similaires. De plus, l'impact des combinaisons nombre d’encoches-pôles sur les pertes moteur et le couple a été étudié, en particulier les pertes Joule (compte tenu de toutes les contraintes de conception). Différentes stratégies pour utiliser des aimants recyclés à faible rémanence sont également présentées. L'utilisation d'un aimant recyclé avec une augmentation de la longueur axiale du moteur pourrait être le meilleur choix compte tenu de différents facteurs, notamment la fabrication de l'aimant Halbach. Sur la base de différentes études paramétriques, une conception du moteur a été proposée et un prototype a été construit. Il a été montré qu'un aimant Halbach de grande puissance pouvait être construit de manière économique avec un aimant NdFeB collé. La densité de flux d'entrefer du rotor, mesurée sur le prototype, est en étroite concordance avec les valeurs calculées.De plus, la méthodologie WIRE (Weighted Index of Recycling and Energy) a été présentée pour comparer différentes conceptions de moteurs en fonction de leur performance et de leur recyclabilité. La méthode développée produit deux indices basés sur-Facilité de recyclage du moteur en ce qui concerne le matériau, le montage et le démontage des aimants.-Impact d'un aimant recyclé sur la consommation d'énergie d'un moteur pendant sa durée de vie.En utilisant ces deux indices, on peut facilement analyser les avantages et les inconvénients des différentes conceptions sur la base de la recyclabilité et de l'efficacité énergétique. La conception proposée a été évaluée à l'aide cette méthode et on montre que le moteur est facile à monter et à démonter. De plus, l’assemblage moteur (sans colle) permet une extraction facile des aimants et une réutilisation directe. L'indice énergétique évalué du moteur montre l'impact de l'utilisation d'un aimant recyclé et sa viabilité pour les applications VE dans différents scénarios<br>Electric vehicles (EVs) or Hybrid electric vehicles (HEVs) offer many advantages over the conventional IC engine vehicles. According to recent trends, the demand for efficient (H)EVs is expected to grow significantly. For a high-power range, permanent magnet based motor technology has been the preferred choice for motors deployed in (H)EVs. Growing demand of highly efficient motors is in direct correlation to the demand of strong magnets (NdFeB or SmCo), which uses rare earth elements (REE). The availability and supply of REEs specially heavy REEs is very critical. Therefore, the aim of this doctoral thesis is to design an outer rotor Halbach motor for a (H)EV application with easy recycling and reuse of the magnet. Further, the project aims to investigate and propose the manufacturing of a Halbach magnet used in a high power motor EV applications.Firstly, the manufacturing of Halbach magnet using a sintered and a bonded NdFeB magnet was investigated. The study shows that the manufacturing of Halbach array using a bonded magnet is much easier and more cost effective than the sintered magnet. The characterisation of a bonded NdFeB magnet used for manufacturing a Halbach magnet was also performed. Various recycling routes for both sintered and bonded magnets were analysed and it can be inferred that bonded magnets are much easier to recycle in a cost effective and environment friendly manner. The thesis also proposes the recycling route for the bonded magnet used in the motor.Secondly, a motor with bonded Halbach magnet was designed using 2D and 3D FEM. To achieve a highly efficient and compact motor, fractional slot tooth coil winding was used. The properties of Halbach magnet was calculated using FEM model and benchmarked against the analytical model. The results obtained from the two approaches were in close agreement. Further, the impact of slot pole combinations on motor losses and the subsequent torque were investigated, specifically eddy loss (considering all the design constraints). Different strategies to use recycled magnet with lower remanence is also presented. It is shown that using a recycled magnet with increased axial length of the motor could be the best choice considering different factors, specially manufacturing of the Halbach magnet. Based on different parametric studies a design of the motor was proposed and prototype was built. It was demonstrated that a high power Halbach magnet could be built economically using a bonded NdFeB magnet. The airgap flux density of the rotor, measured on the prototype is in close agreement with the calculated values.Additionally, WIRE (Weighted Index of Recycling and Energy) methodology was presented to benchmark different motor designs on the basis of performance and recy- clability. The method developed produces two indices based on:• Ease of motor recyclability considering material, assembly and disassembly of magnets.• Impact of a recycled magnet on the energy consumption of a motor during its operational lifetime.Using both the above indices, one can easily analyse the pros and cons of different motor designs on the basis of recyclability and energy efficiency. The proposed motor design was evaluated using the developed method and it is shown that the motor is easy to assemble and disassemble. In addition, the motor assembly (glue free) enables easy magnet extraction and direct reuse. The evaluated energy index of the motor shows the impact of using a recycled magnet and its viability for EV applications in different scenarios
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Paula, Geyverson Teixeira de. "Cálculo da força contra eletromotriz em máquinas síncronas com ímãs na superfície do rotor." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/18/18153/tde-14062016-113636/.
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O presente trabalho trata do cálculo da força contra eletromotriz em carga de uma máquina síncrona com ímãs na superfície do rotor (cuja forma de onda de força contra eletromotriz é não senoidal) sendo esta alimentada por correntes de fase cujas forma de onda são quadradas. Para conduzir esta investigação e calcular a força contra eletromotriz da máquina em estudo, faz-se uma revisão sobre o Método da Permeabilidade Fixa, método este que permite a linearização do ponto de operação da máquina. Dessa forma, as simulações são conduzidas por meio do método dos elementos finitos e do Método da Permeabilidade Fixa, levando-se em conta a forma de onda da corrente de alimentação. Atenção especial é dada ao modo que se analisa o fluxo concatenado e a forma de obtenção da força contra eletromotriz uma vez que as formas de onda do fluxo concatenado sofrem variações abruptas a cada 60º elétricos. Além destes parâmetros, analisa-se também cada uma das parcelas do torque eletromagnético, i.e., torque mútuo, torque de relutância e torque de borda, sendo realizado ao final do trabalho, uma comparação entre a soma da estimativa de cada parâmetro com o valor do torque eletromagnético obtido por meio de uma simulação não linear.<br>This work deals with the assessment of a surface mounted magnet synchronous machine\'s parameters (whose back-EMF is approximately trapezoidal) and that is fed by an ideal square current waveform. In order to investigate and describe each machine\'s parameter, a review on Frozen Permeability Method is presented. Some simulation by means of finite element method with the aid of Frozen Permeability Method are carried out taking into account that the machine is fed by an ideal square current waveform. The results for flux-linkage wave-form and back-EMF waveform are shown and analyzed. A special attention is given to back-EMF calculation since the linkage flux of each phase has an abrupt change every sixty electrical degrees due to the phase commutation. In addition, an attention is given to each torque component on load condition, i.e., mutual torque, reluctance torque, cogging torque and a comparison between the electromagnetic torque and the summation of these components.
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Li, Guangjin. "Contribution à la conception des machines électriques à rotor passif pour des applications critiques : modélisations électromagnétiques et thermiques sur cycle de fonctionnement, étude du fonctionnement en mode dégradé." Phd thesis, École normale supérieure de Cachan - ENS Cachan, 2011. http://tel.archives-ouvertes.fr/tel-00618236.
Full textAbstract:
Dans cette thèse, une comparaison entre différentes topologies des machines a été tout d'abord réalisée. Deux machines électriques: Machine à Réluctance Variable (MRV) et Machine à Commutation de Flux (MCF) sont ensuite choisies pour les études suivantes. Un modèle électromagnétique-thermiquement couplé est effectué pour ces deux structures. Ce modèle est basé sur une caractérisation préalable par la méthode des éléments finis (EF) 2D via le calcul du couple instantané, des deux composantes de l'induction magnétique (Br et Bθ-) de chaque élément du maillage du rotor ainsi que du stator pour différentes densités des courantes efficaces et différentes positions du rotor. Ces résultats sont ensuite utilisés dans les modèles analytiques de pertes Joule et de pertes fer permettant de calculer les pertes Joule et les pertes fer sur un cycle de fonctionnement. Des modèles thermiques transitoires tels que le réseau de résistances thermiques et l'EF 2D sont effectués, dans lesquels les pertes instantanées obtenues précédemment sont utilisées comme sources de chaleur pour le calcul des variations des températures dans différents composants d'une machine électrique sur cycle de fonctionnement. Un modèle défaut-thermique d'une MCF triphasée est aussi mis en ouvre. Les défauts étudiés dans cette thèse sont principalement dus au court-circuit: le court-circuit entre-spires d'une phase, le court-circuit entre-spires et entre-phase dans une MCF sans redondance, le court-circuit d'une phase ou de trois phases dans une MCF avec redondance. A l'aide de MATLAB/Simulink, les courants sains et les courants de court-circuit sont obtenus, et les pertes instantanées peuvent être calculées en utilisant la méthode mentionnée précédemment. Par conséquent, le comportement thermique en cas de défauts peut être prévu. Enfin, des études de défauts pour une MCF hexa-phasée sans redondance sont effectuées, et un convertisseur du type pont complet est utilisé pour alimenter la machine. Cela nous permet de contrôler indépendamment chaque phase en cas de défauts. Les défauts sont entre autres le circuit ouvert ou le court-circuit dans une ou plusieurs phases (jusqu'à trois). Certaines méthodes de correction telles que: l'augmentation de l'amplitude du courant dans les phases saines et / ou modifier leurs phases, sont proposées pour maintenir le couple électromagnétique tout en minimisant l'ondulation de couple. Les résultats analytiques et numériques ont montré la bonne efficacité des méthodes proposées tant en cas de l'ouverture des phases qu'en cas du court-circuit des phases.