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

Use of Halbach Arrays in Axial and Radial Flux Permanent Magnet Machines for Aerospace Applications / Halbach Arrays in Aerospace Axial and Radial Flux Machines

Forsyth, Alexander January 2023 (has links)
In reference to IEEE copyrighted material which is used with permission in this thesis, the IEEE does not endorse any of McMaster University's products or services. Internal or personal use of this material is permitted. If interested in reprinting/republishing IEEE copyrighted material for advertising or promotional purposes or for creating new collective works for resale or redistribution, please go to http://www.ieee.org/publications_standards/publications/rights/rights_link.html to learn how to obtain a License from RightsLink. / The need for reductions in global greenhouse gas emissions, coupled with rising fuel prices, has motivated intense research in the area of hybrid and fully electric crafts for commercial applications in the aviation sector. This thesis explores implementation of Halbach arrays in high-speed radial flux machines (RFMs) and low-speed axial flux machines (AFMs) for aerospace applications. Highly accurate analytical equations are developed for quickly predicting the magnetic field in the latter (both for coreless and steel core stators) due to the complex three dimensional axial flux paths which make traditional finite element analysis time-consuming. Electromagnetic design and optimization of two aerospace machines that use Halbachs are detailed. The first is a ~14 kW AFM intended to replace an existing high lift motor RFM concept in NASA’s Maxwell X57 all-electric plane. Two design variants are selected which achieve a 10 % increase in torque/power and a 10 % decrease in mass/volume, respectively. The second machine is a 20,000 RPM surface permanent magnet RFM capable of 150 kW peak power output that is intended as a proof-of-concept for the later development of a megawatt machine for a hybrid and/or all-electric aircraft. / Thesis / Master of Applied Science (MASc)
2

Contribution à l’étude des émissions vibro-acoustiques des machines électriques : cas des machines synchrones à aimants dans un contexte automobile / Study of noise and vibrations of electromagnetic origin in electrical machines : specific case of permanent magnet synchronous machines used in the automotive industry

Verez, Guillaume 02 December 2014 (has links)
Dans un contexte automobile électrique et hybride, la part des machines synchrones à aimants permanents s'est accrue exponentiellement. Cette évolution s'accompagne d'exigences en termes d'émissions vibro-acoustiques. En termes de dimensionnement de la chaîne de traction, l'analyse multiphysique du moteur s'avère être un enjeu crucial pour son développement. La nécessité de disposer de codes informatiques de conception possédant des temps de calcul faibles pour une précision maximale se fait ressentir pour l'exploration de solutions potentiellement performantes dans les premières étapes du processus de dimensionnement. A ce titre, les aspects vibratoires et acoustiques sont modélisés analytiquement et par éléments finis dans la présente thèse. Ainsi, au moyen du modèle magnétique, l'analyse magnéto-vibro-acoustique faiblement couplée (résolution itérative des différentes physiques) peut être réalisée.La thèse est découpée en quatre parties. La première expose un état de l’art sur les émissions vibro-acoustiques des machines et notamment la modélisation du bruit d’origine magnétique. Les problématiques de la modélisation sont détaillées. Dans une deuxième partie, les modèles sont largement décrits. Les modèles éléments finis sont validés expérimentalement. Une troisième partie se propose de valider les modèles analytiques par éléments finis, en complexifiant progressivement la géométrie d’une machine à aimants montés en surface à flux radial. Enfin, la dernière partie utilise les modèles éléments finis pour étudier des machines non-conventionnelles comme les machines à commutation de flux et les machines à aimants en surface à flux axial. / The proportion of permanent magnets synchronous motors used for electric and hybrid automotive traction has exponentially increased during the past decade. This evolution comes with ever-demanding low noise and vibrations requirements. Multi-physics analysis of the motor is a decisive issue for the development of the powertrain. For the exploration of potentially efficient motor solutions in first design steps, it is thus a necessity to have at disposal fast and accurate computer codes. In this respect, acoustic and vibratory aspects are modeled using finite element and analytical models in this thesis. As a result, using an electromagnetic model, the weakly-coupled magneto-vibro-acoustic analysis (iterative solving of each physic) can be performed.The thesis is divided into four parts. The first part states the art on machine vibro-acoustic emissions and focuses on noise of magnetic origins modeling. Issues of modeling are detailed. Then, models are described to a great extent in the second part. Finite element models are favorably compared to experimental measures. A third part validates analytical models in comparison to finite element analysis, by gradually complicating the geometry of a surface permanent magnets radial flux machine. Finally, a fourth part uses finite element models to study non-conventional machines such as flux switching radial flux machines and surface permanent magnets axial flux machines.

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