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1
Di, Nardo Mauro. "Design of high speed synchronous reluctance machine." Thesis, University of Nottingham, 2017. http://eprints.nottingham.ac.uk/43223/.
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This thesis describes the work done during the several stages of the design, analyse, manufacture and test of a high speed synchronous reluctance machine capable of delivering 5 kW at 80 krpm. In order to meet such demanding speed requirement, several multi-disciplinary design exercises have been carried out having different aims. First the influences of the speed-dependent limiting factors on the machine performance have been investigated by analytical methodologies. After the preliminary analytical design, the main challenges related with the structural and electromagnetic FE-based design refinements have been identified. A comparative study has been then presented with the purpose of identify the most effective rotor design approach in terms of performance of the final design and computational effort related for its achievement. Once the design strategy has been chosen, the advantages of considering rotor parametrization of increasing complexity are evaluated via a comparative study showing the results of several structural optimizations. This study indicated the optimal geometry to manufacture. Prior to the machine prototyping, the influence of the rotor manufacturing tolerance as well as the thermal limitations on the machine performance have been deeply analysed. Tests carried out on the prototype have essentially validated the proposed design approach. In addition, an investigative study aimed at identifying and understanding the reasons of the found discrepancy between the measured and expected performance is also reported.
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Grobler, Andries Johannes. "Thermal modelling of a high speed permanent magnet synchronous machine / Andries J. Grobler." Thesis, North-West University, 2011. http://hdl.handle.net/10394/6528.
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Thermal modelling is of great importance in all electric machines but especially in permanent
magnet synchronous machines (PMSMs). The thermally fragile permanent magnets (PMs) can
more easily be demagnetized at high temperatures. When high speed machines are considered,
heat extraction surfaces are small due to the higher energy density. This thesis focuses on the
thermal modelling of a high speed slotless PMSM using analytical techniques. From literature
it is clear that analytical distributed models have not reached its full potential in thermal modelling
of electric machines. Thermal experiments on high speed electric machine, including
rotor PM temperature measurements are not commonly found in literature.
The thermal behaviour of each component of the machine is influenced by the overall temperature
distribution. The widely used lumped parameter (LP) cylindrical component model
derived by Mellor et al. is used to derive a LP model of the entire machine. A two dimensional
(2-D) analytical distributed model is derived for the rotor PM using the separation of variables
method. Three of the boundaries are assumed to be of the convection type and the fourth of
constant heat flow type. Different convection coefficients are assumed to exist in the radial and
axial directions. The distributed model is verified using COMSOL
R and good correlation is
shown. The distributed model is used to determine the temperature distribution in the PM
and the convection heat flow in the axial direction.
Loss calculation is an integral part of thermal modelling. Temperature changes in an electric
machine is due to the interaction between the heat generation (losses) and heat removal. The
losses found in a high speed slotless PMSM are investigated. A 2-D analytical magnetic model
is used to determine the stator lamination loss as well as the stator winding eddy current loss. A
simple LP model is derived for the rotor eddy current loss. Due to the relatively large resistivity
of the shielding cylinder and PM material, the rotor eddy current loss is a significant part of the
total machine loss. The tangential current width is determined empirically in this thesis but a
3-D distributed model which includes end space effects and skin depth could also be used.
A large part of thermal modelling is empirically based. The convection and interface resistances
are determined through a set of experiments in this thesis. The measured and calculated
convection coefficients correlated well for both forced and natural convection cooling. A large
temperature increase found during the no-load test can be attributed to large bearing loss, possibly
due to axial loading. The LP model is modified to include the phenomena found during
the experiments.
The thermal model is used to predict the temperatures of a high speed PMSM at rated load and speed. Although the PM is not heated above the Curie temperature, demagnetization is
still possible. According to the model, the machine will not be able to operate at full load and
speed for extensive periods due to mechanical stress limits being exceeded. The temperature
distribution of the PM could not be verified since the temperatures in the air gap and end space
could not be measured. It is expected that axial heat flow will be larger than what is currently
predicted by the distributed model. A sensitivity analysis was used to investigate the influence
of the thermal resistances and losses on the machine temperatures. Methods for reducing the
rotor eddy current loss and interface resistances are also discussed.
The first contribution of this thesis is the 2-D analytical distributed model for the PM of a high
speed PMSM. Hot spots and 2-D heat flow can be analysed using this model. Combining the
LP and 2-D analytical distributed models is another contribution. This combines the simplicity
and fast solution times of the LP model with the 2-D thermal distribution of the analytical
distributed model. The systematic experimental investigation of the thermal behaviour of a
high speed PMSM is a further contribution.Thesis (Ph.D. (Electrical Engineering))--North-West University, Potchefstroom Campus, 2011.
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Zheng, Liping. "SUPER HIGH-SPEED MINIATURIZED PERMANENT MAGNET SYNCHRONOUS MOTOR." Doctoral diss., University of Central Florida, 2005. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3552.
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This dissertation is concerned with the design of permanent magnet synchronous motors (PMSM) to operate at super-high speed with high efficiency. The designed and fabricated PMSM was successfully tested to run upto 210,000 rpm The designed PMSM has 2000 W shaft output power at 200,000 rpm and at the cryogenic temperature of 77 K. The test results showed the motor to have an efficiency reaching above 92%. This achieved efficiency indicated a significant improvement compared to commercial motors with similar ratings. This dissertation first discusses the basic concept of electrical machines. After that, the modeling of PMSM for dynamic simulation is provided. Particular design strategies have to be adopted for super-high speed applications since motor losses assume a key role in the motor drive performance limit. The considerations of the PMSM structure for cryogenic applications are also discussed. It is shown that slotless structure with multi-strand Litz-wire is favorable for super-high speeds and cryogenic applications. The design, simulation, and test of a single-sided axial flux pancake PMSM is presented. The advantages and disadvantages of this kind of structure are discussed, and further improvements are suggested and some have been verified by experiments. The methodologies of designing super high-speed motors are provided in details. Based on these methodologies, a super high-speed radial-flux PMSM was designed and fabricated. The designed PMSM meets our expectation and the tested results agree with the design specifications. 2-D and 3-D modeling of the complicated PMSM structure for the electromagnetic numerical simulations of motor performance and parameters such as phase inductors, core losses, rotor eddy current loss, torque, and induced electromotive force (back-EMF) are also presented in detail in this dissertation. Some mechanical issues such as thermal analysis, bearing pre-load, rotor stress analysis, and rotor dynamics analysis are also discussed. Different control schemes are presented and suitable control schemes for super high- speed PMSM are also discussed in detail.Ph.D.
Department of Electrical and Computer Engineering
Engineering and Computer Science
Electrical Engineering
4
Mehna, Ali A. Ahmed Omran. "An investigation of high speed and power permanent magnet synchronous machines." Thesis, University of Newcastle Upon Tyne, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.633015.
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A number of important developments have led to an increasing attractiveness for very high speed electrical machines (either motors or generators). Specifically the increasing switching speed of power electronics, high energy magnets, high strength retaining materials, better high speed bearings and improvements in design analysis are the primary drivers in a move to higher speed. The design challenges come in the mechanical design in both terms of strength and resonant modes and in the electromagnetic design particularly in respect of iron losses and ac losses in the various conducting parts including the rotor.
5
Kalyan, Mohamedreza. "Comparison of interior permanent magnet synchronous machines for a high-speed application." Master's thesis, University of Cape Town, 2018. http://hdl.handle.net/11427/29442.
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Permanent Magnet machines have been increasingly used in high-speed applications due to the advantages they offer such as higher efficiency, output torque and, output power. This dissertation discusses the electrical and magnetic design of permanent magnet machines and the design and analysis of two 10 kW, 30000 rpm Interior Permanent Magnet (IPM) machines. This dissertation consists of two parts: the first part discusses high-speed machine topologies, and in particular the permanent magnet machine. Trends, advantages, disadvantages, recent developments, etc. are discussed and conclusions are made. The second part presents the design, analysis and testing of interior permanent magnet machines for a high-speed application. The machines are designed from first principles and are simulated using Ansys Maxwell software to understand the finite element analysis. In order to obtain a fair comparison between the machines, the required output criteria was used as the judging criteria (10kW, 30000 rpm). As a result, the rotor diameter, stator diameter, airgap length, and stack length were kept the same for both machines. The winding configuration was set as distributed windings, however the number of turns and other details were kept flexible in order to be able to obtain the best design for each machine. Similarly, the magnet volume was kept flexible as this could be used as a comparison criteria relating to the cost of the machines. The two IPM topologies are compared with respect to their torque, magnetic field, airgap flux, core loss, efficiency, and cost. The radial IPM produces a smoother torque output, with lower torque ripple, and has lower losses compared to the circumferential IPM which produces a higher torque and power output. Furthermore, the circumferential IPM also experiences much higher torque ripple and core losses, both of which are highly undesirable characteristics for high-speed machines. In addition, the circumferential IPM has a much more complex manufacturing process compared to the radial IPM which would significantly increase the cost of prototyping the machine, thus the radial IPM was selected for prototyping and brief experimental analysis. The radial IPM has been experimentally tested under no-load conditions. These results were successfully compared to the simulated and analytical results to show correlation between the design and experimental process. Potential areas of further work may include conducting detailed loss analysis to understand the effects that changing various design parameters has on the core loss and overall performance. Detailed thermal and mechanical analysis of the machines may also result in interesting conclusions that would alter the design of the machine to make it more efficient.
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Messager, Gael [Verfasser], Andreas [Akademischer Betreuer] Binder, and Ulrich [Akademischer Betreuer] Konigorski. "Self-bearing permanent magnet synchronous machine configurations and control for high-speed applications / Gael Messager ; Andreas Binder, Ulrich Konigorski." Darmstadt : Universitäts- und Landesbibliothek Darmstadt, 2019. http://d-nb.info/1199006467/34.
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Qazalbash, Arfakhshand. "Rotor eddy current power losses in high speed permanent magnet synchronous generators." Thesis, University of Southampton, 2014. https://eprints.soton.ac.uk/364580/.
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Rotor electromagnetic losses can be problematic in high speed permanent magnet synchronous machines, especially when the speed or the electrical loading are high and the slotting and winding configuration results in high magnitude asynchronous harmonics. Accurate estimation of these travelling flux harmonics in the initial design stage is essential, as small errors can result in significant errors in the estimated rotor losses, which could lead to misinformed design decisions. This Thesis makes a number of contributions to the subject of rotor losses in PM machines. It firstly investigates the accuracy of the commonly used current sheet method for estimating losses for each harmonic. In this method, the losses are calculated using a multi-layer model of the machine in which each asynchronous harmonic in the rotor frame is represented by current sheet on the surface of the bore of a slotless stator. The harmonics are calculated using double Fourier transform of flux density data on the surface of the magnet obtained from a number of magnetostatic finite element (FE) solutions at different rotor position. The losses are also calculated using 2D transient FEA with rotor motion, with appropriate mesh refinement and time step determined based on a mesh and time step dependence study. The results show that the current sheet method accurately calculates the losses in ring magnets if the amplitudes of the harmonics are estimated accurately. Secondly, the Thesis extends 3 analytical methods that have been reported in the literature by Zhu and Howe (1993), Gieras (2004) and et al (2006) to estimate the amplitude of the no-load asynchronous travelling flux density harmonics, the magnet flux tooth ripple harmonics, in the rotor frame. The accuracy of these methods is evaluated by comparison to those calculated using non-linear finite element analysis for variants of a particular machine. The results show that ( et al, 2006) complex permeance method provides the closest estimate, when the level of saturation in the machine is negligible. However, if the saturation, of the tooth tip in particular is significant, then all methods underestimate the amplitudes of the harmonics. And accordingly, the estimated rotor losses are grossly underestimated by a factor of 1:3 in a machine with heavy tooth tip saturation. Thirdly, the Thesis tackles the problem of losses in a loaded generator with sinusoidal currents. It is shown that the total losses in the machine are dependent on the power factor and the phase angle between the emf and current. The total loss cannot be simply calculated by adding the no-load loss due to magnet flux tooth ripple harmonics and the loss due to stator mmf asynchronous harmonics. This is due to the interaction between the stator mmf harmonics and the magnet flux tooth ripple harmonics, which need to be added vectorially. This is verified by comparing the results calculated analytically (using the most accurate ’s meth d f calculating no-load harmonics), with those obtained from transient FEA in a machine with no significant saturation. Fourthly, the Thesis investigates rotor losses in a generator with two slots per pole per phase connected to an uncontrolled diode rectifier, considering the two cases of constant current and constant voltage dc link. Two winding and rectifier configurations are considered: a 3-phase winding with a 3-phase, 6 pulse bridge rectifier and a double 3-phase winding with a 3-phase rectifier each, connected in series i.e., a 12 pulse rectifier. Both magnet flux tooth ripple and armature reaction stator mmf harmonics are considered in the calculation of rotor loss; the harmonics were added vectorially. It is shown that the machine with double 3-phase windings and 12 pulse rectifier has considerably lower rotor losses that the machine with one single 3-phase winding due to cancellation of high order harmonics. Finally, limited studies are performed in the Thesis for the calculation of rotor losses in PMSGs with different slot opening, number of slots per pole and airgap (with magnet thickness adjusted to keep the airgap flux density and emf constant). It is shown that increasing the airgap and reducing slot opening reduced the losses The results plotted in a normalised form of loss per unit rotor surface area are versus the ratios of gap/slot pitch and slot opening divided by pole pitch. These curves are shown to give reasonable quick estimates of rotor losses in machines with different sizes. Also, rotor losses are calculated in three PMSGs with different numbers of slots per pole and winding / rectifier configurations. The results show that the popular 1.5 slots per pole concentrated winding configuration have considerably higher rotor losses due to the strong second harmonic than the other machines with lap windings. The work in the Thesis was based on two-dimensional calculations, assuming ring magnets. Further work is needed to evaluate the 3D effect and magnet segmentation.
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Messali, Amir. "Contribution to Rotor Position and Speed Estimation for Synchronous Machine Drive Using High Frequency Voltage Injection : Application to EV/HEV Powertrains." Thesis, Ecole centrale de Nantes, 2019. http://www.theses.fr/2019ECDN0048.
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Cette thèse s’inscrit dans le cadre de la chaire Renault/Centrale Nantes sur l’amélioration des performances des véhicules électriques (EV/HEV). Elle est dédiée à la problématique de l’estimation de la position/vitesse des moteurs synchrones à aimants permanents (MSAP) sans capteur mécanique, en utilisant les techniques d’injection de signaux haute fréquence (HF) sur toute la plage de vitesse des MSAP. Dans ce cadre, plusieurs contributions ont été proposées dans les parties de démodulation/traitement du signal et d’algorithmes de poursuite des techniques d’injection HF, afin d’améliorer l’estimation de la position/vitesse des MSAP par rapport aux méthodes existantes. Dans la partie démodulation/traitement du signal des techniques d’injection HF, les contributions ont consisté à proposer des solutions originales permettant de réduire les effets de filtrage dans la chaine d’estimation et de rendre cette dernière indépendante des paramètres (électriques) de la machine. Dans la partie poursuite, les contributions portent essentiellement sur l’exploitation de la fonction signe de l’erreur de position (à la place de l’erreur de position) comme information de mesure, pour estimer la position, la vitesse et l’accélération des MSAP sans capteurs mécaniques avec des observateurs par modes glissants d’ordre 1 (classiques, étapes par étapes et adaptatifs). Les contributions proposées dans les deux parties ont pour avantages d’une part, de robustifier la chaine d’estimation en la rendant indépendante des paramètres électriques et mécaniques. Et d’autre part, d’améliorer la précision et les performances de la chaine d’estimation, et par conséquent du contrôle des MSAP sans capteurs mécaniques, dans les phases transitoires et en régimes permanents avec une méthode de réglage aisée. Les méthodes d’estimation développées ont été testées en simulation et en expérimentation sur un banc d’essai de machines électriques. Les résultats obtenus ont permis de mettre en évidence les performances de ces méthodes en terme de suivi de trajectoire et de robustesse sur toute la plage de fonctionnement des MSAP sans capteurs mécaniquesThis thesis is part of the Renault / Centrale Nantes Chair on improving the performance of electric vehicles (EV / HEV). It is dedicated to the problem of estimating the position / speed of self-sensing permanent magnet synchronous motors (PMSM) without mechanical sensors, using high frequency (HF) signal injection techniques over the full speed range of PMSM. In this context, several contributions have been proposed in the demodulation / signal processing and tracking algorithms parts of HF injection techniques, in order to improve the estimation of the position / speed of the MSAP compared to the existing methods. In the demodulation / signal processing part of the HF injection techniques, the contributions consisted of proposing original solutions making it possible to reduce the filtering effects in the estimation chain and to make the latter independent of the electrical machine parameters. In the tracking part, the contributions mainly concern the use of the function sign of the position error (instead of the position error) as measurement information, to estimate the position, the speed and the acceleration of self-sensing PMSM with firstorder sliding mode observers (conventional, step-by-step and adaptive). The contributions proposed in both parts have the advantages of robustifying the estimation chain by making it independent of electrical and mechanical parameters on the one hand. On the other hand, they allow improving the accuracy and performance of the estimation chain, and therefore the control of self-sensing PMSM, in transient and steady-state phases with an easy tuning method. The estimation methods developed were tested in simulation and experimentation on a test bench of electrical machines. The results obtained made it possible to highlight the performances of these methods in terms of trajectory tracking and robustness over the entire operating range of PMSM self-sensing control
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Tarek, Md Tawhid Bin. "Optimal High-Speed Design and Rotor Shape Modification of Multiphase Permanent Magnet Assisted Synchronous Reluctance Machines for Stress Reduction." University of Akron / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=akron1510617496931844.
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Sabirin, Chip Rinaldi [Verfasser]. "Digital Control for Active Magnetic Bearings in High-Speed Permanent-Magnet Synchronous Machine with 40000 rpm and 40 kW / Chip Rinaldi Sabirin." Aachen : Shaker, 2014. http://d-nb.info/106619789X/34.
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Kruger, Gert Lodewikus. "Implementation and evaluation of V/f and vector control in high–speed PMSM drives / Kruger G.L." Thesis, North-West University, 2011. http://hdl.handle.net/10394/7609.
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The McTronX research group, at the Potchefstroom campus of the North–West University, has
been researching Active Magnetic Bearings (AMBs). A fully suspended, flywheel energy storage
system (FESS) has been developed. Due to excessive unbalance on the rotor, the motor drive
could not be tested up to its rated speed. In the interim, until the rotor can be balanced and
other rotor dynamic effects have been investigated, the group decided that the existing drive
control should be improved and tested on a high–speed permanent magnet synchronous motor
(PMSM), using normal roller element bearings.
In order to test the motor control a second (identical) PMSM, mechanically coupled to the
former, operates in generator mode which serves as the torque load. Two different control algorithms,
namely V/f and vector control, are designed and implemented on a rapid control
prototyping system, i.e. dSPACE®. The V/f control is an open–loop, position sensorless technique,
whilst the vector controller makes use of a position sensor.
From the design and implementation it became clear that the vector control is more robust,
in the sense that it is less sensitive on parameter variations and disturbances. It can start up
reliably even under full load conditions.
The V/f control is an attractive alternative to the vector control, especially in AMB systems,
where it may be difficult to mount the position sensor, has to operate in a hazardous environment
not suited to the sensor or could degrade the reliability of the AMB system. The cost of the
position sensor is not really a concern compared to the cost of an AMB system. The V/f control
is more suited to fan and pump applications, which has a low dynamic requirement. The V/f
control has high startup currents and is not recommended for applications requiring a high
starting torque or fast acceleration during operation.
The inverter, which drives the PMSM, also had to be developed. With regard to the motor
control, the effects of inverter non–idealities had to be accounted, especially for the V/f control.
The implemented control algorithms were tested up to 20 krpm. Discrepancies between the expected
and actual results are discussed. Overall, the controllers performed as desired. Generally,
the project goals have been reached satisfactorily.Thesis (M.Ing. (Computer and Electronic Engineering))--North-West University, Potchefstroom Campus, 2011.
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Krøvel, Øystein. "Design of Large Permanent Magnetized Synchronous Electric Machines : Low Speed, High Torque Machiines - Gererator for Diriect Driven Wind Turbine- Motor for Rim Driven Thruster." Doctoral thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for elkraftteknikk, 2011. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-12417.
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This work presents the design of two prototype permanent magnetized electric machines for two different applications where large permanent magnet machines might be used. Existing technology have been used as the fundament for new design and adapted to new applications, contributing, hopefully, to the development of better and more environmental friendly energy conversion. The first application presented is represented with a prototype made in cooperation with the industry in which a PM-motor is integrated into a propeller unit. Both because of the industrial connection, and the integration between the PM-motor and the propeller, the choices made for the PM-motor are conservative trying to reduce the risk. The direct rim driven thruster prototype includes a surface mounted radial flux permanent magnet machine (SM RFPM) with fractional slot winding with a q around 1. Other engineering features were introduced to make the integration of propeller and motor feasible, but without the PM-machine the thruster would not have reached the performance demand. An important part of the project was to show that the SM RFPM enables this solution, providing high performance with a large air gap. The prototype has been tested in sea, under harsh conditions, and even though the magnets have been exposed directly to sea water and been visible corroded, the electric motor still performs well within the specifications. The second application is represented with a prototype PM-generator for wind turbines. This is an example of a new, very low speed high torque machine. The generator is built to test phenomena regarding concentrated coils, and as opposed to the first application, being a pure academic university project, its success is not connected to its performance, but with the prototype’s ability to expose the phenomena in question. The prototype, or laboratory model, of the generator for direct driven wind turbines features SM RFPM with concentrated coils (CC). An opportunity to push the limits for the design was given, and taken, choosing a relative high frequency and open slots to investigate the consequences of large reluctance variations in the air gap and distorted MMF. The main purpose of the PM generator is to explore a very low speed machine with high pole number and concentrated coils with coils wound around every other tooth. The study leading to the design included a discussion of scaling of the prototype from the full size generator, which parameters to keep, which to stress and which to forget. An investigation of the winding layout and winding factors included building a smaller table model for testing of different winding configurations, was also an important part of the work. Though the prototype has its flaws, or experimental setbacks, it successfully enhances the characteristic of the low speed, high pole number and slot geometry focusing on the harmonic content of the MMF and the consequences for the losses and reactance.
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Maalouf, Haddad Amira. "Sensorless control of brushless synchronous starter generator including sandstill and low speed region for aircraft application." Thesis, Cachan, Ecole normale supérieure, 2011. http://www.theses.fr/2011DENS0008.
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In More Electric Aircraft, different power system activities are attributed to electrical means such as the start-up of the main engine. In this context, the study of the sensorless control of the Brushless Synchronous Starter Generator (BSSG) that is used to electrically start the main engine is revealed to be a very interesting issue. For long time, the elimination of the mechanical sensor was highly recommended for reliability, cost, weight, integration issues.Hence, this work aims to transpose the results obtained in the research area to an avionic testbench. It presents an adaptive sensorless technique to use when electrically starting the main engine of the aircraft. This is achieved by elaborating three different methods selected depending on the speed of the machine and based on the :- injection of a high frequency signal- use of the back-emf of the Permanent Magnet Generator (PMG)- use of the extended Kalman Filter EKFIn this work, it is shown that the …first method gives good position estimation results from standstill up to 8% of the rated speed. Then, the back-emfs of the PMG are used to detect the position of the BSSG when the speed exceeds the 8% of the rated speed. Good results are observed with this method at medium and high speed.For redundancy reasons, the EKF was also used in this work. Thus, the estimated position can be delivered via two different estimation algorithms in medium and high speed region.The implementation of the algorithm was achieved on an FPGA board since the latter can ensure a very tiny execution time. The fastness of the treatment ensures quasi-instantaneous position estimation and does not practically introduce any phase lag in the position estimationAujourd'hui, l'aviation est en train de vivre des évolutions technologiques concernant surtout l'attribution de différentes fonctionnalités aux équipements électriques et ceci au détriment d'équipements hydrauliques et mécaniques assurant les mêmes fonctionnalités.Dans le cadre de l'avion plus électrique, le démarrage électrique sans capteurs mécaniques de la turbine de l'avion préoccupe les avionneurs de nos jours. Les problèmes introduits par ce capteur ont été identifiés : problèmes de coût et de poids, problèmes de fiabilité et d'intégration.Ce travail présente alors une commande sans capteurs pour la machine synchrone à trois étages à utiliser durant le démarrage électrique de l'avion. Ceci est réalisé avec trois méthodes de détection de la position selon la vitesse de rotation, basées sur :- l'injection d'un signal à haute fréquence- l'utilisation d'un filtre de Kalman étendu FKE- les fém. du PMG (Permanent Magnet Generator) La première méthode donne de bons résultats d'estimation depuis l'arrêt jusqu'à 8% de la vitesse nominale de la machine. Au-delà de cette vitesse, es valeurs des fém. du PMG deviennent assez élevées pour être utilisées dans l'estimation de la position. De bons résultats sont obtenus à moyenne et haute vitesse.Pour des questions de redondance, le FKE est aussi utilisé. Ainsi, la position estimée peut être fournie par l'un des deux algorithmes à moyenne et haute vitesse.L'implémentation de ces algorithmes est réalisée via une carte FPGA étant donné que celui-ci garantit un temps d'exécution. La rapidité de traitement garantit une estimation de la position quasi-instantanée et donc n'introduit pratiquement pas des retards dans l'estimation
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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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Bonnafous, François. "Etude des pertes dans les circuits magnétiques de machine à reluctance variable alimentée à moyenne fréquence : réalisation d'un logiciel de conception de moteurs rapides." Paris 6, 1986. http://www.theses.fr/1986PA066496.
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Conception des circuits magnétiques de machines à reluctance variable alimentées à moyenne fréquence. On y aborde le problème de l'évaluation des pertes dans le fer dans des tôles de matériau ferromagnétique soumises à des champs de forme non sinusoïdale, fonctions du temps, à l'aide de modèles théoriques et de mesures. Une étude paramétrique débouche sur la réalisation d'un logiciel de conception de moteurs rapides, prenant en compte les pertes dans les diverses parties de leur circuit magnétique.
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Sepulchre, Leopold. "Pour l'optimisation de la commande des machines synchrones à aimants permanents en régime de haute vitesse pour véhicule électrique." Thesis, Toulouse, INPT, 2017. http://www.theses.fr/2017INPT0025/document.
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Dans ce travail nous cherchons à développer des algorithmes de commande adaptés au fonctionnement à haute vitesse d’une machine synchrone à aimants permanents (MSAP) et de son onduleur en optimisant l’efficacité énergétique de l’ensemble. Bien que la vocation soit très large, le domaine de la traction électrique est priorisé. Les MSAP tournant à haute vitesse sont de plus en plus utilisées dans les véhicules électriques en raison de leur forte densité de puissance. La haute vitesse implique une force électromotrice élevée et requiert la réduction du flux (défluxage) dans l’entrefer. Lors d’un fonctionnement de la machine en régime défluxé, si la contribution de l’aimant peut-être totalement compensée alors nous pouvons utiliser une stratégie Maximum Torque Per Volt (MTPV) pour générer les consignes de courant qui respectent les limites électriques théoriques quelle que soit la vitesse de rotation de la machine. En l’absence de boucle de vitesse, le couple de référence doit être limité aux points de fonctionnement atteignables, calculés en fonction des limites de courant (limites onduleur et machine), tension (batterie) et puissance (batterie et partie mécanique). Nous proposons ainsi dans cette thèse de calculer les références de courant avec une stratégie MTPA (Maximum Torque Per Ampere) à basse vitesse et d’utiliser un algorithme de défluxage basé sur une régulation de la norme de la tension associée à une stratégie MTPV à haute vitesse sans commutation d’algorithme mais par une action continue sur la valeur de la saturation de courant. Concernant la boucle de courant nous réalisons une commande numérique dans le repère d-q qui tient compte de la discrétisation, du retard (dû au temps de calcul), et du fort couplage inter-axes à haute vitesse sous des critères de précision, stabilité et rapidité. Nous étudions les stratégies de découplage minimal et de découplage discret avec prédiction de la variation du courant. Les approches par régulateurs avec structure RST et par commande prédictive-optimale sont développées. Une prédiction de la position réelle du rotor est incluse afin de conserver la stabilité à haute vitesse. Finalement nous réalisons une maquette avec une MSAP à échelle réduite sur laquelle nous testons ces stratégies de commande. Nous validons par expérience que l’algorithme proposé dans la thèse est capable de piloter la machine à haute vitesse en respectant les limites électriques et nous vérifions qu’il améliore les performances (couple, vitesse maximale, pertes) obtenues à haute vitesseIn this work we search to develop control algorithms adapted to the high speed operation of a permanent magnet synchronous motor (PMSM) and its inverter by optimizing the energy efficiency of the set. Although the vocation is very broad, the field of electric traction is prioritized. High speed PMSMs are increasingly used in electrical vehicles because of their high power density. The high speed implies a high electromotive force and requires the reduction of the flux (fluxweakening) in the air gap. When the motor is running in flux-weakening mode, if the contribution of the magnet can be fully compensated then we can use a Maximum Torque Per Volt (MPTV) strategy to generate the current references that meet the theoretical limits regardless of the machine rotation speed. In the absence of a speed loop the reference torque must be limited to the achievable operating points, calculated according to the current limits (inverter and machine limits), voltage (battery) and power (battery and mechanical part). We propose in this thesis to calculate the current reference with Maximum Torque Per Ampere (MTPA) strategy at low speed and to use a flux-weakening algorithm based on a regulation of the voltage norm associated with a MTPV strategy at high speed without switching algorithms but by a continuous action on the value of the current saturation. Concerning the current loop, we carry out a numerical control in the d-q frame which takes into account the discretization, the delay (due to the computation time), and the high inter-axis coupling at high speed under criteria of precision, stability and speed. We study the strategies of minimal decoupling and discrete decoupling with prediction of the variation of the current. The approaches by regulators with RST structure and predictive-optimal control are developed. A prediction of the actual rotor position is included to maintain the stability at high speed. Finally a real model with a reduced scale PMSM is realized on which these control strategies are tested. We validate by experiment that the algorithm proposed in the thesis is able to control the machine at high speed respecting the electrical limits and verify that it improves the performances (torque, maximum speed, losses) obtained at high speed
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Gilson, Adrien. "Modélisation et conception des machines haute vitesse pour la turbocompression assistée électriquement." Thesis, Bourgogne Franche-Comté, 2018. http://www.theses.fr/2018UBFCD003.
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Dans le milieu automobile, les règlementations visant à limiter l’émission de particules fines et de gaz à effet de serre sont devenues de plus en plus sévères au cours des dernières années. Cette tendance ne va pas s’inverser et des solutions doivent être trouvées pour améliorer le rendement des moteurs à combustion interne (ICE) qui propulsent la majorité des véhicules de tourisme dans le monde.Une des solutions permettant d’améliorer le rendement thermodynamique de l’ICE est d’utiliser un turbocompresseur. Cet organe de suralimentation permet d’accroître le couple du moteur en augmentant la pression d’air dans les cylindres et par conséquent la quantité de comburant. Le turbocompresseur présente cependant un inconvénient pour l’agrément de conduite. Selon la technologie employée, un temps de latence (turbo lag) plus ou moins important apparait entre le moment ou le conducteur appui sur la pédale d’accélérateur et le moment ou le couple est disponible sur les roues.Pour pallier ce problème, on peut utiliser une machine électrique venant assister le turbocompresseur durant la phase de montée en vitesse. Cette machine peut faire partie d’un système indépendant de compression d’air et placée en amont du turbocompresseur, on parlera alors de turbo assisté électriquement. Cette machine peut aussi être intégrée directement au turbocompresseur, on parlera alors de turbo électrique. Dans les deux cas, le temps de réponse du turbocompresseur est amélioré ce qui impacte directement la dynamique du véhicule et le plaisir de conduite. Dans le cas du turbo électrique, l’intégration de la machine électrique directement sur le turbocompresseur permet son fonctionnement en génératrice en offrant ainsi une amélioration du rendement global de l’ICE.Le sujet de la thèse est la modélisation et la conception des machines électriques haute vitesse pour ces applications. Les principales qualités recherchées pour ces machines seront :-leurs capacités à pouvoir fonctionner à haute vitesse : les vitesses recherchées se situe typiquement entre 70 000 et 150 000 tr/min pour des vitesses périphériques de l’ordre de 150 m/s ;-leurs densités de puissance : on recherche des puissances de 3 à 15 kW pour des machines compactes qui devront être intégrées sous le capot du véhicule ;-des rendements élevés de l’ordre de 95 % ;-une conception adaptée à la production en grande série pour l’automobile.Pour répondre à cette problématique, les travaux suivants ont été entrepris :Dans un premier temps, nous avons modélisé finement les phénomènes électromagnétiques et mécaniques liées aux machines électriques haute vitesse à encoches et aimants permanents positionnés en surface. Pour cela, nous avons développé un modèle de calcul en sous-domaines pour la partie électromagnétique et un modèle multicouches de résistance des matériaux pour le calcul de la tenue du rotor à haute vitesse.Dans un deuxième temps, pour pouvoir explorer des topologies de machines très différentes, nous avons eu recourt aux méthodes de calcul par éléments finis. Nous avons pu identifier et de comparer plusieurs topologies de machines à encoches, sans encoches, à bobinage dentaire ou toroïdal. Cette étude paramétrique a permis de comparer la densité de couple et le rendement de ces machines.Enfin, dans une dernière partie, nous avons traité le cas du prototypage et des mesures de ces machines. Pour cela, sur la base des études réalisées, nous avons prototypé trois machines aux performances prometteuses. La conception mécanique des différentes machines est abordée ainsi que les méthodes de mesures et les difficultés liées aux caractérisations à haute vitesse.Au cours de ce travail de thèse, d’autres aspects ont aussi été abordés tel que la modélisation des pertes du système machine électrique et convertisseur de puissance, la dynamique des rotors ou encore les émissions acoustiquesIn the automotive industry, regulations to limit the emission of greenhouse gases have become more and more severe. This trend is not going to change and solutions must be found to improve the efficiency of internal combustion engines (ICE) that drive the majority of passenger cars in the world.Turbochargers are a clever solution to improve the thermodynamic efficiency of the ICE. This forced induction device increases the air pressure in the cylinders and therefore the engine torque. However, turbochargers have a major disadvantage for the driver experience: a lag time (turbo lag) between the moment when the driver steps on the accelerator and the moment when torque is available.To overcome this problem, an electric machine can be used to assist the turbocharger during the speed up phase. This machine can be a part of an independent system of air compression and placed upstream of the turbocharger or it can be integrated directly into the turbocharger. In both cases, the response time of the turbocharger is greatly reduced which directly impacts the dynamic of the vehicle and the driving pleasure. The integration of the electric machine directly on the turbocharger allows its operation as a generator to improve the overall efficiency of the ICE.The subject of this thesis is the modeling and design of high speed electric machines for these applications. The main requirements are:-High-speed operation: between 70,000 and 150,000 rpm and peripheral speeds around 150 m/s.-Power density: from 3 to 15 kW for compact machines that will have to be integrated under the hood of the vehicle.-High efficiency: around 95 % and above.-A design adapted to mass production for the automotive industry.To cope with this requirements, the following tasks were undertaken:Firstly, we modeled the electromagnetic and mechanical behaviors of high-speed slotted electric machines with surface-mounted permanent magnets. For the electromagnetic part, we developed a subdomain calculation model. For the mechanical part, we worked on a multilayer model to evaluate the rotor strength at high speed.Secondly, we used finite element analysis methods to explore different machine structures. We compared several topologies of slotted and slotless machines, with tooth-coil winding and toroidal winding. This parametric study allowed us to compare the torque density and efficiency of these machines.Finally, we dealt with the case of prototyping and measurements of these machines. Based on the previous studies, we prototyped three machines with promising performances. The mechanical design of the different machines is discussed as well as the measurement methods and the difficulties associated with high speed characterization.During this thesis work, other aspects were also discussed such as the losses in power converters driving high-speed electric machines, rotor dynamics and acoustic emissions
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Sharaf-Eldin, Thanaa. "Design and control of a synchronous reluctance machine drive." Thesis, Heriot-Watt University, 1999. http://hdl.handle.net/10399/1201.
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Chretien, Ludovic. "POSITION SENSORLESS CONTROL OF NON-SALIENT PERMANENT MAGNET SYNCHRONOUS MACHINE." University of Akron / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=akron1145286531.
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Manuk, A. K. "The half-speed linear machine : A new form of linear synchronous motor." Thesis, University of Bristol, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.372018.
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Bowman, C. C. "High speed image processing for machine vision." Thesis, Cardiff University, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383161.
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Srinivasan, Kamakshi. "Integrated design of high-speed permanent-magnet synchronous motor drives." Thesis, Massachusetts Institute of Technology, 1995. http://hdl.handle.net/1721.1/11289.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1996.Includes bibliographical references (p. 273-276).
by Kamakshi Srinivasan.
Ph.D.
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Cuenot, Jérémy. "Architectures d'alimentation et de commande des actionneurs haute-vitesse connectés aux réseaux avioniques à tension variable." Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0263/document.
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La révolution technologique majeure des nouveaux aéronefs repose sur une électrification intensive de nombreux constituants de l'appareil et le fait que la vitesse des génératrices électriques n'est plus fixe mais variable. Cette nouvelle manière de générer la puissance électrique engendre des variations de tension sur les réseaux DC. De plus, pour accroître la compacité des Machines Synchrones à Aimants Permanents (MSAP) à puissance donnée, on augmente autant que possible leur vitesse d'entrainement, en les associant pour certaines applications à des réducteurs mécaniques. La variation du niveau de tension du bus DC alimentant une MSAP haute vitesse implique son dimensionnement afin d'assurer sa contrôlabilité sur toute la plage de vitesse reportant d'importantes contraintes sur l'onduleur de tension. Pour pallier ce problème, une solution consiste à intercaler un convertisseur DC/DC entre le filtre d'entrée et l'onduleur de tension pour maintenir la tension DC d'entrée de l'onduleur à une valeur adaptée au fonctionnement de la MSAP et optimiser son dimensionnement. Cependant, cette solution augmente l'ordre du système, ce qui accroît la complexité de son contrôle, accentuée par les contraintes liées à la nature haute-fréquence des MSAP considérées.Les travaux menés dans cette thèse concernent l'étude, l'optimisation et le contrôle des structures d'alimentation des actionneurs haute vitesse connectés aux réseaux DC avioniques à tension variable. Il en résulte que pour les applications avioniques considérées, ces architectures d'alimentation intégrant un convertisseur DC/DC supplémentaire permettent de réduire sa masse et son volume sans dégrader le rendement global de la chaîne de conversion notamment avec les convertisseurs à source impédante qui permettent de supprimer structurellement les ondulations de courant en entrée du convertisseur. De plus, des stratégies de commande Pulse Amplitude Modulation employées avec des architectures de contrôle non-linéaires (platitude, passivité) permettent d'assurer le contrôle de ces MSAP haute-vitesse tout en assurant leur stabilité sur toute la plage de fonctionnementThe main technological revolution of the new aircrafts is based on intensive electrification of many components of the aircraft. Moreover, the speed of electrical generators is no longer fixed but variable. This new way of generating electrical power generates voltage variations on DC networks. Besides, to increase the compactness of the Permanent Magnet Synchronous Machines (PMSM) at a given power, their mechanical speed is increased as much as possible by combining them with mechanical reducers for certain applications. The variation of the voltage level of the DC bus supplying a high-speed PMSM implies its sizing in order to ensure its controllability over the entire speed range which carries significant stresses on the Voltage Source Inverter (VSI). To solve this problem, one solution consists in adding an extra DC / DC converter between the input filter and the VSI to maintain the inverter input voltage at a value adapted to the operating point of the PMSM and to optimize its dimensioning. However, this solution increases the order of the system, which increases the complexity of its control, accentuated by the constraints related to the high-frequency nature of the PMSMs considered. The work carried out in this thesis concerns the study, the optimization and the control of the power supply architecture of the high-speed actuators connected to variable-voltage avionic DC networks. As a result, for the avionics applications considered, these power supply architectures integrating an additional DC / DC converter make it possible to reduce the mass and the volume of the power supply structure without degrading the overall efficiency of the conversion chain, in particular by using the impedance-source converters which allow to cancel the DC input current ripples. In addition, Pulse Amplitude Modulation (PAM) control strategies used with non-linear control architectures (flatness, passivity) make it possible to control these high-speed PMSMs while ensuring their stability over the entire operating range
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Guan, Yang. "Torque-speed characteristics of induction machine and hybrid permanent magnet assisted synchronous reluctance machine for electric vehicle application." Thesis, University of Sheffield, 2015. http://etheses.whiterose.ac.uk/7867/.
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This thesis describes an investigation into two types of electrical machines for EV/HEV applications, i.e. induction machine (IM) and permanent magnet assisted synchronous reluctance machine (PMA-SynRM). Both are low-cost due to no or less usage of NdFeB permanent magnet (PM), compared with interior PM (IPM) machines. IM is investigated with particular reference to its maximum torque/power-speed characteristic. Firstly, an analytical method based on dq-axis reference frame to obtain the maximum torque/power-speed characteristic is developed and validated by experiments. Then, the influences of some design parameters on the flux-weakening performance are investigated, such as the ratio of leakage to mutual inductance, stator and rotor resistances, and iron saturation, etc. In addition, the influences of some physical parameters on the torque/power-speed characteristic are investigated, including split ratio, number of stator/rotor slots per pole per phase, length of airgap, number of pole pairs and stator/rotor slot area, etc. Finally, the difference in maximum torque/power-speed characteristics between motor and generator modes is described, and how the design parameters influence the difference is investigated. For PMA-SynRM, a novel hybrid-PM assisted SynRM is proposed, which utilizes both ferrite and NdFeB PMs. The design process is presented and the electromagnetic performance and material cost are analyzed and discussed. The analyzed electromagnetic performances include electromagnetic torque, flux density, back electromotive force (EMF), torque/power-speed characteristic, power factor, torque ripple, cogging torque and demagnetization, etc. Finally, the electromagnetic performances and material costs of IM and hybrid-PM assisted SynRM are compared with those of IPM, respectively, including torque capability per Ampere, torque/power-speed characteristic, power factor, torque ripple and efficiency map, etc.
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Rezaie, A. H. "Instrumentation techniques for high speed mechanism." Thesis, University of Bristol, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.381467.
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Bond, Kay. "Design of a novel high speed embroidery machine." Thesis, University of Nottingham, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.282780.
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Mwaba, Gomezyani. "Permanent Magnet Machine Topologies for high speed flywheels." Thesis, University of Cape Town, 2009. http://hdl.handle.net/11427/5145.
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La, Rocca Antonino. "Thermal analysis of a high speed electrical machine." Thesis, University of Nottingham, 2016. http://eprints.nottingham.ac.uk/33156/.
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This work has analysed, designed, commissioned and validated the performance of a novel cooling system for an innovative high speed, three-phase synchronous permanent magnet machine designed for an aero-engine starter/generator with a power rating of 45 kW and maximum speed of 32,000 rpm. The cooling system designed consisted into inserting a 1 mm non-electrically conductive stator sleeve in the machine airgap, this separates the rotor region from the stationary components letting the rotor running dry at all times; the stator region can then be flooded with oil. Oil enters from one side of the machine through some radial openings impinging directly over the end-winding, it then flows through two rows of equally sized axial ducts located along the inner and outer diameter of the stator to give an even distribution of the coolant, and finally it flows over the surface of the rear end-winding and leaves the machine. The thermal modelling was carried out by the joint use of Computational Fluid Dynamics (CFD) and Lumped Parameter Thermal Network (LPTN); this allowed the investigation of heat transfer phenomena and the optimisation of the cooling design. CFD was primarily employed to investigate the fluid flow and to perform conjugate heat transfer analyses; these allowed the determination of heat transfer coefficients and the prediction of temperature distribution inside the machine. Thermal networks were developed to investigate the heat flow through machine components, to perform the design optimisation and to maximise overall machine performance. A thermal network was also developed by the author to investigate the heat transfer phenomena inside the bearing chambers. An experimental apparatus was designed and commissioned in order experimentally validate the thermal models developed. Temperatures, pressures and torque up to 20,000 rpm were recorded throughout the tests and data collected were compared to quantities predicted analytically and numerically. Maximum winding temperatures measured performing a short circuit test agree well with analytical and numerical prediction with a maximum difference of 10%; mechanical losses measured carrying out a no-load test agree well at speeds over 10,000 rpm with differences between 2 and 12%. Throughout tests, pressure drops were monitored across the machine and an agreement of 13% with prediction were achieved. Design improvements are also proposed to further enhance the cooling of stator slots and of rotor components.
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Alsawalhi, Jamal Yousuf. "An asymmetric salient permanent magnet synchronous machine for wide constant power speed range applications." Thesis, Purdue University, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=3686817.
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This work introduces a novel permanent-magnet synchronous machine (PMSM) architecture that employs rotational asymmetry to increase the torque density output in constant power variable speed applications. A population based multi-objective design optimization algorithm is used to design and analyze the new machine topology. A number of design studies are presented to show that the proposed machine structure outperforms a conventional PMSM machine. Validation of the analytical machine design model using a three dimensional finite element analyses is performed and the results are presented. Finally, a case study in which a hybrid electric bus traction motor is designed is presented.
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Bořil, Michal. "Návrh vysokootáčkového synchronního stroje s permanentními magnety o výkonu 3 MW." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2020. http://www.nusl.cz/ntk/nusl-413037.
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The thesis theme is the design of 3 MW high-speed permanent magnet synchronous motor. The work is divided into several parts, and contains the information given on the topic. The first part lists trends and new technologies of high-speed electric machines, and the issues and construction of high-speed synchronous machines are also listed here. In the second part, the machine is analytically designed from the specified values, which is then modelled in the RMxprt program. In the penultimate part, the engine is simulated by programs that are included in the ANSYS Electronics Desktop package, they are RMxprt and Maxwell. The modified engine model in RMxprt is simulated using defined formulas and then converted to Maxwell 2D, where the engine is simulated using the finite element method. In the last part, the results from the analytical calculation are compared with other high-speed machines. In addition, the results of simulations from RMxprt and Maxwell were compared in the last part.
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Morales, Caporal Roberto. "Encoderless predictive direct torque control of the synchronous reluctance machine at low and zero speed." Aachen Shaker, 2007. http://d-nb.info/988798077/04.
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Vorster, Christiaan Willem. "Design of a reluctance synchronous machine for an electric vehicle with a multi speed gearbox." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/95950.
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Thesis (MEng)--Stellenbosch University, 2014.ENGLISH ABSTRACT: Conventional electrical vehicles (EVs) favour mostly permanent magnet machines with single speed gearboxes. This is understandable, the PM machine has a high power density making the electrical machine smaller in size. The PM machine also has a favourable field weakening capability combining this with a single speed gearbox nearly perfectly matches the required traction curve. However the dependency of rare earth metals from China and the environmental issues raised by mining these metals raise concern. Therefore alternatives should be considered. Induction -, switch reluctance - and wound rotor machines are all gaining ground as favourable traction machines to power vehicles. The reluctance synchronous machine (RSM) is known for it’s robustness and high efficiency, however the machine has a limited field-weakening capability. To overcome this short coming a multi gearbox from an internal combustion engine (ICE) is suggested. By combining the RSM and multi speed gearbox it is possible to match the traction curve. There are numerous advantages offered by using this system, especially from an performance and efficiency point of view. However there are also numerous challenges faced by using the suggested powertrain, however the focus of this study is mainly on performance and efficiency of the motor and the powertrain. As a case study a Corsa 140i is used and the design specifications is taken from the ICE. The aim is to design a RSM that meets the specifications of the ICE. The RSM structure is mathematically modelled then optimized using commercial optimization and 2D finite element software. To evaluate the design of the RSM, the motor is then tested. The powertrain is then tested by connecting the motor onto the gearbox of the Corsa and the efficiency of the powertrain is evaluated. The test results it shown that the RSM can be used as a traction motor. There are two motors built one with NO20 and the other with M530-65A lamination steel. Both motors perform well throughout the speed and torque spectrum. The measured efficiency at the rated condition for the motor with the NO20 steel is above 91% and the motor with the M530-65A laminations above 89%. The power train is is tested in 4th and 5th gear. The efficiency of 4th and 5th gear is approximated and the efficiency is above 90% . This high efficiency makes the multi speed gearbox a competitor for the EV power train.
AFRIKAANSE OPSOMMING: Elektrisie voertuie (EVe) het meestal permanent magneet motors met ’n enkel spoed ratkas. Dit is verstaanbaar, die PMS masjien het ’n hoë krag digtigheid wat die masjien kleiner maak in grote. Die PMS masjien het ’n baie goeie vloed veld verswakkings gebied en as dit gekombineer word met ’n enkel spoed ratkas, volg dit die velangde traksie kurwe amper perfek. Die nadeel is dat die PMS motor skaars aard metale nodig het vir die magnete van China af. Die probleem is dat daar baie omgewings probleme gepaard gaan om die metale te myn en China beheer die mark. As gevolg hiervan moet ander tipe motors oorweeg word as traksie motors vir voertuie. Skakel reluktansie, induksie en ’n wikkel rotor motors is almal besig om vordering te maak as traksie motors vir EV’e. Die sinchroon reluktansie motor (RSM) is bekend as ’n robuuste en effektiewe motor. Die probleem met die RSM is dat dit nie ’n goeie vloed veld verswakkings gebied het nie. Om die probleem te oorkom, word ’n veranderlike spoed ratkas van ’n binnebrand engin voorgestel. Deur om die RSM en die veranderlike spoed ratkas as ’n dryfstelsel te gebruik kan die verlangde traksie kurwe ook verkry word. Daar is talle voordele om ’n veranderlike spoed ratkas te gebruik, veral van af ’n draaimoment verrigting en effektiwiteits oogpunt. Daar is ongelukkig ook baie uitdagings wat gepaard gaan as ’n veranderlike spoed ratkas gebruik wil word in die dryfstelsel. Alhoewel daar baie uitdagings is kyk die studie slegs na die draaimoment verrigting en die effektiwiteit van die dryfstelsel. ’n Corsa 140i word as ’n gevallestudie gebruik en die spesifikasies vir die elektrisie motor word vanaf die spesifikasies van die binnebrand engin geneem. Die doel is om ’n motor te ontwerp wat dieselfde spesifikasies het as die binnebrand engin. Die RSM strukstuur word wiskundig gemodelleer en dan geoptimeer deur gebruik te maak van kommersiele optimering en 2D eindige element sagteware. Om die ontwerp te verifieer word die motor getoets. Die dryfstelsel word dan getoets deur om die motor met die raktas te konnekteer. Die draaimoment verrigting en die effektiwiteit word dan ge-evalueer. Twee motors word gebou, een met NO20 laminasies en een met M530-65A laminasies. Beide motors het goeie verrigting deur die spoed en draaimoment gebied. Die gemeete effektiwiteit van die motor met die NO20 laminasies is bo 91% en die motor met die M530-65A laminasies het ’n gemeete effektiwiteit bo 89%. Die toets resultate wys dat die RSM as ’n traksie motor gebruik kan word. Die dryfstelsel word in 4de en 5de rat ge-evalueer. Die effektiwiteit van die ratkas in 4de en 5de word benader en ’n effektiwiteit bo 90% is verkry. Hierdie hoë effektiwiteit maak die veranderlike spoed ratkas ’n lewensvatbare mededinger in die EV dryfstelsel.
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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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Ahmed, Adeeb. "Maximum Torque per Ampere (MTPA) Control for Permanent Magnet Synchronous Machine Drive System." University of Akron / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=akron1375726072.
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Okwudire, Chinedum. "Modeling and control of high speed machine tool feed drives." Thesis, University of British Columbia, 2009. http://hdl.handle.net/2429/12551.
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Aerospace, die and mold, and automotive industries machine parts at high cutting speeds to reduce production cycle periods. Machine tools which carry out the cutting operations rely on either precision ball screw or linear motor direct drives to accurately position the workpiece relative to the cutting tool. However, the precise positioning capability of the drives is limited by low servo bandwidth and poor disturbance rejection resulting from structural flexibilities in ball screw drives as well as weak dynamic stiffness/robustness in direct drives.
This thesis proposes modeling, parameter identification, control and online parameter estimation techniques which aim at increasing the servo bandwidth and disturbance rejection ability of high speed machine tool feed drives.
A hybrid finite element methodology is used to model the structural dynamics of ball screw drives. As part of the model, two stiffness matrices are developed for connecting the finite element representation of the ball screw to the lumped-mass representation of the nut. The developed model is used to analyze the coupled axial-torsional-lateral vibration behavior of a critical structural mode that limits high bandwidth control of ball screw drives. Moreover, a method for accurately identifying the mass, damping and stiffness matrices representing the open-loop dynamics of ball screw drives is developed. The identified matrices are used to design gain-scheduled sliding mode controllers, combined with minimum tracking error filters, to effectively suppress the critical axial-torsional-lateral mode of ball screw drives thereby achieving high bandwidth control and good disturbance rejection.
For direct-driven machines, a high bandwidth disturbance adaptive sliding mode controller is designed to improve the dynamic stiffness of the drive, compared to similar controller designs, without increasing the controller’s complexity. Furthermore, the cutting forces applied to the drive are estimated accurately using a disturbance recovery algorithm and used to improve the dynamic stiffness of low-frequency structural modes of direct-driven machine tools.
Finally, a method for estimating the changing mass of the workpiece during machining operations with cutting forces that are periodic at spindle frequency is introduced.
The techniques presented in this thesis are verified through simulations and/or experiments on single-axis ball screw and linear motor feed drives.
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Wasson, Kevin L. (Kevin Lee). "Hydrostatic radial bearings for high speed precision machine tool applications." Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/12287.
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zhao, limei. "NEW OPTIMAL HIGH EFFICIENCY DSP-BASED DIGITAL CONTROLLER DESIGN FOR SUPER HIGH-SPEED PERMANENT MAGNET SYNCHRONOUS MOTOR." Doctoral diss., University of Central Florida, 2005. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4071.
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This dissertation investigates digital controller and switch mode power supply design for super high-speed permanent magnet synchronous motors (PMSM). The PMSMs are a key component for the miniaturic cryocooler that is currently under development at the University of Central Florida with support from NASA Kennedy Space Center and the Florida Solar Energy Center. Advanced motor design methods, control strategies, and rapid progress in semiconductor technology enables production of a highly efficient digital controller. However, there are still challenges for such super high-speed controller design because of its stability, high-speed, variable speed operation, and required efficiency over a wide speed range. Currently, limited research, and no commercial experimental analysis, is available concerning such motors and their control system design. The stability of a super high-speed PMSM is an important issue particularly for open-loop control, given that PMSM are unstable after exceeding a certain applied frequency. In this dissertation, the stability of super high-speed PMSM is analyzed and some design suggestions are given to maximize this parameter. For ordinary motors, the V/f control curve is a straight line with a boost voltage because the stator resistance is negligible and only has a significant effect around the DC frequency. However, for the proposed super high-speed PMSM the situation is quite different because of the motor's size. The stator resistance is quite large compared with the stator reactive impedance and cannot be neglected when employing constant a V/f control method. The challenge is to design an optimal constant V/f control scheme to raise efficiency with constant V/f control. In the development, test systems and prototype boards were built and experimental results confirmed the effectiveness of the dissertation system.Ph.D.
Department of Electrical and Computer Engineering
Engineering and Computer Science
Electrical Engineering
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Chi, Song. "Position-sensorless control of permanent magnet synchronous machines over wide speed range." Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1186974583.
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Park, Jae Do Hofman Heath F. "Modeling and control of a high-speed solid-rotor synchronous reluctance flywheel motor/generator." [University Park, Pa.] : Pennsylvania State University, 2007. http://etda.libraries.psu.edu/theses/approved/WorldWideIndex/ETD-1881/index.html.
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Naoom, Mazin Fawzi. "Initial design studies for a high-speed distributed prolog database machine." Thesis, Heriot-Watt University, 1986. http://hdl.handle.net/10399/1075.
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Xu, Jin. "Machine Learning – Based Dynamic Response Prediction of High – Speed Railway Bridges." Thesis, KTH, Bro- och stålbyggnad, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-278538.
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Targeting heavier freights and transporting passengers with higher speeds became the strategic railway development during the past decades significantly increasing interests on railway networks. Among different components of a railway network, bridges constitute a major portion imposing considerable construction and maintenance costs. On the other hand, heavier axle loads and higher trains speeds may cause resonance occurrence on bridges; which consequently limits operational train speed and lines. Therefore, satisfaction of new expectations requires conducting a large number of dynamic assessments/analyses on bridges, especially on existing ones. Evidently, such assessments need detailed information, expert engineers and consuming considerable computational costs. In order to save the computational efforts and decreasing required amount of expertise in preliminary evaluation of dynamic responses, predictive models using artificial neural network (ANN) are proposed in this study. In this regard, a previously developed closed-form solution method (based on solving a series of moving force) was adopted to calculate the dynamic responses (maximum deck deflection and maximum vertical deck acceleration) of randomly generated bridges. Basic variables in generation of random bridges were extracted both from literature and geometrical properties of existing bridges in Sweden. Different ANN architectures including number of inputs and neurons were considered to train the most accurate and computationally cost-effective mode. Then, the most efficient model was selected by comparing their performance using absolute error (ERR), Root Mean Square Error (RMSE) and coefficient of determination (R2). The obtained results revealed that the ANN model can acceptably predict the dynamic responses. The proposed model presents Err of about 11.1% and 9.9% for prediction of maximum acceleration and maximum deflection, respectively. Furthermore, its R2 for maximum acceleration and maximum deflection predictions equal to 0.982 and 0.998, respectively. And its RMSE is 0.309 and 1.51E-04 for predicting the maximum acceleration and maximum deflection prediction, respectively. Finally, sensitivity analyses were conducted to evaluate the importance of each input variable on the outcomes. It was noted that the span length of the bridge and speed of the train are the most influential parameters.
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Morales, Caporal Roberto [Verfasser]. "Encoderless Predictive Direct Torque Control of the Synchronous Reluctance Machine at Low and Zero Speed / Roberto Morales Caporal." Aachen : Shaker, 2008. http://d-nb.info/1163609846/34.
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Wang, Wei-Hui. "Modelling machine induced noise and vibration in a ship structure." Thesis, University of Plymouth, 2000. http://hdl.handle.net/10026.1/2823.
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Most high speed vessels are fitted with powerful high speed engines which are installed in confined spacesa nd, as a consequencec, ausea n extremely high level of noise and vibration. Often structure-borne sound power is transmitted to a sound carrying structure from a source via a number of contact points. In turn, the noise and vibration are propagated in the structure and could possibly cause an undesired noise radiation. In this study, a model for predicting power flow based on the mobility theory has been addressed. The unique parts of the study include the establishment of the relationship of mobility functions with respect to four-pole parameters and the dynamic stiffness coefficients of a coupled machine/mount/foundation system. Also expressions to represent the sound input power, the output power and the transmitted power in relation to mobility functions are clarified. From a detailed analysis of relevant literature, it is shown that no validated models for predicting the propagation of structure-bome noise within the intermediate frequency range of 125 Hz to lkHz exist. As a consequence, a new numerical stress wave model has been developed to bridge this knowledge gap. This innovative approach extends the earlier works of Cremer, Heckl and Ungar in the field of stress wave propagation. Finally, a novel holistic model has been developed to line up the transmission, propagation and radiation predictions of a machine induced noise and vibration in ship's structure to take in account the fluid-structure interaction effect. A number of experiment measurements have been performed to validate the established models. From the comparisons, the prediction models are shown to be credible with an accuracy higher than 95 per cent. The established models are of a generic nature and can be applicable to diverse engineering fields regarding to the predictions of structure-borne noise and vibration transmission, propagation and radiation. Applications of these models to characterize the vibration reduction countermeasures,a s in the case of resilient mounts and squeeze-film damping plates, from a machine are also discussed.
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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.
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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 faibleThis 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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Calvert, John R. "Design of a synchronous pipelined multiplier and analysis of clock skew in high-speed digital systems." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2000. http://edocs.nps.edu/npspubs/scholarly/theses/2000/Dec/00Dec_Calvert.pdf.
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Thesis (M.S. in Electrical Engineering) Naval Postgraduate School, December 2000.Thesis advisors, Douglas J. Fouts, Herschel H. Loomis, Jr. Includes bibliographical references (p. 131). Also Available online.
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Smith, J. Christopher. "Ceramic lubrication : vapor phase tribopolymerization and a new high speed, high load pin-on-disk machine /." Thesis, This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-03242009-040520/.
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Lee, Jinho. "Design of controllers for improving contour accuracy in a high-speed milling machine." [Gainesville, Fla.] : University of Florida, 2005. http://purl.fcla.edu/fcla/etd/UFE0010702.
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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.
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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.Thesis (M.Ing. (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2011.
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Calverley, Stuart David. "Design of a high-speed switched reluctance machine for automotive turbo-generator applications." Thesis, University of Sheffield, 2002. http://etheses.whiterose.ac.uk/3539/.
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The efficient generation of relatively large quantities of electrical energy in vehicles is becoming an increasingly important issue, as a result of increasing demands of ancillary equipment and the emergence of hybrid power-train vehicles. An attractive solution to meeting these demands is to extract the electrical energy by means of a generator driven by a high-speed exhaust mounted turbine, a technology that is beginning to emerge commercially. This thesis is concerned with the design of a system, which extends this concept to enable both electrical generation and highly flexible air-management. The heart of the system is a high-speed switched reluctance machine, the rotor of which is located on a common shaft with the turbine and compressor wheels of a standard commercial turbocharger. The design synthesis of a -switched reluctance machine capable of meeting the required performance specification is particularly onerous given the harsh environment in which it operates, specifically in terms of the restricted space envelope, the high ambient temperature and the very high rotational speeds. This thesis describes the design of a switched reluctance machine for a prototype system, a procedure that encompasses the detailed analysis of centrifugal stress in the rotor, aerodynamic losses, iron loss, rotordynainic performance and dynamic performance. The design and analysis of the system is supported by experimental evaluation at both component and system level.
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Fan, Sai Kit. "An study of unit machine operations for tool paths in high speed milling /." View abstract or full-text, 2008. http://library.ust.hk/cgi/db/thesis.pl?IELM%202008%20FAN.
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