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Littérature scientifique sur le sujet « Magnet losse »

Auteur : Grafiati

Publié le 1 avril 2023

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Articles de revues sur le sujet "Magnet losse"

Sirimanna, Samith, Thanatheepan Balachandran et Kiruba Haran. « A Review on Magnet Loss Analysis, Validation, Design Considerations, and Reduction Strategies in Permanent Magnet Synchronous Motors ». Energies 15, n^o 17 (23 août 2022) : 6116. http://dx.doi.org/10.3390/en15176116.

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Eddy current losses in magnets are a major consideration in the rotor design of permanent magnet synchronous motors (PMSMs). Stator design choices and the use of modern inverters with high switching frequency introduce harmonics that can contribute to significant losses in the magnets, causing the rotor to heat up. In typical PMSMs, the lack of rotor cooling can cause the magnet’s performance to degrade at high temperatures and eventually demagnetize. This review examines a large number of studies analyzing magnet eddy current losses using analytical methods and finite-element analysis. In some of these studies, magnet segmentation is carried out to reduce the losses; however, their loss-reduction effects depend highly on the type of PMSM and the mix of stator harmonics. Magnet segmentation without considering these effects can, in fact, increase the magnet losses, in addition to the extra manufacturing efforts. Multiple design analysis show the influence of rotor–stator geometric features on magnet losses. Although measuring magnet eddy current losses for these motor designs is a tedious task, authors have proposed calorimetric and loss segregation-based techniques to provide validation. This paper addresses magnet loss modeling techniques, PM material considerations, magnet segmentation effectiveness, motor and stator design effects, and experimental validation to inform motor designers about the costs and benefits of rotor designs that minimize rotor losses.

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Et.al, Byeong-Chul Lee. « Analysis Of Eddy Current Loss Of IPMSM According To The Material Of Permanent Magnet ». Turkish Journal of Computer and Mathematics Education (TURCOMAT) 12, n^o 6 (10 avril 2021) : 508–13. http://dx.doi.org/10.17762/turcomat.v12i6.1959.

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In order to reach the performance of the permanent magnet embedded rotor, the choice of magnet is very important. It must be thermally stabilized, and at this point, discussion of eddy current losses is necessary.To proceed with this study, a permanent magnet embedded synchronous motor used in the compressor currently being designed was selected. To derive the eddy current losses in the neodymium-magnets, current density was calculated through the equation. The eddy current loss was mathematically derived using the magnetic conductivity and residual magnetic flux density. Finally, comparative verification was performed through finite element analysis simulation. In this paper, eddy current losses in a N series magnet are mathematically analyzed and we perform comparative verification through simulation using finite element analysis. The Br value indicating the residual magnetic flux density is the lowest in N30 series and the largestin the N48 series. In the case of using the N30 series, the amount of magnetic flux that can be generated is low, so in order to increase the same output, the electric field must be increased by drawing more current from the stator winding. That is, the torque can be further increased. However, since the magnetic flux density experienced by the permanent magnet also increases, eddy current loss that may occur in the magnet eventually increases. There are also a method of using a split magnet to reduce eddy current losses. Inthe case of a permanent magnet holding a large residual magnetic flux density, the magnets loss is reduced, but there is a disadvantage that the price may be expensive. The losses in the permanent magnet are dissipated as heat. If the eddy current loss increases, the magnet demagnetizes, which in turn leads to a decrease in performance. In the selection of magnets, analysis of losses is essential.

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Zoubida, Belli, et Mohamed Rachid Mekideche. « Investigation of magnet segmentation techniques for eddy current losses reduction in permanent magnets electrical machines ». COMPEL : The International Journal for Computation and Mathematics in Electrical and Electronic Engineering 34, n^o 1 (5 janvier 2015) : 46–60. http://dx.doi.org/10.1108/compel-11-2013-0374.

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Purpose – Reducing eddy current losses in magnets of electrical machines can be obtained by means of several techniques. The magnet segmentation is the most popular one. It imposes the least restrictions on machine performances. This paper investigates the effectiveness of the magnet circumferential segmentation technique to reduce these undesirable losses. The full and partial magnet segmentation are both studied for a frequency range from few Hz to a dozen of kHz. To increase the efficiency of these techniques to reduce losses for any working frequency, an optimization strategy based on coupling of finite elements analysis and genetic algorithm is applied. The purpose of this paper is to define the parameters of the total and partial segmentation that can ensure the best reduction of eddy current losses. Design/methodology/approach – First, a model to analyze eddy current losses is presented. Second, the effectiveness of full and partial magnet circumferential segmentation to reduce eddy loss is studied for a range of frequencies from few Hz to a dozen of kHz. To achieve these purposes a 2-D finite element model is developed under MATLAB environment. In a third step of the work, an optimization process is applied to adjust the segmentation design parameters for best reduction of eddy current losses in case of surface mounted permanent magnets synchronous machine. Findings – In case of the skin effect operating, both full and partial magnet segmentations can lead to eddy current losses increases. Such deviations of magnet segmentation techniques can be avoided by an appropriate choice of their design parameters. Originality/value – Few works are dedicated to investigate partial magnet segmentation for eddy current losses reduction. This paper studied the effectiveness and behaviour of partial segmentation for different frequency ranges. To avoid eventual anomalies related to the skin effect an optimization process based on the association of the finite elements analysis to genetic algorithm method is adopted.

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DING, XIAOFENG, et CHRIS MI. « MODELING OF EDDY CURRENT LOSS AND TEMPERATURE OF THE MAGNETS IN PERMANENT MAGNET MACHINES ». Journal of Circuits, Systems and Computers 20, n^o 07 (novembre 2011) : 1287–301. http://dx.doi.org/10.1142/s021812661100789x.

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The eddy current loss in the magnets of permanent magnet (PM) motors in a hybrid electric vehicle (HEV) and plug-in HEV is usually not taken into consideration in traditional motor design and analysis. However, due to the high conductivity of the rare-earth magnet, neodymium-iron-boron (NdFeB), and slot/tooth harmonics, there is eddy current loss generated inside the magnets. This loss may not attribute very much to the efficiency of the motor, but the temperature-rise inside the magnets caused by this loss can lead to the unpredictable deterioration of the magnets, such as the degradation of performance and potential demagnetization. In addition, the output voltage of pulse-width-modulated (PWM) inverter contains abundant high frequency harmonics, which induce excessive loss in the magnets. The excessive heat in PM motor induced by the eddy current loss combined with other losses can degrade the performance of the machine. This paper presents the modeling and analysis of eddy current loss in surface-mounted-magnets PM synchronous motors (SPMSM) and interior-magnets PM synchronous motors (IPMSM), operated by PWM inverter supply. Analytical methods are implemented, in conjunction with time-stepped finite-element analysis (FEA) for the calculation of eddy current loss in the magnet. Based on the calculated losses in the machines, simplified analytical models are developed as thermal circuits with network of interconnected nodes, thermal resistances and heat sources representing the heat processes within the SPMSM and IPMSM, to predict the temperature of the magnets. The predicted machine temperatures are found to be consistent with the experimental measurement.

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Meyer, Alexander, Christoph Ringelhan, Carina Fischer et Jörg Franke. « Energy Efficient Strategies for Processing Rare Earth Permanent Magnets ». Applied Mechanics and Materials 856 (novembre 2016) : 195–200. http://dx.doi.org/10.4028/www.scientific.net/amm.856.195.

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Due to high magnetic fields causing strong interactions between permanent magnets and other ferromagnetic material, transport and handling of magnetized magnet bodies is challenging. To avoid undesired effects, such as influences on sensitive devices or difficult separation of the single magnets from stack, spacing and shielding of the magnet bodies is required leading to larger package sizes and thus in some cases higher energy demand during transport referred to the transported magnet mass. An optimization of the transport chain can be reached using the software tool presented in this paper. Further magnetizing high coercive rare earth magnets needs strong magnetic fields. To create the necessary field strength, copper coils are used requiring current strengths of several kA. Since the electrical resistance of copper differs from zero, this also means enormous thermal losses. Hence to reduce the losses and to avoid thermal damage of the coil, only short current pulses are applied generated by a pulse magnetizer. However, the efficiency of the process is very poor and lies in the lower per mil range. The presented paper explains the magnetization process in detail with focus on the losses within the magnetization device. Further different material parameters influencing the saturation field strength, such as conductivity, size and diameter to length ratio are presented and possibilities to improve the energy efficiency are shown.

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Gong, Jinlin, Bassel Aslan, Frédéric Gillon et Eric Semail. « High-speed functionality optimization of five-phase PM machine using third harmonic current ». COMPEL : The International Journal for Computation and Mathematics in Electrical and Electronic Engineering 33, n^o 3 (29 avril 2014) : 879–93. http://dx.doi.org/10.1108/compel-10-2012-0220.

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Purpose – The purpose of this paper is to apply some surrogate-assisted optimization techniques in order to improve the performances of a five-phase permanent magnet machine in the context of a complex model requiring computation time. Design/methodology/approach – An optimal control of four independent currents is proposed in order to minimize the total losses with the respect of functioning constraints. Moreover, some geometrical parameters are added to the optimization process allowing a co-design between control and dimensioning. Findings – The optimization results prove the remarkable effect of using the freedom degree offered by a five-phase structure on iron and magnets losses. The performances of the five-phase machine with concentrated windings are notably improved at high speed (16,000 rpm). Originality/value – The effectiveness of the method allows solving the challenge which consists in taking into account inside the control strategy the eddy-current losses in magnets and iron. In fact, magnet losses are a critical point to protect the machine from demagnetization in flux-weakening region.

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Młot, Adrian, Mariusz Korkosz et Marian Łukaniszyn. « Iron loss and eddy-current loss analysis in a low-power BLDC motor with magnet segmentation ». Archives of Electrical Engineering 61, n^o 1 (1 janvier 2012) : 33–46. http://dx.doi.org/10.2478/v10171-012-0003-5.

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Iron loss and eddy-current loss analysis in a low-power BLDC motor with magnet segmentation This paper considers a Brushless Direct Current (BLDC) machine prototype with six poles and 36 stator slots including a three phase double-layered distributed winding. Presented modifications of rotor construction are identified in order to achieve the best possible compromise of eddy-current losses and cogging torque characteristics. The permanent magnet (PM) eddy-current loss is relatively low compared with the iron loss; it may cause significant heating of the PMs due to the relatively poor heat dissipation from the rotor and it results in partial irreversible demagnetization. A reduction in both losses is achieved by magnet segmentation mounted on the rotor. Various numbers of magnet segmentation is analysed. The presented work concerns the computation of the no-load iron loss in the stator, rotor yoke and eddy-current loss in the magnets. It is shown that the construction of the rotor with segmented magnets can significantly reduce the PM loss (eddy-current loss). The eddy-current loss in PMs is caused by several machine features; the winding structure and large stator slot openings cause flux density variations that induce eddy-currents in the PMs. The effect of these changes on the BLDC motor design is examined in order to improve the machine performance. 3-D finite-element analysis (FEA) is used to investigate the electromagnetic behaviour of the BLDC motor.

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Kudrjavtsev, O., A. Kallaste, A. Kilk, T. Vaimann et S. Orlova. « Influence of Permanent Magnet Characteristic Variability on the Wind Generator Operation ». Latvian Journal of Physics and Technical Sciences 54, n^o 1 (1 février 2017) : 3–11. http://dx.doi.org/10.1515/lpts-2017-0001.

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Abstract The paper discusses problems concerning the influence of permanent magnet material characteristics on the low-speed permanent magnet generator losses and output characteristics. The variability of the magnet material and its effect on the output parameters of the machine has been quantified. The characteristics of six different grades of neodymium permanent magnets have been measured and compared to the supplier specification data. The simulations of the generator have been carried out using transient finite element analysis. The results show that magnet materials from different suppliers have different characteristics, which have a significant influence on the generator output parameters, such as efficiency and power factor.

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Prakht, Vladimir, Vladimir Dmitrievskii, Vadim Kazakbaev et Ekaterina Andriushchenko. « Comparison of Flux-Switching and Interior Permanent Magnet Synchronous Generators for Direct-Driven Wind Applications Based on Nelder–Mead Optimal Designing ». Mathematics 9, n^o 7 (29 mars 2021) : 732. http://dx.doi.org/10.3390/math9070732.

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The permanent magnet flux-switching machine (PMFSM) is one of the most promising machines with magnets inserted into the stator. To determine in which applications the use of PMFSM is promising, it is essential to compare the PMFSM with machines of other types. This study provides a theoretical comparison of the PMFSM with a conventional interior permanent magnet synchronous machine (IPMSM) in the gearless generator of a low-power wind turbine (332 rpm, 51.4 Nm). To provide a fair comparison, both machines are optimized using the Nelder–Mead algorithm. The minimized optimization objectives are the required power of frequency converter, cost of active materials, torque ripple and losses of a generator averaged over the working profile of the wind turbine. In order to reduce the computational time, the substituting profile method is applied. Based on the results of the calculations, the advantages and disadvantages of the considered machines were revealed: the IPMSM has significantly lower losses and higher efficiency than the PMFSM, and the PMFSM requires much less rare-earth magnets and copper and is, therefore, cheaper in mass production.

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Jian, Cheng, Lei Ma, Weifeng Yang, Qing Huang, Jing Xu, Huan Zhai et Guangsheng Cao. « Influence of high temperature degaussing on lifting capacity of linear motor reciprocating pump ». Journal of Physics : Conference Series 2109, n^o 1 (1 novembre 2021) : 012009. http://dx.doi.org/10.1088/1742-6596/2109/1/012009.

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Abstract The submersible linear motor reciprocating pump is a new type of artificial lift. The degaussing effect of its permanent magnet at high temperature will reduce the lifting capacity of the linear motor reciprocating pump. In this paper, the thermal stability of NdFeB permanent magnet material was studied by simulating the underground temperature and pressure conditions in a high-temperature and high-pressure reactor and combining with a Tesla instrument. The results show that NdFeB material loses its magnetism rapidly at high temperature, and the residual magnetism is proportional to the ambient temperature of the magnet. The high temperature demagnetization effect of large magnets is more serious due to eddy current loss and hysteresis loss.

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Thèses sur le sujet "Magnet losse"

Ng, Kong. « Electromagnetic losses in brushless permanent magnet machines ». Thesis, University of Sheffield, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.579745.

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Atallah, Kais. « Iron losses in brushless permanent magnet DC machines ». Thesis, University of Sheffield, 1993. http://etheses.whiterose.ac.uk/14941/.

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A closed-loop computer-controlled single-sheet test system has been developed to characterise lamination materials and to measure, the iron loss density under any specified flux density waveform. The system has been 'used to validate predictions from a recently developed theoretical model, for the calculation of the excess loss component associated with domaiQ wall movement, under flux density waveforms typical of those encountered in the stator core of brushless permanent magnet dc motors. In addition, an improved expression for the calculation of the iron loss density component, from measured 71 and 7!vectors, due to rotatio~ in non-purely rotating flux conditions, has been derived. A simple analytical model from which the airgap flux density and spread of magnet working points can be determined and which accounts for the effects of curvature for radial-field permanent magnet machines has been developed and validated. The model has been coupled to an analytical technique for the prediction of the open-circuit flux density waveforms in different regions of the stator core, and has subsequently been employed for the prediction of the open-circuit iron loss. In order to predict the iron loss under any specified load condition, a technique which couples a brushless dc drive system simulation to a series of magnetostatic finite element analyses corresponding to discrete instants in a commutation cycle has been developed. It enables the prediction of the local flux density waveforms throughout the stator core under any operating condition, and has been employed to predict the local iron loss density distribution 'and the total iron loss and their variation with both the load and the commutation strategy, Finally, the theoretical findings have been validated against measurements on a representative low power brushless drive system.

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Li, Zhou, of Western Sydney Nepean University et of Mechatronic Computer and Electrical Engineering School. « Numerical computation of core losses in permanent magnet machines ». THESIS_XXXX_MCEE_Li_Z.xml, 2000. http://handle.uws.edu.au:8081/1959.7/284.

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This thesis presents a study on core loss calculations in rotating electrical machines. The basic concepts concerning magnetic moments, ferromagnetism, magnetic domains and magnetic hysteresis are introduced. The three-term models for alternating and rotational core losses in electrical steel sheets are presented. Several core loss measurement techniques are reviewed and an experiment is carried out to measure the total core losses in an electrical sheet steel sample under alternating and rotational magnetic fields of various frequencies and amplitudes. The coefficients in the loss models for alternating and rotational core losses are obtained through curve fitting process. The theory of electromagnetic fields is presented through the Maxwell equations and field scalar equations. A detailed review on core loss models for rotating electrical machines is presented. A rotational core loss model is adopted to calculate the core losses in a PM motor. The total core loss in the PM motor is obtained by summing the element losses using a MATLAB program. An experiment is conducted to measure the total core loss in the PM motor. The calculated total core loss in the PM motor is compared with the experimental results. The calculated total core losses are about 19% lower than the tested results. Various possible causes for this discrepancy are discussed
Master of Engineering (Hons)

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Mi, Chunting. « Modelling of iron losses of permanent magnet synchronous motors ». Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/NQ58959.pdf.

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Garcia, Gonzalez Adolfo. « Magnet Losses in Inverter-fed High-speed PM Machines ». Thesis, KTH, Elektrisk energiomvandling, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-177641.

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This master thesis deals with the estimation of magnet losses in a Permanent Magnet(PM) motor inserted in a nut-runner. This type of machine has interesting featuressuch as being slot-less and running at a very high speed (30000 rpm). An extensiveliterature review was performed in order to investigate the state of the art in estimationof the losses in magnets of a PM machine. Analytical models to calculate the no-loadback-emf and the magnetic ux density in the air-gap due to the currents in the statorare presented rst. Furthermore, several of the analytical models for calculating lossesin magnets described in the literature were tested and adapted to the case of a slotlessmachine with a parallel-magnetized ring. Then, a numerical estimation of thelosses with nite element method (FEM) 2D was carried out. In addition, a detailedinvestigation of the eect of simulation settings (e.g., mesh size, time-step, remanentmagnetic ux density in the magnet, superposition of the losses, etc.) was performed.Finally, calculation of losses with 3D FEM are also included in order to compare thecalculated losses with both analytical and FEM 2D results. The estimation of thelosses includes the variation of these with frequency for a range of frequencies between10 and 100 kHz.
Detta examensarbete handlar om uppskattningen av magnetforluster i en permanentmagnetmotor (PM) inford i en mutterdragare. Denna typ av maskin har intressantafunktioner, som att den ar slot-less och att den kors i en hog hastighet (30000rpm). En omfattande litteraturstudie utfordes for att kunna uppskatta forluster imagneterna pa basta satt. Forst presenteras analytiska modeller for att berakna denelektromotoriska kraften (EMK) och den magnetiska odestatheten i luftgapet somuppkommer pa grund av strommarna i statorn. Dessutom har era av de analytiskamodellerna for berakning av forlusterna som beskrivits i litteraturen testats och anpassatstill en slot-less maskin med en parallelmagnetiserad ring. En numerisk uppskattningav forlusterna har sedan utforts med hjalp av nita elementmetoden (FEM) 2D.Dartill har en detaljerad undersokning genomforts hur olika parameterinstallningarpaverka utfallet. De FEM parametrar som har undersokts har bland annat bestattav berakningsnatets storlek, tidssteg, remanens odestatheten i magneten och om superpositionav forlusterna galler. Till sist har berakningar for forluster med 3D FEMutforts och jamforts med resultaten for bade de analytiska och FEM 2D resultaten.Uppskattning av forluster innefattar variationen av dessa med ett frekvensomrade mellan10 och 100 kHz.

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Li, Zhou. « Numerical computation of core losses in permanent magnet machines ». Thesis, View thesis, 2000. http://handle.uws.edu.au:8081/1959.7/284.

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Li, Zhou. « Numerical computation of core losses in permanent magnet machines / ». View thesis, 2000. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20030901.113715/index.html.

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Thesis (M.Sc (Hons)) -- University of Western Sydney, Nepean, 2000.
"Submitted for the degree of Master of Engineering (Hons), School of Mechatronic, Computer & Electrical Engineering, University of Western Sydney, Nepean" Includes bibliographical references (leaves 107-114).

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Vaez, Sadegh. « Loss minimization control of interior permanent magnet motor drives ». Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq22499.pdf.

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Irenji, Neamat Taghizadeh. « Calculation of electromagnetic rotor losses in high-speed permanent magnet machines ». Thesis, University of Southampton, 1998. https://eprints.soton.ac.uk/47948/.

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High-speed permanent magnet machines are currently being developed for a number of applications including gas-turbine generator sets and machine tools. Due to the high peripheral speed of the rotor and the relatively high conductivity of the magnets used, rotor eddy current loss can be substantial. Quite low levels of loss may present a serious problem if rotor cooling is poor. The accurate calculation of these losses, and appreciation of their dependence on machine parameters, are therefore of great importance for reasons of both efficiency and temperature rise. In this, thesis, a method has been developed to evaluate the asynchronously rotating harmonics with respect to the rotor and to calculate rotor power loss caused by these harmonics. The harmonics are determined by double Fourier analysis of the normal flux density data over the rotor surface. The data is obtained from finite element magnetostatic analysis of the machine at different rotor positions, with all possible harmonic sources present, except rotor induced eddy currents whose effect on harmonics was found to be negligible. Rotor power loss is calculated for each harmonic using a 2D rectilinear current sheet model of the machine. The magnitude of the current sheet, which is placed on the inner surface of a toothless stator, is adjusted to produce the same magnetostatic normal flux density over the rotor surface as that of the corresponding harmonic. The 2D current sheet model does not allow for 3D end effects and magnet segmentation. The accuracy of the analytical rectilinear current sheet model was verified by comparison with a cylindrical FE current sheet model, and by solving a benchmark eddy current problem that can be also solved using FE steady-state AC analysis. The current sheet model was used to calculate rotor loss in a number of generic machines, with two basic types of rotor construction: 1) non-salient rotor with arc shaped surface magnets and 2) salient rotor with chord shaped surface magnets. The results show that rotor loss depends strongly on the ratio of slot opening to slot pitch (s/X.) and on the ratio of total airgap to slot pitch (g/X). For the same fundamental airgap flux density, rotor loss reduces dramatically by increasing airgap length and reducing slot opening. Increasing the number of slots also reduces the loss. The results also show that rotor loss in a generator increases as the power factor moves from lagging to leading due to the armature reaction effect. Using a conducting sleeve, instead of a non-conducting one, with conductivity in the range of practical values, increases rotor losses dramatically. Reducing magnet conductivity reduces rotor loss. Rotor power loss in machines with non-conducting sleeve is concentrated on the surface of the magnet and a small part on the surface of the hub. In machines with chord shaped magnets, the power loss density can be very high in the parts of the steel hub near the intersection of two poles where local total airgap is small. The harmonics caused by inverter switching in a motor or rectifier switching in an alternator can cause a very significant increase in rotor loss, compared to a machine with a sinusoidal mmf. The results also show that the loss depends strongly on the switching strategy, e.g., switching harmonics in 6 step mmf waveform produce 3 times more loss than a 12 step mmf waveform. Although the developed method for calculation of rotor power loss does not take the effect of magnet peripheral discontinuity or segmentation into account, it is clear that segmentation reduces power loss by interrupting the eddy current return path, specially for harmonics with long wavelengths. The effect of segmentation requires further study.

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Niu, Xin. « Traction machine winding and magnet design for electric vehicles ». Thesis, University of Manchester, 2017. https://www.research.manchester.ac.uk/portal/en/theses/traction-machine-winding-and-magnetdesign-for-electric-vehicles(df8dfe16-71cb-48ee-b270-b90b3a24617e).html.

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Work had been established for traction machine design aspects in this research. The effect of multiphase design for Permanent Magnet (PM) machine was investigated. The electromagnetic characteristics of both 3-phase and 9-phase machine, along with different magnet designs, were simulated and analyzed by using the program developed during the process. The software used were FEMM and MATLAB. The iron loss for different designs was established, based on the analytical flux density obtained by 2-D stepping FEA method. The harmonic of flux waveform and rotating field were also considered for difference areas in the machine models. The prediction was compared with experimental data collected in open circuit. The simulation result shown that there was a minimum 4% torque gain and noticeable less torque ripples for 9-phase machine, comparing with 3-phase one, with the same excitation phase current. The embedded magnet rotor design was suggested to monitor the demagnetization of each magnet closely, since some area of the magnet could be demagnetized even when the working point of magnet was well distance away from the nonlinear region of its characteristic. There were about 6% less iron loss was produced in 9-phase model than 3-phase model. The implemented method for calculating iron loss was more accurate within 3500 rpm rotor speed comparing with other approaches.

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Livres sur le sujet "Magnet losse"

E, Schwarze Gene, et NASA Glenn Research Center, dir. Wide temperature core loss characteristics of transverse magnetically annealed amorphous tapes for high frequency aerospace magnetics. [Cleveland, Ohio] : National Aeronautics and Space Administration, Glenn Research Center, 1999.

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Center, NASA Glenn Research, dir. Comparative wide temperature core loss characteristics of two candidate ferrites for the NASA/TRW 1500 W PEBB converter. [Cleveland, Ohio] : National Aeronautics and Space Administration, Glenn Research Center, 1999.

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Hill, David A. Near-field and far-field excitation of a long conductor in a lossy medium. Boulder, Colo : Electromagnetic Fields Division, Center for Electronics and Electrical Engineering, National Engineering Laboratory, National Institute of Standards and Technology, 1990.

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E, Schwarze Gene, Niedra Janis M et United States. National Aeronautics and Space Administration., dir. Comparison of high temperature, high frequency core loss and dynamic B-H loops of a 2v-49Fe-49Co and a grain oriented 3Si-Fe alloy. [Washington, DC] : National Aeronautics and Space Administration, 1991.

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E, Schwarze G., Niedra J. M et United States. National Aeronautics and Space Administration., dir. Comparison of high temperature, high frequency core loss and dynamic B-H loops of a 2v-49Fe-49Co and a grain oriented 3Si-Fe alloy. [Washington, DC] : National Aeronautics and Space Administration, 1991.

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E, Schwarze Gene, Niefra J. M et United States. National Aeronautics and Space Administration., dir. Comparison of high temperature, high frequency core loss and dynamic B-H loops of two 50 Ni-Fe crystalline alloys and an iron-based amorphous alloy. [Washington, DC] : National Aeronautics and Space Administration, 1991.

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Chapitres de livres sur le sujet "Magnet losse"

Minty, Michiko G., et Frank Zimmermann. « Collimation ». Dans Particle Acceleration and Detection, 141–47. Berlin, Heidelberg : Springer Berlin Heidelberg, 2003. http://dx.doi.org/10.1007/978-3-662-08581-3_6.

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AbstractParticles at large betatron amplitudes or with a large momentum error constitute what is generally referred to as a beam halo. Such particles are undesirable since they produce a background in the particle-physics detector. The background arises either when the halo particles are lost at aperture restrictions in the vicinity of the detector, producing electro-magentic shower or muons, or when they emit synchrotron radiation that is not shielded and may hit sensitive detector components. In superconducting hadron storage rings, a further concern is localized particle loss near one of the superconducting magnets, which may result in the quench of the magnet, i.e., in its transition to the normalconducting state.

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Kate, Herman H. J. « AC Losses and Magnet Research ». Dans Advances in Cryogenic Engineering Materials, 559–68. Boston, MA : Springer US, 1994. http://dx.doi.org/10.1007/978-1-4757-9053-5_72.

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Traxler, Alfons. « Losses in Magnetic Bearings ». Dans Magnetic Bearings, 135–50. Berlin, Heidelberg : Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-642-00497-1_5.

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Iwasa, Yukikazu. « AC AND OTHER LOSSES ». Dans Case Studies in Superconducting Magnets, 1–68. Boston, MA : Springer US, 2009. http://dx.doi.org/10.1007/b112047_7.

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Arai, Kazuaki, Naotake Natori, Noboru Higuchi et Tsutomu Hoshino. « AC Loss Characteristics of Superconducting Power Transmission Cable ». Dans 11th International Conference on Magnet Technology (MT-11), 485–90. Dordrecht : Springer Netherlands, 1990. http://dx.doi.org/10.1007/978-94-009-0769-0_83.

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Nakajima, Shin. « Low-Loss Soft Magnetic Materials ». Dans Magnetic Material for Motor Drive Systems, 279–307. Singapore : Springer Singapore, 2019. http://dx.doi.org/10.1007/978-981-32-9906-1_19.

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Beatrice, C., C. Appino, E. Ferrara et F. Fiorillo. « Losses and Domain Structure Vs Induced Anisotropies in Zeromagnetostrictive Amorphous Alloys ». Dans Magnetic Hysteresis in Novel Magnetic Materials, 731–36. Dordrecht : Springer Netherlands, 1997. http://dx.doi.org/10.1007/978-94-011-5478-9_78.

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Bjartmar, C., et B. D. Trapp. « Axonal Loss in Multiple Sclerosis ». Dans Magnetic Resonance Spectroscopy in Multiple Sclerosis, 15–32. Milano : Springer Milan, 2001. http://dx.doi.org/10.1007/978-88-470-2109-9_3.

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Yamazaki, Katsumi. « Iron Loss Analysis of Motors ». Dans Magnetic Material for Motor Drive Systems, 377–90. Singapore : Springer Singapore, 2019. http://dx.doi.org/10.1007/978-981-32-9906-1_24.

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Shimizu, Toshihisa. « Iron Loss of the Inductors ». Dans Magnetic Material for Motor Drive Systems, 391–405. Singapore : Springer Singapore, 2019. http://dx.doi.org/10.1007/978-981-32-9906-1_25.

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Actes de conférences sur le sujet "Magnet losse"

Overstreet, Ross W., George T. Flowers et Gyorgy Szasz. « Design and Testing of a Permanent Magnet Biased Active Magnetic Bearing ». Dans ASME 1999 Design Engineering Technical Conferences. American Society of Mechanical Engineers, 1999. http://dx.doi.org/10.1115/detc99/vib-8282.

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Abstract Magnetic bearings provide rotor support without direct contact. There is a great deal of current interest in using magnetic bearings for active vibration control. Conventional designs use electrical current to provide the bias flux, which is an integral feature of most magnetic bearing control strategies. Permanent magnet biased systems are a relatively recent innovation in the field of magnetic bearings. The bias flux is supplied by permanent magnets (rather than electrically) allowing for significant decreases in resistance related energy losses. The use of permanent magnet biasing in homopolar designs results in a complex flux flow path, unlike conventional radial designs which are much simpler in this regard. In the current work, a design is developed for a homopolar permanent magnet biased magnetic bearing system. Specific features of the design and results from experimental testing are presented and discussed. Of particular interest is the issue of reduction of flux leakage and more efficient use of the permanent magnets.

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Nichols, B. R., P. E. Allaire, T. Dimond, J. Cao et S. Dousti. « Performance and Cost Reduction of Permanent Magnet Biased Magnetic Bearings ». Dans ASME Turbo Expo 2017 : Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/gt2017-64050.

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Active magnetic bearings (AMBs) have the well-documented advantage of reduced operational power losses when compared to conventional fluid-film bearings; however, they have yet to be widely adopted in industry due to the high initial costs of manufacturing and supporting power electronics. As AMBs look to become more cost competitive in more widely based applications, permanent magnet biased designs seek to reduce both the operating electrical power losses and the power electronic hardware costs while maintaining normal load and maximum load capacities. In these new designs, permanent magnet components are used to provide the necessary bias magnetic flux in the bearing usually provided by an electrical bias current in traditional all electromagnetic AMB designs. By eliminating electrical bias currents, operating electrical power losses can be significantly reduced while allowing for smaller, cheaper electronic components. This paper provides a comparison of the performance of permanent magnet biased thrust and radial bearing designs with conventional, all electromagnetic bearing designs. The thrust bearings are designed with nominal and maximum load capacities of 1,333 N and 4,000 N, while the radial bearings are designed with nominal and maximum load capacities of 1,000 N and 3,000 N. The shaft diameter is considered to be 70 mm for all bearings. Finite element modeling is used to calculate load capacities and operating electrical power requirements. Power requirements for a number of loads ranging from nominal to maximum capacity are presented for the permanent magnet biased and all electromagnetic bearing designs. A significant reduction in electrical power requirements under maximum load conditions is shown in the permanent magnet biased designs. This reduction is further magnified under nominal load conditions. Additionally, the number of pole wire turns and maximum wire currents are adjusted to realize even greater electrical power losses. The required bias magnetic flux can be generated with reduced wire currents by increasing the number of wire turns. While reducing wire currents also reduces electrical power requirements, the increase in wire turns increases the circuit induction. This increase in induction decreases the bearing slew rate and, in turn, the bandwidth. This study looks at a number of wire turns and current combinations. Tradeoffs between reduced electrical power losses and bearing bandwidth are presented and discussed. The permanent magnet biased AMB designs are shown to significantly reduce electrical power losses having the potential to improve overall machine efficiency. Implications of adopting this technology to both operating and manufacturing costs are discussed. The use of permanent magnets in AMBs is shown to make the costs of these systems more competitive with oil lubricated bearings when compared to conventional AMB designs.

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Clapham, Lynann, et Vijay Babbar. « Effects of Detector Dynamics on Magnetic Flux Leakage Signals From Dents and Gouges ». Dans 2012 9th International Pipeline Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/ipc2012-90551.

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The current study was designed to model the dynamic effects of detector ride and magnet liftoff on Magnetic Flux Leakage (MFL) signals from dents as well as gouges that have significant denting. The MFL tools have long been used for the detection and sizing of corrosion defects. This is comparatively straightforward for a number of reasons, one of which is that the MFL detector assembly can ride relatively smoothly along the inner pipe wall surface. This is not the case when significant denting is present, since the dent presents a perturbation in the pipe wall that can cause liftoff of the detector or magnet system. Since the tool travels at relatively high speeds down the pipe, the dent itself can cause the detector to lose contact with the trailing half of the dent. In addition, the magnet pole piece may experience partial liftoff as it traverses the dent, thus causing a change in the local flux density. In this study results from ‘static’ measurements are compared with a dynamic case in which detector liftoff is simulated through modeling and experiment. Results are discussed regarding the severity of MFL signal loss at the trailing edge of the defect as a result of detector liftoff. The effect of partial liftoff of the magnet as it passes over the dent is also examined. Magnet liftoff is found to increase the local magnetic flux near the liftoff region, causing the MFL signal from the dent wall to increase rather than decrease in the vicinity of magnet liftoff region.

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Kim, Bongsu, Junseok Ko, Sangkwon Jeong et Seung S. Lee. « Design and Fabrication of a Micro Flywheel Energy Storage System With a High-Temperature Superconductor Bearing ». Dans ASME 2005 International Mechanical Engineering Congress and Exposition. ASMEDC, 2005. http://dx.doi.org/10.1115/imece2005-80862.

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A micro flywheel energy storage system with a high-temperature superconductor (HTS) bearing which is characterized by the diamagnetic effect and the flux pinning effect has been developed. The micro flywheel is made up of circumferential magnets for a motor/generator as well as concentric magnets for an HTS bearing and they are fitted into a 34-mm diameter and 3-mm thick aluminum disk. Mass and moment of inertia of the micro flywheel are 12.75 g and 1.84E−6 kgm2, respectively. For simplicity and miniaturization of the whole system, the micro flywheel directly takes torque from a planar stator, which consists of an axial flux type brushless DC motor/generator. The micro flywheel successfully rotated up to 38,000 rpm in vacuum condition as it is levitating above the stator with a gap of about 1 mm. However, there are some eddy current losses in the stator and non-axisymmetry in magnetic field causing large drag torque. In order to solve these problems, an improved magnet array in the flywheel including a Halbach array is proposed and 3D simulations have been conducted.

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Li, Haoran, Seungjae Ryan Lee, Min Luo, Charles R. Sullivan, Yuxin Chen et Minjie Chen. « MagNet : A Machine Learning Framework for Magnetic Core Loss Modeling ». Dans 2020 IEEE 21st Workshop on Control and Modeling for Power Electronics (COMPEL). IEEE, 2020. http://dx.doi.org/10.1109/compel49091.2020.9265869.

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Sogrin, Andrey. « Study of magnetic losses in rotor of permanent magnet synchronous machine ». Dans 2014 International Conference on Mechanical Engineering, Automation and Control Systems (MEACS). IEEE, 2014. http://dx.doi.org/10.1109/meacs.2014.6986897.

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Hawkins, Lawrence A., Lei Zhu et Eric J. Blumber. « Development of a 125KW AMB Expander/Generator for Waste Heat Recovery ». Dans ASME Turbo Expo 2010 : Power for Land, Sea, and Air. ASMEDC, 2010. http://dx.doi.org/10.1115/gt2010-22763.

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Development and field testing of a low cost expander/generator system that incorporates a high performance, high-speed permanent magnet generator and low loss magnetic bearings is described. The expander/generator is part of a waste heat recovery system based on the Organic Rankine Cycle. The waste heat system can recover energy from a wide variety of heat sources including: landfill gas, reciprocating engine exhaust, solar, geothermal, boilers, and other industrial processes. The varying frequency voltage supplied by the generator is connected to the grid using an active/active power electronics package that can deliver power at 400–480 VAC (50 or 60 Hz). Active magnetic bearings (AMB) were chosen for the application because they can operate directly in the working fluid, have low losses, and provide high reliability and remote monitoring capabilities. The expander operates between 20,000 and 26,500 rpm depending on the energy available from the heat source. The first field unit was installed in April, 2009 at a biogas site. The system design, test results, and magnetic bearing operating experience are discussed.

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Yogal, Nijan, Christian Lehrmann et Markus Henke. « Eddy Current Loss Measurement of Permanent Magnets Used in Permanent Magnet Synchronous Machines ». Dans 2019 IEEE 13th International Conference on Power Electronics and Drive Systems (PEDS). IEEE, 2019. http://dx.doi.org/10.1109/peds44367.2019.8998879.

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Kawase, Yoshihiro, Tadashi Yamaguchi, Zhipeng Tu, Masato Mizuno, Norimoto Minoshima et Masashi Watanabe. « Electrical loss and temperature analysis of interior permanent magnet motor with divided magnets ». Dans 2009 International Conference on Electrical Machines and Systems (ICEMS). IEEE, 2009. http://dx.doi.org/10.1109/icems.2009.5382793.

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McGoldrick, P. « Low loss laminations on a 20000 RPM, 150 kW brushless DC motor ». Dans IEE Colloquium on New Magnetic Materials - Bonded Iron, Lamination Steels, Sintered Iron and Permanent Magnets. IEE, 1998. http://dx.doi.org/10.1049/ic:19980335.

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Rapports d'organisations sur le sujet "Magnet losse"

Gluckstern, R. Coupling impedance and energy loss with magnet laminations. Office of Scientific and Technical Information (OSTI), novembre 1985. http://dx.doi.org/10.2172/6144342.

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Bleser E., J. W. Glenn, P. Ingrassia, Ryan. J. et M. Tanaka. Extraction Losses Produced by the ? H10 Septum Magnet Fringe Field. Office of Scientific and Technical Information (OSTI), novembre 1985. http://dx.doi.org/10.2172/1130928.

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Ginneken, A. V. Energy deposition in TEVATRON magnets from beam losses in interaction regions. Office of Scientific and Technical Information (OSTI), octobre 1988. http://dx.doi.org/10.2172/6711639.

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Koosh, V. F. Ac losses for the self field of an ac transport current with a dc transport current offset in high {Tc} superconducting magnet coils for MagLev application. Office of Scientific and Technical Information (OSTI), octobre 1993. http://dx.doi.org/10.2172/10115071.

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Schlueter, R. D. Iron yoke eddy current induced losses with application to the ALS septum magnets. Office of Scientific and Technical Information (OSTI), août 1991. http://dx.doi.org/10.2172/7129987.

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Green, M. A., H. Wu, L. Wang, L. L. Kai, L. X. Jia et S. Q. Yang. AC Losses in the MICE Channel Magnets -- Is This a Curse or aBlessing ? Office of Scientific and Technical Information (OSTI), janvier 2008. http://dx.doi.org/10.2172/928730.

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Redi, M. H., S. H. Batha et R. V. Budny. Alpha particle loss in TFTR deuterium-tritium plasmas with reversed magnetic shear. Office of Scientific and Technical Information (OSTI), juin 1997. http://dx.doi.org/10.2172/304186.

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Duke, J. R. Jr, P. G. Apen et M. Hoisington. Development of structural materials exhibiting dielectric and magnetic loss at radio frequencies. Office of Scientific and Technical Information (OSTI), octobre 1996. http://dx.doi.org/10.2172/380369.

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Wu, K. C., D. P. Brown, J. Sondricker et D. Zantopp. An Experimental Study Using Helium to Produce a Catastrophic Loss of Vacuum in a RHIC Dipole Magnet Cryostat. Office of Scientific and Technical Information (OSTI), février 1993. http://dx.doi.org/10.2172/1119178.

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