Electromagnetic Characteristic Analysis of High-Speed Motors with Rare-Earth and Ferrite Permanent Magnets Considering Current Harmonics

2020 ◽  
pp. 1-1
Author(s):  
Jong-Hyeon Woo ◽  
Tae-Kyoung Bang ◽  
Hoon-Ki Lee ◽  
Kyong-Hwan Kim ◽  
Seung-Ho Shin ◽  
...  
Keyword(s):  
Rare Earth ◽  
High Speed ◽  
Permanent Magnets ◽  
Characteristic Analysis ◽  
Current Harmonics ◽  
Electromagnetic Characteristic

scholarly journals Optimal Design of a High-Speed Flux Reversal Motor with Bonded Rare-Earth Permanent Magnets

Mathematics ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 256
Author(s):  
Vladimir Prakht ◽  
Vladimir Dmitrievskii ◽  
Vadim Kazakbaev
Keyword(s):  
Rare Earth ◽  
Optimal Design ◽  
Eddy Current ◽  
High Speed ◽  
Permanent Magnets ◽  
Eddy Current Loss ◽  
Specific Power ◽  
Current Loss ◽  
Sintered Magnets ◽  
Flux Reversal

Single-phase flux reversal motors (FRMs) with sintered rare-earth permanent magnets on the stator for low-cost high-speed applications have a reliable rotor and a good specific power. However, to reduce eddy current loss, the sintered rare-earth magnets on the stator have to be segmented into several pieces and their cost increases with the number of magnet segments. An alternative to the sintered magnets can be bonded magnets, in which eddy current loss is almost absent. The remanence of bonded magnets is lower than that of sintered magnets, and they are prone to demagnetization. However, the cost of low-power motors with bonded magnets can be lower because of the simpler manufacturing technology and the lower material cost. This paper discusses various aspects of the optimal design of FRM with bonded magnets, applying the Nelder–Mead method. An objective function for optimizing an FRM with bonded magnets is designed to ensure the required efficiency, reduce torque oscillations, and prevent the bonded magnets from demagnetizing. As a result, it is shown that the FRM with bonded magnets has approximately the same efficiency as the FRM with sintered magnets. In addition, the peak-to-peak torque ripple is minimized and the minimal instantaneous torque is maximized.

scholarly journals Retrospective and perspectives of the superconducting magnetic levitation (sml) technology applied to urban transportation

2018 ◽  
Vol 4 (3 suppl. 1) ◽  
pp. 195-202
Author(s):  
Richard Stephan ◽  
Felipe Costa ◽  
Elkin Rodriguez ◽  
Zigang Deng
Keyword(s):  
Rare Earth ◽  
High Speed ◽  
Permanent Magnets ◽  
Magnetic Levitation ◽  
Urban Transportation ◽  
50Th Anniversary ◽  
Commercial Application ◽  
Small Scale ◽  
The World ◽  
Real Scale

A review of the Superconducting Magnetic Levitation (SML) technology applied to urban transportation will be presented. The historical time line will be highlighted, pointing out the pioneering efforts at Southwest Jiatong University (SWJTU), China, followed by the Supra Trans project in IFW-Dresden, Germany, and the MagLev-Cobra project in UFRJ, Brazil. Background:  Details of the MagLev-Cobra project, the first, and until today the single one, applying the SML technology that counts with a real scale prototype, operating regularly in open air, will be disclosed. The inauguration of the MagLev-Cobra project was on the 1st October 2014, the last day of the “22nd International Conference on Magnetically Levitated Systems and Linear Drives (MAGLEV)” held in Rio de Janeiro. Curiously, this day coincides with the 50th anniversary of the successful operation of the Shinkansen in Tokyo. On the 1st October 1964, the first high-speed wheel and rail train in the world was inaugurated in time for the first Olympic Games that took place in Asia. This historical coincidence is a good omen for the MagLev-Cobra project. In fact, since October 2014, the system operates regularly for demonstration at the UFRJ Campus, every Tuesday. More than 12.000 visitors have already had the opportunity to take a test ride. Aim: The Proceedings of the MAGLEV conferences, which first edition dates back to 1977 (http://www.maglevboard.net), are the documentary files of the importance of this achievement. Initially, the methods named Electromagnetic Levitation (EML) and Electrodynamic Levitation (EDL) were considered. Methods: At the end of last century, due to the availability of Rare Earth Permanent Magnets and High Critical Temperature Superconductors (HTS), an innovative levitation method, called Superconducting Magnetic Levitation (SML), started to be considered. This method is based on the flux pinning effect property of HTS in the proximity of magnetic fields given by rare earth permanent magnets. The first experiments with SML, as expected, were small scale prototypes, or laboratory vehicles for one, two or four passengers, proposed mainly by researchers from Germany, China and Brazil. The Proceedings of the 16th MAGLEV, held in year 2000, confirms this fact. After 14 years of research and development, the team of the Laboratory of Applied Superconductivity (LASUP) of UFRJ achieved the construction of the first real scale operational SML vehicle in the world. Results: This retrospective will be followed by a comparison with the EML technology, that has already four urban commercial systems, will be presented and the application niches delimited. Conclusion: The perspectives of the MagLev-Cobra project and the cooperation efforts with China to turn it a commercial experience will finish the paper. As will be explained, before the commercial application of the MagLev-Cobra technology, the system must be certified and the technical, economic and environmental viability for a first deployment concluded.

scholarly journals Significance of Anisotropic Thermal Expansion in High Speed Electric Machines Employing NdFeB Permanent Magnets

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7558
Author(s):  
Ram Kumar ◽  
Antonino La Rocca ◽  
Gaurang Vakil ◽  
David Gerada ◽  
Chris Gerada ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Rare Earth ◽  
High Speed ◽  
Permanent Magnets ◽  
Mechanical Design ◽  
Electric Machines ◽  
Mechanical Environment ◽  
Anisotropic Thermal Expansion ◽  
Working Temperature ◽  
Rotor Design

Many high speed applications employ a surface permanent magnet (PM) machine topology with a retaining sleeve due to its robustness and ability to achieve high overall peripheral speeds as well as efficiencies. One often overlooked feature in the mechanical design of such machines, which has not achieved sufficient attention to date is the anisotropic thermal expansion of rare earth magnets, the degree of which varies for different magnet technologies. This paper investigates the effects of the aforementioned on the mechanical design of a high speed PM spindle machine with NdFeB magnets. The maximum allowable interference is found to be limited by the working temperature of the magnets while the minimum required interference is increased due to their anisotropic thermal expansion. Based on this, appropriate conditions are formulated to integrate a Neodymium Iron Boron (NdFeB) PM in high speed rotors. These modifications considering the shaft together with the magnet anisotropic thermal expansion are included in a proposed rotor design and validated using simulations in ANSYS mechanical environment.

L10 rare-earth-free permanent magnets: The effects of twinning versus dislocations in Mn-Al magnets

2020 ◽  
Vol 4 (9) ◽  
Author(s):  
Yuxiao Jia ◽  
Yuye Wu ◽  
Shuang Zhao ◽  
Shulan Zuo ◽  
Konstantin P. Skokov ◽  
...  
Keyword(s):  
Rare Earth ◽  
Permanent Magnets

scholarly journals Production of Porous Ceramic Materials from Spent Fluorescent Lamps

2021 ◽  
Vol 11 (13) ◽  
pp. 6056
Author(s):  
Egle Rosson ◽  
Acacio Rincón Rincón Romero ◽  
Denis Badocco ◽  
Federico Zorzi ◽  
Paolo Sgarbossa ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
High Speed ◽  
Porous Ceramic ◽  
Ceramic Materials ◽  
Porous Ceramics ◽  
Fluorescent Lamps ◽  
Naoh Solution ◽  
Commercial Glass ◽  
Triton X

Spent fluorescent lamps (SFL) are classified as hazardous materials in the European Waste Catalogue, which includes residues from various hi-tech devices. The most common end-of-life treatment of SFL consists in the recovery of rare earth elements from the phosphor powders, with associated problems in the management of the glass residues, which are usually landfilled. This study involves the manufacturing of porous ceramics from both the coarse glass-rich fraction and the phosphor-enriched fraction of spent fluorescent lamps. These porous materials, realizing the immobilization of Rare Earth Elements (REEs) within a glass matrix, are suggested for application in buildings as thermal and acoustic insulators. The proposed process is characterized by: (i) alkaline activation (2.5 M or 1 M NaOH aqueous solution); (ii) pre-curing at 75 °C; (iii) the addition of a surfactant (Triton X-100) for foaming at high-speed stirring; (iv) curing at 45 °C; (v) viscous flow sintering at 700 °C. All the final porous ceramics present a limited metal leaching and, in particular, the coarse glass fraction activated with 2.5 M NaOH solution leads to materials comparable to commercial glass foams in terms of mechanical properties.

scholarly journals Special Issue: Advances in Computational Electromagnetics

2021 ◽  
Vol 7 (6) ◽  
pp. 89
Author(s):  
Valerio De Santis
Keyword(s):  
Rare Earth ◽  
Magnetic Materials ◽  
Permanent Magnets ◽  
Computational Electromagnetics ◽  
Superconducting Materials ◽  
Special Issue ◽  
Full Characterization ◽  
Recent Advances

Recent advances in computational electromagnetics (CEMs) have made the full characterization of complex magnetic materials possible, such as superconducting materials, composite or nanomaterials, rare-earth free permanent magnets, etc [...]

scholarly journals Design and thermal characteristic analysis of motorized spindle cooling system

2021 ◽  
Vol 13 (5) ◽  
pp. 168781402110208
Author(s):  
Yuan Zhang ◽  
Lifeng Wang ◽  
Yaodong Zhang ◽  
Yongde Zhang
Keyword(s):  
Flow Rate ◽  
High Speed ◽  
Thermal Deformation ◽  
Cooling System ◽  
Thermal Characteristic ◽  
Water Flow Rate ◽  
Thermal Characteristics ◽  
Characteristic Analysis ◽  
Motorized Spindle ◽  
Experiment And Simulation

The thermal deformation of high-speed motorized spindle will affect its reliability, so fully considering its thermal characteristics is the premise of optimal design. In order to study the thermal characteristics of high-speed motorized spindles, a coupled model of thermal-flow-structure was established. Through experiment and simulation, the thermal characteristics of spiral cooling motorized spindle are studied, and the U-shaped cooled motorized spindle is designed and optimized. The simulation results show that when the diameter of the cooling channel is 7 mm, the temperature of the spiral cooling system is lower than that of the U-shaped cooling system, but the radial thermal deformation is greater than that of the U-shaped cooling system. As the increase of the channel diameter of U-shaped cooling system, the temperature and radial thermal deformation decrease. When the diameter is 10 mm, the temperature and radial thermal deformation are lower than the spiral cooling system. And as the flow rate increases, the temperature and radial thermal deformation gradually decrease, which provides a basis for a reasonable choice of water flow rate. The maximum error between experiment and simulation is 2°C, and the error is small, which verifies the accuracy and lays the foundation for future research.

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