Development of spoke-type IPM magnetic gear

Magnetic gears can change output-torque and -speed without any mechanical contacts. Therefore, they have a low acoustic noise and vibration, and their maintainability and reliability are high. Especially, a flux-modulated type magnetic gear is expected to be put into practical use because its torque density is higher than that of other magnetic gears. For the practical use, further improvement of torque and losses is important, especially, reduction of eddy current loss in permanent magnets (PMs) due to asynchronous harmonic magnetic fluxes is necessary. This paper investigates an interior permanent magnet (IPM) structure to improve the efficiency by reducing the eddy current loss in PMs. In addition, this paper presents a method for increasing torque of the IPM magnetic gear by changing a position of magnetic-bridge.

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Analysis of Eddy Current Loss on Permanent Magnets of Interior Permanent Magnet Synchronous Motor for Railway Transit

Journal of the Korean society for railway ◽

10.7782/jksr.2012.15.4.370 ◽

2012 ◽

Vol 15 (4) ◽

pp. 370-375 ◽

Cited By ~ 1

Author(s):

Chan-Bae Park ◽

Hyung-Woo Lee ◽

Byung-Song Lee

Keyword(s):

Permanent Magnet ◽

Eddy Current ◽

Permanent Magnets ◽

Permanent Magnet Synchronous Motor ◽

Synchronous Motor ◽

Eddy Current Loss ◽

Current Loss ◽

Interior Permanent Magnet

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Interior Permanent Magnet Synchronous Motor Design for Eddy Current Loss Reduction in Permanent Magnets to Prevent Irreversible Demagnetization

Energies ◽

10.3390/en13195082 ◽

2020 ◽

Vol 13 (19) ◽

pp. 5082

Author(s):

Jae-Woo Jung ◽

Byeong-Hwa Lee ◽

Kyu-Seob Kim ◽

Sung-Il Kim

Keyword(s):

Permanent Magnet ◽

Eddy Current ◽

Permanent Magnets ◽

Permanent Magnet Synchronous Motor ◽

Core Loss ◽

Synchronous Motor ◽

Eddy Current Loss ◽

Equivalent Circuit Analysis ◽

Current Loss ◽

Interior Permanent Magnet

We designed and analyzed an interior permanent magnet synchronous motor (IPMSM) to prevent irreversible demagnetization of the permanent magnets (PMs). Irreversible demagnetization of NdFeB PMs mainly occurs due to high temperature, which should thus be minimized. Therefore, it is necessary to reduce the eddy current loss in the PM through optimal design. The shape of the rotor core was optimized using finite element analysis (FEA) and response surface methodology. Three-dimensional (3-D) FEA is required for accurate computation of the eddy current loss, but there is huge time, effort, and cost consumption. Therefore, a method is proposed for indirectly calculating the eddy current loss of PMs using 2-D FEA. A thermal equivalent circuit analysis was used to calculate the PM temperature of the optimized model. For the thermal analysis, the copper loss, core loss, and eddy current loss in PMs were estimated and applied as a heat source. Based on the results, we confirmed the stability of the optimum model in terms of the PM demagnetization.

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Performance analysis of magnetic gear with Halbach array for high power and high speed

International Journal of Applied Electromagnetics and Mechanics ◽

10.3233/jae-209410 ◽

2020 ◽

Vol 64 (1-4) ◽

pp. 959-967

Author(s):

Se-Yeong Kim ◽

Tae-Woo Lee ◽

Yon-Do Chun ◽

Do-Kwan Hong

Keyword(s):

Permanent Magnet ◽

Eddy Current ◽

High Power ◽

High Speed ◽

Torque Ripple ◽

Eddy Current Loss ◽

Element Analysis ◽

Current Loss ◽

Halbach Array ◽

Magnetic Gear

In this study, we propose a non-contact 80 kW, 60,000 rpm coaxial magnetic gear (CMG) model for high speed and high power applications. Two models with the same power but different radial and axial sizes were optimized using response surface methodology. Both models employed a Halbach array to increase torque. Also, an edge fillet was applied to the radial magnetized permanent magnet to reduce torque ripple, and an axial gap was applied to the permanent magnet with a radial gap to reduce eddy current loss. The models were analyzed using 2-D and 3-D finite element analysis. The torque, torque ripple and eddy current loss were compared in both models according to the materials used, including Sm2Co17, NdFeBs (N42SH, N48SH). Also, the structural stability of the pole piece structure was investigated by forced vibration analysis. Critical speed results from rotordynamics analysis are also presented.

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