Title |
Analysis of Permanent Magnet Eddy Current Loss by Permanent Magnet Attaching Method of Magnetic Gears |
Authors |
박의종(Park, Eui-Jong) ; 김성진(Kim, Sung-Jin) ; 정상용(Jung, Sang-Yong) ; 김용재(Kim, Yong-Jae) |
DOI |
https://doi.org/10.5370/KIEE.2017.66.6.911 |
Keywords |
Permanent magnet eddy current loss ; IPM magnetic gear ; Joule loss ; Eddy current loss reduction |
Abstract |
Recently, there has been an increasing interest in the non-contact power transmission method of magnetic gears. Since there is no mechanical contact, noise caused by friction can be reduced, and even if a sudden large force is applied, the impact of the gear is close to zero. Further, since the power is transmitted by the magnetic flux, it has high reliability. However, there is a problem that a loss due to a magnetic field due to use of a magnetic flux. The loss caused by the magnetic field of the magnetic gear is a joule loss called eddy current loss. In addition, the eddy current loss in the magnetic gear largely occurs in the permanent magnet, but it is a fatal loss to the permanent magnet which is vulnerable to heat. Particularly, magnetic gears requiring high torque density use NdFeB series permanent magnets, and this permanent magnets have a characteristic in which the magnetic force decreases as temperature increases. Therefore, in this paper, the eddy current loss of the permanent magnet according to the permanent magnet attaching method is analyzed in order to reduce the eddy current loss of the permanent magnet. We have proposed a structure that can reduce the eddy current loss through the analysis and show the effect of reducing the loss of the proposed structure. |