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Microstructure Role in Permanent Magnet Eddy Current Losses

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Abstract

The impact of granular microstructure in permanet magnets on eddy current losses is investigated. A numerical homogenization procedure for electrical conductivity is defined. Then, an approximated simple analytical model for the homogenized conductivity able to capture the main features of the geometrical and material dependences is derived. Finally eddy current losses analytical calculations are given, and the two asymptotic expressions for losses in the stationary conduction limit and advanced skin effect limit are derived and discussed.

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... Due to the high supply frequency values used in the considered machines, it is also useful to accurately evaluate the eddy-current losses in the magnets in order to reduce the risk of local overheating which could cause partial demagnetizations. The eddy currents induced in permanent magnets [16,17] can be obtained solving the equation: ...
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  • I D Mayergoyz
  • G Bedrosian