Computation of Eddy Current Losses in Soft Magnetic Composites

Abstract

We compute the classical eddy current losses in Soft Magnetic Composite (SMC) materials, taking into account the eddy current 8 paths appearing at the scale of the sample cross-section because of random contacts between the grains. The prediction of this loss 9 contribution is a challenging task, because of the stochastic nature of the associated conduction process. We start our study from an 10 identification of the statistical properties of the contacts between grains, starting from resistivity measurements. We then develop a 11 numerical loss model for random grain-to-grain conduction, by which we demonstrate that the classical loss in SMCs can be 12 decomposed into a contribution deriving from the eddy currents circulating inside the grains and a contribution due to the 13 macroscopic eddy currents flowing from grain to grain via random contacts. An experimental validation of this model is proposed for 14 a representative SMC material, where the magnetic losses are measured in ring samples with a range of cross-sectional areas. 15 16 Index Terms-Soft Magnetic Composites (SMC), Eddy current losses, Classical losses, Conductivity of heterogeneous materials 17 18 228 the eddy current density as MIC MAC J J J = + , where MIC J is 229 restricted at the scale of the grain (i.e. its volume integral on 230 the grain is zero), and another component MAC J W J dS J dS J J dS f

Magnetic Properties of Soft Magnetic FeSi Composite Powder Cores

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Improved core loss calculation method considering the non‐uniform distribution of magnetic flux density in powder cores

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“…1. These attractive features have gained much attention in designing ac and dc inductors used in various applications [1][2][3][4][5].…”

Probing of multiple magnetic responses in magnetic inductors using atomic force microscopy

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“…The eddy current is a circular electrical current induced within conductors by changes in the magnetic field due to Faraday’s law of induction and the direction of the eddy current is opposite that of the coil current which generates a dynamic magnetic field 7 . Accordingly, since the eddy current reduces the magnitude of the original magnetic field, the eddy current can be a source of energy loss in magnetic applications 1 2 3 . Hence, investigating the magnetic energy loss is a key first step towards significant performance improvement.…”