Microstructure Role in Permanent Magnet Eddy Current Losses

TL;DR

This paper investigates how the microstructure of permanent magnets affects eddy current losses, introducing a homogenization method and analytical models to predict losses under different conditions.

Contribution

It presents a novel numerical homogenization procedure and analytical models that capture the influence of microstructure on eddy current losses in permanent magnets.

Findings

Homogenization procedure for electrical conductivity developed.

Analytical models for eddy current losses derived.

Asymptotic expressions for different conduction regimes discussed.

Abstract

The impact of granular microstructure in permanent magnets on eddy current losses are 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.