  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.
