This information is part of the Modelica Standard Library maintained by the Modelica Association.

The relative permeability mu_r as a function of flux density B for all soft magnetic materials currently included in this library is approximated with the following function [Ro00]:

Two of the five parameters of this equation have a physical meaning, namely the initial relative permeability mu_i at B=0 and the magnetic flux density at maximum permeability B_myMax. B_N is the flux density normalized to latter parameter.

mu_r = mu_rApprox(B, mu_i, B_myMax, c_a, c_b, n)

B	Type: MagneticFluxDensity (T) Description: Flux density in ferromagnetic flux tube element
mu_i	Type: RelativePermeability Description: Initial relative permeability at B=0
B_myMax	Type: MagneticFluxDensity (T) Description: Flux density at maximum relative permeability
c_a	Type: Real Description: Coefficient of approximation function
c_b	Type: Real Description: Coefficient of approximation function
n	Type: Real Description: Exponent of approximation function

mu_r	Type: RelativePermeability Description: Relative magnetic permeability of ferromagnetic flux tube element