Isotropic / anisotropic soft magnetic material: spline saturation curve

Presentation

This model defines a nonlinear B(H) dependence for an isotropic material starting from the experimental B, H values.

The definition of the B(H) curve with this model is a little longer than with the analytic models, but the experimental curve is modeled more accurately.

Mathematical model

The model is constructed in the following manner:

  • entry of experimental B, H values
  • linear interpolation between these points with a linear extrapolation beyond the last one

An example of the B(H) curve is given in the figure below.

Advice (regarding software)

To have good convergence performances, it is strongly advised to have a spline saturation curve with only one knee. This means that if your device operates with high values of the magnetic field, where magnetic saturation may be reached, you must not describe the knee of the B(H) curve near the origin, and conversely if it works at a low magnetic field.

Anisotropic material

For an anisotropic material, this model consists in a set of three equations, one per 3D-space direction.

This model is available when the following conditions are satisfied:

  • 2D applications (2D plane domain): Magneto Static / Transient magnetic
  • regions: magnetic non conducting, solid conductor