Saturable Core
Purpose
Magnetic core element with saturation
Library
Magnetic
Description
This component models a segment of a magnetic core. It establishes a non-linear
relationship between the magnetic field strength and the flux density
to
model saturation effects. The user can choose between the following fitting
functions:
atan fit
The atan fit is based on the arctangent function:
coth fit
The coth fit was adapted from the Langevian equation for bulk magnetization without interdomain coupling, and is given as:
Both fitting functions have three degrees of freedom which are set by the
coefficients ,
and
.
is the fully saturated permeability, which
usually corresponds to the magnetic constant
, i.e. the permeability of air.
defines the knee of the saturation transition between unsaturated and saturated
permeability:
The coefficient is determined by the unsaturated permeability
at
:
The figure below illustrates the saturation characteristics for both fitting functions. The saturation curves differ only around the transition between unsaturated and saturated permeability. The coth fit expresses a slightly tighter transition than the atan fit.
Parameters
- Fitting functions
- Saturation characteristic modeled with atan or coth fit.
- Cross-sectional area
- Cross-sectional area
of the flux path, in
.
- Length of flux path
- Length
of the flux path, in m.
- Unsaturated rel. permeability
- Relative permeability
of the core material for
.
- Saturated rel. permeability
- Relative permeability
of the core material for
.
- Flux density saturation
- Knee
of the saturation transition between unsaturated and saturated permeability.
- Initial MMF
- Magneto-motive force at simulation start, in ampere-turns (A).
Probe Signals
- MMF
- The magneto-motive force measured from the marked to the unmarked terminal, in ampere-turns (A).
- Flux
- The magnetic flux flowing through the component, in webers (Wb). A flux entering at the marked terminal is counted as positive.
- Field strength
- The magnetic field strength
in the core element, in A/m.
- Flux density
- The magnetic flux density
in the core element, in teslas (T).