Variable Magnetic Permeance
Purpose
Variable permeance controlled by external signal
Library
Magnetic
Description
This component provides a magnetic flux path with a variable permeance. The
component is used to model non-linear magnetic material properties such as
saturation and hysteresis. The permeance is determined by the signal fed into the
input of the component. The flux-rate through a variable permeance is
governed by the equation:
Since is the state variable the equation above must be solved for
. The
control signal must provide the values of
,
and
as a vector. It is the
responsibility of the user to provide the appropriate signals.
Modeling non-linear material properties
When specifying the characteristic of a non-linear permeance, we need to distinguish
carefully between the total permeance and the differential
permeance
.
If the total permeance is known the flux-rate
through a time-varying
permeance is calculated as:
In this case, the control signal for the variable permeance component is:
In most cases, however, the differential permeance is provided to
characterize magnetic saturation and hysteresis. With
the control signal is
Parameter
- 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.