# How to simulate inductance matrix and variable inductor?

Is it sufficient to use arbitrary inductance device to implement inductance matrix and variable inductor?

Thanks.
Arief

If variable inductor is referred to non-linear inductance against inductor current, I documented that in my device guideline, goto `L. Inductor` section.
You can use Isat, Lsat and Satfrac for this modeling, or flux equation, both can achieve the same purpose.

Qspice/Guideline/Qspice - Device Reference Guide by KSKelvin.pdf at main · KSKelvin-Github/Qspice

Thanks Kelvin for the quick prompt

Its for PMSM, the model itself uses variable and coupled inductor at the same time (not yet accounting for saturation)

Just curious, what kind of variable inductor you are referring to? Any link or picture to show what that is? Inductance change with external input? I am a bit confuse as I never work in motor area.

Its actually for fun project only for me. Following the request from @MacAA

Basically, PMSM has its inductance varied by different rotor angle position.

Anyway, I think using behavioral current source will be the easiest solution for me. For a simple inductor with series resistant, i have managed to do it with B-source.

Do you have any comment on difference between B-source (current) vs Inductor Flux model?

@physicboy

I review your question again. Arbitrary inductance device can be used as variable inductor by taking flux = inductor formula * I(Ln)

Great thanks,

I will try to get some output for the motor model then share the block result here.

Have you tried making a model using the “Lookup Table” function, as done in the “Simulation of electromagnetic actuator with LTspice and FEMM” example (https://www.youtube.com/watch?v=OkN6Wh1oJTs)? Using LUA script to command FEMM remotely (for change armature position, change current and save desired data). Using the so-called Flux LookUp Tables and Force LookUp Tables feature.

X - Current
Y - Position