# Variable mutual inductance implementation

**URL:** <https://forum.plexim.com/t/variable-mutual-inductance-implementation/2921>\
**Category:** PLECS\
**Created:** [March 14, 2026, 1:54am UTC](https://forum.plexim.com/t/variable-mutual-inductance-implementation/2921 "2026-03-14T01:54:30Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Behnam](https://avatars.discourse-cdn.com/v4/letter/b/b4bc9f/32.png) [@Behnam](https://forum.plexim.com/u/Behnam)\
**Post date:** [March 14, 2026, 1:54am UTC](https://forum.plexim.com/t/variable-mutual-inductance-implementation/2921/1 "2026-03-14T01:54:30Z")

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![image](https://europe1.discourse-cdn.com/flex006/uploads/plecs/original/2X/5/59d4e46631e73bea218fe94d604ff1b49fec875c.jpeg)

hi

I am trying to simulate variable mutual inductance M(t) in PLECS. Since the mutual inductor block uses a constant coupling matrix, I implemented a T-equivalent model with a ramp-controlled inductance so that M varies during simulation.

Is this T-model implementation with variable inductance a correct method to simulate time-varying mutual inductance in PLECS, or is there a recommended approach?

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**Author:** ![RetoChristen](https://dub1.discourse-cdn.com/flex006/user_avatar/forum.plexim.com/retochristen/32/1225_2.png) [@RetoChristen](https://forum.plexim.com/u/RetoChristen)\
**Post date:** [March 16, 2026, 9:23am UTC](https://forum.plexim.com/t/variable-mutual-inductance-implementation/2921/2 "2026-03-16T09:23:56Z")

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Hi @Behnam  
Yes, this is possible, as also mentioned in this forum post:

> [@Can we simulate a coupled inductor with variable coupling coefficient or self inductances, varying with time?](https://forum.plexim.com/t/can-we-simulate-a-coupled-inductor-with-variable-coupling-coefficient-or-self-inductances-varying-with-time/1086/2):
>
> The Variable Inductor component supports multiple phases and inductive coupling of the phases. Refer to the documentation of the Variable Inductor for a more detailed description on how this functionality is implemented. You will need to set the parameter “Inductive coupling” to “on”.

In your simulation it appears to be a rather fast change, so modeling it directly within the simulation is appropriate.

If the change were slow or simply a step, another option could be to stop the simulation at certain points and update the parameters before continuing.