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GaN Systems Plecs models do not work

0 votes

Hi to all,

I am struggling with importing the models from GaN Systems available here: Link

So I have read this question but this is not a problem. The implementation of the models seems to be fine and I can access them in the library browser and also can choose the models for the GaN HEMT (see Picture1 attached).

But when I want to start the simulation an error occurs (see Picture2 attached).

Also attached there is a minimal example (Test123) that should reproduce the error (at least on my device). I use PLECS Blockset 4.6.5 and Matlab 2021a.

As the error states, the field name "DeviceData" is not recognized. So in the PLECS file "GaNSystemsHEMTComponent" I deleted every string with "DeviceData{1}." by replacing it with "". Afterward the error occurs that the field name "CauerChain is not recognized. Then I deleted the hole line. Then it worked and I can start the simulation. But I am sure that it is not intended to do so. I think at least the information of the models about the Cauer Chain gets ignored. 

This is where I am now. Is there an error in the library? Do the error occur just at my device? 

Thank you very much for any help!

Kind regards,


asked Apr 16 by niklas21 (16 points)
Definitely do not modify the initialization commands as this will render the block unusable! Are you using the latest set of files available from GaN Systems' website?
Hi Kris,

thank you for your quick response. I think so, I downloaded them on 16th of April at 8:16 a.m.
As I read in the release notes, there are some new features according the thermal package description with in version 4.7 and 4.8. And the GaN models are based on a thermal package description. This might be a problem, however, the install file says that PLECS 4.6.x or later is required to use the GaN Systems models.

With my first described workaround I had the problem that four devices had the exact same junction temperature (within a 3L ANPC). The root cause might be that the thermal package - especially the state-space matrices - description was faulty because of my workaround.

For now I did the workaround to create new thermal descriptions for descrete components based on my selected GaN Systems HEMT. Surely this is not how to do it but it fixed my problem. Moreover I do not need the thermal package description at the moment, maybe in the future.

So is this error also at someone's other machine?

I would likely upgrade my PLECS version but I am limited with my user settings at my company. I will still try it in the next days.
Hi again, we cannot reproduce this with PLECS 4.6.x actually. It works as expected. It's not clear if you modified the library component that you downloaded from GaN Systems website such that it cannot be used with that version of the XML files, but to further troubleshoot this we would likely need to receive your set of files. Can you try with the attached ones in the meantime and report back?
Thanks for the effort!

Unfortunately, the same error occurs (see screenshot).

I have pasted your files into a test project with a similiar structure (see screenshot 2), refreshed the library and restarted Matlab.
Can you test if you just copy the GaN HEMT block from the model I sent into your own circuit (and not pull it from the PLECS library browser)? I see that you are still using the library file (the mask parameters window indicates this with "(link)" in the subtitle), but I wouldn't know if that library file is exactly the one I posted, or an earlier one (that might have some modifications or corruption).

As a quick test, you can create a blank Test123.slx file in another directory location, alongside a folder Test123_plecs/ in which you place the XML file (this is a trick to directly link an XML file to a specific model file). Then, place a PLECS Circuit block into the blank Simulink model, and double-click to open it. Then go to the PLECS File menu and choose "Import from Standalone..." and choose the "GaNSystemsHEMTComponent.plecs" file I attached earlier. Then, navigate to the XML file, which will be the only option showing since you are not here linking to the library directory. What happens then?
Thank you again!


So I did all the steps and the error occurs again. (see the screenshots)

I hope I didn't do anything obvious wrong.

Sorry, that's frustrating! It would be helpful to know if this works with the latest bug fix release for your version (4.6.9), or newer. Archived previous versions are available here:

It's possible there was an issue in your version that was since fixed. (For what it's worth, I am successful with this using 4.6.9) Let me know!


Yes, now it works.

Thank you very much for your great support!
OK great, thanks!

1 Answer

0 votes
The user updated to the latest PLECS release for their version and the issue was solved.
answered Apr 23 by Kris Eberle (1,595 points)