Dynamic power lines

[poljane]

Hello,

I was looking into the documentation and also a bit into the code, and it seems to me that there are no powerlines available which describe the dynamics with differential equations. Is this true?

I saw that there are 2 open PR which tried to do similar things in 2024. One implements a dynamic power line in a dq frame, and the other one uses dynamic phasors. Does someone know why those PR didn't make it into main, and if those features where picked up somewhere else in the code?

Best regards!

[cuihantao]

Your understanding is correct. Those are dynamic phasor-based circuit models. They have not been merged because they cannot consider transformer models with tap and phase shift. You are welcome to contribute. Regards, Hantao Cui

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On Sat, May 9, 2026, 7:00 AM Trb2 ***@***.***> wrote: Hello, I was looking into the documentation and also a bit into the code, and it seems to me that there are no powerlines available which describe the dynamics with differential equations. Is this true? I saw that there are 2 open PR which tried to do similar things in 2024. One implements a dynamic power line in a dq frame, and the other one uses dynamic phasors. Does someone know why those PR didn't make it into main, and if those features where picked up somewhere else in the code? Best regards! — Reply to this email directly, view it on GitHub <#648>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABSNZAYDL3JBMFVKKXRNBBD4ZZRIDAVCNFSM6AAAAACYWVRH7CVHI2DSMVQWIX3LMV43GRDJONRXK43TNFXW4OZRGAYDENZZGEZQ> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[poljane]

Thanks for the quick answer! Before starting coding, I would like to understand the following: I have seen that in models/bus.py, the volatge magnitude and angle are algebraic variables. Is this necessary, or can one define the voltage to be a state variable? Does the DAE system structure still work, if we have the voltage as a state in bus.py? And Jacobian computation, etc.

I ask this because to properly describe the dynamics of the capacitance in a PI line model, I would need to include the dynamics of the parallel capacitance, which would determine the voltage as a state.

Best regards!

[cuihantao]

We can't change the type in Bus due to compatibility reasons. If needed, you can define an alternative, dedicated type of bus.

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On Sat, May 9, 2026, 6:45 PM Trb2 ***@***.***> wrote: Thanks for the quick answer! Before starting coding, I would like to understand the following: I have seen that in models/bus.py, the volatge magnitude and angle are algebraic variables. Is this necessary, or can one define the voltage to be a state variable? Does the DAE system structure still work, if we have the voltage as a state in bus.py? And Jacobian computation, etc. I ask this because to properly describe the dynamics of the capacitance in a PI line model, I would need to include the dynamics of the parallel capacitance, which would determine the voltage as a state. Best regards! — Reply to this email directly, view it on GitHub <#648 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABSNZA56EIHXME5I5QVE3UL4Z4D3PAVCNFSM6AAAAACYWVRH7CVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTMOBWGE3DCMY> . You are receiving this because you commented.Message ID: ***@***.***>