Simulink error: 'Specialized Power Systems cannot solve this circuit' in continuous mode – Transformer issue?

Hi everyone, I'm working with the IEEE 13 Node Test Feeder in Simulink using the Simscape Specialized Power Systems toolbox. When I run the simulation in continuous mode, I get the following error: “Specialized Power Systems cannot solve this circuit... problem arises when transformers with no magnetization branch are connected...”. The circuit runs fine in phasor mode. There's only one transformer in the system, and it currently has Rm = 500 pu and Lm = 500 pu.

Things I’ve tried:

• Changing the transformer parameters to finite values in pu.
• Switching to real units (Ohm, H).
• Double-checked for extreme resistance values in the network.
• Verified solver settings (used ode23tb, small step size, etc.)

Has anyone run into this before? Any suggestions on typical values for Rm/Lm or other modeling practices that could help fix this?

Thanks in advance!

Answer 1

[Shlok]

Hi Felipe,

I faced the same issue when running a model with transformers in continuous mode, it failed with the "Specialized Power Systems cannot solve this circuit" error.

I'm assuming you're using a "powergui" block, since it's required for models built with Specialized Power Systems. I resolved the issue by switching to a discrete solver in the "powergui" block:

• Open the "powergui" block and then go to the "Solver" tab.
• Set the "Simulation type" to "Discrete" and choose an appropriate sample time (e.g., 50e-6).

To know more about the Powergui block, refer to the documentation by running the following command in the MATLAB Command Window:

doc powergui

Hope this helps!