Evaluating structural parameter (or constant) - Translation Error

[KieranF <kieran.fung@…>]

I recently tried to instantiate the WindFarm.mo located within PowerSystems.Examples.Wind.WindFarm and I received an error message reading:

[1] 10:03:42 Translation Error
[PowerSystems.AC3ph.Machines: 2208:3-2208:47]: Could not evaluate structural parameter (or constant): wt1.generator.c.n_r which gives dimensions of array: L_r. Array dimensions must be known at compile time.

This error was just really confusing to me because no where within the WindFarm.mo was there a use of any model from PowerSystems.AC3ph.Machines library.

All the components used within the WindFarm.mo does indeed have components used within PowerSystems.AC3ph however, that is where it ends. The variable "n_r", I believe the rotor speed, is not even used within my model.

If you have any knowledge in this subject, advice or suggestions please feel free to leave a comment! Thanks!

[Francesco Casella]

@KieranF, the issue you faced is already described in #5204.

This error was just really confusing to me because no where within the WindFarm.mo was there a use of any model from PowerSystems.AC3ph.Machines library.

I'm not sure where you took WindFarm.mo. The current release (1.0.0) has the entire Wind package contained in the package.mo file, see the ​GitHub repo. Maybe you are still using an older version.

Anyway, the WindFarm model instantiates some Components.WindTurbine models, which in turn use PowerSystems.AC3ph.Machines.Asynchron_dfig, which explains the error.