PDController: gdPowerPlant and tmSOSystem equations?

[balacij]

Related to #2371

Currently, these 2 chunks are not given any sort of "left-hand side" of their respective equations so I'm not quite sure what kind of a ModelKind model I should be creating for either of them.

[balacij]

I hope it's okay that I assigned both of you @JacquesCarette and @smiths.

[JacquesCarette]

Yes, that's fine. In this case, I think it's going to be @smiths who needs to have first crack at it. Certainly these are not 'equations'. But what is the thing being defined here, I don't know.

[smiths]

I can look at the example, but it might be a bit until I get to it. The PDController example hasn't really had a very detailed review to this point. (This example didn't come to us by the normal channels.) The equations will need to introduce a symbol for the transfer function, but I'll have to look to see if that symbol is used elsewhere or if we'll have to introduce it in multiple places.

[balacij]

Thank you! That would be perfect. No rush, I have many tasks to work on in the mean time.

[balacij]

I can give this a go too if you don't mind validating my work @smiths.