Add inverter models with current limiting

[m-bossart]

The existing inverter models do not include current limiting. It would be good to include some models from the literature that have current limiting. @ciaranrob has started an implementation.

One key question is how to make the addition of current limiting modular and extensible? Does it make sense to define a new model (e.g. CurrentLimitedVoltageModeControl) which is essentially equivalent to VoltageModeControl with the addition of an Imax parameter or is there a better way? @jd-lara @rodrigomha do you have thoughts on this?

[rodrigomha]

That proposed option is okay for now, but it is not reasonable to do that more than once, so if we want to try other limiters we need a long-term solution.

I think the proper solution requires some major changes.

An intermediate solution would be similar of how the outer control work: create a struct for InnerControl that contains the VoltageControl, CurrentLimiter and CurrentControl.

Then, you can probably dispatch the combinations that you want in a clever way (using _mdl_ode_functions to dispatch internally any combination you want) or repeat code.

This would require to do a bunch of things:

• Define a NoCurrentLimiter struct
• Define a NoVoltageControl struct
• Split VoltageModeControl into something like VoltageControlVImpedance, NoCurrentLimiter and StandardCurrentControl
• Split CurrentModeControl into something like NoVoltageControl, NoCurrentLimiter and StandardCurrentControl

What do you think @jd-lara ?

[jd-lara]

looking into this issue it seems we need to modify the structures of the inverters to incorporate current limiter DynamicComponents. We need to PoC this for PSY 3.0.

[rodrigomha]

This closed in #383