New Feature: Add nodes to Power Electronics

[alexander-novo]

Currently, it is the user's responsibility to ensure that the system vector is large enough to accommodate any node variables. As well, they pick the ordering of system variables and mapping from components to nodes.

If the system kept track of nodes, then the system could construct the system vector and its ordering automatically.

This is considered necessary to implement before continuing to implement the system Jacobian sparsity in #307

@pelesh @nkoukpaizan Can I get your thoughts on how you want this to look?

[pelesh]

I believe this has been implemented in phasor dynamics module already; you can use that implementation as a guide to implementing the same in power electronics module. The application needs to instantiate nodes and components connected to them and all of them need to be added to the system model. All you need to do is to make node objects separate from components so you can loop over them to access node variables.

[alexander-novo]

Can you specify more what kinds of things you think will be the same/different between the two modules? The way that the phasor dynamics system evaluates a residual is very different than the way that the power electronics system evaluates a residual, so as it is right now I'm not sure I see why I need to loop over the node variables.

[pelesh]

@alexander-novo, you need to have separate loops for connection nodes and components as the two have different roles in model evaluation.

[alexander-novo]

Okay, so I should be changing model evaluation for power electronics.

How similar will this end up looking to phasor dynamics in your mind's eye? Would it be better to replace power electronics system with phasor dynamics system as well, rather than trying to modify power electronics? I want to make sure I'm seeing the same end goal as you before I start.

[pelesh]

Okay, so I should be changing model evaluation for power electronics.

How similar will this end up looking to phasor dynamics in your mind's eye? Would it be better to replace power electronics system with phasor dynamics system as well, rather than trying to modify power electronics? I want to make sure I'm seeing the same end goal as you before I start.

The way I see it, we cannot use phasor dynamics system assembly as is here, because coupling rules are different. So, we do need to modify the power electronics module itself. But we are talking about really minor modification.