Exciter Implementation and Example

[lukelowry]

Description

This PR includes a working Exciter model (IEEET1) with the relevant GENROU modifications and an example for verification.

Motivation: Once this model is implemented, we can start constructing IEEE cases and synthetic cases which are stable without an infinite bus.

Proposed changes

• Exciter header and source Ieeet1.hpp Ieeet1.cpp
• Exciter data, copying GenrouData.hpp
• Genrou support for Exciter (removed one state and add read/write for efd signal)
• Add Exciter list in SystemModelData
• Two Bus example TwoBusIeeet1.cpp
  -- Update ThreeBus example that relies on old GENROU state vector size.
• Various README updates to align with implementation

Checklist

• All tests pass.
• Code compiles cleanly with flags -Wall -Wpedantic -Wconversion -Wextra.
• The new code follows GridKit™ style guidelines.
• There are unit tests for the new code.
• The new code is documented.
• The feature branch is rebased with respect to the target branch.

Further comments

The data-based signal connections are not supported in this PR, since exact approach is TBD.

I addressed my environment git issue, so no more commit storms. Forgive me!

[superwhiskers]

just some really minor suggestions. i apologize for the abundance of typo corrections.

[lukelowry]

Awaiting review of changes. Thank you @superwhiskers and @pelesh!

[superwhiskers]

some memory safety bugs and memory leaks. everything else looks fine.

[lukelowry]

All review comments addressed. I am excited to get larger cases implemented after this PR. @superwhiskers and @pelesh

[superwhiskers]

no issues appear to remain

[superwhiskers]

nevermind. #193 should be merged before this is ready to be merged as it will provide the signal bus functionality.