Governor (GovernorTgov1) Source and Unit Test

[lukelowry]

Description

This PR contains the following changes to implement the TGOV1 governor. The scope of this PR is limited to the unit-tests, cmake edits, TGOV1 data structure, and class implementation of TGOV1. Non-abstracted accessor functions are added to Genrou for proof of concept.

Proposed changes

• Relevant Source Cmake files in PhasorDynamics source (and relevant sub folders)
• Data structure for TGOV1, stored here as done in GENROU.
• Source and header files for TGOV1
• Declaration of speed and torque accessors in Genrou header
• Definition of speed and torque accesses in Genrou source

For unit test:

• Relevant Cmake edits
• Header file test definition for TGOV1
• And the Source file to run unit test

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

Implementation style should be reviewed as this is the first code PR to GridKit.

Initial implementation had more abstraction, but it has since been removed as the scope became too large.

There are additional changes required to the Genrou class for a functional example to be obtained. Since that implementation is dependent on the changes in this PR, this should be performed once this PR is resolved.

[abirchfield]

Two small comments, otherwise I think it is ready for merging. There is still more to do before this is usable in a complete simulation, but that is what the next PR will be for.

[lukelowry]

Relevant changes made. Awaiting further review from @abirchfield and @pelesh.

[pelesh]

The code does not build correctly:

[  7%] Linking CXX shared library libgridkit_phasor_dynamics_governortgov1.dylib
Undefined symbols for architecture x86_64:
  "GridKit::PhasorDynamics::Genrou<double, long>::getSpeed()", referenced from:
      GridKit::PhasorDynamics::Governor::Tgov1<double, long>::evaluateResidual() in Tgov1.cpp.o
  "GridKit::PhasorDynamics::Genrou<double, long>::getTorque()", referenced from:
      GridKit::PhasorDynamics::Governor::Tgov1<double, long>::initialize() in Tgov1.cpp.o
  "GridKit::PhasorDynamics::Genrou<double, unsigned long>::getSpeed()", referenced from:
      GridKit::PhasorDynamics::Governor::Tgov1<double, unsigned long>::evaluateResidual() in Tgov1.cpp.o
  "GridKit::PhasorDynamics::Genrou<double, unsigned long>::getTorque()", referenced from:
      GridKit::PhasorDynamics::Governor::Tgov1<double, unsigned long>::initialize() in Tgov1.cpp.o
ld: symbol(s) not found for architecture x86_64
collect2: error: ld returned 1 exit status
make[2]: *** [src/Model/PhasorDynamics/Governor/Tgov1/libgridkit_phasor_dynamics_governortgov1.0.1.0.dylib] Error 1
make[1]: *** [src/Model/PhasorDynamics/Governor/Tgov1/CMakeFiles/phasor_dynamics_governortgov1_shared.dir/all] Error 2
make: *** [all] Error 2

The linking error is because Tgov1 uses pointer to a machine to access machine's methods. For this code to work, the Tgov1 object needs to be linked to any generator object it might be connected to. This is most likely unsustainable.

I see two possible paths forward:

1. Implement machine base class and have Tgov1 interface with the base class rather than specific implementation. The base class would in that case need to anticipate any signal port that machine might need.
2. Implement signal bus and have governors connect to machines through those. This is a more robust solution imho.

[lukelowry]

I will make a simple SignalBus class inheriting from BusBase as a starting point for the SignalBus framework.

[pelesh]

Looks good! I fixed a build bug and some compiler warnings in #152. Please review and possibly merge to lukel/phasor_tgov1_code_dev branch.

I also left a couple of minor suggestions to consider.

[lukelowry]

Build bug branch merged, and suggestions applied. No build errors on my end. Awaiting further review from @pelesh and @abirchfield . Once this is merged I will implement a SignalBus before other connected models (i.e., exciter) are implemented.

[pelesh]

All outstanding items have been addressed.