Ditto conversion from CYME to DSS seems to break when there are multiple sources

[JennyAppiah]

It seems that when using ditto to convert from CYME to DSS, we hit the following error when there are multiple sources:

Traceback (most recent call last):
File "C:\Users\userXX\AppData\Local\Programs\Python\Python38\lib\runpy.py", line 194, in _run_module_as_main
return _run_code(code, main_globals, None,
File "C:\Users\userXX\AppData\Local\Programs\Python\Python38\lib\runpy.py", line 87, in run_code
exec(code, run_globals)
File "C:\Users\userXX\OneDrive\Projects\Atlas 2023\Atlas\venv\Scripts\ditto-cli.exe_main.py", line 7, in
File "C:\Users\userXX\OneDrive\Projects\Atlas 2023\Atlas\venv\lib\site-packages\click\core.py", line 1157, in call
return self.main(*args, **kwargs)
File "C:\Users\userXX\OneDrive\Projects\Atlas 2023\Atlas\venv\lib\site-packages\click\core.py", line 1078, in main
rv = self.invoke(ctx)
File "C:\Users\userXX\OneDrive\Projects\Atlas 2023\Atlas\venv\lib\site-packages\click\core.py", line 1688, in invoke
return _process_result(sub_ctx.command.invoke(sub_ctx))
File "C:\Users\userXX\OneDrive\Projects\Atlas 2023\Atlas\venv\lib\site-packages\click\core.py", line 1434, in invoke
return ctx.invoke(self.callback, **ctx.params)
File "C:\Users\userXX\OneDrive\Projects\Atlas 2023\Atlas\venv\lib\site-packages\click\core.py", line 783, in invoke
return __callback(*args, **kwargs)
File "C:\Users\userXX\OneDrive\Projects\Atlas 2023\Atlas\venv\lib\site-packages\click\decorators.py", line 33, in new_func
return f(get_current_context(), *args, **kwargs)
File "C:\Users\userXX\OneDrive\Projects\Atlas 2023\Atlas\venv\lib\site-packages\ditto\cli.py", line 173, in convert
Converter(
File "C:\Users\userXX\OneDrive\Projects\Atlas 2023\Atlas\venv\lib\site-packages\ditto\converter.py", line 246, in convert
self.reader.parse(self.m)
File "C:\Users\userXX\OneDrive\Projects\Atlas 2023\Atlas\venv\lib\site-packages\ditto\readers\cyme\read.py", line 920, in parse
modifier = system_structure_modifier(model)
File "C:\Users\userXX\OneDrive\Projects\Atlas 2023\Atlas\venv\lib\site-packages\ditto\modify\system_structure.py", line 68, in init
raise ValueError("Mupltiple sourcebus found: {srcs}".format(srcs=srcs))
ValueError: Mupltiple sourcebus found: ['A_src' 'B_src' 'C_src' 'D_src']
(venv) PS C:\Users\userXX\OneDrive\Projects\Atlas 2023\Atlas>

[tarekelgindy]

So this issue that is a result of the CYME reader attempting to identify the voltages of individual components after parsing is complete. This is performed by doing a graph traversal to identify components with voltages assigned to them (typically transformers) and updating component voltages upstream and downstream of those devices. This process assumes that a single source exists.

If setting of component voltages is not a priority, a workaround would be avoid doing this step by commenting out or removing https://github.com/NREL/ditto/blob/master/ditto/readers/cyme/read.py#L920 to https://github.com/NREL/ditto/blob/master/ditto/readers/cyme/read.py#L922.

However a more long terms solution should include either accounting for the possibility of multiple sources in the graph traversal or removing the requirement to set voltages in CYME reader. My preference is the first one, and will require a bit of time for development. But suggestions are welcome!