psspy.asys doesn't work !

edit

The reason is that the asys commands create an area subsystem and not a bus subsystem. I find it to be incredibly annoying, and have personally been tripped up multiple times.

Here is how to create a bus subsystem that contain only the buses in the areas you wanted:

subsystem_number = 4 ## desired, could be anything between 0 and 11, right ?

areas = [19,20] ## these areas DO exist

number_of_areas_to_set = len(areas)

ierr = psspy.bsys(subsystem_number, numarea=number_of_areas_to_set, areas=areas)

print ierr

ierr, areas = psspy.aareacount(subsystem_number, _i)

print areas

print ierr

ierr, numbers = psspy.abusint(subsystem_number, _i,"NUMBER")

print numbers

Use the psspy.bsys to define a bus subsystem, they are used throughout the bus subsystem API (like abusint).

psspy.bsys is pretty cool, because you can define subsystems by other means too:

• by base voltage;
• by area;
• by owner;
• by zone; and
• by listing individual buses.

Or by using a combination of any of the above.