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What does psspy.asys do

asked Jan 25 '12

JervisW gravatar image

updated Jan 26 '12

I tried using psspy.asys to create a group of buses that are in two subsystems. After running the command I expected to see 23 buses in the subsystem. Instead there were 0 buses loaded into the subsystem.

What do you use it for, and how do you use it?

(edit) Here are some of the commands I used:

psspy.asys(sid=1, num=2, areas=[3,4])
ierr, buses = psspy.abuscount(sid=1)
# ierr == 2! Invalid SID value; BUSES returned as 0.

My work around

psspy.bsys

I use this to create subsystem of the buses in areas 3 and 4:

psspy.bsys(sid=1, numarea=2, areas=[3,4])
ierr, buses = psspy.abuscount(sid=1)
# ierr == 0! this method works.

2 answers

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answered Jan 30 '12

JervisW gravatar image

Only use bsys to create a subsystem

There are four types of subsystem:

  1. Bus;
  2. Area;
  3. Owner; and
  4. Zone.

Only the bus subsystem is used in the psspy subsystem data retrieval commands. The other three are used for reporting from the GUI:

Power Flow > Reports > Area / Owner / Zone totals..

Changing the area subsystem has no effect on the area selections of the current bus subsystem.

The answer for this was found in Chapter 4.8 - Subsystem Selection in the Program Operation Manual.

link
1

answered Feb 22 '12

Daniel_Hillier gravatar image

updated Feb 22 '12

Your workaround is the correct way of creating a Bus subsystem from all the buses in the areas supplied.

As for what you use Area subsystems for:

psspy.asys() is used to create a subsystem of Areas. The Area subsystem will then refer to a set of areas, much like how a Bus subsystem refers to a set of buses.

Area subsystems are used in functions that indicate they take Area subsystems as the sid input. Most functions in the psspy data retrieval section take bus subsystems as the sid input. Only the functions under the subheading "Area Data" in the data retrieval section and the functions used to define Area subsystems (as far as my quick search could tell) take an Area subsystem as sid.

link

Comments

Great answer. Now I know the _why_ behind area subsystems.

JervisW gravatar imageJervisW (Feb 22 '12)

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Asked: Jan 25 '12

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Last updated: Feb 21 '12