Ask Your Question

aBusReal and aMachReal behaving weirdly

asked 2021-12-04 07:18:18 -0500

Aryan Ritwajeet Jha gravatar image

In my dynamic simulation of the IEEE9 bus system, I wish to retrieve the real power generation data of generator buses w.r.t. time. However there seems to be an inconsistency between the values of Real Power retrieved when I use

ierr, current_PGEN = psspy.amachreal(-1, string = "PGEN")


ierr, current_PGEN = psspy.agenbusreal(-1, string = "PGEN")

which show the same constant values as in steady state

as opposed to the command

chnfobj = dyntools.CHNF(outfile)

which shows the correct values for the real powers generated in its POWR columns in the resultant excel file.

Some context for the simulation:

  1. I'm increasing all the loads with time.
  2. The generators have governors (and therefore their generations should increase).
  3. Since the first two commands (agenbusreal and amachreal) give values for only that instant, I'm appending the output values to one table for the whole run, instance by instance.
  4. Other API retrievals (bus voltages, line currents) seem to work just fine.
  5. I've set up channel object such that PGens are recorded (an example column in the excel file is POWR 1[BUS1 16.500]1)
edit retag flag offensive close merge delete

1 answer

Sort by ยป oldest newest most voted

answered 2021-12-06 02:21:23 -0500

perolofl gravatar image

Parameter Pgen and Qgen are only used for steady state calculation. In dynamics, the generators are converted to current sources and Pgen and Qgen are not updated during a dynamic simulation. The only way to monitor generator electric power is to use channels.

However, the bus voltage array is updated during the simulation so voltage and line flow API's are returning the correct results from a dynamic simulation.

edit flag offensive delete link more

Your Answer

Please start posting anonymously - your entry will be published after you log in or create a new account.

Add Answer

[hide preview]

Question Tools

1 follower


Asked: 2021-12-04 07:18:18 -0500

Seen: 169 times

Last updated: Dec 06 '21