Ask Your Question

A contingency converges with FNSL, but not with ACCC

asked 2019-01-14 11:43:06 -0500

hofsmo gravatar image

Hi, I am having a strange problem with contingency analysis using ACCC. For a contingency consisting of tripping of two lines it doesn't converge. However, if I change the status of these two lines to out of service and run a powerflow (FNSL) it converges. Does anyone have any idea why ACCC would have worse convergence than FNSL?

edit retag flag offensive close merge delete


Did you set the solution options (e.g. taps moving, shunts moving, phase shifter adjusting, etc.) the same when performing ACCC and manual (via FNSL)?

ffl gravatar imageffl ( 2019-01-15 07:26:35 -0500 )edit

Hi, thanks for the answer. Yes, I did. I am wondering if the ACCC activity is doing some simplification, which causes the solution to blow up.

hofsmo gravatar imagehofsmo ( 2019-01-15 11:32:09 -0500 )edit

1 answer

Sort by ยป oldest newest most voted

answered 2019-01-15 14:26:45 -0500

EBahr gravatar image

There is something extremely wrong with FNSL in ACCC. I have noticed similar issues with solving ACCC with FNSL where blown up cases reported meeting convergence even though mismatch was in the thousands. One thing that was found to somewhat work is to solve your power flow case with the exact same settings you intend to run your in your ACCC analysis. I.e. if you setup your case moving shunts, taps, and PSTs with FNLS, but run your ACCC analysis with everything locked with FNSL, make sure to solve your case once with everything locked using FNSL immediately prior to running ACCC.

edit flag offensive delete link more


Hi, thanks for your answer. Your solution reduced the mismatch I get, but I still don't get convergence.

hofsmo gravatar imagehofsmo ( 2019-01-16 01:27:54 -0500 )edit

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: 2019-01-14 11:43:06 -0500

Seen: 361 times

Last updated: Jan 15