Detecting Loop Flows with Python Script

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Has anyone put any effort towards developing a python script to detect loop flows/circulating VARs in a large system? If not, how would you approach the problem?

For a simple case (parallel off-tap transformers connected to a single bus) it may not be that difficult, but can the algorithm be expanded to more general cases? I realize that the detection itself is not trivial and there are a number of papers on the subject.

It would be cool to see what the community could come up with!

Sample papers (might not be the best on the subject):

"Circulating MW and MVAR in power systems" Link to abstract (behind paywall)

"Fast Algorithms for Detecting Circular VAR Flows in Large Power-Flow Models" Link - pdf

"On Detecting and Removing Undesired Reactive Loop Flows" Link - google

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I've had the same problem. One year an entire suite of base cases were plagued with the problem and it took days to sort out.

JervisW (Feb 9 '13)

@JervisW what exactly is the problem that you faced? To be frank, I have till date not been able to identify loop flows as described in this post.

amaity (Feb 11 '13)

@amaity Our power system has a 500 kV ring circling around a 220 kV inner network. There are multiple connection points between the outer and inner rings. The circulating VARS were found going down one transformer, across the 220kV network then up another transformer and back to where it started!

JervisW (Feb 11 '13)

How do you even go about finding that!?!

jsexauer (Feb 12 '13)

Yes, how did you identify them?

amaity (Feb 12 '13)

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answered May 14 '15

mbong
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The jist of the techniques assume a lossless network and thus for : 1. circulating real power flows only occur for any device that alters the angles (phase shifting transformers UPFC etc) and 2. for circulating VAR flows only occurs for branches which have voltage regulating equipment

1) Preal flows occur from lower angle to higher angle signals a possible circulating flow 2) Pimag flows occur from Lower voltage to higher voltage signals possible VAr flows

link

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answered Feb 13 '13

JervisW
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updated Feb 16 '13

Hi this is a really interesting problem.

(EDIT) Here is the open source project. Feel free to follow along and make suggestions or even take a copy for yourself: https://github.com/jtrain/Circulating...

Firstly I've never tackled this in an automated way, or know of anyone that has. Hopefully someone else could help out there.

In my experience it was caused by tap settings on parallel transformers that weren't co-ordinated (short summary). But my process was a manual one, and it did take a few days to get sorted out.

An automated approach that at least notifies where possible var circuits are would be helpful. Then a human could track it down and fix the problem.

I agree that it would be cool to see what the community comes up with. I'm willing to help out. What we'd need is some (realistic) saved cases set up that exhibit the problem. We could document what that looks like, and then begin writing some code based on the literature you've found.

link

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Your approach sounds good. Perhaps we could begin with one of the generic IEEE cases and make some topology/setting tweaks to create the problem? This way there are no data privacy issues. I agree that notification only is much simpler and a logical first step before developing a resolution.

cajief (Feb 14 '13)

Alright, let's do this in the open. I'll set up an account and anyone that wants to join in by: 1. submitting code; or 2. generally commenting; or 3. tweaking the base case please feel free to jump in. I'll edit this Answer with a link

JervisW (Feb 16 '13)

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Detecting Loop Flows with Python Script

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