Starting this thread as not de-rail another one. How do you guys set the reclose logic for two terminal 69 and 115kv lines with non communicating, non PLC relays? The desired outcome is to have only one relay do a single reclose attempt after 30 seconds, and once the line holds for 20 seconds have the other relay close its breaker after a sync check. Ie, have the remote relay not reclose but also not lockout.
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Relcosing logic for 311C 1
- Thread starter Mbrooke
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I think davidbeach's setting of 135% works better with the zone 2 supervision he uses.
If you are using OC only (with voltage supervision - which I would recommend) that pickup will be too high.
50% minimum TPH fault is a good level to use (or 10A secondary - whichever is less) for OC line test. You want to consider the system configuration for when you actually want line-test to work. The line is dead, and one terminal gets closed in first. That's the line test scenario. You could be testing because someone left grounds on the line (maybe the most common reason for this), but also consider other types of possible faults that could happen while a line is dead.
I believe our standard voltage setting for supervision of the OC element is 0.3 pu, probably based on a 500kV application. You may want to tweak that depending on your set-up, but I think 0.3 should be safe for most applications.
If you are using OC only (with voltage supervision - which I would recommend) that pickup will be too high.
50% minimum TPH fault is a good level to use (or 10A secondary - whichever is less) for OC line test. You want to consider the system configuration for when you actually want line-test to work. The line is dead, and one terminal gets closed in first. That's the line test scenario. You could be testing because someone left grounds on the line (maybe the most common reason for this), but also consider other types of possible faults that could happen while a line is dead.
I believe our standard voltage setting for supervision of the OC element is 0.3 pu, probably based on a 500kV application. You may want to tweak that depending on your set-up, but I think 0.3 should be safe for most applications.
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Not being one of those admitted to the inscrutable world of protection scheme jargon, I searched both here in Eng-Tips and on line generally for what SOTF means, and the only answer I've received so far is Survival of the Fittest; it must be a jungle out there...
So: I apologize for my ignorance, but what is SOTF an abbreviation for in the Protection and Control world?
CR
"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]
So: I apologize for my ignorance, but what is SOTF an abbreviation for in the Protection and Control world?
CR
"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]
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davidbeach
Electrical
SOTF is a feature in the relays that activates selected elements while the breaker is open and for the first while after the breaker is closed. We typically use a 30 cycle SOTF time, so for the first 30 cycles following breaker close the zone 2 distance elements and any included overcurrents will trip instantaneously. Once the 30 cycle timer expires the SOTF tripping equation is ignored.
I guess I should say, welcome to hell. Or almost hell.
The issue is not that most of the requirements are a concern, it's the paperwork and documentation, that required us to hire so many lawyers who don't even understand the requirements.
Also the auditors who have no idea what they are auditing. They just want to see the paperwork.
It's sort of like a federal government takeover of the utilities.
The issue is not that most of the requirements are a concern, it's the paperwork and documentation, that required us to hire so many lawyers who don't even understand the requirements.
Also the auditors who have no idea what they are auditing. They just want to see the paperwork.
It's sort of like a federal government takeover of the utilities.
Except that NERC is a North American "multinational" organization, which explains how my utility, which is Canadian, can be a member.
I am wondering: are there any US/Mexico tie lines that will need to be routed through a "power wall" in some manner?![[bigsmile]](/data/assets/smilies/bigsmile.gif "[bigsmile] [bigsmile]")
CR
"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]
I am wondering: are there any US/Mexico tie lines that will need to be routed through a "power wall" in some manner?
CR
"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]
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![[thumbsup2]](/data/assets/smilies/thumbsup2.gif "[thumbsup2] [thumbsup2]")
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