Relay Settings For H Bus String 1

[Mbrooke]

Not sure where the other thread went but it was getting good replies. Has anyone ever relayed the center breaker in an "H" bus substation? What is typical in such a scheme?

Here is an example of what I have in mind on page 5 from a publicly disclosed report found on Google:

https://portal.ct.gov/-/media/CSC/FinalReport111103Rev3pdf.pdf

Disclaimer: I have zero affiliation (both past and present) with the companies mentioned in the above PDF. Copy and Pasting pictures from public documents obtainable via Google does not constitute CEII for those concerned.

 

[Mbrooke]

I'd imagine there would be some complexity with EM relays.

I'm also wondering why X if effected more than R... I have theory but I might be way off.

 

[rcw retired EE]

David- Slightly off topic, -"Astoria Blue Fire" event- I was involved with two new power plants that tied into ConEd at the Astoria Substation, one at 345 kV and one at 138 kV (?). I saw the late night news about the arcing and immediately started trying to find out everything I could. I was concerned that "my" relaying design, settings or commissioning contributed to the fault. I had lot of information that I wanted to share when we were discussing the event, but I couldn't.
It was interesting watching the videos and reading reports, having been in that yard and in some of the older relay rooms. I could visualize the equipment.

It was a relief when we heard that all of "our" protection acted as intended.
The HV protection design was actually done by a New York PE firm under contract to my company. I only did the generation plant relaying but sat in many meetings coordinating protection and commissioing with ConEd and others.

 

[Mbrooke]

@RCWillson: Are you talking about the Astoria Energy II generating station? And the Charles Poletti 345kv GIS substation which connects to East 13th/15th st via cables Q35L and Q35M?


What is interesting (according to public docs, in regards to the 345kv cables I mentioned above) is that zone 3 and zone 4 aren't enabled in the relays, just zone 1 at 87% and Zone 2 at 200% for phase, 70% and 200% for ground respectively.

In regards to Astoria East 138kv AIS and the blue light event I was told that the remote relays at 179th st were set such that they couldn't "see" past the series current limiting reactor on the cable/bay involved.