NYC power outage

[mbrooke]

A "network" can handle the loss of any medium voltage feeder cable without customer outages, or in the case of Con Edison two feeder cables can simultaneously fail without customers loosing power.


Here is a generic structure:

Typical Con Ed substation and network schematic:

Source from here:

https://www.researchgate.net/figure/Area-distribution-network_fig16_254057380

 

[ron]

But inadvertently 49th st also cut power to 5 other 138kv cables supplying 50th and 42nd.

So at least 4 substations were de-energized as a result.

I was sent an oscillogram from a PQ meter at a client's data center in Pittsburgh that wanted me to evaluate a 5 cycle momentary undervoltage that they saw at ~7PM on Saturday. I don't have a 138kV transmission diagram of the Northeast, but I bet it was related. Their 23kV is derived from 138kV.

 

[mbrooke]

Here is the West 49st substation. It is a bulk substation.

It takes in Five 345kv feeders and steps down 345kv to 138kv via 5 auto-transformers.


It puts out 11 138kv feeders which supply 4 local substations.


5 138kv feeder cables supply west 65th and Astor, 5 138kv cables supply 50th and 42nd, and one 138kv cable is a tie (interconnect) to Vernon substation over in Queens.

 

[mbrooke]

Here is the public supporting data:

Page 15:

https://www.epa.gov/sites/production/files/2017-02/documents/colby_presentation_2017_workshop.pdf

 

[mbrooke]

The 4 substations supplied by West 49th st:

 

[mbrooke]

I was sent an oscillogram from a PQ meter at a client's data center in Pittsburgh that wanted me to evaluate a 5 cycle momentary undervoltage that they saw at ~7PM on Saturday. I don't have a 138kV transmission diagram of the Northeast, but I bet it was related. Their 23kV is derived from 138kV.

Thank you for sharing this! This is why I post here.

Could be a coincidence, could be related.

I can't see a 13.8kv fault pulling the voltage down all the way to Pittsburgh, but if it somehow triggered a 345kv competent to fail I could see that happening.


I have a feeling that a lot more happened then we are told about.

And considering that both primary and secondary relaying also failed at Astoria 5 month earlier leads me to think Con Ed has some profound issues and is hiding it from everyone.

 

[mbrooke]

190715-2016 EDT

ggunn:

I was using the 70,000 customers to try get an estimate of the size of a single transformer to support that load. But I also don't think a single transformer was the cause. That is why I mentioned a cascading event.

I have now done a search for the weight of a 100 MVA transformer. Found this site https://www.btbplaza.com/index.php/...-inventory/items/view/88-100-mva-220-33-kv-09
It lists a weight of 104,900 kg or at 2.2 #/kg the weight is 230,780 # or 115 tons. Huge to quickly change.

It is possible this is the size of the transformer going to our local substation.

.

.

Transformers- I know you were asking about them.


West 49th st has Five 345kv-138kv auto transformers, each rated 420 MVA.

There is room for two more if seven total are ever needed.

The substation can supply power with two of the five auto transformers out of service.

Ie, the station is only loaded to 1,260MVA peak. And is designed for N-2 contingency.



From an investment report:

 

[mbrooke]

190715-2016 EDT

ggunn:

I was using the 70,000 customers to try get an estimate of the size of a single transformer to support that load. But I also don't think a single transformer was the cause. That is why I mentioned a cascading event.

I have now done a search for the weight of a 100 MVA transformer. Found this site https://www.btbplaza.com/index.php/...-inventory/items/view/88-100-mva-220-33-kv-09
It lists a weight of 104,900 kg or at 2.2 #/kg the weight is 230,780 # or 115 tons. Huge to quickly change.

It is possible this is the size of the transformer going to our local substation.

.

.

The local substations:


1) West 50th st has Five 138kv-13.8kv transformers each 65 MVA. This station supplies the Hudson network.

2) Astor has Five 138kv-13.8kv transformers each rated 65MVA. This station supplies Herald Square and possibly one other network (Empire).

Both these stations can run with two out of five transformers out of service or two out of five 138kv supply cables out of service.

Ie, West 50th and Astor are each loaded to 195 MVA.


3) West 65th st has ten 138kv-13.8kv transformers each rated 65MVA. Five of the transformers feed one section of 13.8kv gear the other Five feed another section of 13.8kv gear.

Section 1 feeds the Lincoln Square network while section 2 feeds the Plaza network and Rockefeller center network.

Like other stations 65th is also designed for N-2. The station can work with two of the five 138kv feeds out of service or each 13.8kv section can handle the two of the five transformers out of service.


4) West 42nd st has ten 138kv-13.8kv transformers each rated 65MVA. Five of the ten transformers feed one 13.8kv section of gear while the other five of the ten transformers feed a second section of gear.

Section 1 feeds the Pennsylvania network, while section 2 feeds the Columbus Circle network and the Midtown West network. (Midtown west was a chunk taken from the Pennsylvania network to off load section #1 when section #2 was freed up from herald square network being transferred to Astor)


If you do the math, 3 x 65 x 6 = 1,170 MVA of 1,260 MVA.

 

[ron]

I have a feeling that a lot more happened then we are told about.

And considering that both primary and secondary relaying also failed at Astoria 5 month earlier leads me to think Con Ed has some profound issues and is hiding it from everyone.

I attended this lecture https://events.vtools.ieee.org/m/198911 in May and they were pretty forthcoming with what happened, at least what they knew at the time. Taft was a knowledgeable speaker and other than outing the relay and communication manufacturer names that were related to the issue, he went millisecond by millisecond almost through the timeline for ~4 minutes to get to the point where an unexpected tertiary distance relay cleared the fault through a short circuit limiting reactor.

 

[mbrooke]

I attended this lecture https://events.vtools.ieee.org/m/198911 in May and they were pretty forthcoming with what happened, at least what they knew at the time. Taft was a knowledgeable speaker and other than outing the relay and communication manufacturer names that were related to the issue, he went millisecond by millisecond almost through the timeline for ~4 minutes to get to the point where an unexpected tertiary distance relay cleared the fault through a short circuit limiting reactor.

Was lecture recorded? Is there any paper out on the event? I would give anything know.

 

[ron]

Was lecture recorded? Is there any paper out on the event? I would give anything know.

As you might imagine, no recording and they frowned when I took a picture from my cellphone from the audience.

 

[mbrooke]

As you might imagine, no recording and they frowned when I took a picture from my cellphone from the audience.

Perhaps not the event, but if they are telling you guys is there anything the public can read on? Anything in PAC world? IEEE?

 

[zog]

Probably these guys again

 

[kwired]

Probably these guys again

View attachment 23376

Or the pink slime.

 

[hbiss]

Here is the public supporting data:

I believe the Sprain Brook substation is fed from Indian Point, the nuke plant they are closing.

I also cringe at the fact that all those facilities are indoors. One transformer explosion would take out the whole facility.hmy:

-Hal

 

[mbrooke]

I believe the Sprain Brook substation is fed from Indian Point, the nuke plant they are closing.

Millwood (feeding through East view) and Pleasant valley actually. Only one 345kv line connects to Buchanan directly. Buchanan then connects to Indian point.

See pics

I also cringe at the fact that all those facilities are indoors. One transformer explosion would take out the whole facility.hmy:

-Hal

Outdoors and AIS- which is worse.

There have been transformer fires at these places without loosing the entire substation. The indoor versions will probably fair just as well as the transformers are in their own rooms (pens), open ceiling grates and fire suppression.


The real nightmare by far is flooding and storm debris to a lesser but still major degree.


Farragut, East 13th st, Rainy, Hell Gate, Gowanus, Fresh Kills, Vernon and a few smaller stations are all capable of flooding during a hurricane. Even West 49th st could worse case. We are talking about 50% to 2/3 the system needing to be shut down if a Cat 3 hits on flood water lone.

I've been saying it for years but all of the above stations need to be rebuilt as GIS on an elevated building both due to extreme age the damage flooding would cause.

 

[romex jockey]

is this as bad as the '77 outage....?

~RJ~

 

[mbrooke]

is this as bad as the '77 outage....?

~RJ~

Nooo.

77 was the loss of the entire Con Ed system. July 2019 was just West 49th st and all the substations it feeds.

 

[mbrooke]

I believe the Sprain Brook substation is fed from Indian Point, the nuke plant they are closing.

I also cringe at the fact that all those facilities are indoors. One transformer explosion would take out the whole facility.hmy:

-Hal

FWIW several years ago I mussed and drew up some plans on my own for gradually converting the entire system over to GIS and ditching the fluid filled cables. Some 500kv loops starting at Pleasant Valley and Ramapo- 161kv to area subs using the existing pipes.

My First iteration as you can tell- ie line and loads need to be alternated- I've got buss sections at 8,000amps in this one LOL.

 

[mbrooke]

First iteration of West 49th and 65th. :lol: Needs a transfer bus among other things.