US power outage: Sequence of voltage cascade revealed

MY PAL Marty says he's seen the official reports so far of the power out that affected swathes of North America on the 14th of August last and it's not a happy story.

The Joint US/Canada Task Force investigating the power down has so far isolated the time line of the cascade in the electrical grid on that day. Marty assures me that Adamson Rust's attempt to pin the blame on Chicken Little and Foxy Woxy is up to his usual lame standards. [Can't you get over this guy, Eva? Ed.]

The time line is pretty much OK, though the Task Force is unhappy about the time stamps that should note the disconnects. Some time stamps are inaccurate because the computers that record the disconnects either got backlogged or the clocks weren't calibrated properly to the national time standard. Heads will no doubt roll because of this - it makes it harder to pin down the times and the events.

It's pretty clear the whole North American power grid needs quite a bit of care and attention.

According to Marty, nearly all of the events in the blackout happened from noon Eastern Daylight until 4.15PM Eastern Daylight. But the power sleuths are tracking from 8AM on the day, EDT, just to see if anything happened earlier.

Conesville Unit, central Ohio (375MW) A generator trip happened at 12.05
Greenwood Unit, north of Detroit Generator trip at 1:14
Eastlake Unit (597MW), Northern Ohio Generator trip 1:31
Stuart Atlanta (345kV) Transmission disconnect at 2PM, because a brush fire shorted the conductors
Harding Chamberlain Transmission line disconnect at 3PM
Hanna Juniper Transmission line disconnect at 3.30PM

The Hanna Juniper line hit a tree, and that caused a short circuit to ground and the line disconnected. An acorn fell off the tree, hit Chicken Little on the head, and she went off to tell the rest of her flash mob that the "sky was falling down" as Adamson Rust puts it in his rather non technical description.

Star South Canton Transmission line disconnect at 3.40PM
Canton Central Tidd Disconnect at 3.45
Samnis Star Disconnect at 4PM
Galion Ohio Central Muskingum Disconnect at 4.08PM
East Lima Fostoria Central Disconnect at 4.10
Kinder Morgan Disconnect at 4.10

At this point, says Marty, power flows from Indiana and over the west-east Michigan transmission loads started to feel the strain, while at around ten past four, the Eastern Interconnection frequency showed a demand loss of between 700 to 950MW. The following sequences happened almost at the same times.

Harding Fox Disconnect 4.10
Lake Erie Twenty generators stop at 4.10PM
West-East Michigan Disconnect
Midland Cogeneration Venture Disconnect
Detroit Transmission system northwest of Detroit goes down
Perry Ashtabula Erie West 4.10PM, transmission line cuts northern Ohio off from Pennsylvania

The investigators at this point reckon that when the lines along the south of Lake Erie fell, the power reversed direction and started going in a counterclockwise loop heading from Pennsylvania to NY, to Ontario and into Michigan.

Homer City to Watercure Road 4.10PM a disconnect
Homer City to Stalle Road 4.10PM a disconnect
South Ripley to Dunkirk 4.10PM a disconnect
East Towanda to Hillside 4.10PM a disconnect

Exceedingly heavy power flows heading towards the New York and New Jersey lines.

Fostoria Central Galion Down at 4.10PM
Perry I Nuclear unit This 1252MW unit disconnected off at 4.10PM
Avon Lake 9 Off line
Beaver-David Besse Cleveland load auto disconnected

Campbell Unit Three Disconnect
Keith Waterman Disconnect 4.10PM
Wawa Marathon Disconnect 4.10PM
Branchburg Ramapo Down 4.10PM

The Eastern Interconnect was divided into two sections.

Picture copyright 2003 Juan Leger

New York split east west 4.10 Transmission lines disconnect. New England becomes an electricity island for a while
New York split continued 4.10PM. Northern New Jersey and south west Connecticut stay attached to New York system east. Ontario, east Michigan stays connected to New York West
Ontario, New York separate at Niagara Falls 4.10PM
Long Mountain, Plum Tree disconnect 4.11PM
Ontario, east Michigan Separation 4.12PM

Eastern New York blacks out with small pockets of power left. Western New York manages to support 50% of load.

The End Game The cascade at 4.13PM is nearly finished. Some small pockets stayed up for a few minutes more

According to the Task Force, there's more data to be collected and research to do before it can say exactly what and why it happened, and what the relationship between all of these events are. µ