via Truth is Treason
Blackout Caused By One Person
The transmission lines that make up the western grid have built in safety nets to prevent this. When the frequency of the voltage varies past the set thresholds, main transmission breakers will open to prevent a cascade effect. This variance is a portion of a hertz, maybe up to 1Hz. This is mainly caused by a generation issue, not a substation. Transmission breakers will also open when you have a Hz, fault or a major voltage fluctuation
A massive power outage triggered by human error left well over 5 million people without electricity in southern California and parts of Arizona and Mexico.
An ill-fated procedure by an Arizona power utility employee in a small town unleashed a chain of events which brought down power in a large swath of the south-west, the Arizona utility said. A high-power line supplying electricity to southern California failed first.
Also all transmission breakers must pass a NERC test and be reported.
So I'm hitting the bullshit button.
Former power plant control room operator here... Generators, especially newer ones, have some fairly twitchy protection mechanisms built in. Frequency protection is one of the twitchiest, at least with the large (160 MW) GE units I operated. If line frequency dropped just a few decimal points below 60 HZ for a matter of seconds, the generator breakers would trip. This will cause a cascade of units tripping offline as frequency drops further due to loss of generation. In Texas, plants are independent, and the grid is operated by separate entities and controlled by ERCOT. SoCal may be different in that regard, but generators are generators and their protection limits are very conservative. They ain't cheap, nor readily available for replacement next week. The large step-up output transformers are even harder to replace, so they are closely protected.
ReplyDeleteThat being said, the grid also has built in protection to prevent wide spread outages by isolating the source of problems. Something else happened here, not just the error of one person. Something (or things) else failed, maybe due to "deferred maintenance", fail safes overridden, stuff operating in "limp mode"... And we'll probably never know the real story. But you are 100% correct in hitting the bullshit button!
Craig-Thx for the info. My knowledge on generation is very limited. I'm a sys op/dispatcher for a small co-op here in E Tex. My main knowledge is for distribution and some 138Kva transmission.
ReplyDeleteFrom some of the articles online, it appears it was a 500Kva DC line.
This morning some of the eng's were discussing it and somebody is gonna get their wee-wee slapped.
But as far as the true cause, the public will never know.
Ah, didn't realize you are in TX, sorry. And you know system operation I see. Double D'OH! : ) I know a little on the 138 Kva side from plant operation experience, but not much on distribution. Don't know how far SCADA control reaches, but appears to go to the substation level? Also not sure as to the level of automation where protection is concerned, but it seems to me there would be some automatic safeguards. Certainly there are on a 500Kva DC tie! Lotsa expensive gear on either end of that bugger. Methinks something got "smoke tested" there...
ReplyDeleteThe bright side is that they couldn't see Hussein babble on.:)
ReplyDeleteWe control all our substations via SCADA. We monitor and can be proactive as far as opening a breaker if it doesn't lock open due to faults.
ReplyDeleteFor under freq, at the distribution level, we will get alarms via SCADA and the more modern upgrades will initiate an auto shed (on transmission side) until the load stabilizes.
From what I understand talking to the eng's was that this incident was moving at warp speed and only automation is what stopped it from spreading larger.
I would hate to be on the bad end of this inquiry. Lot's of $$$ lost, both revenue & equip cost.
HAHA...The Lord gives us many blessings.
ReplyDelete