Because electricity in power lines cannot be stored, generation and load have to match up at all times or the grid enters blackout territory. That can result from a lack of generating capacity—the cause of the 2000 California blackouts—or because of one or more faults, as in the 2003 blackout. The interconnectedness of the grid makes it easier to compensate for local variations in load and generation but it also gives blackouts a wider channel over which to spread.
Transmission system operators scattered across some 300 control centers nationwide monitor voltage and current data from SCADA (supervisory control and data acquisition) systems placed at transformers, generators and other critical points. Power engineers monitor the data looking for signs of trouble and, ideally, communicate with one another to stay abreast of important changes.
One of the realizations since 2003 is that "you can't just look at your system. You've got to look at how your system affects your neighbors and vice versa," says Arshad Mansoor, vice president of power delivery and utilization with the Electric Power Research Institute of Palo Alto, Calif.
Until recently, there was no one place to view information from across the grid. McClelland says FERC is working with industry and other government agencies to pull data into a prototype coast-to-coast real-time monitoring system at its Washington, D.C., headquarters. "We have put the system together and it is functional," he says, although "some parts are better than others": FERC has full coverage of the western U.S. and good information from the Southeast, he says, but data from Texas and other areas is still spotty.
Gathering the data is only the beginning. The holy grail is a smart grid capable of monitoring and repairing itself, similar to the way air traffic control systems are used to coordinate aircraft routes. Mansoor says that dream is still a good 20 years away because it depends on better data, a reliable communications network and computer programs capable of making decisions based on the data.
One promising tool for collecting better data is called a phasor measurement unit (PMU), which measures voltage and current on power lines and uses GPS (global positioning system) connections to time-stamp its data down to the microsecond. That level of resolution across a network of PMUs could reveal an important electrical property of power lines called phase, which tells whether power generators are rotating in sync with respect to one another, Hines says.
When a blackout approaches, that difference, called the phase, is believed to grow rapidly. "A lot of people have conjectured that if we could have seen that the [phase] distance between generators was increasing [on August 14, 2003], we could have prevented the blackout," Hines says.
There are currently about 100 PMUs installed in the eastern interconnection, up from zero in 2003, as part of the North American SynchroPhasor Initiative based at the Pacific Northwest National Laboratory in Richland, Wash. "We still need a couple of hundred more [PMUs] to get a full coverage," Mansoor says, but he adds that they are already helping local utilities diagnose the causes of blackouts much faster than they could before.
Another challenge for keeping the grid balanced is the growing demand for electricity—increasing load, in other words—as consumers buy more computers, air conditioners and rechargeable handhelds. The U.S. Department of Energy's Energy Information Administration projects a load growth of 1.05 percent a year from now until 2030, which means transmission capacity will have to keep pace.
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11 Comments
Add CommentI feel quite astnished as 45 years ago, when I was a student in electrical engineering, here in Li�ge (Belgium) I spent my hollidys working in an electric power plant on the subject "Phase-energy control system in the national grid.
Reply | Report Abuse | Link to thisVery few electronic components and systems where available at that time but the old fashionned "relay logic" was able to do the job in Belgium. The current status was to expand the geographic aspect to the next countries, France, Germany and others. What was USA doing since that time? I apologise for my english writing (french would have been easier for me !)
I feel quite astnished as 45 years ago, when I was a student in electrical engineering, here in Liege (Belgium) I spent my hollidys working in an electric power plant on the subject "Phase-energy control system in the national grid". Very few electronic components and systems where available at that time but the old fashionned "relay logic" was able to do the job in Belgium. The current status was to expand the geographic aspect to the next countries, France, Germany and others. What was USA doing since that time? I apologise for my english writing (french would have been easier for me !)
Reply | Report Abuse | Link to thisAlright. As a person with no power experience, but with an extensive background in analog electronics I have to say that I am throughly confused by this article. A number of statements are made that simply fly in the face of long established knowledge.
Reply | Report Abuse | Link to this1) "One of the realizations since 2003 is that "you can't just look at your system. You've got to look at how your system affects your neighbors and vice versa," [...]
It has long been known that you have to have information about neighboring sections of a net if you expect to be able to do anything other than react blindly to changes. It's the nature of power flow in a net! If they're refering to comprehensive knowledge of every node by every other node I'd have to agree that it'd make for a more stable system, but this is prior art and not a discovery. And for it to be fully utilized layers of regional and global supervisory systems have to be created. Perhaps this is what is being refered to but not including these things is not based upon sound knowledge of how to run these systems. Perhaps they're trying to soften their admission on long standing bad practices.
2) "That level of resolution across a network of PMUs could reveal an important electrical property of power lines called phase, which tells whether power generators are rotating in sync with respect to one another, Hines says."
This is astonishing to me. Phase is an essential quantity that must be known at every node for even the simplest systems to be able to work without blowing themselves up. Once again, it's the nature of the beast. Phase has to not only be established before initiating connections but it must be maintained carefully on a moment by moment basis if the net is not to detroy itself. Allowing phase to drift will produce instabilities all by itself and these instabilities are typically underdamped and lead to self destructive oscillations. This has always been known since the earliest attempts (and failures!) to connect systems and I've been told that phase is and has always been carefully monitored. Once again I'm told of a "discovery" that would have made operation of the system impossible up to now had it not been known!
At least the trend towards DC transmission will eventually eliminate phasing problems and reduce the total required knowledge to just load sharing. (Although, extended DC networks still have AC behavior and damping in some form has to address instabilities potentially becoming oscillations.)
i think that this major power failure was caused by a bunch of idiots who dont know how to install a proper security system. seriously this is like million dollar equipment and the government trusts idiots to put up the system. why would they do this if you reach into your money grubing pockets to pay someone real money. This would have saved more money if you only payed a little bit more money. Silly government just doesnt know what their doing.
Reply | Report Abuse | Link to thisYou have no idea what you're talking about. Government doesn't run control centers. Power companies do. Security had nothing to do with the black out. The root cause was a software glitch combined with human error combined with bad tree trimming. Before you type comments, you should get educated on the topic and quit blaming your government for every little thing you read about that annoys you.
Reply | Report Abuse | Link to thisYou honestly don't know what you're talking about with your references to "idiots" and "security systems". That had nothing to do with the blackout. Maybe you should run for office.
Reply | Report Abuse | Link to thisalso i dnt think tht this is a very good discussion hahahahaha
Reply | Report Abuse | Link to thiseven tho i have a twin tht thinks the same way u do dont mean i have to lyk it
Reply | Report Abuse | Link to thiseven though i am gayyy.......i think this is sooo stupid get a life u faggsss <3
Reply | Report Abuse | Link to thisi agree with John_in_PA hahaha u dnt kno wht ur tlkn bout u fool
Reply | Report Abuse | Link to thisget a lifeeeee!!!!!!!!!!
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