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Update on Preliminary Analysis of Measurement Data by
The following figure shows the line frequency as measured on transmission
lines in four different Midwestern states during the blackout. This data is based
on GPS time stamped recordings taken once per second. The
frequency is calculated as an average over each 1 second
interval. It is interesting to note how close the frequency measurements
are to each other. This helps illustrate just how strongly interconnected
the power system is. Most experienced power engineers would (and have) commented that
this is no surprise since this is how the system is designed to operate. This data
is however instructive in clearly demonstrating that fact. Many thanks
to Jeff Smith at Electrotek for helping to put this comparison together.
This next figure is another frequency profile plot for the entire day
of the blackout similar to those shown in the original article
only it was taken at a site in Wisconsin. Again, this plot is nearly
identical to those taken in New Jersey, Tennessee, Iowa, Minnesota,
Alabama, Kentucky, and Mississippi.  Another frequency plot from a site in Kentucky:  And one more from Florida (thanks to
Russell Simmons and Tom Ventresca at JEA) using a PML meter. 
The cool photo of the U.S. showing the blackout area that I had
posted here earlier turned out to be a hoax (
http://members.cox.net/mconner1/blackout.html,
http://www.breakthechain.org/exclusives/blackoutsat.html,
http://www.globalsecurity.org/eye/blackout_2003.htm ).
Those that have attended seminars I have taught over the years
may remember that I often say that the only measurements you
can trust are those that you do yourself or with a trusted
colleague. Well since I don't have access to a satellite
(at least not at the moment!), I couldn't take this measurement
myself and was fooled by the offer of this data. It pays
to practice what you preach. - Erich. |
Copyright © 2003 EnerNex Corporation. All rights reserved. |
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