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Preliminary Analysis of Measurement Data from New York Blackout of 2003 by
Note: Updated measurement data and analysis can be found at:
http://www.enernex.com/special/blackout_update1.htm. The following plot illustrates the frequency excursion experienced by the power grid in Knoxville, Tennessee due to the sequence of events leading to the blackout in the northeast on Thursday, August 14, 2003 at 4:10:40.250 PM. Due to the interconnected nature of the nation's electric power system, major disturbances to the grid can be measured hundreds of miles away. Note that this and the following measurements were taken using the Dranetz-BMI Signature System. More information on this system is provided at the end of this article.   In the New York Metropolitan area, the first sign that powered equipment had that a power disturbance was underway was a voltage sag down to 80 percent of normal voltage as is shown in the following figure. There are measurements from locations in Michigan that have unverified time stamps slightly before this one that may indicate that there were precursor events before this one.  The next event depicted below occurred 3 seconds later. It shows a deep sag down to 50 percent of normal. Since these measurements are on the low voltage side of a 13 kv to 480 volt transformer, the local load reaction to the initiating sag event may be impacting the voltage measurement due to high current flow during the initial sag.  As the event caused cascading failures in the power system, two more events were detected on the power grid in the Newark area as shown in the next two plots. The first is another sag - this time down to 85 percent of normal voltage, and then a temporary voltage swell that lasts for almost two minutes as the power system comes to a new steady state with a higher than normal voltage due to the enormous load dropped from the grid. 
 The first event was GPS time stamped at 4:10:40.250 PM EDT and the event recovery swell shown above ended at 4:13:09.770 PM EDT. Over the course of those two minutes and twenty eight seconds (with all of the "fast events" happening in the first 20 seconds), millions of people lost power over several states and in Canada. The final figure that follows shows the voltage profile for the entire day of August 14, 2003 - the day to be remembered for years to come as the day the Blackout of 2003 occurred.  EnerNex Corporation provides measurement and analysis services to utilities, industry, and government agencies to analyze these types of events for the purpose of understanding their cause and then work to develop methods and practices to minimize the chances of their occurrence in the future. An analysis of the impact of the 1977 blackout performed by one of our associates (Dr. William T. Miles) and published in July of 1978 can be found at http://www.enernex.com/special/impact_77_blackout.pdf. (3.29 MB). For information regarding the design of a new utility communications architecture to help minimize such events in the future, please check out http://www.iecsa.org. For more information, please contact erich@enernex.com. The measurements used in this analysis were taken using the Dranetz-BMI Signature System - a state-of-the-art power measurement system for which this author was the chief architect for while at Electrotek Concepts, Inc. - a sister company of Dranetz-BMI under WPT, Inc. |
Copyright © 2003 EnerNex Corporation. All rights reserved. |
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