On 11/6/06, Marco IK1ODO <[EMAIL PROTECTED]> wrote: > > Saturday evening part of Europe experienced a blackout, caused, it > seems, by a single failure in Northern Germany, then propagated up to > southern Italy. > > A friend that routinely monitors the 0-120Hz ULF/ELF frequency > spectrum captured the power line frequency jump following the fault. > Hre are the links: > > > Thanks for sending this. Those graphs were very interesting. I've certainly never seen a frequency deviation of that magnitude or duration before! (Too bad I wasn't monitoring in 2003 during the US/East blackout! I was just on the edge of the grid collapse region at the time; our line voltage went absolutely insane for 1-2 minutes on one or two occasions, but we never lost power completely. I bet _that_ would have made for some interesting waveforms.)
On the other hand, I don't take my own measurements yet, either. What got me started on power grid monitoring was the US Department of Energy's "Gridwise Screensaver". This is a screensaver (and a standalone app) which downloads 10 samples per second of power grid frequency monitoring data from a server measuring wall-plug frequency in some DoE-funded college laboratory in the western United States. This system appears to have been designed by an engineering undergraduate working as an intern or co-op, and although it is not a bad effort at all as such, it is not what one might call well-put-together. Also, the servers on which it relies for the frequency data are often down for days or weeks at a time. As a silver lining, I did notice that you can get the DoE frequency servers to spit raw data at you, consisting of 10 frequency values per second. (You can do this by connecting with 'telnet' or 'netcat' to the monitoring port on an operable server and simply saving the data to a file.) This did at least allow me to do some rudimentary analysis in Matlab, although I did not obtain any particular conclusions, nor did I observe any especially out-of-the-ordinary events in the short time I was monitoring this. Your report, though, inspires me to look into more reliable and precise ways to measure the frequency of one's local grid. I had not actually considered monitoring electric fields "off the air" before, but it seems like this might be fairly practical. >Renato told me that during the frequency jump a faint 50Hz line was >still present. Possibly some part of the network that had detached >from the rest, or is the Russian network not interconnected with the >European Union? Could be either as far as I know. I don't know the nature of the Russian/EU interconnect (if one exists), but it is possible that the two networks are connected but only over high-voltage DC links. This is how, for example, the US Eastern and US Western interconnect zones are linked, and the rectifiers/inverters on each end of the links allows for independent frequencies in the two systems. On the subject of faint lines, I wonder if that line just below 20Hz is from 16.6Hz railway electrical networks. I could be wrong but I think they use these in Germany, although I don't know about Italy. Finally, if I may ask, I am curious why your friend monitors the 0-120Hz ULF/ELF frequency spectrum. Is the power grid the primary target of this monitoring? I don't know what else would be interesting in that range, but maybe there is something I don't know about. Rusty _______________________________________________ time-nuts mailing list [email protected] https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
