[time-nuts] 60 Hz data

Poul-Henning Kamp phk at phk.freebsd.dk
Thu Jun 30 09:44:02 UTC 2011


In message <20110630093603.850EE800037 at ip-64-139-1-69.sjc.megapath.net>, Hal Mu
rray writes:

>Here is the same data plotted as frequency measured over 10 seconds.
>  http://www.megapathdsl.net/~hmurray/time-nuts/60Hz-a.png

The strong drops in the first approx 15 minutes of the hour indicates
valid data.

Power plants and power trading are usually scheduled in full hours and
therefore during the first 15 minutes of hours things ramp up and down.

Because of the assymetry in the frequency/power regulation and the fact
that you can shave your margins, plats usually ramp down faster than
they ramp up, causing these very recognizable dips.


-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
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Never attribute to malice what can adequately be explained by incompetence.



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