[time-nuts] Line Frequeny Stablity
jn6wfo at gmail.com
Wed Apr 5 19:57:11 EDT 2017
A fun way to monitor the state of the grid is to watch the web site of
Information Technology Laboratory <http://powerit.utk.edu> at the University
of Tennessee <http://www.utk.edu>, Their site lists in both tabular and
graphical (map) form the frequency of the grid. Most of it is USA-based but
there are a few other countries also monitored.
I have one of the monitors (in the table display page <
http://fnetpublic.utk.edu/tabledisplay.html> my monitor is #853 in the
Western Interconnection—I'm in California).
The monitors, about the size of a thick hardback book, plug into a
convenient AC line outlet, connect to your Internet router, and have a
small puck-style GPS antenna so that it knows the time and where it is. The
unit has an LCD display of date, time, line voltage, and line frequency.
The voltage is shown to 3 decimal digits of resolution and the frequency to
I got my monitor from the U of T after I sent them a report on my home-made
monitor's results. It's interesting to watch the frequency wander up and
down but always average very close to 60.000 Hz. They saw I had an interest
and offered me one of their toys. The only thing it doesn't do is connect
to my PC so I can monitor it long-term. I suppose if I were clever with
network stuff there'd be a way to tap into its data stream.
On Wed, Apr 5, 2017 at 2:12 PM, Bob kb8tq <kb8tq at n1k.org> wrote:
> Back in high school, one of the radio club members figured out that the
> “clock adjustment” took place
> locally between 4:30 and 5:00 PM. Needless to say, pretty much everybody
> spent the next week listening
> to WWV and watching the clock’s second hand go out of sync with the beeps.
> This was back in the late 1960’s
> and the idea of a grid was a bit looser than it is today. Indeed it was
> post 1964 so there *were* grids big
> enough to take out the whole north east section of the US. Since we were
> very much in that area the
> topic of grid sync came up. Nobody ever really had a good answer to that
> question. That included the
> guys who ran the local power company.
> > On Apr 5, 2017, at 3:05 PM, Hal Murray <hmurray at megapathdsl.net> wrote:
> > preilley_454 at comcast.net said:
> >> When I installed power plants in the 1970's they has a special "clock"
> >> showed the cumulative error in terms of clock time.
> > How big were the grids back then?
> > What was the typical range of error over a day or month?
> >> If the generator ran a little too fast the clock would move forward.
> >> the operator observed the clock moving away from zero he would reduce
> >> plant's power and the clock would move backward toward zero. ...
> > Does that operator control a single generator or a whole grid?
> > Does having a human in the loop help the control loop stability?
> > --
> > These are my opinions. I hate spam.
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