[time-nuts] Yukon Energy causes time sync problems
Eric Garner
garnere at gmail.com
Sat Apr 10 15:31:10 UTC 2010
My question is why is it done that way at all? It seems impractical in
the extreme. Why not use a meter? Or the afore mentioned vibrating
reeds?
What happens when the clock rates sync up again, since the wall clock
time will still be ahead/behind the sat clock? Do they reset the wall
clock? Or is it only the rate that matters?
Given the sophistication of the rest of the network there must be a
reason.
Sent from my Banana Jr. mobile device
On Apr 8, 2010, at 3:48 PM, "Bill Hawkins" <bill at iaxs.net> wrote:
> Brooke,
>
> There are some interesting misconceptions here.
>
> Yukon Power did not cause time to slow down. They did what every
> generating
> station does, which is to adjust drive power to make a synchronous
> power
> line
> clock match a precision reference clock. The tolerance is seconds
> because
> the
> means for controlling drive power has a time constant of several
> seconds.
>
> The real problem is the way demand varies. If you pour mechanical
> power into
> a generator, it will speed up when lightly loaded or slow down when
> heavily
> loaded. This is less of a problem when many generators are tied
> together by
> a power grid, as they are all synchronous machines. Central
> dispatching
> stations compare line and reference clocks, and direct plants with
> capacity
> to do so to make up lost cycles, or buy less from the most expensive
> sources
> when extra cycles are generated.
>
> If you have a 5 digit counter (or more) tied to a computer, you can
> plot the
> deviation of line frequency for 24 hour intervals. TVB had this on
> his site.
> What I saw in MN was that generators speeded up in the early morning
> to make
> up cycles so there was no reference error at 6 AM. Then the loads
> turned on
> and the cycles fell behind and recovered as power was dispatched,
> within +/-
> 6 seconds. This is good enough for social time, where the mundanes
> don't
> know
> about time-nuts.
>
> The Alaskan network is probably too sparse for central direction, so
> each
> power plant makes its own adjustments. Note that this doesn't
> necessarily
> produce stable control, ever.
>
> In this case, the reference clock appears to refer to GPS satellite
> time,
> but
> uses a standard wall clock to display it. It is the reference clock
> that
> slowed down when it should have failed to work at all. Perhaps the
> wall
> clock
> (maybe it was really a HP 113) needed oil. There's the real question
> for
> time
> nuts: How did the reference clock slow down?
>
> The first comment to the article shows what happens when your ego
> fails to
> shame you into silence when you don't know what you're talking about:
>
> "I don't understand how the amount being generated has anything to
> do with
> what happens to household electronics." [see above]
>
> "It would make more sense if the plant was generating at 55Hz versus
> 60Hz
> as some electronics will use the line frequency rather than integrated
> oscillators to set clocks." [The plant probably has breakers that
> take it
> off line when the frequency gets below 58 cycles, to keep it from
> dragging
> the network down.] [I thought that all electronics today converted
> the line
> to DC without sampling it, and ran timing from a crystal. Anyone
> know?]
>
> "Regardless, it shows YEC continues to be a bunch of bumbling
> oafs." [People
> who live in glass houses shouldn't stow thrones, or something like
> that.]
>
> Thanks, Brooke. I had some fun explaining all this.
>
> Bill Hawkins
>
>
> -----Original Message-----
> From: Brooke Clarke
> Sent: Thursday, April 08, 2010 12:58 PM
> To: Discussion of precise time and frequency measurement
> Subject: [time-nuts] Yukon Energy causes time sync problems
>
> Hi:
>
> http://whitehorsestar.com/archive/story/time-passed-more-slowly-over-the-eas
> ter-holiday/
>
> --
> Have Fun,
>
> Brooke Clarke
> http://www.PRC68.com
>
>
>
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