[time-nuts] Yukon Energy causes time sync problems

Brooke Clarke brooke at pacific.net
Sat Apr 10 11:59:22 EDT 2010


Hi Eric:

So line powered wall clocks keep the correct time.

Have Fun,

Brooke Clarke
http://www.PRC68.com


Eric Garner wrote:
> 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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