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Author Topic: Grid experiment may hurry clocks  (Read 6204 times)

systemdm

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Grid experiment may hurry clocks
« on: June 26, 2011, 11:06:45 PM »

Interesting read..... -:)  This came out of Saturdays San Jose Mercury News here in California.


Grid experiment may hurry clocks


Changes to electric current could affect many appliances

By Seth Borenstein

Associated Press

WASHINGTON — A yearlong experiment with the nation’s electric grid could mess up traffic lights, security systems and some computers — and make plug-in clocks and appliances such as programmable coffeemakers run up to 20 minutes fast.

“A lot of people are going to have things break and they’re not going to know why,” said Demetrios Matsakis, head of the time service department at the U.S. Naval Observatory, one of two official timekeeping agencies in the federal government.

Since 1930, electric clocks have kept time based on the rate of the electrical current that powers them. If the current slips off its usual rate, clocks run a little fast or slow. Power companies now take steps to correct it and keep the frequency of the current — and the time — as precise as possible.

The group that oversees the U.S. power grid is proposing an experiment that would allow more frequency variation than it does now without corrections, according to a company presentation obtained by The Associated Press.

Officials say they want to try this to make the power supply more reliable, save money and reduce what may be needless efforts. The test is tentatively set to start in mid-July, but that could change.

Adjusting the power grid’s frequency is expensive and takes a lot of effort, said Joe McClelland, head of electric reliability for the Federal Energy Regulatory Commission.

“Is anyone using the grid to keep track of time?” Mc-Clelland said. “Let’s see if anyone complains if we eliminate it.”

No one is quite sure what will be affected. This won’t change the clocks in cellphones, GPS or even on computers, and it won’t have anything to do with official U.S. time or Internet time.

But wall clocks and those on ovens and coffeemakers — anything that flashes “12:00” when it loses power — may be just a bit off every second, and that error can grow with time.

It’s not easy figuring what will run fast and what won’t. For example, VCRs or DVRs that get their time from cable systems or the Internet probably won’t be affected, but those with clocks tied to the electric current will be off a bit, Matsakis said.

This will be an interesting experiment to see how dependent our timekeeping is on the power grid, Matsakis said.

The North American Electric Reliability Corp. runs the nation’s interlocking web of transmission lines and power plants. A June 14 company presentation spelled out the potential effects of the change: East Coast clocks may run as much as 20 minutes fast over a year, but West Coast clocks are only likely to be off by 8 minutes. In Texas, it’s only an expected speedup of 2 minutes.

Some parts of the grid, like in the East, tend to run faster than others. Errors add up. If the grid averages just more than 60 cycles a second, clocks that rely on the grid will gain 14 seconds per day, according to the company’s presentation.

Spokeswoman Kimberly Mielcarek said the company is still discussing the test and gauging reactions to its proposal and may delay the experiment a bit.

Mielcarek said in an email that the change is about making the grid more reliable and that correcting the frequency for time deviations can cause other unnecessary problems for the grid. She wrote that any problems from the test are only possibilities.

In the future, more use of renewable energy from the sun and wind will mean more variations in frequency on the grid, McClelland said. Solar and wind power can drop off the grid with momentary changes in weather. Correcting those deviations is expensive and requires instant backup power to be always at the ready, he said.


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pomonabill221

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Re: Grid experiment may hurry clocks
« Reply #1 on: June 26, 2011, 11:59:14 PM »

hmmm!!!! VERY interesting AND money money money is what is ultimately driving this!
   BUT  I thought that most digital clocks, uwave, clock radios, cm15, etc., kept their time with a crystal inside the clock, being divided by the clock chip, and did not rely on 60Hz power.
  There may be SOME clocks that do use the line frequency for their time base, but if you think about it, it would be MUCH cheaper to manufacture a clock that used the internal soft/firm/hardware of the clock chip to divide it's crystal oscillator to derive the time base, rather than reduce the incoming power line, clamp it for almost a square wave, have either the clock chip detect the rising/falling edge of the "square wave" or an external comparator or Schmidt trigger device drive an input to the clock chip.
  This would require external voltage divider, two diodes (for the clamping), and still the chip would have to detect the edges.
 I know that this used to be done years ago, but now we have real cheap crystals with low drift vs. temperature and time, and no external components are required.
  Analog clocks that have a synchronous motor driving them WILL drift however.
  For industrial apps., huge motors that drive fans, compressors do use synchronous motors so these would change speed directly, although not by much.
  The consequences will be widespread, and include all SYNCHRONOUS clocks AND motors that rely on 60 Hz for their synchronous speed!
  This article is interesting though, and will be interesting to see what happens.
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JeffVolp

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Re: Grid experiment may hurry clocks
« Reply #2 on: June 27, 2011, 01:10:43 AM »

   BUT  I thought that most digital clocks, uwave, clock radios, cm15, etc., kept their time with a crystal inside the clock, being divided by the clock chip, and did not rely on 60Hz power.

Actually, it is much cheaper to use 60Hz for an accurate time reference than a crystal oscillator with similar accuracy.

Except for computers, which normally have a battery powered crystal time base to maintain time and date when they are disconnected, most AC powered devices use the 60Hz powerline for time reference.  It has been historically very accurate over long term.

Any clock that has to be reset following a power interruption uses 60Hz as a timing reference.  Some devices use 60Hz when powered, and switch to a less accurate internal time base when AC power is interrupted.

Jeff
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dave w

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Re: Grid experiment may hurry clocks
« Reply #3 on: June 27, 2011, 10:09:42 AM »

One would think over time, small variations would even out.

I am confused about the article statement that power in the east tends to run fast. What, all generators east of the Divide are GE and all west of the Divide are Siemens?   rofl
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Brian H

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Re: Grid experiment may hurry clocks
« Reply #4 on: June 27, 2011, 11:03:12 AM »

I thought that they kept it close to 60Hz so as they swap from grid to grid with loads change. You don't get slightly out of phase AC banging into each other.  :'
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dave w

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Re: Grid experiment may hurry clocks
« Reply #5 on: June 27, 2011, 01:05:31 PM »

I thought that they kept it close to 60Hz so as they swap from grid to grid with loads change. You don't get slightly out of phase AC banging into each other.  :'
Yeah! One would think phase differentials between generating stations would create losses of power until they are synced. So I would think it would cost more NOT to be synced.

I have a relative that works for Omaha Power and will ask him next time I see him. OPPD has a nuke plant north of Omaha surrounded by flood waters.
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HA Dave

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Re: Grid experiment may hurry clocks
« Reply #6 on: June 27, 2011, 10:10:00 PM »

WASHINGTON — A yearlong experiment with the nation’s electric grid......

There will be no time changes or problems. This is merely a scheme by the current administration to put a few billion into the hands of favored contributors (like GE and certain University's). The reseach money will disappear... and that will be it.
« Last Edit: July 20, 2011, 08:30:30 PM by Dave_x10_L »
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dave w

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Re: Grid experiment may hurry clocks
« Reply #7 on: June 28, 2011, 10:23:24 AM »

WASHINGTON — A yearlong experiment with the nation’s electric grid......
This merely a scheme by the current administration to put a few billion into the hands of favored contributors (like GE and certain University's). The reseach money will disappear... and that will be it.
Hadn't thought about it that way, but I can't get around the possible power loss if things aren't in sync...this begins to make sense.
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Re: Grid experiment may hurry clocks
« Reply #8 on: July 20, 2011, 12:19:54 AM »

Reminds me a bit of the research grant that paid for a study of hikers, campers, sport fishermen, etc.

The conclusion?

They like the outdoors.   rofl

I tend to agree that this is just a way to give payola to some friends of the administration.   :'

The conclusion?

The obvious one that the grid must remain synchronized or bad things happen.   :o

Secondary conclusion:

It pays to support the political winner.   ;)

 >!
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