[time-nuts] 60Hz line data
Bill Byrom
time at radio.sent.com
Sun Jul 26 14:25:54 EDT 2015
There have been a number of proposals to completely eliminate manual
time correction (used to keep synchronous clocks accurate over long time
periods). There apparently was a manual procedure activated when the
error reached +/- 30 seconds from true time, but I think that since 2011
the power grid reliability considerations have caused grid operators to
not make any frequency changes for clock time correction. Frequency
changes are often made to change the power transfer rate.
See: FERC Docket RM14-10-000 Order: Real Power Balancing Control
Performance Reliability Standard (issued April 16, 2015) - this doesn't
mention use of time error correction!
http://www.ferc.gov/whats-new/comm-meet/2015/041615/E-3.PDF
FERC docket RM09-13-000: Time Error Correction Reliability Standard
http://www.balch.com/files/upload/%284-24-2010%29%20NERC_BAL-004_NOPR_Comments.pdf
In October 2012 this petition was withdrawn.
60Hz Stability on Power Grid Going Away?
http://www.radiomagonline.com/deep-dig/0005/60hz-stability-on-power-grid-going-away/33527
NERC Frequency Response Standard Background Document
http://www.nerc.com/comm/oc/rs%20landing%20page%20dl/related%20files/bal-003-1_background_document_clean_20121130.pdf
It appears from various comments that with no manual time correction,
the accumulated time error in the East Interconnection will typically
gain 20+ minutes/year. The West will gain 8 minutes/year and ERCOT
(Texas area) will gain 2 minutes/year.
http://www.ercot.com/content/meetings/rms/keydocs/2011/0518/03_manual_time_error_correction_elimination_field_trial.doc
So don't trust an AC synchronous motor clock in North America.
--
Bill Byrom N5BB
On Sun, Jul 26, 2015, at 07:08 AM, Bob Camp wrote:
> Hi
>
> That correlates quite well with data from the 1960’s before “everybody”
> was
> on one big network.
>
> Bob
>
>> On Jul 25, 2015, at 7:25 PM, Hal Murray <hmurray at megapathdsl.net> wrote:
>>
>>
>> I've updated the graph at:
>> http://www.megapathdsl.net/~hmurray/time-nuts/line/Calif-60Hz-2014-2015.pn
>> g
>>
>> and added July-2015 at:
>> http://www.megapathdsl.net/~hmurray/time-nuts/line/Calif-60Hz-2015-Jul.png
>>
>> July 19th shifted 15 seconds in one day!
>> The shift is 25 seconds over July 17-19.
>>
>> --
>> These are my opinions. I hate spam.
>>
>>
>>
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