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On 25/06/2024 10.34, Paul S Person wrote:On Tue, 25 Jun 2024 08:56:17 -0500, "Michael F. Stemper">
<michael.stemper@gmail.com> wrote:
On 20/06/2024 11.21, Paul S Person wrote:On Thu, 20 Jun 2024 02:59:25 GMT, Random <random@who.cares> wrote:>>A conventional bulb's filament is not sensitive to AC voltage fluctionations,>
where the conversion electronics is. My guess is that your wiring to that
light is causing voltage dips and is stressing the electronics in the LED bulb
base.
I've seen a similar claim about timers that actually count
cycles-per-second: if those vary then the timer misperforms.
This isn't really an issue in North America. According to NERC[1], frequency in
the Eastern Interconnection (EI) is above 59.972 Hz 95% of the time. This is
99.95% of nominal frequency, or an error of 28 mHz.
>
If frequency sat that low for a 24 hour period (which it doesn't; frequency error
regularly crosses zero), it would be a loss of 40 seconds in a day.
>
As a matter of fact, a few years back, the EI had an ongoing problem with frequency
being high: 3 mHz fast as a sustained average over several years. This was considered
a significant enough issue to require an investigation[2].
>
If uncorrected, it would have caused clocks to gain over 4 seconds per day. This
led to regularly implementing Time Error Correction. In this case, that meant a
coordinated (across the EI) reduction in generation to reduce frequency until the
time error crossed zero again.
>
Four seconds error per day is considered a problem. If you live in North America,
you can count[3] on your analog clock.
Three things:
-- I was talking about a timer, not a clock. In particular, a timer
controlling our porch light, when went wonky after about 10 years. It
could, of course, have simply aged out, or my switch to CFLs may have
been responsible, who can say? And the timer was put in in the 90s.
Still works fine as manual switch, though.
Functionally, there is no difference between a timer that works by
counting cycles and a clock that does the same. The laws of physics
are uninterested in what you call it. If it integrates frequency,
it's a clock.
>-- My memory is that our City Light was reducing the CPS deliberately>
-- or allowing it to fluctuate as it chose -- for some reason.
Seattle City Light can not let their frequency vary independently, unless
they were to disconnect from the WI, which would mean that they could no
longer buy or sell energy. It would also mean that they would need to
keep more generators running than would be needed for local consumption,
just to meet spinning reserve requirements.
-- Seattle is not in the Eastern Interconnection. Not that I think>
whatever Interconnection it /is/ in does any different than the EI.
That'd be the Western Interconnection (WI), run by the Western Electricity
Coordinating Council (WECC). (It's often referred to as "WECC", since
that's the only Regional Entity for the WI.
>
Recent data[1] show that their worst performance was 2020 Q3,
when they had a whopping 20+ minutes of absolute frequency error
(actual versus scheduled) outside of 68 mHz.
[1] <https://www.wecc.org/PerformanceAnalysis/Pages/ReliabilityIndicatorDashboard.aspx?6#Indicator6%3aTrendininterconnectionfrequencyresponseandperformance>
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