Mains power voltage drop to reduce usage?...

[Commander Kinsey]

Instead of rolling blackouts when there\'s a power shortage, why don\'t we just allow (or deliberately) the voltage and frequency to drop? Wouldn\'t that make a lot of devices use less?

 

[danny burstein]

In <op.1u7t9bhtmvhs6z@ryzen.home> \"Commander Kinsey\" <CK1@nospam.com> writes:

>Instead of rolling blackouts when there\'s a power shortage, why don\'t we just allow (or deliberately) the voltage and frequency to drop? Wouldn\'t that make a lot of devices use less?

In the US that\'s a common technique the utilites use
called a \"brownout\" [a]. They\'ll drop the voltage
by five or even ten percent.

As to whether this makes any difference with power demand
these days, given the types of loads, is another story.

[a] that term is often misused to refer to \"shedding load\",
where a power company will black out some sections of the
grid to keep everything else up and running.


--
_____________________________________________________
Knowledge may be power, but communications is the key
dannyb@panix.com
[to foil spammers, my address has been double rot-13 encoded]

 

[Peeler]

On Sun, 06 Nov 2022 14:23:25 -0000, Birdbrain Macaw (aka \"Commander Kinsey\",
\"James Wilkinson\", \"Steven Wanker\",\"Bruce Farquar\", \"Fred Johnson, etc.),
the pathological resident idiot and attention whore of all the uk ngs,
blathered again:

<FLUSH the subnormal sociopathic trolling attention whore\'s latest
attention-baiting sick bullshit unread again>

--
damduck-egg@yahoo.co.uk about Birdbrain Macaw\'s (now \"Commander Kinsey\" LOL)
trolling:
\"He is a well known attention seeking troll and every reply you
make feeds him.
Starts many threads most of which die quick as on the UK groups anyone
with sense Kill filed him ages ago which is why he now cross posts to
the US groups for a new audience.
This thread was unusual in that it derived and continued without him
to a large extent and his silly questioning is an attempt to get
noticed again.\"
MID: <be195d5jh0hktj054mvfu7ef9ap854mjdb@4ax.com>

--
ItsJoanNotJoann addressing Birdbrain Macaw\'s (now \"Commander Kinsey\" LOL):
\"You\'re an annoying troll and I\'m done with you and your
stupidity.\"
MID: <e39a6a7f-9677-4e78-a866-0590fe5bbc38@googlegroups.com>

--
AndyW addressing Birdbrain:
\"Troll or idiot?...
You have been presented with a viewpoint with information, reasoning,
historical cases, citations and references to back it up and wilfully
ignore all going back to your idea which has no supporting information.\"
MID: <KaToA.263621$g93.262397@fx10.am4>

--
Phil Lee adressing Birdbrain Macaw:
\"You are too stupid to be wasting oxygen.\"
MID: <uv2u4clurscpat3g29l7aksbohsassufe2@4ax.com>

--
Phil Lee describing Birdbrain Macaw:
\"I\'ve never seen such misplaced pride in being a fucking moronic motorist.\"
MID: <j7fb6ct83igfd1g99rmu4gh9vf610ra3jk@4ax.com>

--
Tony944 addressing Birdbrain Macaw:
\"I seen and heard many people but you are on top of list being first class
ass hole jerk. ...You fit under unconditional Idiot and should be put in
mental institution.
MID: <VLCdnYC5HK1Z4S3FnZ2dnUU7-dPNnZ2d@giganews.com>

--
Pelican to Birdbrain Macaw:
\"Ok. I\'m persuaded . You are an idiot.\"
MID: <obru31$nao$3@dont-email.me>

--
DerbyDad03 addressing Birdbrain Macaw (now \"Commander Kinsey\" LOL):
\"Frigging Idiot. Get the hell out of my thread.\"
MID: <4d907253-b3b9-40d4-be4d-b32d453937e0@googlegroups.com>

--
Kerr Mudd-John about Birdbrain Macaw (now \"Commander Kinsey LOL):
\"It\'s like arguing with a demented frog.\"
MID: <op.yy3c02cqmsr2db@dell3100.workgroup>

--
Mr Pounder Esquire about Birdbrain Macaw (now \"Commander Kinsey\" LOL):
\"the piss poor delivery boy with no hot running water, 11 cats and
several parrots living in his hovel.\"
MID: <odqtgc$iug$1@dont-email.me>

--
Rob Morley about Birdbrain:
\"He\'s a perennial idiot\"
MID: <20170519215057.56a1f1d4@Mars>

--
JoeyDee to Birdbrain
\"I apologize for thinking you were a jerk. You\'re just someone with an IQ
lower than your age, and I accept that as a reason for your comments.\"
MID: <0001HW.1EE2D20300E7BECC700004A512CF@news.eternal-september.org>

--
Sam Plusnet about Birdbrain (now \"Commander Kinsey\" LOL):
\"He\'s just desperate to be noticed. Any attention will do, no matter how
negative it may be.\"
MID: <rOmdndd_O7u8iK7EnZ2dnUU78TGdnZ2d@brightview.co.uk>

--
thekmanrocks@gmail.com asking Birdbrain:
\"What, were you dropped on your head as a child?\"
MID: <58ddfad5-d9a5-4031-b91f-1850245a6ed9@googlegroups.com>

--
Christie addressing endlessly driveling Birdbrain Macaw (now \"Commander
Kinsey\" LOL):
\"What are you resurrecting that old post of mine for? It\'s from last
month some time. You\'re like a dog who\'s just dug up an old bone they
hid in the garden until they were ready to have another go at it.\"
MID: <59d8b0db.4113512@news.eternal-september.org>

--
Mr Pounder\'s fitting description of Birdbrain Macaw:
\"You are a well known fool, a tosser, a pillock, a stupid unemployable
sponging failure who will always live alone and will die alone. You will not
be missed.\"
MID: <orree6$on2$1@dont-email.me>

--
Richard to pathetic wanker Hucker:
\"You haven\'t bred?
Only useful thing you\'ve done in your pathetic existence.\"
MID: <orvctf$l5m$1@gioia.aioe.org>

--
clare@snyder.on.ca about Birdbrain (now \"Commander Kinsey\" LOL):
\"\"not the sharpest knife in the drawer\"\'s parents sure made a serious
mistake having him born alive -- A total waste of oxygen, food, space,
and bandwidth.\"
MID: <s5e9uclqpnabtehehg3d792tmll73se0g8@4ax.com>

--
Mr Pounder exposing sociopathic Birdbrain:
\"You will always be a lonely sociopath living in a shithole with no hot
running water with loads of stinking cats and a few parrots.\"
MID: <os5m1i$8m1$1@dont-email.me>

--
francis about Birdbrain (now \"Commander Kinsey\" LOL):
\"He seems to have a reputation as someone of limited intelligence\"
MID: <cf06cdd9-8bb8-469c-800a-0dfa4c2f9ffa@googlegroups.com>

--
Peter Moylan about Birdbrain (now \"Commander Kinsey\" LOL):
\"If people like JWS didn\'t exist, we would have to find some other way to
explain the concept of \"invincible ignorance\".\"
MID: <otofc8$tbg$2@dont-email.me>

--
Lewis about nym-shifting Birdbrain:
\"Typical narcissist troll, thinks his shit is so grand he has the right to
try to force it on everyone
MID: <slrnq16c27.1h4g.g.kreme@jaka.local>

 

[Peeler]

On Sun, 6 Nov 2022 14:29:38 -0000 (UTC), danny burstein, another brain dead,
troll-feeding senile ASSHOLE, blathered:


> In the US that\'s a common technique

You mean the technique of miserable senile assholes like who are thankfully
feeding the most idiotic and deranged trolls around, troll-feeding senile
asshole?

 

[NY]

\"Commander Kinsey\" <CK1@nospam.com> wrote in message
newsp.1u7t9bhtmvhs6z@ryzen.home...

Instead of rolling blackouts when there\'s a power shortage, why don\'t we
just allow (or deliberately) the voltage and frequency to drop? Wouldn\'t
that make a lot of devices use less?

No.

Reducing the frequency will cause mains-referenced clocks to run slow. And
that is many clocks with digital displays (which I thought until recently
used quartz crystals like a watch) and not just older clocks with
synchronous motors. Reducing the frequency too far may affect the efficiency
of transformers: I think reducing the frequency makes it more likely that
the magnetic core will saturate (though I may have got that the wrong way
round!). (*)

Reducing the voltage will reduce the power consumption of resistive loads
such as immersion heaters and cooker hobs/ovens, but may have little
difference to switched-mode power supplies as used in electronic equipment
because they will drawn proportionally more current to maintain the rated
output (eg 5V for phone or 20 V for laptop).

And if the temperature of an oven reduces, or the power output of a kettle
reduces, the appliance will need to be on longer to cook the food or boil
the same amount of water, so there will be no saving. In most cases you are
interested in the transfer of a certain amount of energy to do a given job,
and it doesn\'t matter whether that is transferred as high power for a small
amount of time or a lower power for a longer period of time.



(*) I\'ve heard it said that transformer-driven devices from the US don\'t
necessarily work efficiently in Europe (even if you correct for the
different voltage) whereas European devices run OK in the US (having
corrected for voltage) because of the difference between 60 Hz (US) and 50
Hz (UK). Or maybe it\'s the opposite way round.

 

[JNugent]

On 07/11/2022 02:45 pm, NY wrote:

\"Commander Kinsey\" <CK1@nospam.com> wrote in message
newsp.1u7t9bhtmvhs6z@ryzen.home...
Instead of rolling blackouts when there\'s a power shortage, why don\'t
we just allow (or deliberately) the voltage and frequency to drop?
Wouldn\'t that make a lot of devices use less?

No.

Reducing the frequency will cause mains-referenced clocks to run slow.
And that is many clocks with digital displays (which I thought until
recently used quartz crystals like a watch) and not just older clocks
with synchronous motors. Reducing the frequency too far may affect the
efficiency of transformers: I think reducing the frequency makes it more
likely that the magnetic core will saturate (though I may have got that
the wrong way round!). (*)

That sounds more likely to be right than wrong in an extreme case.

Applying a high-enough-voltage DC supply to the primary side of a
transformer can eventually overheat the coil and burn off the winding
wire\'s insulation coating. Reducing the frequency isn\'t the same as
supplying DC, but the lower the frequency, the more like DC it becomes.

Reducing the voltage will reduce the power consumption of resistive
loads such as immersion heaters and cooker hobs/ovens, but may have
little difference to switched-mode power supplies as used in electronic
equipment because they will drawn proportionally more current to
maintain the rated output (eg 5V for phone or 20 V for laptop).

Charging units work more or less just as well when transplanted from the
USA to the UK and vice-versa. Reducing frequency by about a fifth or a
sixth shouldn\'t have a disastrous effect.

And if the temperature of an oven reduces, or the power output of a
kettle reduces, the appliance will need to be on longer to cook the food
or boil the same amount of water, so there will be no saving. In most
cases you are interested in the transfer of a certain amount of energy
to do a given job, and it doesn\'t matter whether that is transferred as
high power for a small amount of time or a lower power for a longer
period of time.

We like induction hobs. There\'s no power wasted heating the environment
- just the cooking vessel - and they are so efficient that they can work
off a 13A power point. Same point as above regarding Hz change, though.

(*) I\'ve heard it said that transformer-driven devices from the US don\'t
necessarily work efficiently in Europe (even if you correct for the
different voltage) whereas European devices run OK in the US (having
corrected for voltage) because of the difference between 60 Hz (US) and
50 Hz (UK). Or maybe it\'s the opposite way round.

See above re phone and laptop chargers.

 

[Fredxx]

On 07/11/2022 14:45, NY wrote:

\"Commander Kinsey\" <CK1@nospam.com> wrote in message
newsp.1u7t9bhtmvhs6z@ryzen.home...
Instead of rolling blackouts when there\'s a power shortage, why don\'t
we just allow (or deliberately) the voltage and frequency to drop?
Wouldn\'t that make a lot of devices use less?

No.

Reducing the frequency will cause mains-referenced clocks to run slow.
And that is many clocks with digital displays (which I thought until
recently used quartz crystals like a watch) and not just older clocks
with synchronous motors. Reducing the frequency too far may affect the
efficiency of transformers: I think reducing the frequency makes it more
likely that the magnetic core will saturate (though I may have got that
the wrong way round!). (*)

No, you\'re spot on. It has been discussed in this group before. In
general, 60Hz transformers can either be more efficient or smaller than
their 50Hz cousins.

 

[Peeler]

On Mon, 7 Nov 2022 14:45:34 -0000, NY, the really endlessly blathering,
notorious, troll-feeding, senile asshole, blathered, yet again:

No.

Reducing the frequency will cause mains-referenced clocks to run slow. And
that is many clocks with digital displays (which I thought until recently
used quartz crystals like a watch) and not just older clocks with
synchronous motors. Reducing the frequency too far may affect the efficiency
of transformers: I think reducing the frequency makes it more likely that
the magnetic core will saturate (though I may have got that the wrong way
round!). (*)

Reducing the voltage will reduce the power consumption of resistive loads
such as immersion heaters and cooker hobs/ovens, but may have little
difference to switched-mode power supplies as used in electronic equipment
because they will drawn proportionally more current to maintain the rated
output (eg 5V for phone or 20 V for laptop).

And if the temperature of an oven reduces, or the power output of a kettle
reduces, the appliance will need to be on longer to cook the food or boil
the same amount of water, so there will be no saving. In most cases you are
interested in the transfer of a certain amount of energy to do a given job,
and it doesn\'t matter whether that is transferred as high power for a small
amount of time or a lower power for a longer period of time.

(*) I\'ve heard it said that transformer-driven devices from the US don\'t
necessarily work efficiently in Europe (even if you correct for the
different voltage) whereas European devices run OK in the US (having
corrected for voltage) because of the difference between 60 Hz (US) and 50
Hz (UK). Or maybe it\'s the opposite way round.

You don\'t have much to say in real life, eh, troll-feeding senile asshole?
That\'s why you, like many other poor senile assholes, will even happily keep
feeding the dumbest trolls, just so you got someone to talk to. <BG>

 

[Rod Speed]

NY <me@privacy.invalid> wrote

Commander Kinsey <CK1@nospam.com> wrote

Instead of rolling blackouts when there\'s a power shortage, why don\'t
we just allow (or deliberately) the voltage and frequency to drop?
Wouldn\'t that make a lot of devices use less?

No.

Reducing the frequency too far may affect the efficiency of
transformers: I think reducing the frequency makes it more likely that
the magnetic core will saturate (though I may have got that the wrong
way round!). (*)

(*) I\'ve heard it said that transformer-driven devices from the US don\'t
necessarily work efficiently in Europe (even if you correct for the
different voltage)

We had a brand new US manufactured mass spectrometer quite
literally catch fire because it didnt like running on 50Hz instead
of 60Hz. The main transformer overheated and caught fire.

whereas European devices run OK in the US (having corrected for voltage)
because of the difference between 60 Hz (US) and 50 Hz (UK).

Or maybe it\'s the opposite way round.

Nope, you have it the right way round.

 

[Peeler]

On Tue, 08 Nov 2022 04:58:05 +1100, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again:

<FLUSH the abnormal trolling senile cretin\'s latest trollshit unread>

--
The Natural Philosopher about senile Rodent:
\"Rod speed is not a Brexiteer. He is an Australian troll and arsehole.\"
Message-ID: <pu07vj$s5$2@dont-email.me>

 

[Wim Ton]

On Monday, 7 November 2022 at 17:58:15 UTC, Rod Speed wrote:

NY <m...@privacy.invalid> wrote
Commander Kinsey <C...@nospam.com> wrote
Instead of rolling blackouts when there\'s a power shortage, why don\'t
we just allow (or deliberately) the voltage and frequency to drop?
Wouldn\'t that make a lot of devices use less?

No.
Reducing the frequency too far may affect the efficiency of
transformers: I think reducing the frequency makes it more likely that
the magnetic core will saturate (though I may have got that the wrong
way round!). (*)
(*) I\'ve heard it said that transformer-driven devices from the US don\'t
necessarily work efficiently in Europe (even if you correct for the
different voltage)
We had a brand new US manufactured mass spectrometer quite
literally catch fire because it didnt like running on 50Hz instead
of 60Hz. The main transformer overheated and caught fire.
whereas European devices run OK in the US (having corrected for voltage)
because of the difference between 60 Hz (US) and 50 Hz (UK).

Or maybe it\'s the opposite way round.
Nope, you have it the right way round.

Are you aware that the UK uses 240 Volts instead of 110 Volts in the US? I managed to blow up the SMPS of a large HDD that way.
Wim

 

[John Larkin]

On Mon, 7 Nov 2022 12:35:59 -0800 (PST), Wim Ton <wim.ton@gmail.com>
wrote:

On Monday, 7 November 2022 at 17:58:15 UTC, Rod Speed wrote:
NY <m...@privacy.invalid> wrote
Commander Kinsey <C...@nospam.com> wrote
Instead of rolling blackouts when there\'s a power shortage, why don\'t
we just allow (or deliberately) the voltage and frequency to drop?
Wouldn\'t that make a lot of devices use less?

No.
Reducing the frequency too far may affect the efficiency of
transformers: I think reducing the frequency makes it more likely that
the magnetic core will saturate (though I may have got that the wrong
way round!). (*)
(*) I\'ve heard it said that transformer-driven devices from the US don\'t
necessarily work efficiently in Europe (even if you correct for the
different voltage)
We had a brand new US manufactured mass spectrometer quite
literally catch fire because it didnt like running on 50Hz instead
of 60Hz. The main transformer overheated and caught fire.
whereas European devices run OK in the US (having corrected for voltage)
because of the difference between 60 Hz (US) and 50 Hz (UK).

Or maybe it\'s the opposite way round.
Nope, you have it the right way round.
Are you aware that the UK uses 240 Volts instead of 110 Volts in the US? I managed to blow up the SMPS of a large HDD that way.
Wim

120, actually. Usually measures about 122.

Residences have some 240 outlets and boxes too, for big loads like a/c
and clothes dryers.

The power supplies that we buy are agnostic.

 

[Commander Kinsey]

On Mon, 07 Nov 2022 16:10:13 -0000, Fredxx <fredxx@spam.uk> wrote:

On 07/11/2022 14:45, NY wrote:
\"Commander Kinsey\" <CK1@nospam.com> wrote in message
newsp.1u7t9bhtmvhs6z@ryzen.home...
Instead of rolling blackouts when there\'s a power shortage, why don\'t
we just allow (or deliberately) the voltage and frequency to drop?
Wouldn\'t that make a lot of devices use less?

No.

Reducing the frequency will cause mains-referenced clocks to run slow.
And that is many clocks with digital displays (which I thought until
recently used quartz crystals like a watch) and not just older clocks
with synchronous motors. Reducing the frequency too far may affect the
efficiency of transformers: I think reducing the frequency makes it more
likely that the magnetic core will saturate (though I may have got that
the wrong way round!). (*)

No, you\'re spot on. It has been discussed in this group before. In
general, 60Hz transformers can either be more efficient or smaller than
their 50Hz cousins.

Hence the very tiny kHz ones in SMPS.

 

[Commander Kinsey]

On Mon, 07 Nov 2022 16:10:13 -0000, Fredxx <fredxx@spam.uk> wrote:

On 07/11/2022 14:45, NY wrote:
\"Commander Kinsey\" <CK1@nospam.com> wrote in message
newsp.1u7t9bhtmvhs6z@ryzen.home...
Instead of rolling blackouts when there\'s a power shortage, why don\'t
we just allow (or deliberately) the voltage and frequency to drop?
Wouldn\'t that make a lot of devices use less?

No.

Reducing the frequency will cause mains-referenced clocks to run slow.
And that is many clocks with digital displays (which I thought until
recently used quartz crystals like a watch) and not just older clocks
with synchronous motors. Reducing the frequency too far may affect the
efficiency of transformers: I think reducing the frequency makes it more
likely that the magnetic core will saturate (though I may have got that
the wrong way round!). (*)

No, you\'re spot on. It has been discussed in this group before. In
general, 60Hz transformers can either be more efficient or smaller than
their 50Hz cousins.

Does this mean the power station generators spin faster over there? Or just have more coils?

 

[Peeler]

On Fri, 11 Nov 2022 17:55:38 +0000, sick, another sick demented
troll-feeding senile asshole, blathered:

It is a legal requirement to keep the frequency at 50Hz over a set period.
Therefore if it lags at any point they have to increase to catch up.

This was a legal requirement due to mains clocks.

Yet another sick troll-feeding asshole who thinks that the troll hasn\'t yet
been fed enough! <BG>

 

[Commander Kinsey]

On Wed, 09 Nov 2022 20:16:03 -0000, Carlos E.R. <robin_listas@es.invalid> wrote:

On 2022-11-09 20:55, Commander Kinsey wrote:
On Wed, 09 Nov 2022 19:48:27 -0000, Carlos E.R.
robin_listas@es.invalid> wrote:

On 2022-11-09 20:10, Commander Kinsey wrote:
On Wed, 09 Nov 2022 16:07:42 -0000, Anthony Stewart
tony.sunnysky@gmail.com> wrote:

On Sunday, 6 November 2022 at 09:23:34 UTC-5, Commander Kinsey wrote:
Instead of rolling blackouts when there\'s a power shortage, why don\'t
we just allow (or deliberately) the voltage and frequency to drop?
Wouldn\'t that make a lot of devices use less?

Most loads are energy-based with negative feedback (anything with a
sensor like a thermostat) and not power-based. The countries like
Indo-Paki have always lived with brownouts which stimulated mass-sale
of \"voltage stabilizers\" which are negative incremental impedance
converters that cumulatively adds more instability.

As local demand current increases from voltage reduction and
tap-change to increase the voltage which causes more current and
voltage drop when accumulated by many users of further reduces
disti-load voltage, leading to unstable frequent daily blackouts.

So end-users of stabilizers increase grid instability.

Current (pun intended) customer outages are:
USA 60k (s. east+west coast)
Canada 14k
UK 1.5k
UA massive outage from RU destruction

Are you sure they cause instability? They don\'t increase the power
used, they increase the current to compensate for the voltage drop.
Instability would only occur if the generators stalled, which happens if
the power drawn exceeds what they can provide. If they\'re anything like
a car alternator, the same power can come out at any revs.

Think.

The generator(s) can not cope with the load, so the voltage drops. The
stabilizers at the clients rise the current and keep the power constant,
instead of decreasing, causing the generators to drop speed instead
(because they can not cope). Normally, when the speed drops below a
value, the generator disconnects. Cascade failure. General blackout,
unless some areas disconnect from the too loaded areas and isolate.

I was assuming a voltage drop caused on purpose later on, not at the
generator. I was originally asking about reducing peak usage problems
for short periods. The electric company could drop a winding or two
somewhere to lower everyone\'s voltage. So resistive loads would use
less, and loads you\'re talking about would use precisely the same (as
far as the generator is concerned, as it\'s output voltage and current
remain the same).

Hum.

Dunno.

Maybe.

But if this strategy \"works\", the current increase causes more stress on
the hardware: it heats more. Maybe destructively.

Stuff shouldn\'t be running so close to the limit and without cutouts. What happens if you try to overrev your car engine?

 

[Commander Kinsey]

On Wed, 09 Nov 2022 20:17:08 -0000, Bob F <bobnospam@gmail.com> wrote:

On 11/9/2022 11:48 AM, Carlos E.R. wrote:
On 2022-11-09 20:10, Commander Kinsey wrote:
On Wed, 09 Nov 2022 16:07:42 -0000, Anthony Stewart
tony.sunnysky@gmail.com> wrote:

On Sunday, 6 November 2022 at 09:23:34 UTC-5, Commander Kinsey wrote:
Instead of rolling blackouts when there\'s a power shortage, why
don\'t we just allow (or deliberately) the voltage and frequency to
drop? Wouldn\'t that make a lot of devices use less?

Most loads are energy-based with negative feedback (anything with a
sensor like a thermostat) and not power-based. The countries like
Indo-Paki have always lived with brownouts which stimulated mass-sale
of \"voltage stabilizers\" which are negative incremental impedance
converters that cumulatively adds more instability.

As local demand current increases from voltage reduction and
tap-change to increase the voltage which causes more current and
voltage drop when accumulated by many users of further reduces
disti-load voltage, leading to unstable frequent daily blackouts.

So end-users of stabilizers increase grid instability.

Current (pun intended) customer outages are:
USA 60k (s. east+west coast)
Canada 14k
UK 1.5k
UA massive outage from RU destruction

Are you sure they cause instability? They don\'t increase the power
used, they increase the current to compensate for the voltage drop.
Instability would only occur if the generators stalled, which happens
if the power drawn exceeds what they can provide. If they\'re anything
like a car alternator, the same power can come out at any revs.

Think.

The generator(s) can not cope with the load, so the voltage drops. The
stabilizers at the clients rise the current and keep the power constant,
instead of decreasing, causing the generators to drop speed instead
(because they can not cope). Normally, when the speed drops below a
value, the generator disconnects. Cascade failure. General blackout,
unless some areas disconnect from the too loaded areas and isolate.


If different generators get out of sync, everything craps out, as the
current tries to correct that. Huge currents and forces can result,
destroying equipment. Keeping the sources of power in sync is probably
one of the most important constraints of running the power networks.

\"Synchronizing a generator to the power system must be
done carefully. The speed (frequency) and voltage of the
isolated generator must be closely matched, and the rotor
angle must be close to the instantaneous power system phase
angle prior to closing the generator breaker to connect the
isolated generator to the power system. Poor synchronizing
can:
• Damage the generator and the prime mover because of
mechanical stresses caused by rapid acceleration or
deceleration, bringing the rotating masses into
synchronism (exactly matched speed and rotor angle)
with the power system.
• Damage the generator and step-up transformer
windings caused by high currents.
• Cause disturbances to the power system such as power
oscillations and voltage deviations from nominal.
• Prevent the generator from staying online and picking
up load when protective relay elements interpret the
condition as an abnormal operating condition and trip
the generator\"

https://cms-cdn.selinc.com/assets/Literature/Publications/Technical%20Papers/6459_FundamentalsAdvancements_MT_20120402_Web2.pdf?v=20191007-203006#:~:text=Poor%20synchronizing%20can%3A&text=Damage%20the%20generator%20and%20the,angle)%20with%20the%20power%20system.

I thought they just powered up the generator as a motor off the grid, so it\'s precisely in phase, then started up the fuel input.

 

[server]

On Sat, 12 Nov 2022 22:22:24 +0100, \"Carlos E.R.\"
<robin_listas@es.invalid> wrote:

On 2022-11-12 15:17, Commander Kinsey wrote:
On Sat, 12 Nov 2022 13:39:00 -0000, Carlos E.R.
robin_listas@es.invalid> wrote:

On 2022-11-12 14:22, Commander Kinsey wrote:
On Fri, 11 Nov 2022 17:55:38 -0000, rick
rick_hughes@_remove_btconnect.com> wrote:

On 06/11/2022 14:23, Commander Kinsey wrote:
Instead of rolling blackouts when there\'s a power shortage, why
don\'t we
just allow (or deliberately) the voltage and frequency to drop?
Wouldn\'t that make a lot of devices use less?

It is a legal requirement to keep the frequency at 50Hz over a set
period.
Therefore if it lags at any point they have to increase to catch up.

This was a legal requirement due to mains clocks.

But you can drop it to 49 for a while then put it up to 51 when there\'s
plenty power.

And do it in the entire Europe, simultaneously?

We\'re linked by DC, so no.

Wrong.

Most parts of continental Europe are connected to a single 50 Hz
synchronous network (UCTE). UK is connected to this network with under
sea DC cables. Scandinavia is also connected to this UCTE network with
DC cables. All these three networks are nominally 50 Hz but there are
phase differences varying all the time.

Due to the AC/DC/AC connection across the Channel UK could do some
strange thing with their network without affecting the continental
Europe.or Scandinavia.

 

[Jeroen Belleman]

On 2022-11-12 21:59, upsidedown@downunder.com wrote:

On Sat, 12 Nov 2022 08:43:56 -0500, hubops@ccanoemail.com wrote:

System frequency is maintained within very tight tolerances -
- for a variety of reasons. Large thermal generators are quite
fussy about frequency.

Big generators are synchronous generators and the question is how do
you connect a large number in parallel (in the national grid) and how
properly share the generated power between them. The power delivered
depends on the _phase_difference_ between generators i.e. a constant
phase difference.

[...]

They strive to keep the generators perfectly in phase with
the rest of the network. Allowing a phase difference would
cause reactive power, which is wasteful. The power delivered
is adjusted by regulating the field excitation. The input for
the regulator is the mains frequency. There are set limits
to that process, of course, to protect the installations.

The overall coupling constant for the European network is
about 20GW/Hz, IIRC.

Jeroen Belleman

 

[The Natural Philosopher]

On 12/11/2022 13:39, Carlos E.R. wrote:

On 2022-11-12 14:22, Commander Kinsey wrote:
On Fri, 11 Nov 2022 17:55:38 -0000, rick
rick_hughes@_remove_btconnect.com> wrote:

On 06/11/2022 14:23, Commander Kinsey wrote:
Instead of rolling blackouts when there\'s a power shortage, why
don\'t we
just allow (or deliberately) the voltage and frequency to drop?
Wouldn\'t that make a lot of devices use less?

It is a legal requirement to keep the frequency at 50Hz over a set
period.
Therefore if it lags at any point they have to increase to catch up.

This was a legal requirement due to mains clocks.

But you can drop it to 49 for a while then put it up to 51 when
there\'s plenty power.

And do it in the entire Europe, simultaneously?

That can in fact be done. And was done. And it wrecked equipment in
German factories, so they installed their own exactly 50Hz inverters.

I think the problem originated in one of the ex eastern bloc nations.
--
\"First, find out who are the people you can not criticise. They are your
oppressors.\"
- George Orwell