Mains power voltage drop to reduce usage?...

[Jeroen Belleman]

On 2022-11-18 18:33, Martin Brown wrote:

On 18/11/2022 17:05, John Larkin wrote:
On Fri, 18 Nov 2022 16:08:54 GMT, scott@slp53.sl.home (Scott
Lurndal) wrote:

John Larkin <jlarkin@highlandSNIPMEtechnology.com> writes:

The HP machine was basically a 16-bit PDP-8, a page-addressing
machine with a couple of accumulators. HP also created a really
slow, klunky hyper-CISC machine that wasn\'t successful. HP was
stunningly not-creative when it came to computers.

HPIB interface was pretty good for scientific and engineering
[...]

I think HPIB was abominable, but it was the only thing that
worked at the time. Its only merit was that there were lots
of electronic instruments that had that interface.

 

[John Larkin]

On Fri, 18 Nov 2022 21:12:12 +0100, Jeroen Belleman
<jeroen@nospam.please> wrote:

On 2022-11-18 18:33, Martin Brown wrote:
On 18/11/2022 17:05, John Larkin wrote:
On Fri, 18 Nov 2022 16:08:54 GMT, scott@slp53.sl.home (Scott
Lurndal) wrote:

John Larkin <jlarkin@highlandSNIPMEtechnology.com> writes:

The HP machine was basically a 16-bit PDP-8, a page-addressing
machine with a couple of accumulators. HP also created a really
slow, klunky hyper-CISC machine that wasn\'t successful. HP was
stunningly not-creative when it came to computers.

HPIB interface was pretty good for scientific and engineering
[...]

I think HPIB was abominable, but it was the only thing that
worked at the time. Its only merit was that there were lots
of electronic instruments that had that interface.

Has anyone read the original HPIB spec? There is a state diagram that
will give you nightmares. And words that have to be translated into
concepts like \"logic high\".

There was a hardware ack line in the cable. When SCPI began to be used
over RS232 and Ethernet, ack was forgotten somehow. It\'s post and
pray.

 

[Commander Kinsey]

On Thu, 17 Nov 2022 19:16:00 -0000, Scott Lurndal <scott@slp53.sl.home> wrote:

\"Commander Kinsey\" <CK1@nospam.com> writes:
On Sun, 13 Nov 2022 07:56:00 -0000, <upsidedown@downunder.com> wrote:

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.

What does USA do with it\'s 60Hz shit?

Support the largest and most successful economy on the planet.

You meant \"steal\".

Or does it do as it does with the rest of politics, ignore everyone non-American?

https://www.csis.org/analysis/mapping-us-canada-energy-relationship
https://www.statista.com/statistics/189033/us-electricity-imports-from-mexico-since-1999/

So they don\'t have enough. Oh dear. Canadia and Mexico should shut them off.

 

[Commander Kinsey]

On Thu, 17 Nov 2022 19:16:47 -0000, Carlos E.R. <robin_listas@es.invalid> wrote:

On 2022-11-13 08:56, upsidedown@downunder.com wrote:
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.

Yes.

That is correct. What he said, was not.

I treat Europe as one country, since you have that Brussels shit.

 

[Commander Kinsey]

On Thu, 17 Nov 2022 19:22:17 -0000, Carlos E.R. <robin_listas@es.invalid> wrote:

On 2022-11-13 11:47, The Natural Philosopher wrote:
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.

Yep.

Well, I wouldn\'t say that as proof \"it can be done\". There were
consequences :-D

I can kill you, whether there are consequences doesn\'t matter, it can still be done.

 

[Commander Kinsey]

On Thu, 17 Nov 2022 23:02:30 -0000, SteveW <steve@walker-family.me.uk> wrote:

On 17/11/2022 19:22, Scott Lurndal wrote:
SteveW <steve@walker-family.me.uk> writes:
On 17/11/2022 19:03, Commander Kinsey wrote:

Yes, the European mainland grid whilst it is not all of Europe, is
synchronised.
I believe Norway, the UK and Ireland, are definietly totally separate.

I thought there was a problem with capacitance sending AC a long
distance, hence DC to the UK? Yet they\'re managing AC throughout most
of Europe?

They\'re not having to send it undersea though.

https://en.wikipedia.org/wiki/HVDC_Gotland

Except of course that that is DC link - because it is underwater.

Underwater is irrelevant, it\'s the capacitance in the wire.

 

[Commander Kinsey]

On Thu, 17 Nov 2022 23:38:10 -0000, <hubops@ccanoemail.com> wrote:

On Thu, 17 Nov 2022 15:09:11 -0800, Bob F <bobnospam@gmail.com> wrote:

On 11/17/2022 11:20 AM, Carlos E.R. wrote:
On 2022-11-17 20:03, Commander Kinsey wrote:
On Sun, 13 Nov 2022 10:48:31 -0000, The Natural Philosopher
tnp@invalid.invalid> wrote:

Yes, the European mainland grid whilst it is not all of Europe, is
synchronised. I believe Norway, the UK and Ireland, are definietly
totally separate.

I thought there was a problem with capacitance sending AC a long
distance, hence DC to the UK? Yet they\'re managing AC throughout
most of Europe?

There is a problem with capacitance and inductance sending high voltage
underground or undersea for significant distances, which DC doesn\'t have.


More power can be sent through above ground lines too with DC than with AC.

This one runs about almost 1000 km and transmits 2000 MW
if I\'m reading this correctly

https://en.wikipedia.org/wiki/Nelson_River_DC_Transmission_System

Lots of very specialized engineering and other considerations
that distinguish it from long AC EHV transmission.

That\'s a fucking big invertor.

 

[Carlos E.R.]

On 2022-11-19 08:20, Commander Kinsey wrote:

On Thu, 17 Nov 2022 23:02:30 -0000, SteveW <steve@walker-family.me.uk
wrote:

On 17/11/2022 19:22, Scott Lurndal wrote:
SteveW <steve@walker-family.me.uk> writes:
On 17/11/2022 19:03, Commander Kinsey wrote:

Yes, the European mainland grid whilst it is not all of Europe, is
synchronised.
I believe Norway, the UK and Ireland, are definietly totally
separate.

I thought there was a problem with capacitance sending AC a long
distance, hence DC to the UK?  Yet they\'re managing AC throughout most
of Europe?

They\'re not having to send it undersea though.

https://en.wikipedia.org/wiki/HVDC_Gotland

Except of course that that is DC link - because it is underwater.

Underwater is irrelevant, it\'s the capacitance in the wire.

LOL

--
Cheers, Carlos.

 

[Peeler]

On Sat, 19 Nov 2022 12:51:41 +0100, cretinous Carlos E.R., another brain
dead troll-feeding senile ASSHOLE, blathered


> LOL

Is that the sound you make when you greedily suck off the trolling wanker,
you troll-feeding dumb spick?

 

[John Larkin]

On Thu, 17 Nov 2022 19:04:36 -0000, \"Commander Kinsey\"
<CK1@nospam.com> wrote:

On Sun, 13 Nov 2022 07:56:00 -0000, <upsidedown@downunder.com> wrote:

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.

What does USA do with it\'s 60Hz shit? Or does it do as it does with the rest of politics, ignore everyone non-American?

Cool, we form hostile tribes over skin color, language, religion,
location, and political party, and now we can war over frequency.

If we keep inventing things to divide over, specifically about 33
things, every tribe could have one member. Then everyone could attack
anybody else on sight.

 

[John Larkin]

On Sat, 19 Nov 2022 07:20:04 -0000, \"Commander Kinsey\"
<CK1@nospam.com> wrote:

On Thu, 17 Nov 2022 23:02:30 -0000, SteveW <steve@walker-family.me.uk> wrote:

On 17/11/2022 19:22, Scott Lurndal wrote:
SteveW <steve@walker-family.me.uk> writes:
On 17/11/2022 19:03, Commander Kinsey wrote:

Yes, the European mainland grid whilst it is not all of Europe, is
synchronised.
I believe Norway, the UK and Ireland, are definietly totally separate.

I thought there was a problem with capacitance sending AC a long
distance, hence DC to the UK? Yet they\'re managing AC throughout most
of Europe?

They\'re not having to send it undersea though.

https://en.wikipedia.org/wiki/HVDC_Gotland

Except of course that that is DC link - because it is underwater.

Underwater is irrelevant, it\'s the capacitance in the wire.

What\'s the dielectric constant of copper?

 

[Peeler]

On Sat, 19 Nov 2022 06:47:16 -0800, John Larkin, another mentally deficient,
troll-feeding, senile ASSHOLE, blathered:

What does USA do with it\'s 60Hz shit? Or does it do as it does with the rest of politics, ignore everyone non-American?

Cool, we form hostile tribes

Above all, the senile assholes among you religiously feed the trolling
wanker! There IS something completely wrong with all you miserable senile
Yanks!

 

[Peeler]

On Sat, 19 Nov 2022 06:52:28 -0800, John Larkin, another mentally deficient,
troll-feeding, senile ASSHOLE, blathered:


> What\'s the dielectric constant of copper?

Yeah, troll-feeding senile shithead, keep asking the attention-starved troll
questions! That\'s the way to keep him coming back for always more! Fucking
stupid senile Yanks! <tsk>

 

[Carlos E.R.]

On 2022-11-19 15:52, John Larkin wrote:

On Sat, 19 Nov 2022 07:20:04 -0000, \"Commander Kinsey\"
CK1@nospam.com> wrote:

On Thu, 17 Nov 2022 23:02:30 -0000, SteveW <steve@walker-family.me.uk> wrote:

On 17/11/2022 19:22, Scott Lurndal wrote:
SteveW <steve@walker-family.me.uk> writes:
On 17/11/2022 19:03, Commander Kinsey wrote:

Yes, the European mainland grid whilst it is not all of Europe, is
synchronised.
I believe Norway, the UK and Ireland, are definietly totally separate.

I thought there was a problem with capacitance sending AC a long
distance, hence DC to the UK? Yet they\'re managing AC throughout most
of Europe?

They\'re not having to send it undersea though.

https://en.wikipedia.org/wiki/HVDC_Gotland

Except of course that that is DC link - because it is underwater.

Underwater is irrelevant, it\'s the capacitance in the wire.

What\'s the dielectric constant of copper?

--
Cheers, Carlos.

 

[Jim Joyce]

On Fri, 18 Nov 2022 17:33:56 +0000, Martin Brown
<\'\'\'newspam\'\'\'@nonad.co.uk> wrote:

On 18/11/2022 17:05, John Larkin wrote:
On Fri, 18 Nov 2022 16:08:54 GMT, scott@slp53.sl.home (Scott Lurndal)
wrote:

John Larkin <jlarkin@highlandSNIPMEtechnology.com> writes:

The HP machine was basically a 16-bit PDP-8, a page-addressing machine
with a couple of accumulators. HP also created a really slow, klunky
hyper-CISC machine that wasn\'t successful. HP was stunningly
not-creative when it came to computers.

HPIB interface was pretty good for scientific and engineering and their
HP200 computers using 68k were OK. IBM PC\'s were very rough by
comparison and their graphics truly abominable.

https://www.hpmuseum.net/exhibit.php?class=1&cat=1

NEC9801 was pretty cool! HPIB and up to 1120 × 750 graphics in up to 16
colours (or 256 if you had wads of cash). Monitors with that resolution
were ludicrously expensive back then. Our ARGS On the VAX was 512x512.

It was a long while before the 7220 was surpassed. I quite liked TI\'s
9918 video chip with support for hardware sprites also ahead of its time.

None of the minicomputer companies survived, sort of like none of the
tube or early semiconductor companies are still around, or at least
still in the device business.

Intel is running on inertia now.

Their latest chips are still pretty good given the architecture.
Pipeline stalls are much less frequent than they used to be.

sqrt on the i5-12600 somehow benchmarks faster than divide on mine!
(it must be a quirk of how the thing pipelines instructions)

Mention of HPIB reminds me of my first encounter with that, the
AN/ALM-191 Radar Warning Receiver Test Set. That was a small rack of
interconnected test equipment that we used to test and align the RWR
preamps so that airborne threats could be properly classified and
located, resulting in proper threat display on a set of cockpit scopes
for the pilot and his EWO. Good times.

I also worked with tons of other equipment on these (and related) pages:
https://www.designation-systems.net/usmilav/jetds/an-ala2aln.html#_ALM

AN/ALR-46
AN/ALR-69
AN/ALQ-119
AN/ALQ-131
AN/ALE-40
and so many others.

 

[Commander Kinsey]

On Fri, 18 Nov 2022 10:49:40 -0000, The Natural Philosopher <tnp@invalid.invalid> wrote:

On 18/11/2022 10:42, upsidedown@downunder.com wrote:
On Thu, 17 Nov 2022 19:03:47 -0000, \"Commander Kinsey\"
CK1@nospam.com> wrote:

On Sun, 13 Nov 2022 12:42:11 -0000, <upsidedown@downunder.com> wrote:

There us a good map of the various synchronous networks in Europe in
https://en.wikipedia.org/wiki/Synchronous_grid_of_Continental_Europe

It should be noted that some areas in North Africa is connected to
UCTE. Denmark is interesting, Jutland is in UCTE while the islands
are in the Nordic net.

The CIS (Russia etc) has an own synchronous network.
The situation in Ukraine is currently unclear.

That\'s just dust from the bombs, you\'ll get a good view tomorrow.

The network issue in Ukraine has been messy for years.

According to https://en.wikipedia.org/wiki/Ukrenergo
Ukraine was disconnected from the Russian/CIS net hours before the
Russian invasion.

In March, there is a limited connection to Central Europe.
I think there is in fact a connection now.

I read it somewhere - but lord knows where so call it \'unconfirmed\' for now.

That\'s asking for a big fucking jolt to come through when Russia blows up a power station over there.

 

[Commander Kinsey]

On Fri, 18 Nov 2022 10:42:17 -0000, <upsidedown@downunder.com> wrote:

On Thu, 17 Nov 2022 19:03:47 -0000, \"Commander Kinsey\"
CK1@nospam.com> wrote:

On Sun, 13 Nov 2022 12:42:11 -0000, <upsidedown@downunder.com> wrote:

There us a good map of the various synchronous networks in Europe in
https://en.wikipedia.org/wiki/Synchronous_grid_of_Continental_Europe

It should be noted that some areas in North Africa is connected to
UCTE. Denmark is interesting, Jutland is in UCTE while the islands
are in the Nordic net.

The CIS (Russia etc) has an own synchronous network.
The situation in Ukraine is currently unclear.

That\'s just dust from the bombs, you\'ll get a good view tomorrow.

The network issue in Ukraine has been messy for years.

According to https://en.wikipedia.org/wiki/Ukrenergo
Ukraine was disconnected from the Russian/CIS net hours before the
Russian invasion.

By which side?

 

[Commander Kinsey]

On Thu, 17 Nov 2022 19:30:41 -0000, Carlos E.R. <robin_listas@es.invalid> wrote:

On 2022-11-14 03:09, Commander Kinsey wrote:
On Sun, 13 Nov 2022 11:47:06 -0000, Martin Brown
\'\'\'newspam\'\'\'@nonad.co.uk> wrote:

On 12/11/2022 14:18, Commander Kinsey wrote:
On Sat, 12 Nov 2022 13:37:24 -0000, Carlos E.R.
robin_listas@es.invalid> wrote:

On 2022-11-12 14:11, Commander Kinsey wrote:
On Sat, 12 Nov 2022 13:05:02 -0000, John Walliker
jrwalliker@gmail.com
wrote:

On Saturday, 12 November 2022 at 12:08:20 UTC, Commander Kinsey
wrote:

Why would an invertor disconnect at lower frequency? It should be
able to match any frequency.

Its a regulatory requirement.

That is not an explanation. There\'s no reason to disconnect.

It is to me... If I am the engineer designing or installing an
inverter,
I have to follow the law and regulations.

No, you\'re *supposed* to.

And a puny domestic inverter will die horribly if it stays on too long.

Anyway, that doesn\'t explain why the regulation is there. Surely an
invertor is capable of producing a sine wave at any frequency?

The semiconductor electronics are certainly capable of that but the
transformer will saturate and then get hot ultimately catching fire if
the frequency drops too low. Some US kit built for 60Hz only would get
awfully hot on UK 50Hz mains. A cheap and nasty US brand of shavers sold
mostly at Xmas relied on a 60Hz mechanical resonance for good measure.

Japanese kit can pretty much always be relied upon to work on either 50
or 60Hz since roughly half of their country is on each frequency.

Then it must be possible to let it go way below 50Hz. The regulation\'s
a bit daft if some can do it.

No, because existing equipment can not handle it. The regulation simply
takes into account that equipment, those design constraints, and tells
you not to drop the frequency.

Sure, go to your own island and put your own rules, from scratch, then talk.

\"Some US kit built for 60Hz only would get awfully hot on UK 50Hz mains.\"

And yet you think only a couple of Hz would be a problem?

 

[Commander Kinsey]

On Fri, 18 Nov 2022 12:04:03 -0000, Martin Brown <\'\'\'newspam\'\'\'@nonad.co.uk> wrote:

On 17/11/2022 19:30, Carlos E.R. wrote:
On 2022-11-14 03:09, Commander Kinsey wrote:
On Sun, 13 Nov 2022 11:47:06 -0000, Martin Brown
\'\'\'newspam\'\'\'@nonad.co.uk> wrote:

On 12/11/2022 14:18, Commander Kinsey wrote:
On Sat, 12 Nov 2022 13:37:24 -0000, Carlos E.R.
robin_listas@es.invalid> wrote:

On 2022-11-12 14:11, Commander Kinsey wrote:
On Sat, 12 Nov 2022 13:05:02 -0000, John Walliker
jrwalliker@gmail.com
wrote:

On Saturday, 12 November 2022 at 12:08:20 UTC, Commander Kinsey
wrote:

Why would an invertor disconnect at lower frequency? It should be
able to match any frequency.

Its a regulatory requirement.

That is not an explanation. There\'s no reason to disconnect.

It is to me... If I am the engineer designing or installing an
inverter,
I have to follow the law and regulations.

No, you\'re *supposed* to.

And a puny domestic inverter will die horribly if it stays on too long.

Anyway, that doesn\'t explain why the regulation is there. Surely an
invertor is capable of producing a sine wave at any frequency?

The semiconductor electronics are certainly capable of that but the
transformer will saturate and then get hot ultimately catching fire if
the frequency drops too low. Some US kit built for 60Hz only would get
awfully hot on UK 50Hz mains. A cheap and nasty US brand of shavers sold
mostly at Xmas relied on a 60Hz mechanical resonance for good measure.

Japanese kit can pretty much always be relied upon to work on either 50
or 60Hz since roughly half of their country is on each frequency.

Then it must be possible to let it go way below 50Hz. The
regulation\'s a bit daft if some can do it.

No, because existing equipment can not handle it. The regulation simply
takes into account that equipment, those design constraints, and tells
you not to drop the frequency.

I think they probably could increase the low frequency bound for
domestic and modest sized solar or wind farms not to drop off grid. It
is preferable to stress a few motors and transformers for a few minutes
when compared to the major cost of dropping large segments of load.

Otherwise you get the cascade failure mode that afflicted the UK after a
freak lightning strike took out a fairly small electric plant and caused
a cascade of failures that took down mains for London and much of England.

Surely a \"fairly small electric plant\" going off wouldn\'t change much at all? What was it, 0.01% of the grid?

https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/836626/20191003_E3C_Interim_Report_into_GB_Power_Disruption.pdf

It didn\'t help that electric trains required an engineering reset before
they could be moved from where they ground to a halt when the mains went
down.

What fool designed those?

 

[Martin Brown]

On 20/11/2022 18:15, Commander Kinsey wrote:

On Fri, 18 Nov 2022 12:04:03 -0000, Martin Brown
\'\'\'newspam\'\'\'@nonad.co.uk> wrote:

On 17/11/2022 19:30, Carlos E.R. wrote:
On 2022-11-14 03:09, Commander Kinsey wrote:
On Sun, 13 Nov 2022 11:47:06 -0000, Martin Brown
\'\'\'newspam\'\'\'@nonad.co.uk> wrote:

On 12/11/2022 14:18, Commander Kinsey wrote:
On Sat, 12 Nov 2022 13:37:24 -0000, Carlos E.R.
robin_listas@es.invalid> wrote:

On 2022-11-12 14:11, Commander Kinsey wrote:
On Sat, 12 Nov 2022 13:05:02 -0000, John Walliker
jrwalliker@gmail.com
wrote:

On Saturday, 12 November 2022 at 12:08:20 UTC, Commander Kinsey
wrote:

Why would an invertor disconnect at lower frequency? It should be
able to match any frequency.

Its a regulatory requirement.

That is not an explanation.  There\'s no reason to disconnect.

It is to me... If I am the engineer designing or installing an
inverter,
I have to follow the law and regulations.

No, you\'re *supposed* to.

And a puny domestic inverter will die horribly if it stays on too
long.

Anyway, that doesn\'t explain why the regulation is there.  Surely an
invertor is capable of producing a sine wave at any frequency?

The semiconductor electronics are certainly capable of that but the
transformer will saturate and then get hot ultimately catching fire if
the frequency drops too low. Some US kit built for 60Hz only would get
awfully hot on UK 50Hz mains. A cheap and nasty US brand of shavers
sold
mostly at Xmas relied on a 60Hz mechanical resonance for good measure.

Japanese kit can pretty much always be relied upon to work on
either 50
or 60Hz since roughly half of their country is on each frequency.

Then it must be possible to let it go way below 50Hz.  The
regulation\'s a bit daft if some can do it.

No, because existing equipment can not handle it. The regulation simply
takes into account that equipment, those design constraints, and tells
you not to drop the frequency.

I think they probably could increase the low frequency bound for
domestic and modest sized solar or wind farms not to drop off grid. It
is preferable to stress a few motors and transformers for a few minutes
when compared to the major cost of dropping large segments of load.

Otherwise you get the cascade failure mode that afflicted the UK after a
freak lightning strike took out a fairly small electric plant and caused
a cascade of failures that took down mains for London and much of
England.

Surely a \"fairly small electric plant\" going off wouldn\'t change much at
all?  What was it, 0.01% of the grid?

https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/836626/20191003_E3C_Interim_Report_into_GB_Power_Disruption.pdf

It was a big enough chunk that their spinning reserve was about half
what was needed to stabilise the grid and frequency fell below 48Hz. AT
that point automatic load shedding began in earnest.

A subtle part of the problem was that it was a nice sunny day and
although they shed 1GW of nominal load they also shed 600MW of embedded
generation with it so that the equations didn\'t immediately balance and
they were then forced to take more drastic action.

The recoil also disconnected a major wind farm in the North Sea and that
coupled with the high N to S power transfer at that time of day was
enough to take down a fairly wide area of the southern network.

It didn\'t help that electric trains required an engineering reset before
they could be moved from where they ground to a halt when the mains went
down.

What fool designed those?

People who thought that the mains supply in the UK is stable.
(and usually it is)

--
Regards,
Martin Brown