Mains power voltage drop to reduce usage?...

[Commander Kinsey]

On Wed, 23 Nov 2022 10:01:52 -0000, The Natural Philosopher <tnp@invalid.invalid> wrote:

On 22/11/2022 23:39, Carlos E.R. wrote:
On 2022-11-22 23:08, Commander Kinsey wrote:
On Tue, 22 Nov 2022 21:06:22 -0000, John Larkin
jlarkin@highlandsnipmetechnology.com> wrote:

On Tue, 22 Nov 2022 19:20:16 -0000, \"Commander Kinsey\"
CK1@nospam.com> wrote:

On Tue, 22 Nov 2022 15:38:21 -0000, Clive Page <usenet@page2.eu> wrote:

On 18/11/2022 12:04, Martin Brown wrote:

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.

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.

It turned out **that** the design spec of the trains was **that**
they should cope with a frequency drop to as low as 49 Hz

Why do people put \"that\" everywhere? Retry your sentence without
\"that\" in the two instances marked. No change in meaning whatsoever.

but they were built by German engineers who assumed that in a
modern country like Germany, but not as it turned out the UK, the
mains frequency could *never* drop below 49.5 Hz, so they built in
(or failed to avoid) a serious failure mode when this actually
occurred. Hence all their class 700 trains stopped.

Surely a failure mode is one where the motor would have been
damaged? Why make it fail before it has to?

Messrs Thameslink, the train operator, compounded the problem by
only installing in some of their trains a software update which
would have allowed the driver to restart the train after it had
stopped from this cause.

Why on earth would anyone not give the driver such an ability?
Imagine if you had to call someone out because you stalled your car.

Since only a few trains could be restarted, the lines were still
pretty well blocked, and the network was effectively at a
standstill for about half a day. A combined German and British
cock-up you might think.

The whole idea of running things on rails is preposterous. You
can\'t go round a broken down vehicle, and you can\'t stop in a
sensible time if a lorry has broken down crossing the track.

But rails bear enormous loads and trains are very efficient.

Actually, they use more fuel per passenger than a car.

Not true.

Rather depends on how full they are. Commuter trains are very good.
Social routes with one passenger every fortnight, not so much

I regularly see buses here with ONE passenger! Full size single deckers! You\'d think at least they\'d put a Hoppa on that route.

 

[Commander Kinsey]

On Wed, 23 Nov 2022 10:47:47 -0000, Martin Brown <\'\'\'newspam\'\'\'@nonad.co.uk> wrote:

On 22/11/2022 16:32, John Larkin wrote:
On Tue, 22 Nov 2022 15:38:21 +0000, Clive Page <usenet@page2.eu
wrote:

On 18/11/2022 12:04, Martin Brown wrote:

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.

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.

It turned out that the design spec of the trains was that they should cope with a frequency drop to as low as 49 Hz, but they were built by German engineers who assumed that in a modern country like Germany, but not as it turned out the UK, the mains frequency could *never* drop below 49.5 Hz, so they built in (or failed to avoid) a serious failure mode when this actually occurred. Hence all their class 700 trains stopped.

Messrs Thameslink, the train operator, compounded the problem by only installing in some of their trains a software update which would have allowed the driver to restart the train after it had stopped from this cause. Since only a few trains could be restarted, the lines were still pretty well blocked, and the network was effectively at a standstill for about half a day. A combined German and British cock-up you might think.

I can\'t imagine anything that would cause a reasonable train
propulsion system to fail at 49 Hz, or even 45 Hz.

The fact that the UK mains distribution grid will drop them off load at
48Hz has a lot to do with it. They represent a large \"pure\" load (and so
are a target once the usual intermittent supply folk have been dropped).

Automated load shedding triggers at <48.000Hz.

Snag was that with the modern configuration of local solar panels and
wind shedding 1GW of domestic load also shed 600MW of local generation
so only made a 400MW net contribution. Rinse and repeat leading to a
cascade failure of a much larger section of grid than was strictly
necessary. It will almost certainly fail the same way next time.

Surely they just had to shed 2.5 times as many things as previously thought?

Maybe the trains will have a boot from cold function added to their
firmware in future but I\'m not holding my breath.

It was a damn obvious thing to have in the first place. What idiot thought it would be a good idea to require en engineer just to switch something on?

 

[Max Demian]

On 23/11/2022 11:14, Commander Kinsey wrote:

On Wed, 23 Nov 2022 10:00:06 -0000, The Natural Philosopher
tnp@invalid.invalid> wrote:

Seawater is a good conductor, unlike air, so the cables must be
insulated, and that insulation forms the bulk of the dielectric.

That\'s why they had to be DC - charging and discharging that capacitance
via a resistive cable cant be done 50 times a second without massive
losses.

Are all insulators dielectrics?

Potentially.

--
Max Demian

 

[NY]

\"Commander Kinsey\" <CK1@nospam.com> wrote in message
newsp.1v22x7gpmvhs6z@ryzen.home...

Maybe the trains will have a boot from cold function added to their
firmware in future but I\'m not holding my breath.

It was a damn obvious thing to have in the first place. What idiot
thought it would be a good idea to require en engineer just to switch
something on?

It seems to be a symptom of the rail industry at present that someone needs
to attend in person to reboot, instead of the person who is already on-site
(the driver) being able to do it (with suitable checks and authorisation
first).

It\'s like the events leading up to the Stonehaven crash when a signaller was
not able to move the points to switch the train from one track to another,
but instead the train had to wait for a signal technician to drive there to
move the points. Have whatever safety checks are necessary, but once those
have been passed, give the person on site the authority to restart things
without waiting for people to attend from elsewhere.

That\'s what\'s wrong with the rail industry: too much emphasis on process,
and not on \"just f-ing do it\". The needs of passengers are paramount.

 

[Martin Brown]

On 23/11/2022 11:16, Commander Kinsey wrote:

On Wed, 23 Nov 2022 10:47:47 -0000, Martin Brown
\'\'\'newspam\'\'\'@nonad.co.uk> wrote:

On 22/11/2022 16:32, John Larkin wrote:
On Tue, 22 Nov 2022 15:38:21 +0000, Clive Page <usenet@page2.eu
wrote:

I can\'t imagine anything that would cause a reasonable train
propulsion system to fail at 49 Hz, or even 45 Hz.

The fact that the UK mains distribution grid will drop them off load at
48Hz has a lot to do with it. They represent a large \"pure\" load (and so
are a target once the usual intermittent supply folk have been dropped).

Automated load shedding triggers at <48.000Hz.

Snag was that with the modern configuration of local solar panels and
wind shedding 1GW of domestic load also shed 600MW of local generation
so only made a 400MW net contribution. Rinse and repeat leading to a
cascade failure of a much larger section of grid than was strictly
necessary. It will almost certainly fail the same way next time.

Surely they just had to shed 2.5 times as many things as previously
thought?

But they didn\'t know that at the time so they shed the right amount of
load but because that also dropped a lot of local generation as well
they were forever playing catch up. The grid didn\'t respond as expected
when they shed the 1GW because then net shedding was only 400MW.

It took them time to realise what was happening and by then they were
forced to shed even more load to regain control. They managed to
rebalance the grid and get the frequency back in tolerance in under 5
minutes which isn\'t bad going but they had to drop off rather more load
than was strictly necessary because of the way that local generation has
altered the rules of the game.

--
Regards,
Martin Brown

 

[Commander Kinsey]

On Wed, 23 Nov 2022 11:41:11 -0000, Max Demian <max_demian@bigfoot.com> wrote:

On 23/11/2022 11:14, Commander Kinsey wrote:
On Wed, 23 Nov 2022 10:00:06 -0000, The Natural Philosopher
tnp@invalid.invalid> wrote:

Seawater is a good conductor, unlike air, so the cables must be
insulated, and that insulation forms the bulk of the dielectric.

That\'s why they had to be DC - charging and discharging that capacitance
via a resistive cable cant be done 50 times a second without massive
losses.

Are all insulators dielectrics?

Potentially.

If you\'re gonna start on that, the superconductor left without resistance.

 

[Commander Kinsey]

On Wed, 23 Nov 2022 11:45:08 -0000, NY <me@privacy.invalid> wrote:

\"Commander Kinsey\" <CK1@nospam.com> wrote in message
newsp.1v22x7gpmvhs6z@ryzen.home...

Maybe the trains will have a boot from cold function added to their
firmware in future but I\'m not holding my breath.

It was a damn obvious thing to have in the first place. What idiot
thought it would be a good idea to require en engineer just to switch
something on?

It seems to be a symptom of the rail industry at present that someone needs
to attend in person to reboot, instead of the person who is already on-site
(the driver) being able to do it (with suitable checks and authorisation
first).

Just what checks are needed to turn it back on because of a powercut? Clearly a driver already knows how to see where other trains are. In fact if a diesel train was oncoming, he\'d be a lot safer being able to start it!

It\'s like the events leading up to the Stonehaven crash when a signaller was
not able to move the points to switch the train from one track to another,

But \"a signaller was not aware of any obstruction on the line.\" - https://www.bbc.co.uk/news/uk-scotland-59200887

It shows how unfit for purpose trains are, they have insufficient brakes. Imagine your car took as long to stop as a train, it would fail the MOT.

but instead the train had to wait for a signal technician to drive there to
move the points. Have whatever safety checks are necessary, but once those
have been passed, give the person on site the authority to restart things
without waiting for people to attend from elsewhere.

That\'s what\'s wrong with the rail industry: too much emphasis on process,
and not on \"just f-ing do it\". The needs of passengers are paramount.

The same should apply to the police at a road accident.

 

[Commander Kinsey]

On Wed, 23 Nov 2022 11:51:24 -0000, Martin Brown <\'\'\'newspam\'\'\'@nonad.co.uk> wrote:

On 23/11/2022 11:16, Commander Kinsey wrote:
On Wed, 23 Nov 2022 10:47:47 -0000, Martin Brown
\'\'\'newspam\'\'\'@nonad.co.uk> wrote:

On 22/11/2022 16:32, John Larkin wrote:
On Tue, 22 Nov 2022 15:38:21 +0000, Clive Page <usenet@page2.eu
wrote:

I can\'t imagine anything that would cause a reasonable train
propulsion system to fail at 49 Hz, or even 45 Hz.

The fact that the UK mains distribution grid will drop them off load at
48Hz has a lot to do with it. They represent a large \"pure\" load (and so
are a target once the usual intermittent supply folk have been dropped).

Automated load shedding triggers at <48.000Hz.

Snag was that with the modern configuration of local solar panels and
wind shedding 1GW of domestic load also shed 600MW of local generation
so only made a 400MW net contribution. Rinse and repeat leading to a
cascade failure of a much larger section of grid than was strictly
necessary. It will almost certainly fail the same way next time.

Surely they just had to shed 2.5 times as many things as previously
thought?

But they didn\'t know that at the time so they shed the right amount of
load but because that also dropped a lot of local generation as well
they were forever playing catch up. The grid didn\'t respond as expected
when they shed the 1GW because then net shedding was only 400MW.

If it\'s automatic it should have been a couple of seconds surely?

> It took them time to realise what was happening

So the idiot in charge had never heard of local solar generation.

and by then they were
forced to shed even more load to regain control. They managed to
rebalance the grid and get the frequency back in tolerance in under 5
minutes which isn\'t bad going but they had to drop off rather more load
than was strictly necessary because of the way that local generation has
altered the rules of the game.

5 minutes, ffs. Automation!

 

[The Natural Philosopher]

On 23/11/2022 11:41, Max Demian wrote:

On 23/11/2022 11:14, Commander Kinsey wrote:
On Wed, 23 Nov 2022 10:00:06 -0000, The Natural Philosopher
tnp@invalid.invalid> wrote:

Seawater is a good conductor, unlike air, so the cables must be
insulated, and that insulation forms the bulk of the dielectric.

That\'s why they had to be DC - charging and discharging that capacitance
via a resistive cable cant be done 50 times a second without massive
losses.

Are all insulators dielectrics?

Potentially.

Ability to form a capacitor is connected to the formation of dipoles in
the material Monopoles are characteristic of conductors.


--
Labour - a bunch of rich people convincing poor people to vote for rich
people by telling poor people that \"other\" rich people are the reason
they are poor.

Peter Thompson

 

[Commander Kinsey]

On Wed, 23 Nov 2022 13:13:53 -0000, The Natural Philosopher <tnp@invalid.invalid> wrote:

On 23/11/2022 11:41, Max Demian wrote:
On 23/11/2022 11:14, Commander Kinsey wrote:
On Wed, 23 Nov 2022 10:00:06 -0000, The Natural Philosopher
tnp@invalid.invalid> wrote:

Seawater is a good conductor, unlike air, so the cables must be
insulated, and that insulation forms the bulk of the dielectric.

That\'s why they had to be DC - charging and discharging that capacitance
via a resistive cable cant be done 50 times a second without massive
losses.

Are all insulators dielectrics?

Potentially.

Ability to form a capacitor is connected to the formation of dipoles in
the material Monopoles are characteristic of conductors.

There must be some insulators which cannot form dipoles.

 

[Carlos E.R.]

On 2022-11-23 11:47, Martin Brown wrote:

On 22/11/2022 16:32, John Larkin wrote:
On Tue, 22 Nov 2022 15:38:21 +0000, Clive Page <usenet@page2.eu
wrote:

On 18/11/2022 12:04, Martin Brown wrote:

....

I can\'t imagine anything that would cause a reasonable train
propulsion system to fail at 49 Hz, or even 45 Hz.

The fact that the UK mains distribution grid will drop them off load at
48Hz has a lot to do with it. They represent a large \"pure\" load (and so
are a target once the usual intermittent supply folk have been dropped).

Automated load shedding triggers at <48.000Hz.

Snag was that with the modern configuration of local solar panels and
wind shedding 1GW of domestic load also shed 600MW of local generation
so only made a 400MW net contribution. Rinse and repeat leading to a
cascade failure of a much larger section of grid than was strictly
necessary. It will almost certainly fail the same way next time.

Maybe the trains will have a boot from cold function added to their
firmware in future but I\'m not holding my breath.

What happens if they simply lower the Pantograph? I suppose they do that
eventually, when parked.

--
Cheers, Carlos.

 

[Peeler]

On Wed, 23 Nov 2022 11:45:08 -0000, NY, the really endlessly blathering,
notorious, troll-feeding, senile asshole, blathered, yet again:


> It seems to be a symptom

Yours seems to be a symptom of troll-cock sucking, you disgusting useless
typical senile sucker of troll-cock!

 

[Carlos E.R.]

On 2022-11-23 11:01, The Natural Philosopher wrote:

On 22/11/2022 23:39, Carlos E.R. wrote:
On 2022-11-22 23:08, Commander Kinsey wrote:
On Tue, 22 Nov 2022 21:06:22 -0000, John Larkin
jlarkin@highlandsnipmetechnology.com> wrote:

On Tue, 22 Nov 2022 19:20:16 -0000, \"Commander Kinsey\"
CK1@nospam.com> wrote:

On Tue, 22 Nov 2022 15:38:21 -0000, Clive Page <usenet@page2.eu
wrote:

On 18/11/2022 12:04, Martin Brown wrote:

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.

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.

It turned out **that** the design spec of the trains was **that**
they should cope with a frequency drop to as low as 49 Hz

Why do people put \"that\" everywhere?  Retry your sentence without
\"that\" in the two instances marked. No change in meaning whatsoever.

but they were built by German engineers who assumed that in a
modern country like Germany, but not as it turned out the UK, the
mains frequency could *never* drop below 49.5 Hz, so they built in
(or failed to avoid) a serious failure mode when this actually
occurred.  Hence all their class 700 trains stopped.

Surely a failure mode is one where the motor would have been
damaged?  Why make it fail before it has to?

Messrs Thameslink, the train operator, compounded the problem by
only installing in some of their trains a software update which
would have allowed the driver to restart the train after it had
stopped from this cause.

Why on earth would anyone not give the driver such an ability?
Imagine if you had to call someone out because you stalled your car.

Since only a few trains could be restarted, the lines were still
pretty well blocked, and the network was effectively at a
standstill for about half a day.  A combined German and British
cock-up you might think.

The whole idea of running things on rails is preposterous.  You
can\'t go round a broken down vehicle, and you can\'t stop in a
sensible time if a lorry has broken down crossing the track.

But rails bear enormous loads and trains are very efficient.

Actually, they use more fuel per passenger than a car.

Not true.

Rather depends on how full they are. Commuter trains are very good.
Social routes with one passenger every fortnight, not so much

Of course.

--
Cheers, Carlos.

 

[Peeler]

On Wed, 23 Nov 2022 11:51:24 +0000, Martin Brown-noser, another
troll-feeding senile shithead, bullshitted yet again:


> But they didn\'t know that at the time

But you sick troll-feeding senile asshole KNOW already that you are feeding
a troll, and you still continue doing so, simply because you ARE a typical
miserable useless troll-feeding senile cretin!

 

[Peeler]

On Wed, 23 Nov 2022 11:41:11 +0000, Max Dumb, the REAL dumb, notorious,
troll-feeding senile idiot, blathered again:


> Potentially.

Not only \"potentially\" are you a miserable sucker of troll cock, Mr. Dumb!
<BG>

 

[Fredxx]

On 23/11/2022 11:41, Max Demian wrote:

On 23/11/2022 11:14, Commander Kinsey wrote:
On Wed, 23 Nov 2022 10:00:06 -0000, The Natural Philosopher
tnp@invalid.invalid> wrote:

Seawater is a good conductor, unlike air, so the cables must be
insulated, and that insulation forms the bulk of the dielectric.

That\'s why they had to be DC - charging and discharging that capacitance
via a resistive cable cant be done 50 times a second without massive
losses.

Are all insulators dielectrics?

Potentially.

With at least a relative permittivity of unity.

 

[John Larkin]

On Wed, 23 Nov 2022 10:47:47 +0000, Martin Brown
<\'\'\'newspam\'\'\'@nonad.co.uk> wrote:

On 22/11/2022 16:32, John Larkin wrote:
On Tue, 22 Nov 2022 15:38:21 +0000, Clive Page <usenet@page2.eu
wrote:

On 18/11/2022 12:04, Martin Brown wrote:

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.

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.

It turned out that the design spec of the trains was that they should cope with a frequency drop to as low as 49 Hz, but they were built by German engineers who assumed that in a modern country like Germany, but not as it turned out the UK, the mains frequency could *never* drop below 49.5 Hz, so they built in (or failed to avoid) a serious failure mode when this actually occurred. Hence all their class 700 trains stopped.

Messrs Thameslink, the train operator, compounded the problem by only installing in some of their trains a software update which would have allowed the driver to restart the train after it had stopped from this cause. Since only a few trains could be restarted, the lines were still pretty well blocked, and the network was effectively at a standstill for about half a day. A combined German and British cock-up you might think.

I can\'t imagine anything that would cause a reasonable train
propulsion system to fail at 49 Hz, or even 45 Hz.

The fact that the UK mains distribution grid will drop them off load at
48Hz has a lot to do with it. They represent a large \"pure\" load (and so
are a target once the usual intermittent supply folk have been dropped).

Automated load shedding triggers at <48.000Hz.

Snag was that with the modern configuration of local solar panels and
wind shedding 1GW of domestic load also shed 600MW of local generation
so only made a 400MW net contribution. Rinse and repeat leading to a
cascade failure of a much larger section of grid than was strictly
necessary. It will almost certainly fail the same way next time.

Maybe the trains will have a boot from cold function added to their
firmware in future but I\'m not holding my breath.

Greenies-in-charge has just begun. Get used to cold and dark.

And hungry.

 

[John Larkin]

On Wed, 23 Nov 2022 08:25:55 -0000, \"Commander Kinsey\"
<CK1@nospam.com> wrote:

On Tue, 22 Nov 2022 23:39:35 -0000, Carlos E.R. <robin_listas@es.invalid> wrote:

On 2022-11-22 23:08, Commander Kinsey wrote:
On Tue, 22 Nov 2022 21:06:22 -0000, John Larkin
jlarkin@highlandsnipmetechnology.com> wrote:

On Tue, 22 Nov 2022 19:20:16 -0000, \"Commander Kinsey\"
CK1@nospam.com> wrote:

On Tue, 22 Nov 2022 15:38:21 -0000, Clive Page <usenet@page2.eu> wrote:

On 18/11/2022 12:04, Martin Brown wrote:

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.

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.

It turned out **that** the design spec of the trains was **that**
they should cope with a frequency drop to as low as 49 Hz

Why do people put \"that\" everywhere? Retry your sentence without
\"that\" in the two instances marked. No change in meaning whatsoever.

but they were built by German engineers who assumed that in a modern
country like Germany, but not as it turned out the UK, the mains
frequency could *never* drop below 49.5 Hz, so they built in (or
failed to avoid) a serious failure mode when this actually
occurred. Hence all their class 700 trains stopped.

Surely a failure mode is one where the motor would have been
damaged? Why make it fail before it has to?

Messrs Thameslink, the train operator, compounded the problem by
only installing in some of their trains a software update which
would have allowed the driver to restart the train after it had
stopped from this cause.

Why on earth would anyone not give the driver such an ability?
Imagine if you had to call someone out because you stalled your car.

Since only a few trains could be restarted, the lines were still
pretty well blocked, and the network was effectively at a standstill
for about half a day. A combined German and British cock-up you
might think.

The whole idea of running things on rails is preposterous. You can\'t
go round a broken down vehicle, and you can\'t stop in a sensible time
if a lorry has broken down crossing the track.

But rails bear enormous loads and trains are very efficient.

Actually, they use more fuel per passenger than a car.

Not true.

It is true, a study was conducted in the UK. The weight of a train is ridiculous.

People are light and volume inefficient. Efficiency would be better if
people were properly packed and stacked in a rail car, like freight
and products are.

Now add in the train is never going exactly to and from where each person wants to be, and cars are way better.

Public transport is for poor people.

Here, trains are for rich tourists with time on their hands.

 

[Fredxx]

On 23/11/2022 13:30, Commander Kinsey wrote:

On Wed, 23 Nov 2022 13:13:53 -0000, The Natural Philosopher
tnp@invalid.invalid> wrote:

On 23/11/2022 11:41, Max Demian wrote:
On 23/11/2022 11:14, Commander Kinsey wrote:
On Wed, 23 Nov 2022 10:00:06 -0000, The Natural Philosopher
tnp@invalid.invalid> wrote:

Seawater is a good conductor, unlike air, so the cables must be
insulated, and that insulation forms the bulk of the dielectric.

That\'s why they had to be DC - charging and discharging that
capacitance
via a resistive cable cant be done 50 times a second without massive
losses.

Are all insulators dielectrics?

Potentially.

Ability to form a capacitor is connected to the formation of dipoles in
the material Monopoles are characteristic of conductors.

There must be some insulators which cannot form dipoles.

Only useful if you know what a dipole is, and an insulator.

Of course taking into account, there is no such thing as a perfect
insulator, and no such thing as a perfect conductor, superconductors
excepted.

 

[John Larkin]

On Wed, 23 Nov 2022 11:14:14 -0000, \"Commander Kinsey\"
<CK1@nospam.com> wrote:

On Wed, 23 Nov 2022 10:00:06 -0000, The Natural Philosopher <tnp@invalid.invalid> wrote:

On 22/11/2022 19:52, SteveW wrote:
On 19/11/2022 07:20, 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.

It is not irrelevant at all. Overhead, high-voltage wires are
uninsulated. Underwater ones cannot be and also have to have physical
(metal) protection. That alone turns them into very long capacitors.

Yes. When I visited as a teenager the very first UK-FR undersea link,
the engineers said \'if we switch it off and disconnect it, we can draw
an arc for half an hour from the stored electricity\'.

Seawater is a good conductor, unlike air, so the cables must be
insulated, and that insulation forms the bulk of the dielectric.

That\'s why they had to be DC - charging and discharging that capacitance
via a resistive cable cant be done 50 times a second without massive losses.

Are all insulators dielectrics?

Certainly. Every insulator has a dielectric constant.

If you mean \"is every insulator suitable for manufacturing cables and
capacitors?\" some aren\'t. Gasoline and crumpled newspaper might be
poor choices.

But then, capacitive liquid level gages use gasoline as the
dielectric.