Ideal electrical systems (just idle curiosity)

Hello all.

The world has a few differing domestic electrical standards, 100, 120,

240 volts, 50 and 60 Hz and so on. Industrial customers have yet more.

Distribution via high voltage AC, and now DC in places.

I understand why various areas of the world have these differences - due to historical reasons, etc.

My question is that if we were to have a brand new electrical system, common to all areas, what would, or could, it be? Still AC? 300 volts? Different frequency?

No real reason to ask other than idle curiosity.

Thanks in advance,

David Paste.

Reply to
David Paste
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The idea system would be 1.5Volts. Then we would be able to run everything from D cells.

Bill

Reply to
Bill Wright

AC for simple long-distance transmission. High voltage so the same power uses less current and therefore thinner cable. Actual voltage some large multiple of 12 so you get easy submultiples for step-down transformers. I'm agnostic about frequency, though 50Hz/3000rpm "feels" righter than 60Hz/3600rpm.

All that is pushing me to 240v @ 50Hz ;)

jgh

Reply to
jgh

AC for national and local distribution certainly. 200 - 250V seems about right, with plugs and socketry good for something in the region of 15A gives capability of adequate appliance sizes while not requiring huge cable sizes.

Not sure I have strong feelings about frequency. Higher gives greater transformer efficiencies, but less ideal speeds for sych motors.

Reply to
John Rumm

Except for underwater cables, where it can cause unacceptable transmission losses.

Reply to
Nightjar

240V was too high for mains filament lamps. Now that they are gone, there's no reason not to stay there or even go a little higher, to reduce I²R losses back to substation. If we went to 250V, nothing would need changing. If we were starting afresh, 300V or 350V would be even better. (Nowadays, conductors are more expensive than their insulation.) Nothing to choose between 50 or 60Hz. 100Hz would halve the size of storage capacitors in PSU's, but has implications for the size of mains synchronisation zones.

DC is too hard to handle at the power levels associated with a house.

Reply to
Andrew Gabriel

And the problem of phase locking 2 large systems with a bit of wet string :)

Reply to
Tim Watts

If to run existing appliances, 230v. If if were done in say 1900, maybe a b it higher voltage to save copper.

Frequency? Maybe 200 or 400Hz. It cuts the cost of transformers, reservoir caps, speed control caps, motor caps. Also cuts the cost of some motors, bu t increases the cost of some. It would however mean increased cost of power station generators and using dc links between transmission zones - really need a spreadsheet to work out what frequency would give the lowest total c ost.

AC for transformers, cheaper switches, longer lived lamps, etc etc. The mai n downside of ac is limited transmission zones, but long distance links are better dc now anyway.

I suspect multivoltage distribution around the house would make sense, addi ng 12v & 5v.

NT

Reply to
meow2222

How does immersing a 11kV AC cable in water increase transmission losses? This isn't a joke question, I can't see how the medium surrounding a cable changes the action of the cable itself, other than cooling effects.

jgh

Reply to
jgh

I doubt there's any such thing as an "ideal" system you could roll out world-wide. There are pros and cons with all systems before you even get to considering regional and national particularities.

Reply to
Cursitor Doom

Any sane system can do the task. A large spreadsheet should be able to work out what's cheapest.

NT

Reply to
meow2222

It's losses in the dielectric, so it applies to underground cables too. Dielectric losses in air are low.

Reply to
newshound

When the national grid was established in the 1920s, AC was chosen for a very good reason; its undoubted advantage for changing voltage, allowing the use of very high voltages for long distance transmission. 50Hz was a compromise frequency. Electric motors worked best at 25Hz and long distance transmission has fewer losses at lower frequencies, but 25Hz produced visible flicker in incandescent lamps while 100Hz gave completely flicker-free lighting (some people can still detect flicker at 50Hz) and allowed transformers to be built using less materials.

If we were starting from scratch, with today's technology, I suspect that we might go for HVDC transmission for the supergrid, converting it to AC for more local transmission and distribution. Otherwise, the inevitable compromises needed for differing needs would probably end up with us having much the same system as we have now.

If I move into very hypothetical areas, I could possibly see a move to have residential areas supplied at 50v or less, under the elfen safety banner. There would also be an advantage to choosing a lower frequency, which would reduce transmission losses (around 12% at lower voltages). The flicker effect of a lower frequency could be overcome by mandating only high frequency fluorescents or all LED lighting.

Reply to
Nightjar

+1
Reply to
newshound

snipped-for-privacy@care2.com wrote in news: snipped-for-privacy@googlegroups.com:

I sometimes stay awake at night wondering how it would be if electrons only went at about 100mph!!

Reply to
DerbyBorn

But you'd get absurdly high currents.

Reply to
charles

Like the man says, although the problem is significantly greater under water. 30km is about the limit for AC transmission under water, which is why our links to the continent are HVDC. Even then, the cables are very specialised and there are IIRC only three manufacturers of HVDC underwater cables in the world. That is a limiting factor on how many offshore wind farms can be built, as they need HVDC underwater cable, the manufacturers have a limited capacity and well filled order books, while increasing capacity is not something that can be done overnight.

Reply to
Nightjar

Since when did being absurd dissuade the elfs?

Reply to
Nightjar

High power inverters at either end of the DC line...

Reply to
tony sayer

Inductive and Capactive losses theres some stuff on the AAB website somewhere;!...

Seek ye here!...

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Reply to
tony sayer

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