A massive expansion leads to the first ultrahigh-voltage AC-DC power grid

a reply to: bobs_uruncle

Maybe they know something that you don't.

originally posted by: LookingAtMars
China has a cutting edge power grid that puts most all of the worlds power grids to shame.

China has the benefit of starting from scratch, and in a country where centralised planning often tramples the locals and destroys the environment. It's all good PR.

In countries with embedded and established AC networks, it would be expected that stepped upgrades will happen to accommodate the new ways of power generation, including the integration of DC where appropriate.

originally posted by: andy06shake
I know here in bonny Scotland our gooberment pay the electricity-producing wind farms/companies not to produce power at certain times, down to the inadequacies and inability to transmit power of our national grid to the tune of 100 of millions of £££££ each year.

Poor planning from the Scottish government who are intent on destroying the environment with wind farms. They would have factored the existing electricity network into their calculations when they approved wind farms. The big offshore wind farms in the UK are being built nearer the populations they will serve.

originally posted by: LookingAtMars
a reply to: bobs_uruncle

That was my first impression of the image too

I am guessing it is some kind of air intake to cool the transformer.

I'd see those extensions as the EHV 'bushings' for the megavolt single phase transformer IE where the cables are attached to it.

Using air as an insulator requires about 1 metre per 100kV separation at the end of the bushings where the incoming overhead busbars are connected to it. Insulating oil inside the bushings and transformer allow clearances to be greatly reduced. The protection and metering CTs & VTs would be mounted inside the bushings as well.

a reply to: paraphi

In the UK all the generators are competing in the national grid which is centrally managed aren't they?

Introducing another generation source such as a wind farm in a remote place (where they always seem to be) creates a few stability issues needing to be addressed and it takes time.

EG having a new local source of energy supplying the remote area needs consideration of all possible credible events and the affect on the system. Like how much frequency rise is likely if the transmission line fails leaving that remote area 'islanded' supplied only by the wind farm (there are stipulated limits for frequency excursions). Sometimes it's the transmission line rating that restricts output until the line is enhanced for more energy transfer without excessive line sag. Or it might be the amount of ancillary services available network-wide to cover loss of the wind generation due to fault or wind too strong and so on.

China has a cutting edge power grid that puts most all of the worlds power grids to shame.

Yeah it's a real pain to spy,censor, and tank their social credit score when the power goes out.

Yay China!

a reply to: bobs_uruncle

Cahora Bassa, in Mozambique, was built in the 1970s and is capable of transmitting at 533 kV, so I don't see insurmountable problems with 800 kV 40 years later.

PS: I haven't kept up to date on this technology for the last 30 years or so, so I may be wrong.

originally posted by: Pilgrum

originally posted by: LookingAtMars
a reply to: bobs_uruncle

That was my first impression of the image too

I am guessing it is some kind of air intake to cool the transformer.

I'd see those extensions as the EHV 'bushings' for the megavolt single phase transformer IE where the cables are attached to it.

Using air as an insulator requires about 1 metre per 100kV separation at the end of the bushings where the incoming overhead busbars are connected to it. Insulating oil inside the bushings and transformer allow clearances to be greatly reduced. The protection and metering CTs & VTs would be mounted inside the bushings as well.

I understood some of that

What do you think the other things sticking out are that look kinda like totise pops?

originally posted by: ArMaP
a reply to: bobs_uruncle

Cahora Bassa, in Mozambique, was built in the 1970s and is capable of transmitting at 533 kV, so I don't see insurmountable problems with 800 kV 40 years later.

PS: I haven't kept up to date on this technology for the last 30 years or so, so I may be wrong.

Thanks for that link. Never heard of it, wow and built in the 70's. Sure used a lot of thyristors.

Phases 2 and 3 used improved thyristors with a rating of 2.4 kV each and only required 192 in series per valve – still a large number by modern standards – with two in parallel. As a result, each converter station contained a total of 22,656 thyristors.

a reply to: neo96

Never said their government was cutting edge

originally posted by: scraedtosleep
a reply to: bobs_uruncle

Maybe they know something that you don't.

I think it pretty obvious they know quite a lot that old Dave does not know.

And because of inside the box guys like Dave, our electrical grid sucks.

a reply to: LookingAtMars


An AC/DC power grid? So when I plug in my phone to recharge it, Thunderstruck starts immediately playing?

originally posted by: scraedtosleep
a reply to: bobs_uruncle

Maybe they know something that you don't.

Anything's possible. However Quantum mechanics and classical physics work in well defined ways that have been emperically established over the past 100+ years, for electricity anyway. It is highly improbable that nature and physics would perform a 180 degree about-face for the Chinese. Throw enough money at it though and maybe they can find a work-around :-)

Cheers - Dave

originally posted by: sligtlyskeptical

originally posted by: scraedtosleep
a reply to: bobs_uruncle

Maybe they know something that you don't.

I think it pretty obvious they know quite a lot that old Dave does not know.

And because of inside the box guys like Dave, our electrical grid sucks.

I hope you're not one of those "greenie" carbon footprint people because the cost of manufacturing all those thyristors plus the cost of replacing all those cables is about 3 to 5 times the cost of running an AC gtid. Now, they could stave off replacing the cables by reversing the charge direction in the lines often, but that might require the complete or partial shut down of the grid every time they do it. As far as Mozambique, I've been operational there, you can have their grid lol. Everytime it goes down, like south africa, somebody is stealing the wires to sell back to them....and they go down often, like a 20 dollar hooker.

Cheers - Dave

a reply to: bobs_uruncle

Fascinating - thanks for the tech explanations.

like south africa, somebody is stealing the wires to sell back to them.

Reminds me of the Mexico tragedy last month. I can just picture some of those 3000 terrorists you mentioned flying through the air.


www.abc.net.au...

Fuel thieves punctured the Tula-Tuxpan pipeline a few miles from one of Mexico's main refineries on Friday. Up to 800 people flocked to fill plastic containers from the 7m fuel geyser that ensued,

surprised the Chinese didn't learn anything from America when we went through our whole period of expanding infrastructure, transportation, etc and experimenting with all kinds of new technologies and all that, like they are going through right now.

that most of these things will be a failure or never work out the way they're expecting, these things rarely go as planned.

originally posted by: bobs_uruncle
As far as Mozambique, I've been operational there, you can have their grid lol. Everytime it goes down, like south africa, somebody is stealing the wires to sell back to them....and they go down often, like a 20 dollar hooker.

I see you commented on something that wasn't talked on the thread (the Mozambican grid) and avoid talking about what was posted (the Cahora Bassa system).

originally posted by: namehere
that most of these things will be a failure or never work out the way they're expecting, these things rarely go as planned.

The method has been used for more that 50 years, so it's a proven way of transporting electricity for long distances, and is used because it's easier and cheaper to do it with DC than with AC.

originally posted by: ArMaP

originally posted by: bobs_uruncle
As far as Mozambique, I've been operational there, you can have their grid lol. Everytime it goes down, like south africa, somebody is stealing the wires to sell back to them....and they go down often, like a 20 dollar hooker.

I see you commented on something that wasn't talked on the thread (the Mozambican grid) and avoid talking about what was posted (the Cahora Bassa system).

The dam/generating system is part of the grid along with the eskom power lines crossing the Oliphants River, or was it the Satara River.

I don't remember for sure, I know my lethal perimeter system went from komatipoort up past the satara, but I never inspected that far north, but the system was run out of the nykgomo military base north of crocodile bridge. However, the US weapons deal with Saddam that was a precursor to the gulf war was signed at the Oliphants game farm on the Oliphants River in Kruger park. This second paragraph is an example of actually going off topic.

Cheers - Dave

originally posted by: TheConstruKctionofLight
a reply to: bobs_uruncle

Fascinating - thanks for the tech explanations.

like south africa, somebody is stealing the wires to sell back to them.

Reminds me of the Mexico tragedy last month. I can just picture some of those 3000 terrorists you mentioned flying through the air.


www.abc.net.au...

Fuel thieves punctured the Tula-Tuxpan pipeline a few miles from one of Mexico's main refineries on Friday. Up to 800 people flocked to fill plastic containers from the 7m fuel geyser that ensued,

It's actually kinda funny down there, they steal the wires that run the trains and the tracks that the trains run on and then bitch and moan about not being able to get to work or people getting injured/killed when the trains derail. Of course it's always blamed on colonialization and whitey. Africa is a really messed up place, everybody is entitled, nuts and refuse to take personal responsibility. South African Parliament is a good example. Did you know you can get your local witch doctor paid for on your health care insurance lol.

Cheers - Dave

a reply to: paraphi

Poor planning indeed.

Not much that's not planned poorly these days if truth be told.