Powerful EDFs

Dragon wrote:


I'd like to know more about that cable from France as apparently we are supplied by DC from France, is there a big DC AC converter in Kent. I was told that this sort of thing is done for very long high voltage lines where DC is used in preference to AC so the conversion must be made back to AC somewhere locally. My neighbour knows a guy that deals with this and he said it was common in long distance power transmission lines but is it efficiency or a phase synchronisation issue.
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Yes; there are four pairs of cables running from Les Mandarins, near Calais, to Sellindge in Kent. Capacity is 2 GW, and the link is bi-directional (i.e. it can export as well as import - and sometimes does). Thus I believe there are AC-DC and DC-AC converters at each end.

Yes, it is quite normal. To run on the same AC grid, all generators must be synchronised, otherwise there would probably be a big bang somewhere. Obviously it is too much of a constraint to have the UK grid synchronised with the continent, and indeed I think there are several independently-synchronised grids on the continent. AFAIK, it has nothing to do with efficiency.
For more information, you might find the National Grid Seven Year Statement is interesting:
http://www.nationalgrid.com/uk/Electricity/SYS/current /
I used to do quite a lot of work on UK power generation projects - mostly commercial and project development rather than engineering, but I had to get a decent feel for that.
David
--
David Littlewood

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On Mon, 13 Aug 2012 23:26:06 +0100, David Littlewood wrote:

The main reason is synchronisation, but - at least underwater - DC transmission is apparently more efficient than AC. The cable is surrounded by a lossy conductive medium (seawater) which would attenuate the AC signal a bit...
- Brian
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news:50297898$0$1154

http://en.wikipedia.org/wiki/HVDC_Cross-Channel
New England receives electricity from New France too: http://en.wikipedia.org/wiki/Quebec_%E2%80%93_New_England_Transmission
jsw
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wrote:

Its a TLA
Regards, Tony
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