On 13/03/18 15:26, NY wrote:
"The Natural Philosopher" wrote in message
news
On 13/03/18 12:13, NY wrote:
What were the reasons for the UK having its own grid, with a *DC*
connection to mainland Europe? Was it just that the UK wasn't part of
Europe at the time, or was there another more technical, less
political reason?
Well you see its this odd and not very political thing called
GEOGRAPHY. You maye have heard of it although its not as fashoinable
as gay marriage, but what it means is that if you walked all round the
COAST like that ponce on TV you find that is water on every side!
And that means its a long way to string pylons in shipping lanes so
teh GB grid is naturally isolated and always was, since ints inception
in IIRC the 1930s
Yes, that's a very good reason for not having *any* connection between
UK and mainland Europe. But given that there *is* a connection, is there
a reason why it is DC rather than AC?
Efficiency.
People have mentioned propagation
delay? How does the north-south length of the UK compare with the length
and width of the linked parts of mainland Europe?
small. Its about 600 miles tip to tip. USA is split into 1000 mile sizes
Presumably if power is to be exported/imported over the DC link, there
needs to be a means of converting the DC back to AC at the correct
frequency and phase - probably at one time this would have involved
rotary converters (DC motor driving AC generator).
No. It never did.
Always done with choppers.
Originally mercury arc
https://en.wikipedia.org/wiki/Mercury-arc_valve
I visted te first cross cvhannel link in the mid 1960s.
https://en.wikipedia.org/wiki/HVDC_C...W_system_(1961)
The valbesd were impressibe BUT the most ompressive thing was the acre
or so of hsehd sized chokes and capacitors smoothing out the chop!
The whole site sounded like a digeridoo, and since we wher scvhoolbotys,
'Sun arise, come with de morning' was soon echoing around..
https://www.youtube.com/watch?v=0XOO0I8ZsIk
Wouldn't this cause
greater losses than in transformers of an AC link?
Yes, but that is completely dwarfed by the savinhgs in losses in the
cable itself.
And the system needs
to be reversible so energy can be sent in either direction according to
who has a surplus at any instant.
Yes, sometimes that breaks and it's one way only :-)
--
€œBut what a weak barrier is truth when it stands in the way of an
hypothesis!€
Mary Wollstonecraft