On 13/03/18 17:46, NY wrote:
I presume if the cables were transmitting AC and were to be widely
separated, the capacitive effects between them could be made negligible
but the capacitive effect wrt earth would not be - and I imagine that
water makes a better dielectric than air, which is why wires strung
between pylons in the air don't suffer the same losses as cables buried
in(and insulated from) water.

Yes. That's the issue - capacity to earth.


Interesting. I'd always thought that the purpose of the DC link was to
isolate the frequency/phase of the UK system from the European system,
but it seems that this is a by-product of the main purpose of avoiding
capacitive losses.

Yup. And very handy it is too.


--
"Socialist governments traditionally do make a financial mess. They
always run out of other people's money. It's quite a characteristic of them"

Margaret Thatcher