Alistair Riddell wrote:
So whilst we are on the subject of switching power lines, how do
different generating stations get themselves syncronised? I presume
two genny's are pumping power into the national grid at the same time,
and thus must be properly syncronised or else.....

IANAEE[*] but you are right that the whole grid must be synchronised or
Bad Things(tm) will happen. When a genset is brought online, it is first
spun up to speed and then synchronised with the grid by carefully
monitoring its output compared to the grid until there is no phase
variance. It is then switched into the grid. I believe this used to be
done manually but I am sure it all happens automatically now.

I remember watching them actually do this many years ago when on a
school visit to a power station, there was a big meter indicating the
phase difference and when it reached zero the generator went on line.

(IAAEE)

--
Chris Green