Far from an expert in this area, but: I heard something recently, that=20
once that switch was thrown to bring the generator online to the grid,=20
the the electromagnetic forces took over. If the generator was trying to=20
run too fast (governor set higher RPM), the load increased slowing the=20
generator and bringing into phase, and if too slow, then the load was=20
lessened and speed increased. There is probably a better explanation of=20
the phenomena. The main generating station compares the clock to a=20
standard time piece, and adjusts their speed to provide us with correct=20
time within a second or so.

On 05/08/2011 08:07 AM, Olin Lathrop wrote:
> Justin Richards wrote:
>> I can see how a diesel fired station is controlled but I cant see how
>> you could control a hydro powered turbine.
> The water flow is controlled.
>
> I once saw a generator being switched on line at a hydro power station in
> northern Washington.  This was in the mid 1970s, so things are probably m=
ore
> automated now.  They had a big dial on the wall, which must have been
> showing the phase angle between the generator and the grid.  People were
> manually fuzting with things trying to make the needle stay on straight u=
p.
> When it got close and steady enough for their judgement, someone flipped =
a
> switch.  There was sortof a thud, and then that was it.
>
> It seems to me that could have been done better and more reliably with se=
rvo
> electronics, even in the 1970s.  Maybe there was some of that behind what
> the people were controlling, but there was a surprising amount of manual
> interaction.
>
>
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--=20
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