🚀 go-pugleaf

bhv@areaplg2.corp.mot.com (Bronis Vidugiris) writes:

>The way I vaguely remember things from college, the phase of a generator
>with respect to the 'grid' determined the direction and amount of power
>flow.  The generator and grid were modelled as being connected together
>by some inductance.

>In one phase direction, the generator contributed power to the grid.  In
>the opposite phase, the generator *took* power from the grid (and acted as
>a motor).

Fortunately, if the generator is lagging, it generates less power and catches
up, while if it is leading it generates more power and slows down. This allows
multiple sets to be brought in-line in the power grid. 

To bring a new set on line, you have to spin up the new unit to almost the
same speed as the network and drop it online when the unit and the machine
are in phase. EE (power) students get to practice this at school. 

Dropping the new unit online too far out of phase will cause sufficient
current to flow to drop circuit breakers, which is not the desired result.
Some years ago, someone did this on the network back where I come from and
took down half the state; it had a real interesting effect on the lights in
the few seconds before the network collapsed, with the power being delivered
with a beat frequency of perhaps 1 Hertz.

Tying together big areas, like the US, must get real interesting (impossible?). 
At 60 Hz, one wavelength is 5000 Kilometres, so the US is roughly a 
wavelength across.  Can anyone tell us what is the largest AC network 
that has ever been set up.