Power Grid Experiment

[Mike O'Dell]

once a generator comes on-line, it locks to
the line frequency and roughly speaking, 
drive torque is the best feedback variable.

this works onlly within limits, however.

if a generator doesn't trip offline when it
loses drive power (or if the drive power
runs away upwards), a large generator is
readily capable of destroying the building
housing it from the massive vibrations generated
when it takes a phase slip. i think there's some
youtube video of one such incident. the spinning
mass in a several 100 megawatt generator is
terrifying to contemplate getting lose, which
is what it tries to do. i've seen pictures
of the aftermath when a generator managed
to rip the rotor free from the bearings.
the high-pressure steam plant doesn't 
care for this either. turbine blades try
to come through the housing, etc, etc.
all in all, a *very* bad place to be.

    -mo