Hello All:
I need to weigh in here. Address a couple points,
sorry this is not so much
comms related.
Somehow I missed "the" video, could someone point me
to it.
-I am a Chief Powerplant Operator at a mainstem
Columbia River dam, in the
northwest.
I have worked in hydro powerplants, and high voltage
switchyards for 27
years.
All large generators are protected by vsarious
protective relay schemes, and
are well protected. They are protected for many
conditions, such as loss of
excitation, generator ground, generator differential,
phase imbalance,
negative sequence current, overvoltage, and the list
goes on, in the old
days, these relays were descrete relays for each
function, but now, they are
basically microprocessors, and one box has many
functions, and the "relays"
as we still call them, have sophisticated comms
between them, and the
control systems.
It would be hard to damage a large generator from
hacking into the network,
but you could certainly casue problems if you go it,
such as opening the
spillway, or shutting down the generators.
-Not all large bulk power generators are the same,
steamers turn very fast
(3600 RPM) and depending
on head of water, and type of turbine, etc, hydro
units turn slow (100-400
RPM) so synchronizing these is very different.
I have many seen "bad shots" taken on synchrnizing on
different sizes of
hydro units, with varying results.
Anything from, the unit pulled into synchronism
(slower unit) to the
protective relays operating, and shutting the down the
unit.
I have never heard of a large generator "self
destructing" although damage
is possible, especially if the protective relays
failed, or breaker failed. You have to remember, these
large generators are
made to feed huge electrical faults,
and the breakers are made to interrupt such faults.
For the record, for
manual synchronism, we use a synchroscope,
which looks at the phase angle between the power
system "grid" and the
generator to be synchronized, we can determine
if the generator is too fast or slow, and when the
moment of synchronism
occurs, that is when you close the breaker.
This happens in a nice controlled operation, no
slamming, or banging, if it
is accomplished correctly.
There is a noise that occurs on a shot that is not
right on, can it can be
anything from a thump sound, to a heightened buzzing
(transformer type hum)
from the stator, I believe this is from the slight
physical movement of the
coils, it quiets down after the generator is warmed
up.
We also have an automatic synchronizer, it can produce
various quality of
synchronism.
And, yes, even in a hydro plant, we have "pre heated"
diesel generators
sets, both for the spillway, and for the powerhouse.
-In the Northwest, we have a lot of generation, and in
the Southwest, they
have a lot of load, the "normal" flow of power is from
the
North to South, along the west coast, if that tie
separates, we in the
Northwest are left with a large excess of generation,
and, there is a remedial action scheme, which includes
tripping large
generators off line, and (I am not kidding) a very
large load bank
(read giant resistor here) that switches in for just
long enough to help
brake the system, and then switches out before it over
heats, it is
nicknamed the "toaster". So, yes, it exists.
- As far as comms go, I do know our "computer
engineers" both for the
security system, and the plant control system, and
power system control
computers, can get in from home, over the public
network, and that access is
"deeper" that my access running the plant. Not sure of
the security but,
there is also a modem that can be called over a public
phone line, so the
manufacturer can get in if needed.
I feel we are lacking on security, and it would be
easy to get in if you
wanted to.
-Plant physical security is better than before 9-11,
but it is still
horrible, you can "tag in" or follow someone in
through a security gate, and
we have so
many contractors working on site, that anyone could
walk in or out, and no
one would notice, how could we?
-OK, this is way to long, sorry.




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