On Jun 25, 7:43*pm, "Charlie" wrote:
"Erik" wrote in message

...

I smell issues arising with this...

http://www.google.com/hostednews/ap/...C9wYlOzOkUg9wN...
Kugkw?docId=371623ab59694aef9f0a02fe83faca8a

Erik

A long time ago I was working at *company that was running a lot of
equipment that was using the frequency of 60 Hz power line to control some
critical processes.

I got the task of getting the specs of the frequency tolerance. *It took a
few phone calls to get to the engineering offices of Boston Edison. The
engineer I reached told me the allowable frequency deviation and reminded me
of something I had learned years before. *If alternators running in parallel
are not in phase,one tries to act as if it were a motor and the system could
lock up, *We had done this experiment in an AC power lab coupling a pair of
alternators that were being driven by DC motors so that their speeds could
be adjusted and they could be brought into phase with each other. Students
who tried to put them in parallel when they were not close enough got to
produce a pretty loud squeal from the complaining *equipment.

As the electric company engineer and I talked he pointed out that the Great
Northeast Blackout *in 1964 was not simply that some parts of the grid had
been overloaded but that a surge/spike/anomaly had created a phase mismatch
which snowballed along as some units fell out of the allowable frequency and
knocked alternators of the grid. *The short term fix was to get off the grid
and come back on when the frequency mismatches had been resolved.

At any rate, I can hardly wait to see what happens,

Charlie
BSEE 1956

Alternators have to be synchronised before they can be connected into
the grid.
Either they are synchronised or they are not.

The term you seek is not "phase angle" but "load angle".

http://www.control.com/thread/1250544684