However if the mechanical drive to an induction generator is an
electric motor, then the power meter will not run backwards as any
power generated by the induction generator comes from the electric
motor.

As far as I know most induction generators are directly connected to
the power grid. And while you think that induction generators and
RPC's are quiet different animals, I think of the usual RPC as being an
induction generator with the drive being a three phase motor run on
single phase. It may not work for you, but it seems to explain exactly
how a RPC works for me. To me a three phase motor connected to single
phase power can supply mechanical power or can be supplied mechanical
power and the in between point with no power being supplied or being
supplied is exactly what most RPC's are.

Dan

Robert Swinney wrote:
As dan said, " Induction generators do not work well when not connected to
the power
grid. But they do work well if they are connected to the power grid."

And therein lies part of the problem. If you've got a mechanically driven
induction generator connected to the "grid" for excitation purposes and if
you mechanically drive it faster than slip speed you will, in fact, generate
AC. If this were done, you'd see your watt/hour meter running in reverse
compared to its usu. direction of rotation. This would indicate power was
being supplied to the grid rather than consumed from the grid.

In the more general case of a "line excited" induction generator there would
have to be some way of supplying excitation to the generator rather than it
being directly connected to the grid as is done in the motor's case. Don't
confuse RPC's with induction generators - they are quite different animals.

Bob Swinney

wrote in message
oups.com...
Sorry, I misunderstood what you were thinking. If I were doing this, I
would not simply drive the generator with no electric feed lines.
So if you leave your RPC connected as is and change the pony motor to
a ten hp motor driving the RPC through a belt drive, it will work very
well. By leaving the RPC connected to electric power, you will not
have to generate that phase. You could probably get by with less than
a 10 hp motor.

About 25 years ago I made someone a three phase source using a 7.5 hp
three phase motor and a two hp single phase motor. It powered a
centerless sander that had a 5 hp three phase motor as I remember. It
worked well for some twenty years until the business was sold and the
sander was moved to a location with three phase power.


Dan