Re: 3 phase power converters

[John Hasler <jhasler@newsguy.com>]

A static converter doesn't produce three phase.  It converts a
three-phase motor into a capacitor start, capacitor run single phase
motor by connecting two of the phases to the single phase lines and
connecting the third phase to one of the lines through capacitors.  It
only works for motors and needs to be tuned for a specific motor.

A real motor generator set *will* produce 60 Hz three phase because the
motor and generator will be synchronous.  The power will also be
seperately derived (not connected in any way to the single phase).

More comon than real motor-generator sets are "rotary converters".
These are large three phase motors wired up like the static converter
discussed above but with slightly different capacitor values and not
connected to any mechanical load.  Three phase loads are then connected
to the phases of the motor.  This produces a fair approximation of three
phase but note that two of the phases are connected to the single phase
lines.  This means that you have neither a neutral nor a grounded
conductor (unless you are in Europe in which case you have
corner-grounded delta).
-- 
John Hasler 
jhasler@newsguy.com
Elmwood, WI USA