As already stated, if you are using 3phase, the capacitors required are much less due to the percentage ripple with 3 phase rectification against 1ph (100% ripple),
The capacitor simply go on the output of the 3 phase rectifier, if this is what you are using.
And again your DC is going to be x 1.414 of your AC, it is not necessary to size the P.S. voltage to the motor rated voltage, anywhere between x 110% and 130% is normal as the maximum rpm is governed by the controller and drives.
Another way to reduce the output if you have star secondary transformers is to use the star point as common and use half wave rectification on each phase.
Al.
CNC, Mechatronics Integration and Custom Machine Design
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E.