[Linked Image]

T2a = 3 Ph. Delta pri. to 9 Phase secondary [Delta / Wye / Wye] - Rectifier
Transformer.
X1, X2, X3 = Delta sec. - Y1, Y2, Y3 = Wye sec "A" - Z1, Z2, Z3 = Wye
sec "B"

This image shows a "9 Phase" transformer, which will be used in conjunction with a large UPS system. It feeds the rectifier - hence the name "Rectifier Transformer".

It has three separate 3 phase 3 wire secondary points of connection, one being a Delta connection [X1, X2, X3], the other two being Wye connections [Y1, Y2, Y3 and Z1, Z2, Z3].

Running a rectifier with high frequency makes the DC end [output] a lot more stable, so this transformer takes that approach by using multiple secondaries to feed a 9 phase rectifier [similar to a 6 phase AC motor].

The frequency on the output end of a full wave rectifier using 3 phase AC would be 360 Hz [that's the pulsation frequency].
Using the 9 phase arrangement, the pulsation frequency is increased to 1,080 Hz [360 x 3].
Each 3 phase 3 wire rectifier would use 3 forward [+] current Diodes and 3 reverse [-] current Diodes.

I'm trying to get some info on this Xformer - plus the others - which I'll add to the thread later.

Any comments??

Scott SET

Last edited by Scott35; 02/21/13 01:03 PM.
Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!