Feedback Transformer for SPRS neutral float in open circuit test w.r.t ground

[anisincool]

Feedback transformer used for slip power recovery system. In this Hv side 6.6KV and LV have two winding delta and Wye both output Phase to phase 413V. my question is when we supply 6.6KV and secondary make open. In this situation we found that line voltage is R-Y= 390, Y-B 393, B-R 393V. but phase to ground found R-E= 225V, B-E = 190, Y-E = 300 and neutral point of Wye ungrounded. While both LV open how?

 

[iceworm]

I may not be able to help. I don't know what a "slip power recovery system" is. Nor do I know what a part a "Feedback transformer" plays. A one-line would help.

Although it coud be as simple as:

For un-grounded transformer outputs, the line-to-ground voltage is undefined. It can be about anything

ice

 

[Tony S]

Sounds like a GEC Kramer system.

What current is returned to the recovery transformer?

 

[Phil Corso]

Anisincool...

Although line-to-line voltages are normal, but line-to-ground voltages vary, is indicative of a difference in line-ground capacitance!

Regards, Phil Corso

 

[Tony S]

As there is no ground reference on the recovery transformer that is the probable case.