Grounded Y û Y MV transformers compare to ? û Y gounded Tr

[Arba]

Would any body tell me what are the benefits of both grounded Y – Y medium voltage transformers compare to generally used ? – Y grounded transformer?

 

[dpc]

Less chance of ferro-resonance.

Grounded wye winding can have graded insulation and insulated for line-ground voltage which may make it less expensive.



David Castor

http://www.cvoes.com

 

[davidbeach]

The grounded wye-grounded wye provides a zero sequence connection between primary and secondary while the delta-grounded wye does not. The delta-grounded wye provides a ground source on the wye side while the grounded wye-grounded wye does not (presence of a delta tertiary changes things). For some applications one set of characteristics is more desirable than the other.

 

[Arba]

Hi Dpc, and David, thank you very mach for your response. Now I believe that in my case where the voltage levels are 13.8 KV and 4.16 KV with transformers power at 5 MVA levels, DRY types the transformer dimension would be the ONLY ADVANTAGE for Y – Y transformers selection.

 

[slavag]

Hi.
Is depend on your application.
What is a 13.8kV grid.
You have check, if you can use ground wye, it will be second ground point in the sistem, not always possible.
Best Regards.
Slava

 

[jghrist]

See

http://www.geindustrial.com/publibrary/checkout/38652.30055.7762.44019/generic/GET-3388B.pdf

for a discussion of wye connected transformers.