Power Transformers Vectors Group
Power Transformers Vectors Group
(OP)
Guys,
I've been searching the net for a full description of all vector groups for power transformer without success. I've got one site with some of the group and a daigram showing the difference but not all of them. Dose any body aware fo such site??
Thanks
I've been searching the net for a full description of all vector groups for power transformer without success. I've got one site with some of the group and a daigram showing the difference but not all of them. Dose any body aware fo such site??
Thanks






RE: Power Transformers Vectors Group
See: Thread238-76446 Thread238-79243
www.siemens.com.mx/PTD/downloads/Power%20Engineering%20...
www.mss.de/eng/stromversorgungen/produkte/pdf/gr3e-inh....
RE: Power Transformers Vectors Group
RE: Power Transformers Vectors Group
RE: Power Transformers Vectors Group
The "J&P Transformer Book" is a very good general reference text of 900-odd pages which covers pretty much all aspects of transformers to a reasonable depth without going into the great detail found in more specialised works. It's a useful book to have on the shelf.
"J&P" dates back to the original edition by Johnson & Philips published in 1925.
ISBN 0-7506-1158-8
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Do it right, or don't do it at all.
RE: Power Transformers Vectors Group
Now, due to the difference in the Transformers vecotr groups, is it possible to parell the two incomers without having any problem? if not, what is the most preactical soultion to such problem?
RE: Power Transformers Vectors Group
The 400V supply derived from the 13.8/6.3kV - 6.3/0.4kV will be in phase with the 13.8kV supply. The other 400V supply, derived from the 13.8/0.4kV transformer, will be 30 degrees out of phase (lagging).
You would need to fit protection at the 400V system to prevent paralleling. This could be mechanical in nature (keys) and also electrical (check sync permissive).
Probably the best solution to allow paralleling would have been to have the 13.8/0.4kV transformer as a Yy vector group. Alternatively, the 6.3/0.4kV transformer could be a Yy vector group. If you already have the transformers and are (naturally) reluctant to change them, you could possibly fit in a 0.4/0.4kV Dy11 transformer between the 13.8/0.4kV transformer and the 400V switchboard.
Do check the two 13.8kV incoming supplies though, as it is possible that they could be derived from different sources and they could be the right vector groups for you. If the 13.8kV that supplies the 13.8/0.4kV transformer is 30 degrees in advance of the other 13.8kV power supply then your two 400V supplies will be in phase and all will be well.
Concur with ScottyUK re the J&P transformer book; its a classic and well worth having. There is a new edition available from Newnes. Alternatively, you can get previous editions from the 2nd hand book market.
RE: Power Transformers Vectors Group
Dy1 and Dy11 have relative voltage displacement of 60° rather than 30°. Therefore, any corrections of angle displacement will have to consider 60°.
RE: Power Transformers Vectors Group
http://www.siemens.fi/evu/ev/download/peg97/pegt04.pdf
etc. for vector diagrams