Why Delta-Wye Transformer preferred in the electrical supply network?

[tipu_sultan]

Why we preferred Delta-Wye transformer over Wye-Delta?
May be it is due to difference in line and phase voltages or may be other reason?

 

[FvM]

The transformers must be able handle asymmetrical loads without a primary ground return. Delta-Wye is one of the possible circuits that does it. There are also Wye-Zigzag or Wye-Wye with compendation windings, review your electrical power engineering text book.

 

[tipu_sultan]

Review your electrical power engineering text book.

Would you please tell me the name of the book from which I can clear my concept about networks.
Actually I am working in the designing of the LV network where I can found only and only the Delta-Wye Transformer be used only not another transformer is used so I judge that there is certainly some logic behind it.
Thanks anyway.

 

[chuckey]

If you are talking about the final transformer for domestic distribution, the the final transformer (UK) is a 3 phase 440 V Y connected. This is so the consumers can be connected one phase and neutral giving 230v to them. In a road the consumers will be spread around the phases so on average the neutral currents balance out. The neutral point is earthed at the transformer, so the neutral voltage is never above 6 V from earth. Inter-transformer distribution can be delta, so saving on a neutral conductor.
In the USA, they use a Y transformer with an additional tap at 110V PER consumer, this gives 220V 3 phase + 110V single phase!!!
Frank