There is also an advantage of a zero phase shift between primary and secondary side. In a Yd or Dy connection there is always a plus or minus 30 degree phase shift(Dy11 or Dy1). A Yy vector group can be selected to match paralleling of transformers from different sources on the same bus.
Dear AKR,
You can try ECC- Larsen and Toubro's Engineering and Construction Division in Chennai India. You can forward a mail to kvrn@lntecc.com
ECC just completed a 132 kV D/C transmission line project of ours in Oman and they have a fabrication unit in Chennai.
They have supplied towers to...