Why is it that almost all industrial step down power transformers belong to the Dyn 11 Vector Group?

Answer 1

Depending on the utility company, some use Dyn11 and others Dyn1 or some other vector group that is universal to their
system.

The reason being is that they can be interconnected with the low voltage side of another transformer that is connected to the same high voltage supply circuit.
Dyn 11 means that the vector group is at the 11 o'clock position. If for instance two transformers on the same high voltage line side had different vector groups say Dyn11 and Dyn 1 they would always be 30° out of phase, this would mean that should they be interconnected they would immediately trip the incoming CB/fuses.

Source: Electrical Engineer (ret.) with 45yrs experience

Answer 2

Transformer is an electric gadget which transfers electric power from one coil (customary) to a various (secondary) via the theory of mutual induction. The enter is given for the duration of the customary and the output is tapped from the secondary. If the secondary coil has extra form of turns than that of the customary it quite is called "STEP UP" transformer. because of the fact , the secondary voltage willbe extra desirable than that of the customary voltage. if it incredibly is any incorrect way it quite is called "STEP DOWN" transformer. right here the secondary voltage would be decrease than that of the customary. In an suitable transformer, the ability enter would be equivalent to the ability output. yet just about it quite is impossible because of particular transformer losses. quite the transformer will develop or decreases the voltage. So the present would be inversely proportional. ie. if the voltage is extra desirable contemporary would be decreased. and vice versa.