Transformer technical description?

Question

I am looking for transformer 30/400kV characteristics. I have to make calculations for the impact of the generators but i can not find specifications of the transformers unless i buy them first... can anybody give any help? thank you in advance

Answer 1

Usually, on large transformers, we specify the impedance to limit short circuit current on the MV switchgear.

The basics of transformer specification:

1.  Rated (nominal) self-cooled power, in MVA

2.  Additional forced-cooled power ratings, in MVA.  There can be several additional levels.

3.  Primary (high-side) voltage, in kV line-line.

4.  Secondary (low-side) voltage, in kV line-line.

5.  Additional winding details, if any.

6.  Vector group of the associated windings.

7.  Impedance of each winding pair, in per unit on the transformer nominal MVA rating.

8.  Lots lots more details....

This is just a start.

A 100 MVA, 400/30 kV transformer would probably have an impedance of 15-20%, with an X/R ratio of 25-50.

Answer 2

it works on electro magnet induction principle ...