Transformer impedances
Transformer impedances
(OP)
Is there a place I can get an IEC standard impedance for a say, 20 MVA, 110 KV-11 KV transformer, 50 Hz, for use in the Middle East, without laying down 3500 bucks for the IEC transformer collection? Thanks.






RE: Transformer impedances
RE: Transformer impedances
At least from experience I think that the typical value for the size and voltage should be around 9%.
However, I think you may ask directly to a manufacturer.
In general, the value will depend on several factors like: shortcircuit level desired at low voltage switchgear, regulation voltage and so on.
Best Regards,
RE: Transformer impedances
RE: Transformer impedances
RE: Transformer impedances
It is better to stick to IEC stipulation, unless there is a specific case where the secondary fault levels are not acceptable to the designer.
RE: Transformer impedances
IEC might also be the same, because the clause 0.6 of the above standard states that "This standard has been based on IEC Pub 76-1 Power Transformers Part 1 - General"!!