Transformer Data 1

[Drivesrock]

I have a transformer spec that includes the text Uk = 8%. Can anyone explain what this means? I have an idea but would rather check!

 

[wbd]

From the few international references I have:

Uk in % is impedance voltage drop of three pahse transformer

 

[cuky2000]

Percentage Impedance voltage drop (Uk) is a factor inherent in the design of any transformer, and is a characteristic to which particular attention must be paid when design for parallel operation.
The percentage drop is determine by the formula:

Uk = (Ur²+Ux²)^1/2
_{The following values are defined for full rating of transformer as follow:
Uk = is the percentage impedance drop
Ur = percentage resistance drop
Ux = percentage reactance drop}

Ref The J & P Transformer Book

 

[waross]

Is this directly related to % impedance voltage?