Loading curve for Power Transformers

[enginkollu]

That's a great comminity here.
Now I have a problem with ambient temperature rise. Let's describe the problem. For the power transformers the power of transformer is related with ambient temperature. And IEC 354 shows how it is calculate for a transformer . But its so complex and I couldn't convert it to computer program. Can anybody know the power of transformer acc to temperature.

For example:
Design temperature of a power transformer : 40°C
Power of the transformer at 40°C : 25000KVA
What will be the power of this transformer at the temperatures of 20°, 30° and 50°C.
Assuming hot spot temp is 118°C

Thanks so much .

 

[berkeman]

Are you referring to the core losses as a function of temperature? That would be specific to the transformer and material used. Don't the datasheets for those transformers give this data?

 

[enginkollu]

Thanks for replay.
As you see at the attachmend, there is a formula in the IEC 354 for hot spot temperature(Qh) calculation. But this formula is so complex and i couldn't find out a function that indicates power curve(depends K) referring to hot spot and the other variables at the formula.
I mean i am trying to solve this function that gives K.