Temperature correction for transformer load loss

[molino]

How temperature impacts the load loss of a distribution transformer?

 

[GreyGoose]

load losses come from 3 places:
1. resistive losses in the windings
2. eddy current losses in the windings
3. eddy current losses in the tank

temperature would affect #1 in that the resistance of the windings increases as the temperature increases (copper & aluminum have a positive temperature coefficients for resistivity). as the resistacne goes up so do the losses.