Good afternoon, (assuming it's afternoon wherever you are. If not: Good whatever portion of the day it happens to be in your current location).
I'm wondering if there are any set standards detailing how large power transformer's aging is affected by loading/temperature changes. I'm familiar...
ksupriya,
Branch fault would be most appropriate, I would think. The current produced can be compared with the ratings of the devices and the protective device settings modified accordingly.
-Glenn
As to how one would go about drawing this by hand, I don't know; but the main difference in a 2 winding vs. a 3 winding transformer is the fact that the tertiary windings have effects on the 3rd harmonic currents and stabilization of the neutral that you would not have were there only two windings.