Hi, I think your model is wrong, because it is classic scenario, when double phase current on LV side appears in all tree phase on HV side in Y/D transformer. I think good way for calculating is transform phase currents in symmetrical components, turn them depending on windings group and then...
Second picture is wrong. The algebraic sum of currents meeting at a point is NOT zero. You should reverse 4800 currents. But in this case zero sequence doesen't equal to zero. So first picture is the best IMHO. Zero sequence is zero. The algebraic sum of currents meeting at a point is zero too.
Hi, for this case I often use this interactive model "SHORT CIRCUIT CURRENT TRANSFORMATION from 0.4kV to 6(10)kV" https://pro-rza.ru/models/eng/symtrans/. You can change currents on LV side by big blue circles, and change windings group also. So group 11 is for you.
You also can use https://pro-rza.ru/models/eng/faults/ to check your calculations. This is interactive online model of simple short circuits and phase breakes.
