Three single-phase transformers are connected to form a three-phase transformer. The voltage rating of each 40 MVA single-phase transformer is 115/230 kV and has a per-unit resistance of 0.02 pu and a per-unit reactance of 0.055 pu. The excitation branch elements are Rc = 110 pu and Xm = 20 pu.

If transformer supplies a load of 80 MVA at 0.85 PF lagging calculate transformer primary phase current (I_ab). (Assume line to line voltage at the load side to have a phase angle of zero).

24.567 - j 65.257 A

34.567 - j 78.839 A

125.532 - j 45.258 A

463.542 - j 14.473 A