Question: Three single-phase step-up transformers rated at 10MVA, 4.6kV/13.8kV are connected in Wye-Delta configuration. The three transformers are used to feed a 20MVA load at 0.9 p.f. With an efficiency of 96%. Using per unit system, calculate following:
[A.] The primary & secondary line currents when supplying this load.
[B.] The secondary line voltage.