3-singlephase 2 winding transformers, each rated 500 MVA, 13.8/199.2 kV, with leakage reactance Xeq = 0.10 per unit, are connected to form a three-phase bank.
Winding resistances and exciting current are neglected. The high-voltage windings are connected in Y. A three-phase load operating under balanced positive-sequence conditions on the high-voltage side absorbs 1000 MVA at 0.90 p.f. lagging, with VAN = 199.2 0° kV.
Determine the voltage Van at the low-voltage bus if the low-voltage windings are connected (a) in Y, (b) in ?