A G1 generator connected in Y (solidly grounded) is connected to bus 3. On the other side of bus 3 the transformer T1 connected in delta-Y (solidly grounded) is connected. The Y-side of T1 connects to bus 1 which in turn connects to bus 2 through a transmission line. On the other side of bar 2 the transformer T2 connected in Y-delta (the Y solidly grounded) is connected. The delta side of T2 is connected to bar 4 that has the other side of generator G2 connected in Y (solidly grounded). The delta side of T2 is connected to bar 4 that has the generator G2 connected in Y (solidly grounded) on the other side. The data in PU for this system are:

G1: X1 = X2 = 0.20+ (2300 / 70,000) X0 = 0.02 + (2300 / 80,000) G2: X1 = X2 = 0.20+ (2300 / 70,000) X0 = 0.02 + (2300 / 80,000) T1: X1 = X2 = X0 = 0.15+ (2300 / 40,000) T2: X1 = X2 = X0 = 0.15+ (2300 / 40,000) Line X1 = X2 = 0.20+ (2300/18233); X0 = 0.35 + (2300/7500)

A) Draw the monoline diagram B) Find the sequence impedances (Thevenin) for a fault on bus 1. C) For a bolted fault in bus 1 find the fault current in per unit in the following cases: line-to-ground fault, line-to-line fault, line-to-line (double-line) fault to ground