Question: The six-bus and 3-phase power system network of an electric utility company is shown Figure-1 The positive (negative equal) and zero sequence reactances of the lines, generators, and transformer in per unit on a 160 MVA -380-kV base is tabulated. Line & Transformer Data Generator Data From To X¹=X² Xº # X¹=X² Xº Xn Emf 1 4 0.225 0.400 1 0.20 0.06 0.00 1.15 Z60° 1 5 0.105 0.200 2 0.15 0.04 0.05 1.0 200° 1 6 0.215 0.390 3 0.25 0.08 0.00 0.93 Z-120° 2 4 0.035 0.035 3 5 0.042 0.042 4 6 0.125 0.205 Transformer between buses 3-5 is grounded through a reactor of reactance 0.10 pu. 50 6 0.175 0.350 1. Draw the sequence networks; 2. Calculate the fault current and contributions of it, a. when the 3-phase symmetrical fault occurs at bus 2 terminals. b. when the bolted SLG fault occurs at bus 1, c. when the L-L fault occurs at bus 4, d. when the DLG fault occurs at bus 5 with z=0.01 pu. Δ 5