Answer Happy

Problem 2: Equipment ratings and per-unit reactances for the system shown below are given as follows: 4 G1 ОН GI G2 jo.03 Synchronous generators: 100 MVA 100 MVA Transformers: T1 T2 100 MVA 100 MVA 1 Transmission lines: TL12 100 MVA TL13 100 MVA TL23 100 MVA 25 kV 13.8 kV 230 kV 230 kV 230 kV TL13 3 TL12 25/230 kV 13.8/230 kV X₁ X₂ = 0.2 X₁ X₂ = 0.2 TL23 X₁ X₂ = 0.1 X₁ X₂ = 0.1 X₁ X₂ = 0.1 = 2 T2 b X₁ X₂ = Xo = 0.05 X₁ X₂ Xo = 0.05 X₁ = 0.05 X, = 0.05 X₁ = 0.3 Xo = 0.3 Xo = 0.3 O j0.03 G2
Problem 3: For the system of Problem 2, compute the fault currents and voltages at the fault for: (a) a bolted single line-to-ground fault at bus 3, (b) a bolted line-to-line fault at bus 3, (c) a bolted double line-to-ground fault at bus 3. Also, for the single line-to-ground fault at bus 3, determine the currents and voltages at the terminals of generators G1 and G2. Consider the effect of A-Y transformer phase shifts.