Question

can you calculating this question and explain why? thanks

The ratings and sequence reactances of the components for the power system shown in Figure 2 are given in Table 1. The pre-fault voltage is 1/0° per unit (pu). Bus 8 L3 Bus 1 T1 Bus 4 T2 Bus 2 Bus 5 L1 L2 G1 Bus 3 T3 Bus 7 Bus 6 D.6975 Figure Draw the per unit impedance sequence networks and determine the per unit (a) Thevenin impedances of the sequence networks seen from Bus 8 (8 Marks) If a bolted phase-a-to-ground fault occurs at Bus 8, calculate the phase (b) voltages at Bus 6 and Bus 7 and the currents circulating in the A loops of T3 and T2 2778L180 (10 Marks) If a bolted line-to-line fault occurs at Bus 8 between phase c and phase a, c calculate the current from phase c to phase a and the current circulating in the A loop of T4 0.024180 O.3 C90 (7 Marks) .02325-00f Table 1 Xo (pu) X2 X1 (pu) Ratings Components 0.05 0.10 200 MVA, 20 kV G1,G2 0.10 0.10 200 MVA, 20/230 kV T1, T2, T3, T4 0.20 0.10 200 MVA, 230 kV L1, L2, L3 3

Answer 1

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