6.2 For Problem 4.5, Fig. P4.5, calculate the fault currents at bus H for the following...
For the system shown in Fig. P4.5 set up the positive, negative, and zero sequence networks in per unit on a 30-MVA base. As suming no load, reduce the three networks to equivalent single circuits, as shown in Fig. 4.13 for a fault at bus H. (This problem is continued in Problems 6.2, 6.3, and 7.4.) 7 GEN. 324.5 kV Line X = X 6A GEN 30 NVA 30 MVA 13.8 kV 13.8:34.5 kV X, X, 125 X = 68...
Problem 7. Three-phase Balanced Fault Analysis. For the two-generator system below, a three-phase short occurs at point A. Ignoring prefault currents and assuming a prefault bus voltage of 1.0 р.u., determine the fault current, in kA, contributed from generator G Assume base values of 50 MVA and 50 kV on transmission line side. 25 kV 50 MVA, 2.5% 1:2 50 MVA, 2090 25 kV 75.MVA, 15% г,-0.4% Figure 1
Problem 7. Three-phase Balanced Fault Analysis. For the two-generator system below,...
A single line diagram of a power system is shown in Fig. 2. The system data with equipment ratings and assumed sequence reactances are given the following table. The neutrals of the generator and A-Y transformers are solidly grounded. The motor neutral is grounded through a reactance Xn 0.05 per unit on the motor base. Assume that Pre-fault voltage is takin as VF-1.0 ,0° per unit and Pre- fault load current and Δ-Y transformer phase shift are neglected In the...