Consider an overhead radial three-phase distribution feeder having the following characteristics: Substation three-phase transformer: 161-12.47 kV, 15 MVA, Zeq = 1 + 1 8 % (on the transformer base impedance). Assume wye-wye grounded. Three-phase short-circuit power on the primary side of substation transformer (bus 2): 2,000 MVA. Infinite bus is number 1 and transformer high voltage side is bus 2. Feeder segment distances: From To Length in ft 3 4 1800 4 5 3500 5 4000 6 7 6000 6 . Configuration of the three-phase feeder correspond to Fig. 10.29(a) of the textbook. Aggregated three-phase peak loads at each bus (summer time) Bus Pin kW Q lag in kVAr 3 2500 600 4 1600 750 5 1800 1000 6 2100 800 7 800 500 (2) Calculate the short-circuit impedance of the infinite bus. Consider an overhead radial three-phase distribution feeder having the following characteristics: Substation three-phase transformer: 161-12.47 kV, 15 MVA, Zeq = 1 + 1 8 % (on the transformer base impedance). Assume wye-wye grounded. Three-phase short-circuit power on the primary side of substation transformer (bus 2): 2,000 MVA. Infinite bus is number 1 and transformer high voltage side is bus 2. Feeder segment distances: From To Length in ft 3 4 1800 4 5 3500 5 4000 6 7 6000 6 . Configuration of the three-phase feeder correspond to Fig. 10.29(a) of the textbook. Aggregated three-phase peak loads at each bus (summer time) Bus Pin kW Q lag in kVAr 3 2500 600 4 1600 750 5 1800 1000 6 2100 800 7 800 500 (2) Calculate the short-circuit impedance of the infinite bus