(Solved): Question 1 (Mandatory) (35 Points) A single-line diagram of a four-bus system is shown in Figure 1. ...

Question 1 (Mandatory) (35 Points) A single-line diagram of a four-bus system is shown in Figure 1. On a base of 100 MVA and 345 kV in the zone of the transmission line, the series reactances of the transmission line are Xi - X2 = 0.15 and Xo = 0.5 per unit. Equipment ratings and per-unit reactances are given as follows. Machines 1 and 2: Transformers 1 and 2: 100 MVA V345Y KVA X1 X2 = Xo=0.12 Machine 1 oy ONZE HO Machine Yoo ?? ? ? (a) Draw each of the sequence networks. (b) Assume the system to be operating at nominal system voltage without pre-fault currents, when a double-line-to-ground fault occurs at bus 3. Compute the three-phase voltages and currents at the faulted bus.