15/05/2021 ELK 322E Power Transmission Systems CRN 21770 20120-2021 Spring Semester HOMEWORK 03 Due date: 23/05/2021 Question: The one-line diagram of a three-phase system shown above: a) Find the bus admittance matrix, for this case consider the generator are injected the I G1 and IG2 currents and loads drawn the currents ID3 and ID4. b) Write the expression for the real power at bus 2 and real and reactive power at bus 3. c) Let assume that the Newton-Raphson method is used for power flow analysis. Complete the table given below. Note: In this problem the solution of the power flow is not asked, but necessary steps for a power flow analysis are asked, such as obtaining the bus admittance matrix, obtaining power the balance equations (but in this problem for bus-2 and bus-3 equation are enough), and classification of buses. Bus no. Bus Type Knowns Unknows 1 Slack bus |V1|, 1 P1 and Q1 2 3 4 1 2 P1 P2 = 0.8 pu z12= j0.2 pu G1 G2 V1 = 1.02pu V2 = 1.012pu z13 =j0.4 pu z24= j0.1 pu z34= j0.2 pu 3 V3 = |V3|3pu Load 1 SD3 = 0.9+ j0.6 pu 4 V4 = |V4|4pu Load 2 SD4 = 0.7+ j0.4 pu Fig. The one-line diagram of a three-phase system