EE3006 POWER SYSTEMS IIAssignment No.2Submission Date: 31/03/20151. For the single line diagram shown in figure 1, form Y Bus. The transmission line parameters are: line lengths L1=120km; L2=90km; L3=195km. R=0.075/km/phase; L=0.511/km/phase; 1/C=0.311/km/phase. Nominal Equivalent circuit may be assumed for the lines. Express all admittances in pu referred to the 3 phase base values: Sb=300 MVA, Vb=230kV.123

L1

L2L3

Figure 12. For the single line diagram shown in figure 2, use 2 iterations of Gauss-Seidel method with flat start to hand-calculate the voltage phase angle 2 at bus 2. Choose the reference bus voltage as V1 = 100 pu and specified bus voltage magnitude at bus 2 as 1pu. Line parameters are the same as in question 1 and the line length is 180km. Controllable reactive power source is available at bus 2 with the constraint 0Qg20.5 pu. Compare the values with the values obtained after 2 iterations of Newton-Raphson method. Also determine the reactive power generation at bus 2, slack bus power, line power flow and real power loss. |V2| = 1puSG1SD1=1.1+j0.3 puSD2= 0.5+j0.15 pu

V1100 pu

Figure 23. For the power system network shown in figure 3, write computer program to compute the bus voltages using the Gauss-Seidel and Newton-Raphson iteration methods. Line reactance and loads are shown in the figure. Bus 1 is the slack bus and buses 2 and 3 are the load and voltage-control buses, respectively. Reactive power constraint at bus 3 is e -0.5puQg30.5 pu. Also determine line currents, slack bus power and power losses in the line. Assume tolerance equal to 0.00001.

Figure 3