In Example 6.9

, double the impedance on the line from bus 2 to bus 5 . Determine the new values for the second row of \(\boldsymbol{Y}_{\text {bus }}\). Verify your result using PowerWorld Simulator case Example 6_9.

Example 6.9

Figure 6.2 shows a single-line diagram of a five-bus power system. Input data are given in Tables 6.1, 6.2, and 6.3. As shown in Table 6.1, bus 1, to which a generator is connected, is the swing bus. Bus 3, to which a generator and a load are connected, is a voltage-controlled bus. Buses 2, 4, and 5 are load buses. Note that the loads at buses 2 and 3 are inductive since \(\mathrm{Q}_{2}=-\mathrm{Q}_{\mathrm{L} 2}=-2.8\) and \(-\mathrm{Q}_{\mathrm{L} 3}=\) -0.4 are negative.

For each bus \(k\), determine which of the variables \(\mathrm{V}_{k}, \delta_{k}, \mathrm{P}_{k}\), and \(\mathrm{Q}_{k}\) are input data and which are unknowns. Also, compute the elements of the second row of \(\boldsymbol{Y}_{\text {bus }}\).

Figure 6.2

Table 6.1

Table 6.2

Table 6.3

V. =1/0 O Y=2 -j4 Y-3-j6 P3 =-1.5 p.u. Q3 = +0.8 p.u. Pe=1.5 p.u. |Vel=1.1 p.u. O