Electrical Power Systems

Z 1 = (0.03 + j0.12)pu; I 1 = (1.3 – j0.50)pu
Z 2 = (0.03 + j0.12)pu; I 2 = (1.2 – j0.25)pu
Z 3 = (0.07 + j0.28)pu; I 4 = (1.0 – j0.30)pu
Z 4 = (0.04 + j0.16)pu; I 5 = (1.5 – j0.45)pu
Z 5 = (0.025 + j0.10)pu;
Optimal System Operation 445
Ans: B 11 = (6.76 × 10 –4 )MW –1 ; B 22 = (5.48 × 10 –4 )MW –1
B 12 = (– 0.133 × 10 –4 )MW –1
16.6 ig. 16.17 shows the ICs of generators 1 and 2. If both generators are running continuously, how
would a load (a) more than 2P gi (b) equal to 2P gi and (c) less than 2P gi be shared between unit 1 and
unit 2.
ig. 16.17: ICs of generating units of P16.6.
Ans: (a) generator 2 will share more load than generator 1.
(b) generators 2 and 1 will share equal load
(c) generator 1 will share more load than generator 2.
16.7 A short transmission line has series impedance Z = r + jx. Prove that if |V 1 | = |V 2 |, x >> r, and d 12
is small then,
PL = rP
2
. 12
2
V1
.
16.8 A two bus power system is shown in fig. 16.18. The incremental production costs of the plants are:
ig. 16.18: Sample two bus power system of P16.8.