QUESTION 1
For the three-phase power system with single-line diagram shown, equipment ratings and per-unit reactances are given as follows:
2
3
MI
TI
\(\frac{3}{3}\) \(\frac{\epsilon}{Y}\)
4
T2
M2
T.L.
+
AY
YA
Figure: Module 27
Machines 1 and 2:
100 MVA 20 kV
$X_1 = X_2 = 0.2$
$X_0 = 0.04$ $X_n = 0.04$
Transformers 1 and 2: 100 MVA
204/345Y KV
$X_1 = X_2 = X_0 = 0.08$
Select a base of 100 MVA, 345 kV for the transmission line. On that base, the series reactances of the line are X1 = X2 = 0.15 and X0 = 0.5 per unit. With a nominal system voltage of 345 kV at bus 3, machine 2 is operating as a motor drawing
50 MVA at 0.8 power factor lagging.
Compute for the zero sequence network parameters.
j0.5, j0.02, j0.02, j0.05, j0.02, j0.02, j0.5
j0.2, j0.04, 0.04, j0.15, j0.04, j0.04, j0.2
j0.1, j0.03, j0.03, j0.10, j0.03, j0.03, j0.1
j0.3, j0.05, j0.05, j0.2, j0.05, j0.05, j0.3
