Questions & Answers of Per-Unit Quantities

Question No. 125

A three phase star-connected load is drawing power at a voltage of 0.9 pu and 0.8 power factor lagging. The three phase base power and base current are 100 MVA and 437.38 A respectively. The line-to-line load voltage in kV is ________.

Question No. 44

For the power system shown in the figure below, the specifications of the components are the following:

G1: 25 kV, 100 MVA, X=9%
G2: 25'kV, 100MVA, X=9%
T1: 25 kV/220 kV, 90 MVA, X=12%
T2: 220kV/ 25 kV, 90 MVA, X=12%
Line1: 220 kV, X= 150 ohms

Choose 25 kV as the base voltage at the generator G1, and 200 MVA as the MVA base. The impedance diagram is