Home » Power Systems » Power systems miscellaneous » Question

Power systems miscellaneous

Easy Questions
Moderate Questions
Difficult Questions

Power Systems

Power systems miscellaneous
  1. The following figure shows the single line diagram of a power system with all reactances marked in per unit (p.u.) on the same base:

    The system is on no-load when a 3-phase fault occurs at ‘F’ on the high voltage side of the transformer T2. The fault current will be
    1. – j 0.8187 p.u.
    2. + j 0.8187 p.u.
    3. – j 8.1871 p.u.
    4. + j 8.1871 p.u.
Correct Option: C

The reactance diagram of the system is as shown. Drawing the Thevenin’s equation circuit, we have VTh = 1.0 p.u.

ZTh = j
0.38 × 0.18
 = j 0.122 p.u.
0.56

∴ jF =
0.1
 = -j 8.1871 p.u.
j0.122


Your comments will be displayed only after manual approval.