1) 13.8 kV, 100 MW, 50 Hz synchronous generator having a CT ratio of 10000/5A is grounded through neutral impedance Zn = 1.732. The pickup current of the earth fault relay is 10%. Calculate the percentage winding from the neutral will be unprotected. %3D 21.71% 15.31% 9.47% None of the above

1) 13.8 kV, 100 MW, 50 Hz synchronous generator having a CT ratio of 10000/5A is grounded through neutral impedance Zn = 1.732. The pickup current of the earth fault relay is 10%. Calculate the percentage winding from the neutral will be unprotected. %3D 21.71% 15.31% 9.47% None of the above

Power System Analysis and Design (MindTap Course List)

6th Edition

ISBN:9781305632134

Author:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Publisher:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Chapter9: Unsymmetrical Faults

Section: Chapter Questions

Problem 9.18P

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1) 13.8 kV, 100 MW, 50 Hz synchronous
generator having a CT ratio of 10000/5A is
grounded through neutral impedance Zn = 1.732.
The pickup current of the earth fault relay is 10%.
Calculate the percentage winding from the
neutral will be unprotected.
21.71%
15.31%
9.47%
None of the above

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