2. A 3-phase, 75 MVA, 11-8 kV star-connected alternator with a solidly earthed neutral point has the fol-lowing p.u. impedances based on rated phase voltage and rated phase current :Positive phase sequence impedanceNegative phase sequence impedanceZero phase sequence impedance=j 2 p.u.=j 0.16 p.u.=j 0.08 p.u.Determine the steady-state fault current for the following: (i) 3-phase symmetrical short-circuit (ii) oneline-to-earth fault (iii) two line-to-earth fault. The generated e.m.f. per phase is equal to the rated voltage.[(i)1840 A (ii) 4920 A (iii) 3580 A]

Step 1: Step 2: Step 3: Step 4:

Answered: 2. A 3-phase, 75 MVA, 11-8 kV…

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

Chapter2: Fundamentals

Section: Chapter Questions

Problem 2.7MCQ

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