QI A 3-phase, 80 MVA, 11-8 kV star-connected alternator with a solidly earthed neutral point has the following p.u. impedances based on rated phase voltage and rated phase current: Positive phase sequence impedance = j 2 p.u. Negative phase sequence impedance = j0-18 p.u. Zero phase sequence impedance = j0-09 p.u. Determine the steady-state fault current for the following: (i) 3-phase symmetrical short-circuit (ii) (ii) one line-to-earth fault (iii) (iii) two line-to-earth fault. The generated e.m.f. per phase is equal to the rated voltage.

QI A 3-phase, 80 MVA, 11-8 kV star-connected alternator with a solidly earthed neutral point has the following p.u. impedances based on rated phase voltage and rated phase current: Positive phase sequence impedance = j 2 p.u. Negative phase sequence impedance = j0-18 p.u. Zero phase sequence impedance = j0-09 p.u. Determine the steady-state fault current for the following: (i) 3-phase symmetrical short-circuit (ii) (ii) one line-to-earth fault (iii) (iii) two line-to-earth fault. The generated e.m.f. per phase is equal to the rated voltage.

Introductory Circuit Analysis (13th Edition)

13th Edition

ISBN:9780133923605

Author:Robert L. Boylestad

Publisher:Robert L. Boylestad

Chapter1: Introduction

Section: Chapter Questions

Problem 1P: Visit your local library (at school or home) and describe the extent to which it provides literature...

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Similar questions

Q. Urgent soln...
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Two single phase transformers A and B with equal turns ratio have reactance of j3.2 and j19.2 referred to secondary. When operated in parallel, the load sharing of 100 kW at 0.8 pf lag between A and B transformers would respectively be a) 75 kw and 25kw b) 60 kw and 40 kw c) 20 kw and 80 kw d) 25 kw and 75 kw
powe system Q8
Subject name: Power System Protection
urgent required.
A 3-phase, 15 MVA, 10 kV alternator has internal reactance of 6% and negligible resistance. Find the external reactance per phase to be connected in series with the alternator so that the steady current on 3-phase short circuit does not exceed 6 times the full load current.
A 3-phase, 11 kV, 5 MVA alternator has synchronous reactance of 10 per phase. Its excitation is such that the generated emf is 14 kV. If the alternator is connected to infinite bus bar, the maximum output at the given excitation is?
A synchronous generator is rated 645 MVA, 24 kV, 0.9 pf lagging. It has a synchronous reactance 1.2 . The generator is feeding full load at 0.9 pf lagging at rated voltage. Calculate: (a) Excitation emf (E,) and power angle 8 (b) Reactive power drawn by the load Carry out calculations in pu form and convert the result to actual values.
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Q3/ For the system shown in figure. The generator is supplying 1.0 pu MW power under prefault condition. When three-phase fault occur at point F. What should the value of fault reactance must be to make the critical clearing angle equal to 58.9. Sc j0.1 j0.1 10.21 BE j0.38 38 j0.21 IEgl-12 pu 10.19 F 10.19 IVI-1.00 pu j0.1 j0.1 Q4/ Figure below shows the one-line diagram