to an A 3-phase, 11 kV, 20 MVA generator is connected 11 KV line. The positive, negative and Zero sequence impedances of the generator are: rating, while 18% 12% and 10% those for the line ( on are : 6216221 and 12 52. For a S-L-G fault at the fear end of the line determine the fault current and phase voltages at fault point. Assunce the generater is star point is solidly grounded. Find also the fault level (FOF 720 A) 1

to an A 3-phase, 11 kV, 20 MVA generator is connected 11 KV line. The positive, negative and Zero sequence impedances of the generator are: rating, while 18% 12% and 10% those for the line ( on are : 6216221 and 12 52. For a S-L-G fault at the fear end of the line determine the fault current and phase voltages at fault point. Assunce the generater is star point is solidly grounded. Find also the fault level (FOF 720 A) 1

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

Single line to ground fault of a solidly grounded generator positive sequence current is j2.5 p.u, then the current flow in the neutral during the fault is O j1.05 p.u O jo.25 p.u O j2.5 p.u O j7.5 p.u
A hydro powered 50 MVA generator, with a synchronous reactance 0.33 p.u., delivers 40 MW over a transmission line of 0.15 p.u. reactance to an infinite system. A 3-phase short circuit transient fault occurs on the busbar between the generator and transmission line. Given that the generator emf is 1.4 p.u. prior to and during the fault and all reactances are to a 50 MVA base: Sketch the single line schematic diagram of the system. Determine the maximum load angle the generator can swing to without losing stability. i) ii) iii) iv) Sketch the corresponding power-angle curve for the system showing the accelerating and decelerating areas. Calculate the critical clearing angle of the system to keep its stability.
33
Q2\ The one-line diagram of a simple power system is shown in figure below. All impedances are expressed in per unit (pu) on a common MVA base. All resistances and shunt capacitances are neglected. The generators are operating on no load at their rated voltage. A three-phase fault occurs at bus 1 through a fault impedance of Zf = j0.08 per unit. Using Thevenin's theorem obtain the impedance to the point of fault and the fault current in per unit. Determine the bus voltages and line currents of generators during fault. X₁ = = 0.1 XT-0.1 3 1 to ojo XL=0.2 2 040 X₁ = 0.1
B1
The negative sequence current of a solidly grounded generator for single line to ground fault is j 2.5 p.u. Then the positive sequence current during the fault is equal to o j7.5 pu o jo.75 pu o j2.5 pu o jo.25p.u
If the source impedance at a 13.2 kV distribution substation bus is (0:5 + 1:5) Q per phase, compute the RMS and maximum peak instantaneous value of the fault current, for a balanced three-phase fault. For the system (X/R) ratio of 3.0, the asymmetrical factor is 1.9495 and the time of peak is 7.1 ms (see Problem 1). Comment on the withstanding peak current capability to which all substation electrical equipment need to be designed. Problem 1 Consider the expression for i(f) given by i(t) = v21ms [sin(@t-0-)+ sin 0,.eR/X)] where ez = tan-1 (WL/R). (a) For (X/R) equal to zero and infinity, plot i(f) as a function of (wf). (b) Comment on the DC offset of the fault current waveforms. (c) Find the asymmetrical current factor and the time of peak, tp, in milliseconds, for (X/R) ratios of zero and infinity.
please solve it before 10 min
Q. when a three-phase fault occurs at 75% of the distance from bus G. This fault has 10 arc resistance. 100 MVA, 115 KV Line GH a-Assume that the angle of the mho characteristic is 70°.Determine if the zone I mho unit at H set for 90% of the line GH can operate for this fault. b-Determine the apparent impedance seen by the distance relays at H for this fault. G Z, = 0.365 Z83° - 80% l6 = 1.96 Z–31.42° 4 = 2.60 Z–47.76° ķ = 4.51 Z-40.68° All values in per unit on 100 MVA, 115 kV.
1- Which of the following is true in decoupled load flow method a- Jacobians J1 and J2 are considered b-Jacobians J2 and J3 are considered c-Jacobians J2 and J3 are neglected d- Jacobians J1 and J2 are neglected 2-If all the three sequence currents at the fault point in a power system are equal, then the type of the fault is a.Line to line fault b.Three phase fault c.Double line to ground fault d.Single line to ground fault