Calculate the fault current in each phase for a L-G faultoccurs at bus at machine-2 for the system shown in belowfig.All the reactaces are given in p.u on 100 MVA baseE =x4 = j0.2X2 = 10.2*0 = J0. 25LineX1 = x = j0.11Xp = j0.33Xa " j0.16X2 = J0.16Xo = j0.06%3DNA%3!%3DX, = x2 = j0.10X1 = x2 = Xo = 0.10None-j1.7747p.u-j1.4487p.u-j1.8847p.u

Sequence networks of the given system From the above sequence networks Positive sequence equivalent…

Calculate the fault current in each phase for a L-G fault occurs at bus at machine-2 for the system shown in below fig.All the reactaces are given in p.u on 100 MVA base E = 16º x = j0.2 Line X1 = x = j0.11 Xp = j0.33 X2 = 10.2 Xe = J0. 25 Xa* j0.16 X2 = J0.16 Xo = j0.06 X, = X2 = j0.10 X1 =X2 = Xg = 0.10 None -j1.7747p.u -j1.4487p.u -j1.8847p.u

Calculate the fault current in each phase for a L-G fault occurs at bus at machine-2 for the system shown in below fig.All the reactaces are given in p.u on 100 MVA base E = 16º x = j0.2 Line X1 = x = j0.11 Xp = j0.33 X2 = 10.2 Xe = J0. 25 Xa* j0.16 X2 = J0.16 Xo = j0.06 X, = X2 = j0.10 X1 =X2 = Xg = 0.10 None -j1.7747p.u -j1.4487p.u -j1.8847p.u

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 9.57P

See similar textbooks

Similar questions

The 60 mile, 115 kV line GH (Figure P12.8) is operating with the voltages ateach end 30° out of phase when a three-phase fault occurs at 80% of the distance from bus G. This fault has 12 Ω arc resistance. The currents flowing tothe fault are as shown and are in per unit at 100 MVA, 115 kV.d. Determine if the zone 1 mho unit at H set for 90% of the line GH can operate for this fault. Assume that the angle of the mho characteristic is 75°.e. Describe how this three-phase fault can be cleared by the line distance relays.
At a 220 kV substation of a power system, it is given that the three-phase fault level is 4000 MVA and single-line to ground fault level is 5000 MVA. Neglecting the resistance and the shunt susceptances of the system, (B) And the zero sequence driving point reactance at the bus is: (@)2.2Q (b) 4.84Q (€)18.18 Q (d)22.72Q
Why is it necessary to carry out fault calculations? Compare between the p.u. system method and the referred Ohmic impedance method for fault calculations.
Calculate the fault current in each phase for a L-G fault occurs at bus at machine-2 for the system shown in below fig.All the reactaces are given in p.u on 100 MVA base
Figure 2 shows the circuit of a simple power system. The ratings of the generators, transformers and the motors are as shown in the figure. The reactance of lines 1 and 2 are 40 ohms and 50 ohms respectively. Assume that system is unloaded, and the generators are generating their rated voltage. Select the generator G₁ ratings as base values. Choose the fault location in bus 1 And give the below answers For a symmetrical three phase fault on the bus (a).Determine the Thevenin's equivalent circuit which can be used to calculate the fault current. (b) Calculate the fault current contribution from the generator connected to the bus on which you have selected for fault calculation
3.On a double line-to-ground faultImmersive reader A) The short-circuit currents in the faulted phases are equal. B) The voltages at the fault point on the faulted phases are zero. C) The phase not involved in the fault has a zero voltage at the fault point. D) There are no circulating currents through the neutrals to ground. E) N. A.
The 60 mile, 115 kV line GH (Figure P12.8) is operating with the voltages ateach end 30° out of phase when a three-phase fault occurs at 80% of the distance from bus G. This fault has 12 Ω arc resistance. The currents flowing tothe fault are as shown and are in per unit at 100 MVA, 115 kV.a. Determine the apparent impedance seen by the distance relays at G forthis fault.b. Determine if the zone 1 mho unit at G set for 90% of the line GH canoperate on this fault. Assume that the angle of the mho characteristic(Figure 6.12b) is 75°.c. Determine the apparent impedance seen by the distance relays at H for thisfault.
For an A-phase to ground fault close-in to bus 2, determine the sequence and phase voltages/currents on both sides of the transformer and ohase currents inside the delta. Provide all answers in volts/amps...
For the following network, calculate the fault currents (IF1, IF2, IF3 and IF4) in pu and in kA, and circuit breaker ratings (i.e. fault MVA ) at the indicated locations. Internal reactance of generators are j0.9 pu. Base quantities: 11 kV, 400 MVA on the generator side.
In a short circuit test on 132 kV, 3-phase system, the breaker gives the following results: Power factor of the fault = 0.45. Recovery voltage 0.9 time of full line voltage. The breaking current is symmetrical. The restriking transient has a natural frequency of 15 kHz. Calculate the rate of rise of restriking voltage (RRRV) in the following types of faults: (1) Grounded fault (2) Undergrounded fault.
For the following single line diagram of a three-phase system, a three-phase fault occurs at point P and just before the fault the line voltage is 18 kV at P. Find out the transient fault current in pu and original value at point P. Take, the given kVA and kV of the G1 as the new base. Answer follow image.
b) A fault occurs at bus 4 of the network shown in Figure Q3. Pre-fault nodal voltages throughout the network are of 1 + j0 p.u, and the impedance of the electric arc is neglected (Zf = 0 + j0 p.u.). The positive, negative and zero sequence impedance parameters of the generator, transmission lines and transformer are given in Figure Q3. (i) Determine the positive sequence fault current for the case when a three-phase-to-ground fault occurs at bus 4 of the network (ii) Determine the short-circuit fault current for the case when a one-phase- to-ground fault occurs at bus 4. Recall that phasors can be expressed in terms of their symmetrical components as shown in the picture attached. where F stands for any three-phase quantity (e.g., current, voltage) (iii) Determine the short-circuit fault current for the case when a phase-to-phase fault occurs at bus 4 ReplyForward