Please solve Q1(C) ONLY. Q1(A) is for reference. Problem 1(A)- In reference to the power system shown below, the system is operating at nominalvoltage without pre-fault currents (load currents ignored) when a bolted ( = 0p .u .) single line-toground fault occurs on phase A at bus 3. Both machines are grounded through reactance.X, = X, =15%X, = 50%1234my O어。100MVA,20KV100MVA100MVA100MVA,20KVX, = X = 20%20Υ/345Y - kV20Y /345Y – kVX, = X = 20%X2 = 20%X, = X, = X, = 8%X, = X, = X, = 8%X2 = 20%%3DX, = 4%X, = 4%X, = 5%X = 5%Fig. 1-Single-line diagram for the system in problems 1-A, 1-B, and 1-C(a) The system's Thevenin equivalent positive-, negative-, and zero-sequence networks(b) The fault current (p.u.) at phase A Problem 1(C)- If the fault in Problem 1(A) was a double line to ground fault a phases B and Cthrough a fault impedance Zf = 0.5 p. u., determine the fault current (p.u.).

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Answered: Problem 1(C)- If the fault in Problem…

Problem 1(C)- If the fault in Problem 1(A) was a double line to ground fault a phases B and C through a fault impedance Z, = 0.5 p.u., determine the fault current (p.u.). %3D

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

Chapter7: Symmetrical Faults

Section: Chapter Questions

Problem 7.14P: Equipment ratings for the five-bus power system shown in Figure 7.15 are as follows: Generator G1:Â...

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PowerWorid Simulator case Problem 3_60 duplicates Example 3.13 except that a resistance term of 0.06 per unit has been added to the transformer and 0.05 per unit to the transmission line. Since the system is no longer lossless, a field showing the real power losses has also been added to the oneline. With the LTC tap fixed at 1.05, plot the real power losses as the phase shift angle is varied from 10 to +10 degrees. What value of phase shift minimizes the system losses?
Figure 3.39 shows a oneline diagram of a system in which the three-phase generator is rated 300 MVA, 20 kV with a subtransient reactance of 0.2 per unit and with its neutral grounded through a 0.4- reactor. The transmission line is 64km long with a cries reactance of 0.5-/km. The three-phase transformer T1 is rated 350MVA.230/20kV with a leakage reactance of 0.1 per unit. Transformer T2 is composed of three single-phase transformers, each rated 100 MVA, 127/13.2kV with a leakage reactance of 0.1 per unit. Two 13.2kV motors M1 and M2 with a subtransient reactance of 0.2 per unit for each motor represent the load. M1 has a rated input of 200 MVA with its neutral grounded through a 0.4- current-limiting reactor, M2 has a rated input of 100 MVA with its neutral not connected to ground. Neglect phase shifts associated with the transformers. Choose the generator rating as base in the generator circuit and draw the positive-sequence reactance diagram showing all reactances in per unit.
Equipment ratings for the five-bus power system shown in Figure 7.15 are as follows: Generator G1:Â Â Â Â 50Â MVA,Â 12kV,Â X=0.2 per unit Generator G2: 100Â MVA, 15 kV, X=0.2 per unit Transformer T1: 50 MVA, 10 kV Y/138kVY,X=0.10 per unit Transformer T2: 100 MVA, 15 kV /138kVY,X=0.10 per unit Each 138-kV line: X1=40 A three-phase short circuit occurs at bus 5, where the prefault voltage is 15 kV. Prefault load current is neglected. (a) Draw the positive-sequence reactance diagram in unit on a 100-MVA, 15-kV base in the zone of generator G2. Determine (b) the ThĂ©venin equivalent at the fault, (c) the subtransient fault current in per unit and in kA rms, and (d) contributions to the fault from generator G2 and from transformer T2.
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
Figure 1 shows a three-bus power system network of an electric utility company with each generator is represented by an electromotive force (e.m.f.) behind the transient reactance. All impedances are expressed in per unit on a common MVA base. The pre-fault system is on noload condition with 1.0 per unit voltage, and pre-fault currents are zero. All answer must be given in FOUR (4) decimal points. (a) Construct the bus impedance matrix for the system using building algorithm method.
The bus impedance matrix for a three-bus power system has per-unit elements as: Z11 = 0.5 Z12 = 0.4 Z13 = 0.8 Z21 = 1 Z22 = 0.5 Z23 = 0.6 Z31 = 0.5 Z32 = 1.2 Z33 = 1 Prefault voltage is 1 per unit and prefault current is neglected. A three-phase short circuit occurs at bus 3. Determine the subtransient fault current. Round your answer to 2 decimal places.
TOPIC: Transmission Lines, Power Systems, and Powerplants:INSTRUCTIONS:- Answer in this format: Given, Illustration, Required Conversion, Solution, Final Answer.- Step-by-step solution, do not skip even simple calculations to avoid confusion.- If answered in written form, make sure it is readable.PROBLEM:The per-unit values of positive, negative, and zero sequence reactances of a network at fault are 0.08, 0.07, and 0.05 respectively. Determine the per-unit fault current if the fault is line-to-line-to-ground. j10 j12 j14 j16
Given the network shown, for a solid three phase fault on bus 2 (a) find the subtransient current in per unit from generator 1 and in the line 1-2; (b) find the voltages at bus 1 and bus 3. Assume that no current is flowing prior to the fault and that the prefault voltage at bus 2 is 1.0 per unit. Show your solution.
The single line diagram of a power system is shown in Figure Q2.1 including generator and transformer winding connection and earthing details. The parameters for this system have been calculated on a common 100 MVA base and are given in Table Q2.1. All resistances and shunt susceptances are neglected. This system experiences a single line to ground fault at a point F on line L1. The point F is at a distance d from Bus 4 along the line L1. The total length ?? of the line L1 is 50 km. Note that the location of ?? is not drawn to scale in Figure Q2.1. The fault current at the fault point F is measured to be 6.106 kA. i) Determine the zero, positive, and negative sequence Thevenin equivalent impedances as seen at the fault point F. These should be evaluated in per unit and shown as a function of d.ii) Use the sequence impedances calculated in part (i) to determine the distance d of the fault (in km) from Bus 4.
The single line diagram of a power system is shown in Figure Q2.1 includinggenerator and transformer winding connection and earthing details. The parametersfor this system have been calculated on a common 100 MVA base and are given inTable Q2.1. All resistances and shunt susceptances are neglected. This systemexperiences a single line to ground fault at a point F on line L1. The point F is at adistance d from Bus 4 along the line L1. The total length l of the line L1 is 50 km.Note that the location of d is not drawn to scale in Figure Q2.1. The fault current atthe fault point F is measured to be 6.106 kA. i) Determine the zero, positive, and negative sequence Thevenin equivalentimpedances as seen at the fault point F. These should be evaluated in per unitand shown as a function of d.ii) Use the sequence impedances calculated in part (i) to determine the distance dof the fault (in km) from Bus 4. It's different from the answer, please don't send it
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
For the power system with a single line diagram; a) By choosing the base values of 1000 MVA and 20 kV in the Generator G3 region, the system is zero, Draw the reactance diagrams of the positive and negative sequence circuits. (for each line ?0 = ?1 = ?2 = 50 ?ℎ?) b) Find the Thevenin equivalents according to the fault condition in busbar 1.