For the network shown in the figure below, all reactances are in p.u. to a base of 100MVA and 13.8 kV. At the power system bus 2, the short circuit MVA of the power system only (line 2-1 isolated) are 1200MVA at 13.6 kV. Calculate the sub-transient fault current for a symmetrical 3-phase fault at bus 1 (Assume that the pre-fault voltage is 120º Problem 2 p.u.) Power system j0.2 ell j0.5 1 3 j0.2 j0.25 2. ll lll ell

For the network shown in the figure below, all reactances are in p.u. to a base of 100MVA and 13.8 kV. At the power system bus 2, the short circuit MVA of the power system only (line 2-1 isolated) are 1200MVA at 13.6 kV. Calculate the sub-transient fault current for a symmetrical 3-phase fault at bus 1 (Assume that the pre-fault voltage is 120º Problem 2 p.u.) Power system j0.2 ell j0.5 1 3 j0.2 j0.25 2. ll lll ell

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 9.54P

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Similar questions

At the general three-phase bus shown in Figure 9.7(a) of the text, consider a simultaneous single line-to-ground fault on phase a and line-to-line fault between phases b and c, with no fault impedances. Obtain the sequence-network interconnection satisfying the current and voltage constraints.
A three-phase circuit breaker has a 15.5-kV rated maximum voltage, 9.0-kA rated short-circuit current, and a 2.50-rated voltage range factor. (a) Determine the symmetrical interrupting capability at 10-kV and 5-kV operating voltages. (b) Can this breaker be safely installed at a three-phase bus where the symmetrical fault current is 10 kA, the operating voltage is 13.8 k V, and the (X/R) ratio is 12?
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.
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