b) A fault occurs at bus 3 of the network shown in Figure Q4. Pre-fault nodalvoltages throughout the network are of 1 p.u. and the impedance of the electricarc is neglected. Sequence impedance parameters of the generator,transmission lines, transformer and load are given in Figure Q4.V₁ = 120° p.u.V₂ = 120° p.u. V₂ = 1/0° p.u.V₂= 120° p.u.jXj0.1 p.u.JX2) 0.1 p.u.jX0j0.15 p.u.jXn-j0.2 p.u.1 JX(2)-j0.2 p.u. 2jX)=j0.25 p.u.JX20-10.15 p.u.jXa(z)-j0.2 p.u. 4jX2(0)=j0.2 p.u.jXT(1) j0.1 p.u.jXT(2)=j0.15 p.u.jXT(0)=j0.1 p.u.Figure Q4. Circuit for problem 4b).=jXj0.1 p.u.j0.1 p.u.-JX(2)JXL(0) 10.1 p.u.=(i) Assuming a balanced excitation, draw the positive, negative and zerosequence Thévenin equivalent circuits as seen from bus 3.(ii) Determine the positive sequence fault current for the case when a three-phase-to-ground fault occurs at bus 3 of the network.(iii) Determine the short-circuit fault current for the case when a one-phase-to-ground fault occurs at bus 3.

Positive, negative and zero sequence data of the given circuit are provided based on that we can…

V₁ = 120° p.u. jXj0.1 p.u. JX2)/0.1 p.u. JX) 10.15 p.u. V₂ - 120° p.u. j0.2 p.u. JX(1) 1 JX2) 0.2 p.u. 2 V₂ - 120° p.u. V₁- 120° p.u. JX20-j0.15 p.u. jXj0.2 p.u. 4 JX20) j0.2 p.u. jXj0.25 p.u. JX) 0.1 p.u. JXT2)-j0.15 p.u. JXT(0) JO.1 p.u. Figure Q4. Circuit for problem 4b). JX) 10.1 p.u. JX)/0.1 p.u. JXL) 10.1 p.u. (i) Assuming a balanced excitation, draw the positive, negative and zero sequence Thévenin equivalent circuits as seen from bus 3. (ii) Determine the positive sequence fault current for the case when a three- phase-to-ground fault occurs at bus 3 of the network. (iii) Determine the short-circuit fault current for the case when a one-phase- to-ground fault occurs at bus 3.

V₁ = 120° p.u. jXj0.1 p.u. JX2)/0.1 p.u. JX) 10.15 p.u. V₂ - 120° p.u. j0.2 p.u. JX(1) 1 JX2) 0.2 p.u. 2 V₂ - 120° p.u. V₁- 120° p.u. JX20-j0.15 p.u. jXj0.2 p.u. 4 JX20) j0.2 p.u. jXj0.25 p.u. JX) 0.1 p.u. JXT2)-j0.15 p.u. JXT(0) JO.1 p.u. Figure Q4. Circuit for problem 4b). JX) 10.1 p.u. JX)/0.1 p.u. JXL) 10.1 p.u. (i) Assuming a balanced excitation, draw the positive, negative and zero sequence Thévenin equivalent circuits as seen from bus 3. (ii) Determine the positive sequence fault current for the case when a three- phase-to-ground fault occurs at bus 3 of the network. (iii) Determine the short-circuit fault current for the case when a one-phase- to-ground fault occurs at bus 3.

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

Chapter3: Power Transformers

Section: Chapter Questions

Problem 3.26P: A bank of three single-phase transformers, each rated 30MVA,38.1/3.81kV, are connected in Y- with a...

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