7. Two similar star-grounded synchronous generators, one of which has its star point grounded, supply 11 kV three-phase busbars. An 11/66 kV delta/star connectea transformer with the star point grounded is supplied from the busbars. The impedances referred to 11 kV, are as given below : Generator Transformer Impedance to positive-sequence currents Impedance to negative-sequence currents Impedance to zero-sequence currents j 3.0 2 j 2.0 2 j 3.0 2 j 3.0 2 j 3.0 2 j1.0 2 Determine the fault current for an LG fault (a) on a busbar, and (b) at an hv terminal of the transformer. (c) Find also the voltage to ground of the two sound busbars in case (a).

7. Two similar star-grounded synchronous generators, one of which has its star point grounded, supply 11 kV three-phase busbars. An 11/66 kV delta/star connectea transformer with the star point grounded is supplied from the busbars. The impedances referred to 11 kV, are as given below : Generator Transformer Impedance to positive-sequence currents Impedance to negative-sequence currents Impedance to zero-sequence currents j 3.0 2 j 2.0 2 j 3.0 2 j 3.0 2 j 3.0 2 j1.0 2 Determine the fault current for an LG fault (a) on a busbar, and (b) at an hv terminal of the transformer. (c) Find also the voltage to ground of the two sound busbars in case (a).

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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3.8. Three identical 9-MVA, 7.2-kV/4.16-kV, single-phase transformers are con- nected in wye on the high-voltage side and delta on the low voltage side. The equivalent series impedance of each transformer referred to the high-voltage side is 0.12 + j0.82 S per phase. The transformer supplies a balanced three- phase load of 18 MVA, 0.8 power factor lagging at 4.16 kV. Determine the line-to-line voltage at the high-voltage terminals of the transformer.
In a star-delta phase shifting transformer, the zero sequence currents cannot flow through the it True False
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It is bartleybe's policy that if questions objective than you need to solve at least first 3 questions.
what is the definition of zero sequence impedance in a transformers? And what is the benefit of this check in transformers?