3.9. A 400-MVA, 240-kV/24-KV, three-phase Y-A transformer has an equivalent series impedance of 1.2 + j6 N per phase referred to the high-voltage side. The transformer is supplying a three-phase load of 400-MVA, 0.8 power factor lagging at a teminal voltage of 24 kV (line to line) on its low-voltage side. The primary is supplied from a feeder with an impedance of 0.6 + j1.2 N per phase. Deter- mine the line-to-line voltage at the high-voltage terminals of the transformer and the sending-end of the feeder. The per phase equivalent circuit referred to the primary is is shown in Figure 25. The load complex power is Z = 0.6 + j1.2 Zei = 1.2 + j6 www Vị V = 138.564 kV

3.9. A 400-MVA, 240-kV/24-KV, three-phase Y-A transformer has an equivalent series impedance of 1.2 + j6 N per phase referred to the high-voltage side. The transformer is supplying a three-phase load of 400-MVA, 0.8 power factor lagging at a teminal voltage of 24 kV (line to line) on its low-voltage side. The primary is supplied from a feeder with an impedance of 0.6 + j1.2 N per phase. Deter- mine the line-to-line voltage at the high-voltage terminals of the transformer and the sending-end of the feeder. The per phase equivalent circuit referred to the primary is is shown in Figure 25. The load complex power is Z = 0.6 + j1.2 Zei = 1.2 + j6 www Vị V = 138.564 kV

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 3.27P: A three-phase transformer is rated 1000MVA,220Y/22kV. The Y-equivalent short-circuit impedance,...

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