Two single-phase transformers, having equal turns ratio, in parallel supply a secondary load of 1,000 A at 0.8 pf lagging. For each transformer the secondary emf on open circuit is 3,300 V and their total leakage impedances referred to secondary are (0.10 + j0.20) ohms and (0.05 + j0.040) ohm, respectively. Determine the output current on each transformer.

Two single-phase transformers, having equal turns ratio, in parallel supply a secondary load of 1,000 A at 0.8 pf lagging. For each transformer the secondary emf on open circuit is 3,300 V and their total leakage impedances referred to secondary are (0.10 + j0.20) ohms and (0.05 + j0.040) ohm, respectively. Determine the output current on each transformer.

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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The ratings of a three-phase three-winding transformer are Primary(1): Y connected 66kV,15MVA Secondary (2): Y connected, 13.2kV,10MVA Tertiary (3): A connected, 2.3kV,5MVA Neglecting winding resistances and exciting current, the per-unit leakage reactances are X12=0.08 on a 15-MVA,66-kV base X13=0.10 on a 15-MVA,66-kV base X23=0.09 on a 10-MVA,13.2-kV base (a) Determine the per-unit reactances X1,X2,X3 of the equivalent circuit on a 15-MVA,66-kV base at the primary terminals. (b) Purely resistive loads of 7.5 MW at 13.2 kV and 5 MW at 2.3kV are connected to the secondary and tertiary sides of the transformer, respectively. Draw the per- unit impedance diagram, showing the per-unit impedances on a 15-MVA,66-kV base at the primary terminals.
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