(b) A 180 kVA, 2300:230 V, 60 Hz, single-phase transformer has the following parameters: R₁ = 0.15, X₁₁ = 0.25 N, R₂ = 0.0015 N, X12 Χι = 0.0025 2, Re = 20 kn, and Xm = 5 kn. The transformer is delivering full-load at 230 V and 0.88 power factor lagging. (i) What is the turns ratio n? (ii) Draw the phasor diagram which relates the primary voltage V₁ to the referred secondary voltage V2. (iii) Calculate the phasor load current 12 (A) referred to the primary. (iv) Calculate the primary voltage V₁. (Do not ignore the exciting current, Iε, and you may find drawing an appropriate equivalent circuit useful. )

(b) A 180 kVA, 2300:230 V, 60 Hz, single-phase transformer has the following parameters: R₁ = 0.15, X₁₁ = 0.25 N, R₂ = 0.0015 N, X12 Χι = 0.0025 2, Re = 20 kn, and Xm = 5 kn. The transformer is delivering full-load at 230 V and 0.88 power factor lagging. (i) What is the turns ratio n? (ii) Draw the phasor diagram which relates the primary voltage V₁ to the referred secondary voltage V2. (iii) Calculate the phasor load current 12 (A) referred to the primary. (iv) Calculate the primary voltage V₁. (Do not ignore the exciting current, Iε, and you may find drawing an appropriate equivalent circuit useful. )

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 3.11MCQ: For a short-circuit test on a 2-winding transformer, with one winding shorted, can you apply the...

See similar textbooks

Similar questions

The symbol shown is a(n) a. iron core transformer. b. auto transformer. c. current transformer. d. air core transformer.
A single-phase step-down transformer is rated 13MVA,66kV/11.5kV. With the 11.5 kV winding short-circuited, rated current flows when the voltage applied to the primary is 5.5 kV. The power input is read as 100 kW. Determine Req1andXeq1 in ohms referred to the high-voltage winding.
An ideal transformer has no real or reactive power loss. (a) True (b) False
A single-phase, 50-kVA,2400/240-V,60-Hz distribution transformer has the following parameters: Resistance of the 2400-V winding: R1=0.75 Resistance of the 240-V winding: R2=0.0075 Leakage reactance of the 2400-V winding: X1=1.0 Leakage reactance of the 240-V winding: X2=0.01 Exciting admittance on the 240-V side =0.003j0.02S (a) Draw the equivalent circuit referred to the high-voltage side of the transformer. (b) Draw the equivalent circuit referred to the low-voltage side of the transformer. Show the numerical values of impedances on the equivalent circuits.
For an ideal 2-winding transformer, an impedance Z2 connected across winding 2 (secondary) is referred to winding 1 (primary) by multiplying Z2 by (a) The turns ratio (N1/N2) (b) The square of the turns ratio (N1/N2)2 (c) The cubed turns ratio (N1/N2)3
For an ideal transformer, the efficiency is (a) 0 (b) 100 (c) 50
The direct electrical connection of the windings allows transient over voltages to pass through the auto transfonner more easily, and that is an important disadvantage of the autotransformer. (a) True (b) False
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.
Consider the three single-phase two-winding transformers shown in Figure 3.37. The high-voltage windings are connected in Y. (a) For the low-voltage side, connect the windings in , place the polarity marks, and label the terminals a, b, and c in accordance with the American standard. (b) Relabel the terminals a, b, and c such that VAN is 90 out of phase with Va for positive sequence.
A 23/230-kV step-up transformer feeds a three-phase transmission line, which in turn supplies a 150-MVA,0.8 lagging power factor load through a step-down 230/23-kV transformer. The impedance of the line and transformers at 230kVis18+j60. Determine the tap setting for each transformer to maintain the voltage at the load at 23 kV.
Rework Problem 3.14 if the transformer is delivering rated load at rated secondary voltage and at (a) unity power factor, (b) 0.8 power factor leading. Compare the results with those of Problem 3.14. -
Solutions please