Consider the system shown in Figure 1. Assume the load voltage (VL) is 4720 V and the load consumptionis 80 kVA at 0.85 lagging power factor. The line impedance (Zline) is 4.6+j8.5 2. The parameters of the14,400/4800-V single-phase transformer referred to the secondary are:Req=0.95 , Xeq = 1.74 , Re = 48.5 kn, and Xm = 31.1 k.vpavs4.6 +19.52ZlineVs ~Pa:1elermisalfReaisleeeV₂zíSFigure 1: System for Q1I wada) Find the current of the load.b) Find the primary and secondary voltages of the ideal transformer.nuomo I un cucc+ BlineXeq,s1V₂²95,74-321.VL 4720Ponerlosture-> PontIL= V₂ -V₂Zine

Given circuit is,Load current?Primary and secondary voltages of ideal transformer.

Consider the system shown in Figure 1. Assume the load voltage (VL) is 4720 V and the load consumption is 80 kVA at 0.85 lagging power factor. The line impedance (Zline) is 4.6+j8.5 . The parameters of the 14,400/4800-V single-phase transformer referred to the secondary are: Req=0.95 , Xeg = 1.74 , Re = 48.5 kn, and Xm = 31.1 k. vp als Vs V₁ P a:1 atf 4.6 +19.5 r Zline Vz zí S Figure 1: System for Q1 I and .as/41. 7452 a) Find the current of the load. b) Find the primary and secondary voltages of the ideal transformer. ^^^ mie 15 Vt 4720 Powerlostere ->Pont

Consider the system shown in Figure 1. Assume the load voltage (VL) is 4720 V and the load consumption is 80 kVA at 0.85 lagging power factor. The line impedance (Zline) is 4.6+j8.5 . The parameters of the 14,400/4800-V single-phase transformer referred to the secondary are: Req=0.95 , Xeg = 1.74 , Re = 48.5 kn, and Xm = 31.1 k. vp als Vs V₁ P a:1 atf 4.6 +19.5 r Zline Vz zí S Figure 1: System for Q1 I and .as/41. 7452 a) Find the current of the load. b) Find the primary and secondary voltages of the ideal transformer. ^^^ mie 15 Vt 4720 Powerlostere ->Pont

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 3.63P: A 23/230-kV step-up transformer feeds a three-phase transmission line, which in turn supplies a...

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Similar questions

An ideal transformer has no real or reactive power loss. (a) True (b) False
For a short-circuit test on a 2-winding transformer, with one winding shorted, can you apply the rated voltage on the other winding? (a) Yes (b) No
A bank of three single-phase transformers, each rated 30MVA,38.1/3.81kV, are connected in Y- with a balanced load of three 1, Y-connected resistors. Choosing a base of 90MVA,66kV for the high-voltage side of the three-phase transformer. spify the base for the low-voltage side. Compute the per-unit resistance of the load on the base for the low-voltage side. Also, determine the load resistance in ohms referred to the high-voltage side and the per-unit value on the chosen base.
The ideal transformer windings are eliminated from the per-unit equivalent circuit of a transformer. (a) True (b) False
Three single-phase, two-winding transformers, each rated 450MVA,20kV/288.7kV, with leakage reactance Xeq=0.10perunit, are connected to form a three-phase bank. The high-voltage windings are connected in Y with a solidly grounded neutral. Draw the per-unit equivalent circuit if the low-voltage windings are connected (a) in with American standard phase shift or (b) in Y with an open neutral. Use the transformer ratings as base quantities. Winding resistances and exciting current are neglected.
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.
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
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.
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.
Three single-phase two-winding transformers, each rated 25MVA,54.2/5.42kV, are connected to form a three-phase Y- bank with a balanced Y-connected resistive load of 0.6 per phase on the low-voltage side. By choosing a base of 75 MVA (three phase) and 94 kV (line-to-line) for the high-voltage side of the transformer bank, specify the base quantities for the low-voltage side. Determine the per-unit resistance of the load on the base for the low-voltage side. Then determine the load resistance RL in ohms referred to the high-voltage side and the per-unit value of this load resistance on the chosen base.
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. -