2) The following no-load results are obtained at the excitation branch of a 10, 20 kVA, 2400/240 V, 50 Hz transformer: Voltmeter 240 V, Ammeter 2,2 A, Wattmeter 120 W d) Express the excitation current as a percentage of the rated current, e) Determine the active power, reactive power and the appearant input power of the transformer at no load condition, f) Calculate the power factor. Important notice: Doublecheck that all the units in your solutions are given and are correct !!

2) The following no-load results are obtained at the excitation branch of a 10, 20 kVA, 2400/240 V, 50 Hz transformer: Voltmeter 240 V, Ammeter 2,2 A, Wattmeter 120 W d) Express the excitation current as a percentage of the rated current, e) Determine the active power, reactive power and the appearant input power of the transformer at no load condition, f) Calculate the power factor. Important notice: Doublecheck that all the units in your solutions are given and are correct !!

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 3.51P: The ratings of a three-phase three-winding transformer are Primary(1): Y connected 66kV,15MVA...

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Similar questions

An ideal transformer has no real or reactive power loss. (a) True (b) False
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Consider an ideal transformer with N1=3000andN2=1000 turns. Let winding 1 be connected to a source whose voltage is e1(t)=100(1| t |)volts for 1t1ande1(t)=0 for | t |1 second. A2- farad capacitor is connected across winding 2. Sketch e1(t),e2(t),i1(t),andi2(t) versus time t.
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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.
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 ideal transformer windings are eliminated from the per-unit equivalent circuit of a transformer. (a) True (b) False
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.
In developing per-unit circuits of systems such as the one shown in Figure 3.10. when moving across a transformer, the voltage base is changed in proportion to the transformer voltage ratings. (a) True (b) False
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. -