Q3/A) A 1000-VA 230/115-V transformer has been tested to determine its equivalentcircunt. The results of the tests are shown below.Open-circuit testVoc - 230 VShort-circuit testVse 19.1 VPressiteloc=0.45 A1sc8.7 AP.Poc 30 WPse 42.3 WAll data given were taken from the primary side of the transformer.(a) Find the equivalent circuit of this transformer referred to the low-voltage side of thetransformer. (b) Determine the transformer's efficiency at rated conditions and 0.8 PFlagging.

given that VOC=230VIOC=0.45APOC=30WPOC =VOCIOCcosϕ∘cosϕ∘=POC VOCIOC=30230×0.45=0.289POC =VOC2RC⇒…

Q3/A) A 1000-VA 230/115-V transformer has been tested to determine its equivalent circunt. The results of the tests are shown below. Open-circuit test Voc-230 V Short-circuit test Vse - 19.1 V 18.7 A Pen. 3. ke loc=0.45 A P. P... Poc - 30 W Psc 42.3 W All data given were taken from the primary side of the transformer. (a) Find the equivalent circuit of this transformer referred to the low-voltage side of the transformer. (b) Determine the transformer's efficiency at rated conditions and 0.8 PF agging. WE

Q3/A) A 1000-VA 230/115-V transformer has been tested to determine its equivalent circunt. The results of the tests are shown below. Open-circuit test Voc-230 V Short-circuit test Vse - 19.1 V 18.7 A Pen. 3. ke loc=0.45 A P. P... Poc - 30 W Psc 42.3 W All data given were taken from the primary side of the transformer. (a) Find the equivalent circuit of this transformer referred to the low-voltage side of the transformer. (b) Determine the transformer's efficiency at rated conditions and 0.8 PF agging. WE

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

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
For the transformer in Problem 3.10. The open-circuit test with 11.5 kV applied results in a power input of 65 kW and a current of 30 A. Compute the values for GcandBm in siemens referred to the high-voltage winding. Compute the efficiency of the transformer for a load of 10 MW at 0.8 p.f. lagging at rated voltage.
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. -
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.
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
An ideal transformer has no real or reactive power loss. (a) True (b) False
Reconsider Problem 3.64 with the change that now Tb includes both a transformer of the same turns ratio as Ta and a regulating transformer with a 4 phase shift. On the base of Ta, the impedance of the two comp onents of Tb is jO.1 per unit. Determine the complex power in per unit transmitted to the load through each transformer. Comment on how the transformers share the real and reactive pors.
Consider Figure 3.25 of the text for a transformer with off-nominal turns ratio. (i) The per-unit equivalent circuit shown in part (c) contains an ideal transformer which cannot be accommodated by some computer programs. (a) True (b) False (ii) In the - circuit representation for real c in part (d), the admittance parameters Y11 and Y12 would be unequal. (a) True (b) False (iii) For complex c, can the admittance parameters be synthesized with a passive RLC circuit? (a) Yes (b) No
The ideal transformer windings are eliminated from the per-unit equivalent circuit of a transformer. (a) True (b) False
Consider Figure 3.4. For an ideal phase-shifting transformer, the imda nce is unchanged when it is referred from one side to the other. (a) True (b) False
Consider the oneline diagram shown in Figure 3.40. The three-phase transformer bank is made up of three identical single-phase transformers, each specified by X1=0.24 (on the low-voltage side), negligible resistance and magnetizing current, and turns ratio =N2/N1=10. The transformer bank is delivering 100 MW at 0.8 p.f. lagging to a substation bus whose voltage is 230 kV. (a) Determine the primary current magnitude, primary voltage (line-to-line) magnitude, and the three-phase complex power supplied by the generator. Choose the line-to-neutral voltage at the bus, Va as the reference Account for the phase shift, and assume positive-sequence operation. (b) Find the phase shift between the primary and secondary voltages.
For an ideal 2-winding transformer, the ampere-turns of the primary winding, N1I1 is equal to the ampere-turns of the secondary winding, N2I2 (a) True (b) False