A 20-KVA, 20,000/480-V, 60-Hz distribution transformer is tested with the followingresults:Open-circuit testShort-circuit test(measured from secondary side)(measured from primary side)Vsc = 1130 VVoc=480 VIoc = 1.60 AIsc = 1.00 APoc = 305 WPsc = 260 WSketch the per-unit equivalent circuit of this transformer referred to the primary side

Given Parameters of a distribution transformer. We need to sketch the per equivalent circuit.…

A 20-KVA, 20,000/480-V, 60-Hz distribution transformer is tested with the following results: Open-circuit test Short-circuit test (measured from secondary side) Voc=480 V (measured from primary side) Vsc=1130 V loc = 1.60 A Isc = 1.00 A Poc = 305 W Psc = 260 W Sketch the per-unit equivalent circuit of this transformer referred to the primary side

A 20-KVA, 20,000/480-V, 60-Hz distribution transformer is tested with the following results: Open-circuit test Short-circuit test (measured from secondary side) Voc=480 V (measured from primary side) Vsc=1130 V loc = 1.60 A Isc = 1.00 A Poc = 305 W Psc = 260 W Sketch the per-unit equivalent circuit of this transformer referred to the primary side

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 3.4P: A single-phase 100-kVA,2400/240-volt,60-Hz distribution transformer is used as a step-down...

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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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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
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A two-winding single-phase transformer rated 60kVA,240/1200V,60Hz, has an efficiency of 0.96 when operated at rated load, 0.8 power factor lagging. This transformer is to be utilized as a 1440/1200-V step-down autotransformer in a power distribution system. (a) Find the permissible kVA rating of the autotransformer if the winding currents and voltages are not to exceed the ratings as a two-winding transformer. Assume an ideal transformer. (b) Determine the efficiency of the autotransformer with the kVA loading of part (a) and 0.8 power factor leading.
An open-delta three-phase transformer system has one transformer center-tapped to provide a neutral for single-phase voltages. If the voltage from line to center tap is 277 V, what is the high-leg 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. -
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