A single-phase l0-kVA, 480/1120 -V transformer is to be used as an auto transformer tying a 600V distribution line to a 480-V load. When it is tested as a conventional transformer, the following values are measured on the primary (480-V) side of the transformer: a. Find the per-unit equivalent circuit of this transformer when it is connected in the conventional manner. b. What is the efficiency of the transformer at rated conditions and unity power factor? c. What is the voltage regulation at those conditions?

A single-phase l0-kVA, 480/1120 -V transformer is to be used as an auto transformer tying a 600V distribution line to a 480-V load. When it is tested as a conventional transformer, the following values are measured on the primary (480-V) side of the transformer: a. Find the per-unit equivalent circuit of this transformer when it is connected in the conventional manner. b. What is the efficiency of the transformer at rated conditions and unity power factor? c. What is the voltage regulation at those conditions?

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 3.14P: A single-phase 50-kVA,2400/240-volt,60-Hz distribution transformer is used as a step-down...

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A single-phase two-winding transformer rated 90MVA,80/120kV is to be connected as an autotransformer rated 80/200kV. Assume that the transformer is ideal. (a) Draw a schematic diagram of the ideal transformer connected as an autotransformer. showing the voltages, currents, and dot notation for polarity. (b) Determine the permissible kVA rating of the autotransformer if the winding currents and voltages are not to exceed the rated values as a two-winding transformer. How much of the kA rating is transferred by magnetic induction?
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