A 400/100 V, 5 kVA single-phase two winding transformer is to be used as an auto-transformer to supply 400 volts from a 500 V voltage source. When tested as a two-winding transformer at rated load and 0.8 pf lagging, its efficiency was found to be 95%. (a) Determine the transformed kVA and conducted kVA. (b) Find its efficiency as an auto-transformer at rated load and at 0.8 pf lagging

A 400/100 V, 5 kVA single-phase two winding transformer is to be used as an auto-transformer to supply 400 volts from a 500 V voltage source. When tested as a two-winding transformer at rated load and 0.8 pf lagging, its efficiency was found to be 95%. (a) Determine the transformed kVA and conducted kVA. (b) Find its efficiency as an auto-transformer at rated load and at 0.8 pf lagging

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 3.58P: A single-phase two-winding transformer rated 90MVA,80/120kV is to be connected as an autotransformer...

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Concept explainers

Single Phase Transformer

A single-phase transformer is a type of power transformer. It is an electrical device that accepts converts the single phase alternating power into single phase alternating power. In this power conversion the voltage is stepped up or down. If the voltage is stepped up, the current will be stepped down and if the voltage is stepped down, the current will be stepped up.

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(a) Determine the transformed kVA and conducted kVA.

(b) Find its efficiency as an auto-transformer at rated load and at 0.8 pf lagging.

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