At normal voltage and frequency, an 800 kVA single-phase transformer draws an input power of 7.5 kW on no-load. With reduced voltage applied and full-load current flowing in short- circuited secondary winding, it draws an input power of 14.2 kW. If the transformer operates on the following duty cycle in a day, calculate its all-day efficiency. Duration Load (kW) Load power factor (hours) 500 0.8 4 700 0.9 4 300 0.95 10 Nil

At normal voltage and frequency, an 800 kVA single-phase transformer draws an input power of 7.5 kW on no-load. With reduced voltage applied and full-load current flowing in short- circuited secondary winding, it draws an input power of 14.2 kW. If the transformer operates on the following duty cycle in a day, calculate its all-day efficiency. Duration Load (kW) Load power factor (hours) 500 0.8 4 700 0.9 4 300 0.95 10 Nil

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 3.11MCQ: For a short-circuit test on a 2-winding transformer, with one winding shorted, can you apply the...

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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.

Question

At normal voltage and frequency, an 800 kVA single-phase transformer draws an input power
of
7)
7.5 kW on no-load. With reduced voltage applied and full-load current flowing in short-
circuited secondary winding, it draws an input power of 14.2 kW. If the transformer operates on
the following duty cycle in a day, calculate its all-day efficiency.
Duration
Load (kW)
Load power factor
(hours)
6.
500
0.8
4
700
0.9
4
300
0.95
10
Nil

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