Single Phase Transformer

Apr 28 • General • 4836 Views • 1 Comment on Single Phase Transformer


It is an apparaturs for converting electrical power in an ac system at one voltage or current into electeical power at other voltage or current without the use of rotating parts.

Transformers can be classified on the basis of

(i) method of cooling

(ii)no. of phases

(iii)insulation between windings

(iv)insulation between windings


On the basis of no. of phases transformer is of two types


a. Single phase

b. Poly phase

Single Phase Transformer

A single phase transformer is used, above all in mains power unit for supplying different types of electrical equipment. A single phase transformer consists of two windings on a common iron ore. If one of the winding is connected to the AC voltage V1, an alternating magnetic field will be set up in the iron ore.This field will induce an AC voltage V2 in the other windings.




The ratio between these two voltage is the same as the no. of turns in the two windings

Vp / Vs = Np / Ns

Standard frequency of a single phase power systems are either 50 or 60 Hz. Special single phase traction power networks may operate at 16.67Hz or other frequencies to power electric railways.

In Elecrical Engineering, single phase electric power refers to the distribution of alternating current electric power using a system in which all the voltages of the supply vary in unison. It is used when loads are mostly lighting,heating with few large electric motors.


1) widely used in rural areas where cost of a three-phase distribution network         is high and motor loads are small and uncommon.

2) Single phase household supply may be 100 or even 125 A meaning that there is little need for 3 phase in domestic or small commercial environment.

3) used in electric railways

Related Questions and Answers

1) Why are Laminated insulations coated with varnish normally used in the transformer.

2) What is a the purpose of Oil used in transformer

3) Why are the transformers windings are divided into several colis?

4)what is the important aspect on which the size and construction of bushings in a transformer depend upon?

5)What is the best way for reduction of humming sound of transformer


1)To reduce the effect of eddy current.

2)Cool the windings

3)It requires less insulation

4)Size of tank and current flowing

5)Proper bracing of transformers assemblies


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One Response to Single Phase Transformer

  1. RANJIT SINGH says:

    This is a very important topic of electrical engineering.Very well explained.

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