A

SEMINAR ON

“TRANSFORMER”

BACHELOR OF TECHNOLOGYIN

ELECTRICAL & ELECTRONICS ENGINEERING

SUBMITTEDBY

PANKAJ CHAUDHARYR.N. - 24823

UNDER THE SUPERVISION OF

ARUNESH DUTT (H.O.D)

NEHRU GRAM BHARATI UNIVERSITY, ALLAHABAD

DEPARTMENT OF ELECTRICAL & ELECTRONICS ENGINEERING

SANJAY GANDHI INSTITUTE OF ENGINEERING & TECHNOLOGY

C O N T E N T S

1) Introduction of transformer

2) Construction of transformer

3) Types of transformer

4) Cooling system

5) Basic principle of transformer

6) Voltage and turns ratio

7) Application .

Transformer.

1. A transformer is a device that transfers

electrical energy from one circuit to

another circuit through the medium of

magnetic field and without a change in

frequency .

• This changing magnetic field induces a

changing voltage in the second circuit (the

secondary). This effect is called mutual

induction.

Construction

A single phase transformer consist of primary

and secondary winding put on a magnetic core

is used to confine flux to a definite path .

Transformer cores are made from thin sheet

of high great of silicon steel.

The lamination reduce eddy-current loss and

the silicon steel reduce hysteresis loss.

There are two types of transformer,

1.Core type transformer

2.Shell type transformer

1.- Core type transformer

The magnetic core is a stack of thin silicon steel

lamination about 0.35 mm thick for 50 Hz

Frequency .

The core is made of cold / role , grain ,oriented

sheet steel (CRGO).

The core is used to reduces eddy current losses

the concentric coils are used for core type

transformer , and this is suitable for high voltage

,high power.

2.- Shell type transformer

In shell type the steel core surrounds a part

of the winding .

For shell type transformer the interloped or

sandwich coils are used . This is preferred for

low voltage and low power levels,

COOLING SYSTEM

Three-phase oil-cooled

transformer with cover cut away.

The oil reservoir is visible at the

top. Reductive fins aid the

dissipation of heat.

Basic principle of Transformer:

• TRANSFORMERS

RULESTransformer is based

on two principles:

Firstly , that an

electric

current can produce a

magnetic.

Secondly,

electromagnetic

induction.

E.M.F EQUATION OF TRANSFORMER

E = 4.44ϕmfT

VOLTAGE & TURNS RATIO

V1 / V2 = T1/ T2

A major application of transformers is to increase voltage

before transmitting electrical energy over long distances

through wires. Wires have resistance and so dissipate

electrical energy at a rate proportional to the square of the

current through the wire. By transforming electrical power

to a high-voltage (and therefore low-current) form for

transmission and back again afterward, transformers

enable economical transmission of power over long

distances. Consequently, transformers have shaped the

electricity supply industry, permitting generation to be

located remotely from points of demand. All but a tiny

fraction of the world's electrical power has passed through

a series of transformers by the time it reaches the

consumer.

APPLICATION

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