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