1.
PES POLYTHECNIC
NAME-ATISH JADHAV
BRANCH-E&TC
SUBJECT-EEN(ELECTRICAL ENGENEERING)
TOPIC NAME- TRANSFORMER
SUBJECT TEACHER –SHINDE MISS

2.
TRANSFORMER
CIRCUIT DIAGRAM

3.
Transformer
A transformer is an electrical device that transfers
energy between two or more circuits through
electromagnetic induction.
A varying current in the transformer's primary
winding creates a varying magnetic flux in the core
and a varying magnetic field impinging on the
secondary winding.
This varying magnetic field at the secondary induces a
varying electromotive force (emf) or voltage in the
secondary winding.

4.
Why the rating of transformer is given in KVA?
1) In Transformer ,there are core losses & copper losses.
2)Core losses depend upon input voltage
3)Copper losses depend upon current flowing through
winding
4)Hence total losses depend upon voltage as well as current
but not on power factor. Hence transformer is rated in KVA
and not in KW

5.
TYPES OF TRANSFORMER
CORE TYPE
SHELL TYPE
BERRY TYPE

6.
CORE TRANSFORMER
CIRCUIT DIAGRAM

7.
CORE TRANSFORMER
The core of these type of transformer is built of
lamination to form a rectangular frame and provides a
single magnetic circuit.
The winding are normally cylindrical in form and both
windings are uniformly distributed over two lines of
the core.
The metallic lamination is at top yoke.

8.
SHELL TYPE
CIRCUIT DIAGRAM

9.
SHELL TRANSFORMER
In shell-type transformers the core surrounds a
considerable portion of the windings. The comparison
is shown in the figure .
The core of this transformer provides double magnetic
circuit.
The windings are normally sand witch type always
central limb of the core.

10.
Circuit Difference

11.
Difference Between Core type and Shell
type
Core type Shell type

12.
2)The core has only one window
3)Winding surrounds the core
4)This transformer is easy to
repair
5)Better cooling
6)Less mechanical protection
7)One path for flux
8)Good efficiency
2)The core has two window
3)Core surrounds the winding
4)It is not easy to repair
5)Cooling not very good
6)Better mechanical protection
7)Two path for flux
8)Loss efficiency

13.
Reference