This document summarizes the key components and design of a single-phase transformer. It discusses that a transformer is a static device that transfers power between two circuits using electromagnetic induction. The two main parts are the transformer core and windings. The core is made of silicon steel laminations to reduce eddy current losses. Cold rolling the silicon steel orients the grains, which reduces the magnetic reluctance and improves efficiency by providing a lower reluctance path for magnetic flux.

1. DEPARTMENT OF ELECTRICALAND ELECTRONICS ENGINEERING
TECHNICAL SEMINAR
DESIGN OF SINGLE PHASE TRANSFORMER
PRESENTED BY
V.RAHUL
2065FA0206

2. DEFINITION AND FEATURES OF TRANSFORMER
 Definition:-
 It is a static device transfer power from one circuit to another
circuit .
 Features:-
 It is a constant frequency device.
 Constant power device .
 It is a constant flux device .
 It is a 180 degree phase shift
 It is an electromagnetic energy conversion device(internal energy
conversion).

3. CONSTRUCTION OF TRANSFORMER
We have mainly two parts.
1. Transformer core.
2. Transformer winding.

4. 1-PHASE TRANSFORMER.

5. TRANSFORMER CORE
 Low reluctance.
 High permeability.
 Feromagnetic material.
 Low iron loss.
‘si’ steel iron+carbon=steel
By adding 4% to 5% of silicon
Silicon Steel

6. HOW SHOULD BE THE CORE
 Consider a solid core.
 The current carrying capacity is
depend the cross sectional are of
conductor.
 Eddy current losses takes place in
the form of heat.
 Due to induced emf in the core eddy current flows(Ie)
 Each and every material offers some amount resistance.
 So, finally due to this Ie^2Rc losses produces. (Rc= Core resistance)

7. CONSIDER A LAMINATED CORE.
 In order to over come the drawbacks of solid core we need to
make the laminations.
 Cros sectional area of the core is reduced.
 Insulating medium is oxide paint, chaina clay, Japan varnish.

8. SHAPE OF SILICON STEEL
 Crystal structure called BCC –(BODY CENTRE CUBIC
STRUCTRE)
 In silicon steel we have lakhs of cubes/grains.
 This are all microscopic pictures.

9. EDGES AND DIAGONELS
In this cubic structure we have edges and
diagonals.
12-Edges.
04-Diagonals.

10. CONSIDER DIAGONAL PATH
Diagonal is the shortest path .
But to air gap it offers high reluctance path.

11. CONSIDER A SMALL PIECE OF SILICON STEEL
Normal silicon steel:
 There is non-orientation of cubes/grains.
 As compare to the length of the silicon material, the flux
is taking more length of the path.

12. DRAWBACKS OF SILICON
 Due to increase in length of the flow of flux.
 Reluctance of the steel little increases.
 But compare with any other material silicon is
best(offers low reluctance path to magnetic
flux).
 We can reduce the reluctance further .
 By converting non-oriented grains into oriented
grains.

13. PROCESS TO COVERT NON- ORIENTED GRAINS
INTO ORIENTED GRAINS
 In Mechanical Engineering we have two
process.
1.Hard Rolling Process.
2.Cold Rolling Process.
 In order to achieve orientation of
cubes/grains we need to go for cold rolling.

14. Cold Rolling Process
 The cold rolling process is performed under some
temperature and pressure.
 As compare to hard rolling process it is very low
(60degrees to 100degree Celsius).

15. Conclusion
 By the cold rolling process the silicon steel is
converted into cold rolled grain oriented steel
(CRGO STEEL).
 As path of flux is reduces .
 Reluctance is reduced.
 Reduced losses.
 Higher efficiency.

16. Thank You