This presentation is all about transformer, especially on manufacturing of distribution transformer. There is a brief description on X-former as well.

1. Welcome
by
Md. Nirob Dhilon Chowdhury
ID# 11105149
Department of EEE
International University of Business, Agriculture and Technology
01

2. Completed internship
in
02

3. Manufacturing of 11KV/.415KV
distribution transformer of
Green Power Electrical &
Electronics
03

4. To introduce Green Power Electrical & Electronics.
To discuss about transformer.
To reveal the manufacturing of distribution X-former of GPEE.
To recommend.
OBJECTIVE
04

5. About Green Power Electrical &
Electronics
05
 Name: Green Power Electrical & Electronics.
 Sister Concern: Green Power Transformer Company
 Organization Type: Proprietorship.
 Year of Establishment: 2004.
 Founder & CEO: Engr: Gulzer Rahman
 Head Office: Hakim Plaza , 209/B, 1st Colony, Mazar Road, Mirpur , Dhaka-
1216.
 Factory Location: 382 Harindhara, Hemayetpur, Savar, Dhaka.

6. Products
06
AVR IPS IVS UPS

7. Products
07
Transformer
HT switchgear
LT Switchgear PFI

8. 08
Working Sequence

9. • Transfers electric power from one
circuit to another
• It does so without a change of
frequency
• It accomplishes this by
electromagnetic induction
• It can raise or lower the voltage in a
ckt but with a corresponding
decrease or increase in current.
09
Basic Functions Of Transformer
Transformer is a static machine
that…..

10.  Input connection
 Output connection
 Winding
 Core
10
Working Procedure of a Transformer
Primary parts to the basic transformer

11. Generally used in transmission
network
It’s rating is given in terms of
the secondary's maximum
voltage and current-delivering
capacity
Operates at high
voltage greater than 33 KV with
100% efficiency
Has a big size
Used in generating station and
transmission substation at high
insulation level 11
Common Types of Transformer
Power Transformer

12. • Used for the distribution of
electrical energy
• Operates at low voltage as less
than 33KV in industrial purpose
and 440v-220v in domestic
purpose
• It works at low efficiency at 50-
70%
• Has small size easy in installation
• Has low magnetic losses & it is
not always fully loaded
12
Common Types of Transformer
Distribution Transformer

13.  Combined with current
transformer & potential
transformer
 Used for both metering
purposes & protection
purposes
 Used for network control to
supply important
information for determining
the state of the operating
conditions of the network 13
Common Types Of Transformer
Instrument or accurate ratio Transformer
Current Transformer
Potential Transformer

14. 14
Installation of Transformers
Power Tx
Distribution Tx

15. 1. Active Part- Core and
Windings.
2. Passive Part- Tank, cooling
liquid, Fans, Protection
devices etc.
15
Manufacturing of 3-phase Distribution
Transformer
The construction of transformer is divided into two
fundamental parts:
Active Parts
Core
winding

16. 16
Main Components of a
Transformer
Tap Changer
Buchholz Relay

17. 17
Steps of Transformer manufacturing

18.  Low reluctance
 Higher reliability
 Lowering material cost
 Reduction in iron loss & magnetizing
current
18
Manufacturing of Transformer
Core
Factors that are taken into consideration…..

19.  Steel that has under gone through both the Silicon
Alloying and Cold Rolling treatment.
 Basic material are Alloy Steel having main content
Silicon & carbon
 Which increases permeability & reduces losses
 Hysteresis loss in transformer mainly depends upon its
core materials
19
Core Materials
For core manufacturing we
use…

20.  The commercially available CRGO
steel sheets will have 3% of Silicon
 Thickness of the CRGO sheets will be
of the order of 0.25mm to 0.33mm
 CRGOS shows excellent Magnetic
properties
 This material has low specific iron loss
 Oxide coating is provided for CRGO
laminations to reduce eddy current
losses
20
Core Materials
CRGOS
Steel
Hot Rolled
Steel (HRS)
Cold Rolled
Grain Oriented
Steel (CRGOS)

21. 21
Core Cutting
A bar:
Length: (590-540) mm
Width: (130-40) mm
Total A bar used: 1392
B bar:
Length: 255 mm
Width: (130-80) mm
Total B bar used: 928
C bar:
Length: (380-470) mm
Width: (130-80) mm
Total C bar used: 464
Types of cutting (200KVA)
Thickness 0.27 mm

22.  The channels are combined in
stepped round shape with a
square mid-section.
 This gives flexibility and allows to
select ideal individual core
section.
 Four channels are to set, two in
top and two in bottom. 22
Channel Setting
Channel

23. This is the simplest form of joints
The flux leaves and enters at the
joint in perpendicular
Preferable to use in small rating
transformer 23
Core Assembling
There are normally two types of joints used in transformer core:
 Interleaved joints
 Mited joints
Interleaved Joints
Yoke

24.  Here the lamination’s are cut at 45°
 The limbs and yoke lamination
edges are placed face to face
 Here the flux enters and leaves
the lamination, gets smooth path in
the direction of its flow. Hence,
cross grain loss is minimum.
24
Core Assembling
Mitred Joints in Transformer Core
Mirted Joints

25. 25
Influence of Diameter of core
Then, cross-sectional area of the core,
Now, Voltage per turn,
[Bm= Max. flux density]
So, E ∞ D2
Again, V = E*N,
[where N is the number of turns in winding &
voltage across the winding of transformer is V]
When, v is constant then, E∞1/N
Finally, N∞1/D2

26.  Core diameter is increased, the number of
turns of winding reduced.
 This increases steel weight that leads to
increased core losses in transformer.
 On the other hand, copper loss in
transformer is reduced.
 If diameter of the core is decreased, the
weight of the steel in the core is reduced.
 Which leads to less core loss of
transformer, but increases extra copper
loss.
 So, core diameter must be optimized
during designing considering both the
aspects. 26
Since, N∞1/D2

27. 27
Manufacturing of Transformer Windings
Primary/High voltage winding Secondary/Low Vol. winding

28.  Horizontal machine is used to prepare
the HV windings
 The HV winding is wound directly
onto the low voltage winding
 HV windings are of layered
construction
 The conductors are made of more
round wires, either with an insulating
paper
 The insulation between the layers
consists of DPC paper
28
Primary or High Voltage Windings

29.  LV windings are usually made of
copper
 Vertical machine is used to prepare
the LV winding
 Stripe paper is used to insulate the
conductor
 Number of turns varies on KVA
rating
 More even heat distributed
through the windings.
29
Secondary or Low Voltage Windings

30. Insulation
30
 DPC paper and fabric tape are used to insulate between two layers

31. 31
 Insulation between core and LV windings
Cotton Tape
Damn Proof Course Paper
Insulation
1
2

32. Insulation between LV & HV
32
 Press board cutting & DPC paper are used to isolate HV from LV winding
Secondary coil
insulation (stripe paper)
Press board cutting
DPC paper

33. The core is covered with
cotton tape and the LV
coil winding is mounted
with the core limb. They
are fitted tightly in all
three limbs using
pressed board.
33
Placement of LV Windings

34. The HV winding is placed
on LV winding as second
layer of core
LV coil then after HV coil
The gap between the LV
and HV coil is filled with
runner of pressed board
using cotton
34
Placement of HV Windings

35. 35
Connections

36. 36
Tap Changer
Tap Changer
 Tapping is terminated just bellow
oil level
 External handle
 Taping is done on HV winding
 Used to regulate the output
voltage to required levels

37. 37
Function of Tap Changer
Changer
Taping wire
connected to
HV coil

38. The whole active part of
the transformer is put
into the Vacuum Drying
Plant
It is kept there for three
days with a continuous
heating temperature of
100° - 141° C to clean the
moistures in it
38
Moisture Removing

39. 39
Tank of a Transformer

40.  It forms a container for the
cooling liquid
 It acts as a heat exchange
surface for the dissipation of
heat losses
 It is a protective earthed
safety shell
 Provides shielding against
electromagnetic field leakage
caused by current carrying
conductors 40
Functions of X-former Tank

41.  Whole active part is
covered by press
board
 Crane is used to
elevate the active
part
 By handling a chain
the active part is put
slowly in the tank
41
Tanking Up the Active Part

42. It is placed to withstand the
electrical field strength
produced in the insulation
Bushing has a conductor
(Horn) surrounded by
insulation
Used to insulate the
incoming or outgoing
conductor into or out of the
transformer tank
42
Bushings
Bushing

43. The function of conservator
is to provide adequate space
for expansion of oil inside
the tank
It also acts as a reservoir
for transformer insulating
oil.
The oil level indicator
indicates the oil level
Oil level should not fall
below the alarm limit 43
Conservator

44. 44
Oil Filling
 To provide insulation (liquid) to
the x-former.
 To dissipate heat of the
transformer e.i. acts as coolant.
 To protect the transformer core
and coil assembly from chemical
attack
 To prevent the build up of sludge
in the transformer
Oil is used….
Poly Chlorinated Bi Phenyl
(Crude oil)

45. continuity test
Ratio test
Magnetizing test
No load current
test
Short circuit test
45
Quality Control Test
 Testing of transformer

46. 46
Overview

47. 47
Identification

48. 48

49. 49
Recommendations
 Working environment of Green Power Transformer
Company should be more modern and ecological for
technicians.
 Every division should be provided more training facilities
for manufacturing purpose.

50. 50
Thank You

51. 51
Do you have any question?