presentation on distribution transformer by nirob dhilon chowdhury
TRANSCRIPT
Welcomeby
Md. Nirob Dhilon Chowdhury
ID# 11105149
Department of EEE
International University of Business, Agriculture and Technology
01
Completed internship in
02
Manufacturing of 11KV/.415KV distribution transformer of
Green Power Electrical & Electronics
03
To introduce Green Power Electrical & Electronics.
To discuss about transformer.
To reveal the manufacturing of distribution X-former of GPEE.
To recommend.
OBJECTIVE
04
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.
Products
06
AVR IPS IVS UPS
Products
07
TransformerHT switchgear
LT Switchgear PFI
08
Working Sequence
• 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…..
Input connection
Output connection
Winding
Core
10
Working Procedure of a Transformer
Primary parts to the basic transformer
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 TransformerPower Transformer
• 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
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
Installation of Transformers
Power Tx
Distribution Tx
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
Main Components of a Transformer
Tap Changer
Buchholz Relay
17
Steps of Transformer manufacturing
Low reluctance
Higher reliability
Lowering material cost
Reduction in iron loss & magnetizing current
18
Manufacturing of Transformer Core
Factors that are taken into consideration…..
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…
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
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
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
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
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
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
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
Manufacturing of Transformer Windings
Primary/High voltage winding Secondary/Low Vol. winding
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
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
Insulation
30
DPC paper and fabric tape are used to insulate between two layers
31
Insulation between core and LV windings
Cotton TapeDamn Proof Course Paper
Insulation
12
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
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
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
Connections
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
Function of Tap Changer
Changer
Taping wire connected to HV coil
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
Tank of a Transformer
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
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
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
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
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)
continuity test
Ratio test
Magnetizing test
No load current test
Short circuit test
45
Quality Control Test
Testing of transformer
46
Overview
47
Identification
48
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
Thank You
51
Do you have any question?