B.COM Unit – 4 ( CORPORATE SOCIAL RESPONSIBILITY ( CSR ).pptx
PRESENTATION ON MANUFACTURING OF TRANSFORMER By Dhruv Jimit
1. Prepared by:
Jimit Dhruv
Elect.Engg,Dept.
Valiya Institute Of Technology-Valiya
2. Introduction
Core material:
Basic material are Alloy Steel having main
content Silicon & carbon
Which increases permeability & reduces losses
3. HRS:
HRS not used now a days
As it has random direction &hard to measure
Magnetic properties
CRGOS:
CRGOS shows excellent Magnetic properties
So CRGOS is more used
4. Core construction
Due to Pulsating flux, core should be
laminated
Transformer of larger size may forms in
cut “C” or cut “E” type.
Types of Interleaving:
I. Simple Interleaving
II. Meter core Interleaving:
1)45 ˙
2) 33 ˙ /55 ˙ overlapping
In 3-Ø Shell type transformer middle
winding is reversed
If not then 73% more core is used
which leads in increase in over all cost
6. Concentric
Sandwich
Spiral: It is used 100
A& for low Voltage
Winding
Mechanically very
strong Sandwich: mostly used
Helical :Intermediate for shell type transformer
range of current Control leakage
Suitable for LV winding
reactance
of large transformer HV & LV are near so
leakage flux is reduced
Cross-over: suitable of
mmf of each section is
current not exceeding 20
same.
A
Use for HV winding of
small transformer
Continuous disc: no of
turns wound radially over
one another
separated by spacers
HV winding
Mechanically strong
7. Insulations
Two main kinds of Insulations:
1. Major Insulation:
Insulating cylinder between LV & core
Also between HV & LV
Insulating barriers between limbs, coils & core
yoke
Oil impregnated paper used as it has high
dielectric strength
2. Minor Insulation:
Insulation between
individual turns & between layers
Conductor Insulation: paper&cotton
Air insulated Transformer
insulation used is glass tap
8. Bushing
Up to 66kv non-condenser bushing are used is
porcelain & oil filled
Above 66kv condenser bushing are used for
economic reasons.
Condenser type bushing: It is formed by
inserting Aluminum foiled layers into a paper
winding at predetermined radius.
“Partial capacitance”
In outdoor substation the
bushing are covered by a
porcelain rain shade
9. Tapping
Main two location:
1. Inside Tank
2. Outside Tank
Considered as integral part of transformer
Tapping operation
(1)On load (2)Off load
tap changer tap changer
Tapping is terminated just bellow oil level
External handle
Taping is done on HV winding
Provided in middle (axial & radial force)
10. Transformer Tank
Plain sheet steel
Tank
Tube Tank
Corrugated Tank
Radiator Tank
Tank with separate
coolers
11. Conservator
What is Conservator ?
The expansion of oil from Transformer
tank takes up in Conservator
When oil contracts, air from
atmosphere enters in Conservator .
Risk of contamination of oil in transformer
Breather valve is mounted to avoide
moisture
Breather contain silica in it
12. Buchholz Relay
Operation:
Gas operated relay
AT the time of fault to maintain the continuity
of the supply
Fault detected particularly in incipient stage ,
major fault can be avoided
Which is placed between conservator
and transformer tank
13. Transformer oil
Double purpose :
ie cooling & Insulating
Permittivity is 2.5
As per I.A.S breakdown strength of oil
used must be 50kv RMS
Major disadvantage is sluging
To overcome this, synthetic oil is prefered
One of the e.g is Chlorinated dephenyl is a
synthetic oil its permittivity is 4.5
15. WINDING SHOP
TYPES OF WINDING
i. NORMAL WINDING
ii. INTERLEAVE WINDING
iii. TERITARY WINDING
ROTARY
HORIZONTAL HELICAL
K-
MACHINES TRANSPOSITION
TYPE
CONTINUOUS
VERTICAL
DISC
• End Rings & shielding for prevention purpose
16. Conductor Insulation:
1. Precompressed press board insulation(CRIP
PAPER)
2. Craft paper
3. Also spacers as insulation
Moisture Control
Winding Auto Clave: Uses temp. of 110º
C to 130º C and Vacuum of about 0.4 to
0.5 mbar.
Insulating Oven : Uses Heating Only
Pressure Machine
Brazing Machine with use of SILPHOS
ALLOY
Post Insulation
18. CORE & ACTIVE
PART
ACTIVE PART
C.R.G.O. STRIPS
1-STRIP HAS WIDTH OF 0.27 mm
COIL OR WINDING ASSEMBLY
PROCEDURE:
Manufacturing of LIMB
Core Insulation
Removal of TOP FRAM for Coil assembly
Winding insulation detail
TOP YOKE FILLING
VAPOUR PHASE OVEN
HV & LV leads from top & bottom to the bushings
REGULATING COILS to the tap changer
19. FINAL ASSEMBLY
Installation of active part and assembly of
accessories
TRANSFORMER TANK
• JOINED AT
BELL TYPE BOTTOM
SIDE
• JOINED AT
CONVECTIONAL
TYPE
UPPER
SIDE
20. ACCESSORIES:
Blanker : Leakage of oil & Radiators
adjointment
Buchholz Relay: To trip the transformer
OSR (oil serge relay): To indicate the level
and quality of oil
MOLG(magnate oil gage): It indicates the
level of oil in the conservator
Breather Valve: Provide dry air using silica
gel and have air seal of neoprene
Cooling Equipment: Generally for cooling
of oil in a tank
1. Radiators
2. Thermosyphan
21. Method of Cooling:
i. ONAN
ii. ONAF
iii. OFAF
iv. For very high temp using HEAT
EXCHANGER
CT(Current Transformer):Two
purposes;
1. Winding temp indicator (WTI)
2. Oil temp indicator (OTI)
BUSHINGS: The leads from top and
bottom of the winding are brought out to a
length of few cm only and the outdoor
terminal of the transformer are provided
by bushings
22. PROCEDURE
Vacuuming of Tank(up to 0.3 mbar) for about
24hrs to 36hrs
The Leak Rate Test with the use of water & air
Oil Test which includes BDV & PPM
Oil Filling
After the IMPREGNATION TIME the whole
accessories are to be attached.
23. QUALITY TEST
ANALYSIS WITH “SIGMA CARD”
Sigma card includes below required data
Design
Process Time
M/C size specification
Process of manufacturing
Dimension specification
Testing specification
Information about control points
24. FINAL TESTING
ROUTINE TESTS TYPE TESTS
NO LOAD TETS
TEMPRETURE
TEST
LOAD LOSS
INSULATION IMPULSE TEST
TEST
CAPACITANCE & ZERO SEQUENCE
TAN δ IMPEDANCE
TEST
SEPARATE
SOURCE HARMONIC AND
NOISE LEVEL
TEST
INDUCED OVER
VOLTAGE
WINDING TEST
VOLTAGE RATIO
25. CT (CURRENT TRANSFORMER)
Generally CT is use for the below four
purposes:
Measurement of Current
Measurement of Power
Isolation between High voltage and Low Voltage
Inputs to Relays & Protection Systems
PROCEDURE OF CURRENT
TRANSFORMER:
CO NDUCTORS USES :ALUMINIUM OR
COPPER(HIGH CURRENT RATING)
In the manufacturing of the primary winding or
protection core there will be the creation of the
capacitance as below.
GRADING & SUB GRADING.
MAIN GRADING HAS WRAPPED
ALUMINIUM FOIL & CRIP PAPER
AT 300MM DISTANCE PERFORATED ALU.
FOIL (400MM) AND CRIP PAPER.
SIMULTANEOUSLY INSULATION MAKE
CAPACITANCE
26.
27. Quartz in CT
Reduces the quantity of oil
Provides mechanical strength for the
conductors
Improves the quality of oil by absorbing
moisture
Being a bad conductor of heat, it allows slow
heating /cooling of the CT.
Finally expansion tank is attached and after
that evacuation of oil and gas filling will be
there .
There is also one imp term is D3 point which
is also called the earth point.