Presentation on Power Transformer by BHEL.

1. PRESENTATION ON
POWER TRANSFORMER
BY
BHEL
PRESENTED BY:-
AJAY KUMAR MAURYA

2. CONTENTS OF PRESENTATION
 INRODUCTION TO BHEL ,JHANSI
 POWER TRANSFORMER
 DESIGN & DRAWING
 WINDING MANUFRACTURING
 CORE BUILDING
 COIL CORE ASSEMBLY
 RELACING OF CORE
 TERMINAL GEAR MOUNTING
 FINAL TANKING

3. BHEL(JHANSI UNIT)
 BHEL, JHANSI foundation was laid by late Mrs. Indira
Gandhi the prime minister on 9th Jan. 1974. The commercial
production of the unit began in 1976-77. It is called second-
generation plant of BHEL set up at an estimated cost of Rs
16.22 crores inclusive of Rs 2.1 crores for township.
 BHEL,JHANSI is equipped with most modern manufacturing
processing and testing facilities for the manufacture of
power, special transformer and instrument transformer,
Diesel shunting locomotives and AC/DC locomotives.

4. PRODUCT PROFILE OF BHEL,JHANSI

5. POWER TRANSFORMER
 A transformer is a static machine used for transforming
power from one circuit to another without changing
frequency.
 Power Transformers refers to the transformers used
between the generator and the distribution circuits, and
these are usually rated at 500 kVAand above.
 Power Transformers are of following type:
1.Small power transformers 500 to 7500 kVA
2. Medium power transformers 7500KVA to 100 MVA
3. Large power transformers 100 MVA and above.

6. COMPONENTS OF POWER TRANSFORMER
 CORE
 COIL
 INSULATION
 TAP CHANGER
 CONSERVATOR TANK
 COOLING SYSTEM

7. DESIGN & DRAWING
 SPECIFICATIONS OF TRANSFORMER
 SELECTION OF CORE DIAMETER
 SELECTION OF TYPE OF CORE
 SELECTION OF TYPE OF WINDINGS
 SELECTION OF TAPCHANGER
 CALCULATION OF NUMBER OF TURNS
It is done by using emf equation:
Volts per turn, Et=4.44BmAƒ

8. WINDING MANUFRACTURING
THERE ARE FOLLOWING TYPE OF WINDINGS:-
 REVERSE SECTION WINDING
 SPIRAL WINDING
 HELICAL WINDING
 INTERLEAVED WINDING
 HALF SECTION WINDING
 COMPOSITE WINDING

9. REVERSE SECION WINDING SPIRAL WINDING

10. HELICAL WINDING INTERLEAVED WINDING

11. CORE BUILDING
 CRGO-Cold Rolled Grain
Steel is used to build the
core. CRGO is used to
reduce the hysteresis
losses and the lamination
made out of these sheets
minimizes the eddy’s
current losses

12. COMPLETE CORE

13. COIL CORE ASSEMBLY
COIL CORE ASSEMBLY
INVOLVES THREE
MAJOR STEPS
 UNLACING OF CORE
 INSERTION OF WINDING
 RELACING OF CORE

14. UNLACED & RELACED CORE

15. TERMINAL GEAR ASSEMBLY
Terminal Gear Assembly
done as described below:
 Cutting of leads as required.
 Crimping/brazing of the leads
with cables.
 Brazing of bus bars.
 Fixing of different cleats.
 Crimping/brazing of cables
with terminal lugs.
 Mounting of the tap
changer/tap switch.

16. TAP CHANGER
Tapchanger is used for adding
or cutting out turns of primary
or secondary winding of the
transformer.
THEY ARE OF TWO TYPES
 ON LOAD TAP CHANGER
 OFF LOAD TAP CHANGER

17. TRANSFORMER WITH TAP CHANGER

18. FINAL TANKING
 The transformer tank
provides the containment
of the core and windings
and for oil. It must
withstand the forces
imposed on it during
transport.
 Transformer tanks are
almost constructed of
welded boiler plate.

19. TRANSFORMER AUXILLARIES
 BUCHHOLZ RELAY
 TEMPERATURE INDICATOR
 PRESSURE RELIEF VALVE
 BUSHINGS
 OIL LEVEL INDICATOR
 SILICA GEL BREATHER

20. TESTING OF TRANSFORMER
 Preliminary Tests
 Core insulation test
 Core loss Test
 Final Tests
 Routine test
 Measurement of winding resistance
 Measurement of voltage ratio
 Measurement of no load loss and current
 Measurement of insulation resistance
 Type Test
 Temperature rise test
 Noise level test

21. COOLING SYSTEM
VARIOUS TYPES OF
COOLING
 ONAN Type Cooling
 ONAF Type Cooling
 OFAF Type Cooling
 OFWF Cooling

22. COMPLETE TRANSFORMER

23. THANK YOU