1. MANUFACTURING OF TURBO GENERATORS
AN INDUSTRY ORIENTED MINI PROJECT ON
MANUFACTURING OF TURBO
GENERATORS
MANNAN INSTITUTE OF SCIENCE AND TECHNOLOGY
PROJECT ASSOCIATES
N.SAI SMARAN (08J51A0236)
P.RAJU (08J51A0237)

2. OBJECTIVE
The Project includes the assembly of Turbo-Generators (4-pole and 2-pole Generators) and various tests done at different stages and shown the performance characteristics.

3. Flow path… BHEL over view Principle to AC Machines Stator Rotor
Insulation system
Winding of stator & rotor
Tests
Conclusion

4. OVERVIEW - B.H.E.L
BHEL is the largest engineering &manufacturing enterprise in India.
It is one of NAVARATNA’S in India.
Established 40 years ago.
In 1970s: At Hyderabad with Germany Collaboration 60MW Air Cooled & 110MW Hydrogen cooled. At present it has extended up to 150MW Air Cooled.

5. TURBO GENERATOR PRINCIPLE
The basic principle of rotating machine remains the same i.e. “Faraday’s laws of electromagnetic induction”.
Hence basic essential parts required in the Production of Power by the Electrical Generator are
A magnetic field
A Conductor / Coil
Relative motion / mechanical force
In turbo Generator , the magnetic field is rotating part & the coil is stationary.

6. GENERATOR PARTS Stator Rotor Excitation system Cooling system
Insulation system
Bearings

7. STATOR & ROTOR ASSEMBLY WINDING, TOP & BOTTOM LAYERS
LAMINATIONS
SLOTS & HOLES
CORE ASSEMBLY
PRESSING
WINDING, TOP & BOTTOM LAYERS
TESTING
IMPREGNATION
TESTING
ASSEMBLY

8. STATOR FRAME
The stator frame is horizontally split type and welded construction and supports the lamination core and the winding. Both the air duct pieces and welded radial ribs provide for rigidly to the stator frame.
These two things are provided to the stator frame to support the stator on the foundation. The stator firmly fixed to the foundation plates with bolt through the feet.

9. STATOR CORE
Stator core is made up of “COLD ROLLED NON GRAINED ORIENTED SILICON STEEL SHEETS”, which has high permeability and low hysteresis and eddy current losses.
To remove the heat, a large number of spacer segments, placed at intervals along the bore length.
Stator laminations are coated with synthetic varnish.

10. TESTINGS CORE ASSEMBLY CORE FLUX TEST
Stator laminations are stacked and held between clamping plates.
CORE FLUX TEST
Immediately after the core is built up
and before it is wound a test is
made to defect the presence of
local “Hot spots”

11. TRANSPOSITION PUTTY OPERATION STACK CONSOLIDATION BENDING
The strips are staggered and are bend for Roebel transposition.
PUTTY OPERATION
Each individual bar consisting of uneven surface and width space are filled with NOMAX
STACK CONSOLIDATION
The bars are subjected to a horizontal and vertical pressure
BENDING
Each of the samples is placed over the universal former & the universal former is aligned to the specifications

12. INSULATION SYSTEM INSULATION MATERIAL
PREPARATION TEST
INSULATION MATERIAL
In electrical machines insulation is most important requirement to sustain high voltages and basically insulation is the heart for electrical machines
CLASSIFICATION OF INSULATING MATERIAL
The insulating material can be classified in the following two ways.
Classification according to Substance and materials.
Classification according to Temperature.

13. CLASSIFICATION ACCORDING TO SUBSTANCE AND MATERIALS
SOLIDS
LIQUIDS
GASES
CLASSIFICATION ACCORDING TO TEMPERATURE
Class
Permissible temperature Y
90 A
105 E
120 B
130 F
155 H
180 C
Above

14. RESIN RICH SYSTEM OF INSULATION
MICA PAPER TAPE %
GLASS PAPER TAPE-20%
EPOXY RESIN-40%
RESIN POOR SYSTEM OF INSULATION
MICA TAPE
HYPER SEAL
SPLIT MICA
RESIN ORIENTED GRAPHITE
INNER CORONA PROTECTION (ICP)
END CORONA PROTECTION (ECP)
OUTER CORONA PROTECTION (OCP)

15. TAPPING PROCESS FOR TWO POLE FOR FOUR POLE Mica tape one layer
ICP one layer
Mica eight layers
OCP one layer
Split mica one layer
ECP at bends
Hyper seal for overhangs
FOR FOUR POLE
Resin oriented graphite nine layer
OCP one layers
Hyper seal six layers
OCP nine layers
ECP at bends

16. STATOR WINDING TYPES OF WINDINGS
Open circuit and Closed circuit winding
Lap and Wave winding
Concentrated and Distributed winding
Full pitch and Fractional pitch winding
Single layer and Double layer winding

17. WINDING DIAGRAM

18. STATOR WINDING ASSEMBLY FOR FOUR POLE
Winding Holder
Ring Holder
Diamond shape coil
Brazing
Wedges
DC HV Testing

19. STATOR WINDING ASSEMBLY FOR TWO POLE
winding holder
Ring holder
Bottom bar placing
HV Testing
Top bar placing
I Transposition
Brazing
Wedges
Phase sequence testing
Impegration process

20. ROTOR CORE
Rotor shaft is a single piece solid forming manufactured from a vacuum casting.
Longitudinal slots for insertion of the field winding are milled into rotor body.
Rotor consists of electrically active portion .
60% of rotor body circumference has longitudinal slots which holds the field winding.
Rotor teeth at the ends of rotor body are provided with axial and radial holes enabling the cooling air to be discharged after cooling.

21. ROTOR WINDING
Rotor winding consists of series connected turns, each of which consists of two half turns connected by brazing in the end section.
Thickness of each strip made upto 10.5mm.
For ventilation purpose the slots are provided on the coil and on inter strip insulation layer on both sides of coil.
Laminated epoxy glass fibre fabric with nomex filter are used for slot insulation.
Slot wedges are made of high electrical conductivity material which are short circuted through rotor body and thus act as damper windings

23. TESTING OCC AND LOAD MAGNETISING CHARACTERISTICS
OPEN CIRCUIT CHARACTERISTICS AND SHORT CIRCUIT CHARACTERISTICS
LOSSES AND EFFICIENCY CHARACTERISTICS

24. CONCLUSION
Bharat Heavy Electrical Limited is the largest engineering and Manufacturing enterprise of is kind in the public sector in India. It ranks Among the top twelve organizations in the world, engaged in the Manufacturing of power generation equipment.
The sector is an important part in Turbo generators. The stator Core is assembled by the laminated sheets. The universal form facture type bar is more flexible and it’s life time more. We use the ROEBEL BAR Transposition for stator winding which is more advantageous . BHEL has acquiring the latest technology in the insulation system.
“Thus turbo generator is used mostly in paper, Sugar, Cement, Petrochemical, Fertilizers, Rayon industries etc”.

25. THANK YOU

26. QUERIES ??