Turbo generators are large electricity generators driven by steam or gas turbines that are directly connected to an electric generator. They consist of two main units - a turbine and a generator. The generator has a stator and rotor. The stator contains windings that produce electric current when rotated by the turbine-driven rotor. Turbo generators use a brushless excitation system to provide direct current to the rotor field windings via a pilot exciter, main exciter, and rectifier wheel, eliminating problems associated with using brushes and slip rings.

1. TURBO GENERATORS
Submitted to:
Mr. Uttam Kumar Gupta (Asst. Prof)
Mr. Rahul Agarwal (Asst. Prof)
Submitted by:
Akanksha Gupta
13EE004 (EE)

2. OVERVIEW OF BHEL
• BHEL is the largest engineering and
manufacturing enterprise in India.
• The first electrical manufacturing
unit of the country was setup at
Bhopal.
• BHEL, Haridwar complex consist of
two manufacturing units HEEP and
CFFP.

3. HEEP CLASSIFICATION
Block-1
(Electrical
Machines)
Block-2
(Fabrication
Block)
Block-3
(Turbine
and
Auxiliary
block)
Block-4
(Feeder
Block)
Block -5
(Heat
exchange
and
Forging
block)
Block-6
(Machining)
Block – 7
(Stamping and
dia
manufacturing)

4. Products
Turbo
Generators
Brushless
Exciters

5. TURBO GENERATORS
• Turbo generators were first invented by
a Hungarian engineer OTTO
BLATHY and its principle was then
given by Faraday’s.
• It consists of two separate units:
(i) Turbine
(ii)Generator

6. A turbo generator is a large electricity generator driven by
a prime mover (steam/gas turbine) and is directly
connected to electric generator for the generation of
electricity. They are mostly used as large capacity
generator.

7. Turbo Generators
Stator Rotor
•Stator Frame
•Stator Core
•Stator Winding
•End Cover
•Bushings
•Rotor Shaft
•Rotor Windings
•Rotor Retaining Ring
•Field Connection

8. STATOR FRAME
• A stator frame consists of a cylindrical
center section and two end shields which
are gas tight and pressure resistant.
• It accommodates the active part of the
stator i.e., the stator core and the stator
windings.
• It provides provision for H2/CO2 filling
and temperature measurements.

9. STATOR CORE
• The stator core is made from the
insulated electrical sheet lamination to
minimize the eddy current losses.
• The purpose of stator core is to:
(i) Provide link between the core and the
rotor.
(ii)Support the stator winding.
(iii)To carry the magnetic flux generated
by rotor winding.

10. STATOR WINDING
• The stator has a 3-phase, double layer,
short pitched and bar type of windings
having two parallel paths. Each slot
accommodates two bars.
• The bars consist of separately
insulated strands which are transposed
to reduce skin effect losses.
• The slot’s lower bars and slot’s upper
bars are displaced from each other by
one winding pitch and connected
together by bus bars.

11. END COVER
The ends of the stator frame are
closed by pressure containing end
shields. The end covers are made up
of non- magnetic material to reduce
stray load and eddy current losses.

12. BUSHINGS
The beginning and ends of the
three phase windings are
brought out from the stator frame
through bushings, which
provides high voltage insulation.

13. ROTOR
• The rotating part of turbo generator is
rotor.
• The rotor houses the field winding.
• When the rotor rotates , the lines of
magnetic flux cut through the winding.
• Rotor of cylindrical type is used in
turbo generator.

14. ROTOR SHAFT
Rotor shaft is a single piece forming
manufactured castings. It is forged
from a vacuum cast steel slots for
insulation of the field winding are
made into the rotor body.

15. EXCITATION SYSTEM
Brushless
Excitation
Pilot
Exciter
Main
Exciter
Rectifier
Wheel

16. PILOT EXCITER
Three phase pilot exciter is 16 pole revolving field units. The stator
accommodates three phase armature winding and magnetic poles are placed
on the rotor. Thus rotating flux is produced which cuts the stationary
armature conductors and three phase AC is generated.

17. MAIN EXCITER
The three phase main exciter is a 6 pole armature type unit. The stator frame
accommodates the field winding. The field winding is placed on the magnetic
poles. The armature consists of stacked lamination and the three phase
winding is inserted into the slots of the laminated armature.

18. RECTIFIER WHEEL
The main component in the rectifier wheel is silicon diodes which are
arranged in rectifier wheel in three phase bridge circuit.
The direct current from rectifier wheel is fed to DC leads and then to the field
winding of the rotor.

19. ADVANTAGES OF BRUSHLESS EXCITER
• Eliminates slip rings and brushes.
• Eliminates all problems associated with transfer of current via sliding contacts.
• Eliminates the hazard of changing brushes on load.
• Brush losses are eliminated.
• Minimum operating and maintenance cost.
• High response excitation with fast acting AVR.