desciption over tehri hydro power plant (1000 MW) and power house.

1. A PRESNTATION ON
on
Hydroelectric Power Plant(H.P.P.)
TEHRI
Presented by: SHUBHAM DOBHAL
(120970105048)
Electrical Engineering
THDC-IHET
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2. ABOUT THE CORPORATION
 THDC India Limited (also known as Tehri Hydro Development
Corporation Ltd.), is a Joint Venture of Govt. of India and Govt. of Uttar
Pradesh.
 The Company was incorporated in July 1988 to develop, operate &
maintain the 2400 MW Tehri Hydro Power Complex (comprising of
1000 MW Tehri Dam HPP, 400 MW Koteshwar & 1000 MW Tehri
Pumped Storage Plant HEP.
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3.  Tehri HPP(1000MW) became fully functional on
March 2007 with the synchronization of 4 units of
250MW each with Northern Grid (MEERUT).
 The Koteshwar HEP began its operation on 2012
when 4 units of 100MW each were synchronizing
with Northern grid.
 Tehri PSP is a 1000MW project which is still
under construction.

4. Apart from hydro projects, THDCIL is also
implementing non hydro power plants as
1320 MW thermal power plant in khurja
(U.P.), solar power plant in Kerala.
AWARDS
1.International Milestone Project award(2009)
2. PMI India Best Project Award (2011)
3. Power Line Award(2012) etc.

5. INTRODUCTION TO TEHRI HPP
 Electric power which is produce by hydro energy is known as
hydroelectric power. On first,the potential energy of water in
reservoir is transformed into kinetic energy through HRT, penstock
,butterfly valve ,MIV(main inlet valve) .this produced kinetic energy
is utilized by turbine blades located at power house tunnel, these
blades on account of kinetic energy starts to move rotationally
,further rotor shaft associated with turbine and having DC excitation
starts to rotate .As the DC excited rotor starts to rotate, it produce
the rotating magnetic field and thus rotating magnetic flux ,which
cuts by stator conductors .due to this electricity begins to flow in the
conductors associated with stator.
 Tehri HPP is currently generating power of 1000MW at 15.75kV.
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6. POWER HOUSE
Power house is the heart of any electric power plant, where various things like
generation of electric energy ,switching, controlling and finally
transmission of electric energy to grid get accomplish. The power house of
Tehri HPP house 4 generating units of 250MW each. The work designated
as power house works include intake structure , controlling of 4 head race
tunnels (HRT), butterfly valve chamber, penstock, machine hall, bus duct
galleries ,draft tubes, upper and lower expansion chambers, tail race tunnels
(TRT), lightings etc. the power house includes the followings,
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Machine Hall Control Room
Head Race Tunnel(4 nos.,8.5m) Ventilation System
Penstock Assembly Chamber(4
nos., 5.75m)
Butterfly Valve Chamber(4 nos.)
Main inlet valve(4 nos.)
Cooling water System Fire Fighting System
Unit Control Board Tail Race Tunnel

7. GENERATOR UNITS
In generating power station there are four generating units, each of
capacity of 250MW producing a total power of 1000MW at FRL. These
hydro-generators connecting in generating station are servo-generators
installed by the soviets in the year 1989 which are the production of
“Uraelectrotiazchmach”, at “Yekaterinburg” which is a Russian –
Ukrainian Company. Generator consists of two parts rotor and stator
housing field & armature windings respectively.
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8. Technical Data of Generators
Name of machine Turbo Generator
Type CB870/300-28
No. of Poles 28
Rated output 278 MVA/250.2 MW
Maximum continuous output 305.8 MVA/275 MW
Power factor 0.9
Rated voltage 15.75kV
Rated current of stator 10190.7 A
Rated current of rotor under rated load 1600 A
Rotational speed (Rated) 214.29 rpm
Direction of rotation Anti clock wise
Efficiency under rated load 0.9 pf 98.18 %
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9. BRAKING SYSTEM
 Electrical and Mechanical (auxiliary) braking is used for
regular braking. When hydro generator is disconnected from
grid, turbine wicket gate is closed and rotation speed is reduced
down to 50% of rated value, short-circuiting of main terminals of
stator winding and current supply into rotor winding from brake
thyristor converter occurs.
 When rotation speed reduced down to 5% of rated value, the
mechanical breaking is automatically switched on .In case of
electrical braking system failure, or electrical damage of
generator, the mechanical breaking is automatically switched
on, when rotation speed will become 10% of rated value.

10. GIS SYSTEM
 The underground 420 kV SF6 Gas Insulated Switchgears
(GIS) & Gas Insulated Bus ducts (GIB) were selected mainly
in Tehri HPP stage-I due to non availability of space for open
switch yard, compact layout of the underground power station,
safe operation, very low operating cost, and efficient &
reliable service conditions ensuring reliable energy supply.

11. OUTDOOR SWITCHYARD
Voltage in KV To ground in mm Between
section(mm)
11 2750 2500
33 3700 2800
66 4000 3000
132 4600 3500
220 5500 4500
Minimum Working Clearance:

12. Why SF6????
Excellent insulating, arc extinguishing.
Gas is highly noninflammable and
chemically stable .
Electric clearance are very much
reduced because of high dielectric
strength of SF6.
Its performance is not affected due to
variation in atmospheric conditions.
Minimum maintenance. Breaker may
require maintenance once in four year.

13. Comparison b/w hydro and thermal
Hydro thermal
 Peak to peak power plant base power plant
 Quick to start and take high time to
Quick to stop start as well a to stop
 Require water as working require coal
Fluid as working fluid
 initial cost is high initial cost is low.
 running cost is low. Running cost is high

14. HYDRO THERMAL
 Most environment least environment friendly
friendly
 Highly efficient less efficient
 Maintenance cost is Maintenance cost is very high.
quite low.

15. CONCLUSION
My journey to Tehri dam was a great experience for me. I have come to
know much about electricity production, methodology adopted for this,
equipment’s used etc.
With this I realized that Tehri dam is a precious gift of science and
technology.
From here I also wish thank and welcome to all the engineers for such a
lovely creation .