1

A PRESNTATION ONon

Hydroelectric Power Plant(H.P.P.)

TEHRIPresented by: SHUBHAM DOBHAL

(120970105048)Electrical Engineering

THDC-IHET

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.

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.

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.

AWARDS1.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.

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,

Machine Hall Control RoomHead Race Tunnel(4 nos.,8.5m) Ventilation SystemPenstock Assembly Chamber(4 nos., 5.75m)

Butterfly Valve Chamber(4 nos.)

Main inlet valve(4 nos.)Cooling water System Fire Fighting SystemUnit 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.

8

Technical Data of GeneratorsName of machine Turbo Generator

Type CB870/300-28No. of Poles 28

Rated output 278 MVA/250.2 MWMaximum continuous output 305.8 MVA/275 MWPower 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 %

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.

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.

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:

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.

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

HYDRO THERMAL

Most environment least environment friendly

friendly

Highly efficient less efficient

Maintenance cost is Maintenance cost is very high.

quite low.

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 .

THANK YOU