Industrial training at IPGCL/PPCL.

1. Prepared by :
Shubhra Dhyani
Btech(EEE) III year
0919221054

2. CONTENTS
• Brief Profile of the company
• Combined Cycle Power Plant
• Working of Gas Power Plant
• Heat Recovery Steam Generator (HRSG)
• Plant Overview
• Water Treatment Plant
• Generator
• Transformer
• Switch Yard Description
• Specifications
• Merits & Demerits
• Bibliography

3. Brief Profile of the company
• Under IPGCL i.e. Indraprastha Power Generation
Company Limited,3 Power Stations are in
operation.They are as follows :
1)I.P STATION
2)RAJGHAT POWER HOUSE
3)GAS TURBINE POWER STATION (GTPS)
• Under PPCL i.e. Pragati Power Cooperation
Limited, one Power Station is in operation and it is:
PRAGATI POWER STATION

4. STATIONS I.P STATION RAJGHAT GTPS PRAGATI
POWER POWER
STATION STATION
Station 247.5 135 282 330
Capacity
(MW)
Units 3*62.5 (GT) + 2*67.5 (GT) 6*30 (GT) + 2*104 (GT) +
60 (ST) 3*34 (WHRU) 1*122
(WHRU)
Year of 1967-71 1989-90 1986 & 1996 2002-2003
Commissionin
g
Coal NCL,BINA NCL,BINA GAIL HBJ GAIL HBJ
Field/Gas Pipeline Pipeline
Water River Yamuna River Yamuna River Yamuna Treated water from
Sen Nursing Home &
Sources Delhi Gate Sewage
Treatment Plants
Beneficiary VIP-South & Central & NDMC- NDMC,South
Areas Central Delhi North Delhi VIP,DMRC Delhi

5. MISSION OF THE COMPANY
• To make Delhi-Power Surplus
• To maximize generation from available capacity
• To plan and implement new generation capacity
in Delhi
• To set ever so high standards of environment
Protection
• To develop competent human resources for
managing the company with good standards

6. Combined Cycle Power Plant
• Combined Cycle Power Plant (CCPP) or
Combined Cycle Gas Turbine plant (CCGT)
• A gas turbine generator generates electricity and
heat in the exhaust is used to make steam,
which in turn drives a steam turbine to generate
an additional electricity.
• In CCPP ,a successful common combination is
the Brayton cycle (in the form of a turbine
burning natural gas) and the Rankine cycle (in
the form of a steam power plant)

7. • The gas turbine is comprised of three main
components: a compressor, combustor and a turbine.
• The air is, compressed in the compressor (adiabatic
compression-no heat gain or loss), then mixed with fuel
and burnt by combustor under constant pressure
conditions in the combustion chamber.
•The resulting hot gas expands through the turbine to
perform work (adiabatic expansion).

8. Working of Gas Power Plant

9. Heat Recovery Steam Generator
(HRSG)
• The Heat Recovery Steam Generator (HRSG) is a horizontal, natural
circulation, single pressure, water tube type steam generator with a single
drum.
• It is unfired type and uses Gas turbine exhaust gases as heat source.
• It has been designed to generate superheat steam at a pressure of 41.5 kg/
cm2 and a temperature of 512 degree Celsius at a Main Stream Value
(MSV).
• It consists of following section :
a) Superheater section
b) Evaporator section
c) Economizer section
d) Condensate Pre heater (C.P.H) and components
e) Steel chimney

12. Water Treatment Plant
•The steam coming out of turbine is
condensed and the condensate is
feedback to the boiler as feed water. Some
water may be lost due to blow-down,
leakage etc and to make up these losses
additional water called make up water, is
required to be fed to the boiler.
•The source of feed water contain
impurities that could lead to scale
formation.
•The water is passed through alum-dosed
clarifier which bonds impurities and thus
removed.
•Chlorine removes the algae and bacteria’s
from the water. These processes takes
place in clarifier from where water is sent
to D.M Plant (De-mineralized plant).

13. ACTIVATED CARBON FILTER:
Water from the clarifier first comes in the ACF. It absorbs some of
the impurities.
STRONG ACID CATION:
It consists of resin named hydrocarbon. It removes the acidic
impurities. This is recharged by HCl acid.
DEGASIFIER:
Here the gases available in the water i.e. oxygen, carbon dioxide
is removed upto 5-6%.
STRONG BASE ANION:
It consists of resin, OH-.It removes the basic impurities. It is
recharged by NaOH. The pH is 8.5-9.5.
MIXED BED:
It consists of both resin, acid and basic. pH is maintained about
6.8-7.2.This is recharged by HCl & NaOH.

14. Generator
•Generator converts the mechanical
energy of turbine shaft into electrical
energy. Rotating field type generators are
employed which are ventilated by the fans
of rotor shaft or separately driven fans.
•At this power plant the requirements
of generator are:
POLES=2
FREQUENCY=50Hz
SPEED=120f/P=3000rpm
•The class of generator under consideration is steam turbine-
driven generators, commonly called turbo generators. Generally
they have the ratings up to 1900MW but here 3000rpm,50Hz
generators are used of capacities 122MW.

15. Transformer
•Transformer is a device that transforms
electrical energy form from one alternating
voltage to another alternating voltage
without change in frequency.
•IEEE defines transformer as a static
electrical device, involving no continuously
moving parts, used in electric power
system to transfer power between circuits
through the use of electromagnetic
induction.
•Types of transformer:
1) Power Transformer
2) Instrument Transformer
3) AutoTransformer
4) On the basis of working

16. 1) Power Transformer
2) Instrument Transformer
3) Auto Transformer
4) On the basis of working
4.1) Step down- converts H.V to L.V
4.2) Step up- converts L.V to H.V

17. SWITCH YARD DESCRIPTION
• For any power station, switchyard is an important part which bridges
the generating station and the distribution system i.e. via switchyard
the generated electricity is fed to the sub-stations. It connects the
GTPS to the northern grid.
• The switchyard of Gas Turbine Power Plant is of 66KV.
• The voltage generated is 11KV, which is then step up to 66KV by
generator transformer. This 66KV is fed to the 66KV switchyard.
• The switchyard has the double bus bar system i.e. one is main bus
and the other one is secondary bus.
• Some of the functions are:
 Change voltage from one level to another
 Switch transmission and distribution circuits into and out of the grid
system.
 Measure electric power qualities flowing in the circuits.
 Eliminate lightning and other surges from the system.

19. • ISOLATORS: They are designed to open a ckt under no load. Its main purpose is to
isolate portion of the ckt from the other & is not intended to be opened while current
is flowing in the line.
• CIRCUIT BREAKERS: It is a piece of equipment which can break the circuit
automatically under faulty conditions and make the circuit either manually or by
remote control under faulty conditions. They can be classified as
iii. oil ckt breaker
iv. Gas(SF6) ckt breaker
v. Air-blast ckt breaker
vi. Vaccum ckt breaker
The switch yard has gas (SF6) or Sulphur Hexa Fluoride ckt breaker.

20. 3)INSULATORS: All the insulators are made of porcelain metal parts. They are free
from radio interference. They support the conductors (bus bar) and confine the
current to the conductors.
4)BUS COUPLERS: Breakers are used as
a bus coupler. They provide coupling
between the two bus bar of zones.
5)CURRENT TRANSFORMER: C.T is an instrument t/f used
for protection & metering of high values of currents.
C.T is used for reducing a.c from higher to lower value of
measurement/protection/control.

21. 6) POTENTIAL TRANSFORMER: They are used to increase
the range of voltmeters in electrical substations and
generating stations. They are also called voltage t/f.
7)LIGHTINING ARRESTORS: It is a protective
device used to protect the station, equipments
against atmospheric discharge.
8)EARTHING LINKS: Switchyard
Earthing is provided to protect
personally from shocks and
hazards from electrical
equipments.
9)MULSIFIER: They are used to protect the transformer against fire.

22. SPECIFICATIONS
• Specifications of SF6 circuit breaker:
2) Rated voltage 72.5kV
3) Rated frequency 50Hz
4) Rated current 2000A
5) Impulse voltage (peak) 325kV
6) Rated breaking capacity
a) Symmetrical 25KA
b) Asymmetrical 28KA
c) Making (peak) 64KA
d) Short time (for 1 sec) 2.5KA
11) Rated Pressure 5.5 bars
12) Total mass of ckt breaker 900kg
13) Total SF6 gas content 3.7kg

23. • Specifications of 66KV Isolators and earthing switches:
2) No. of Pole 03
3) Installation Outdoor
4) Rated Voltage 72.5KV/66KV
5) Rated Current 1250 Amp
6) Rated Frequency 50 Hz
• Specifications of 66KV Current Transformer:
8) No. of Course 4
9) Rated Voltage 72.5KV/66KV
10) Rated Current 2000-1000
11) Rated Frequency 50Hz
12) Total Creep age distance 1700mm
13) Short time Current Rating 25 KV for 1 sec

24. • Specifications of Potential Transformer:
2) Type WH 72.5-17
3) Standard IEC
4) Year of manufacturing 1986
5) Weight 300kg
6) Minimum Temperature 10 degree Celsius
7) Maximum Temperature 50 degree Celsius
8) Frequency 50Hz
9) Voltage factor 1.5
10)Maximum Rating 1000-500 VA
• Specifications of 66KV Lightning Arrestor:
12)Rated Voltage 60KV
13)Power frequency Reseal Voltage 60KV
14)High Current Impulse 100 K Amps
15)Class of Arrestors 10 K Amps for heavy duty
16)Total creep age distance 1700mm

25. Merits & Demerits
• Merits:
 Low operation and maintenance cost
 Less space is occupied
 Less gas storage
 Cheaper fuels like natural gas
• Demerits:
 Temp. of combustion chamber is too high, which results in
shorter life time.
 Gas turbine has low thermal efficiency
 Has starting problem
 Efficient only in combined cycle

26. Bibliography
• Links referred :
http://www.hrsgdesign.com/design0.htm
http://ipgcl-ppcl.gov.in/
http://www.osha.gov/SLTC/etools/electric_po
wer/illustrated_glossary/substation.html#Equ
ipment