NTPC BARH BIHAR SUMMER TRANING REPORT IN 2014

1. INDUSTRIAL TRAINING REPORT
NTPC BARH

2. NTPC Overview
 NTPC Limited (Formerly National Thermal Power Corporation) is the largest
power generation company in India and was founded on November 7, 1975.
Forbes Global 2000 for 2009 ranked it 317th in the world.
 Contributing 26% of country’s entire power generation, it has placed itself in the
Nav - Ratan companies of Indian government and hence is the public sector
company.
 The total installed capacity of the company is 31134 MW (including JVs) with 15
coal based and 7 gas based stations, located across the country. In addition
under JVs, 3 stations are coal based & another station uses naphtha/LNG as fuel.
 NTPC has been operating its plants at high efficiency levels. Although the
company has 18.79% of the total national capacity it contributes 28.60% of total
power generation due to its focus on high efficiency.
 The company has set a future goal of having 75000 MW by 2017.

3. .

4. Coal availability and linkage
:-Coal requirement for Barh STPP, stage-1 is proposed to be metfrom Amarpali block of north Karanpura
coalfields. Coal requirement for the project in estimated as 10 million tones/annum considering a GCV of
3350kcal/kg and 80% PLF
Coal transportation
:
Coal from amarpali block of north karanpura coalfields is proposedto be transported to the project site
through Indian railways system for adistance of approximately 250kms via shorter route .
Construction power
The requirements of the construction power supply for the projectwould be met at 33Kv level from the
nearby BSEB substations. Necessary33kV substation and 11kV ring main /LT substations shall be provided
for the power plant area.

5. Power Evacuation system
Power generated is proposed to be stepped up to 400kV bygenerator transformer and will be evacuated through
the transmission systemto be evolved and implemented by Power Grid Corporation of India Ltd. Theswitchyard at
power plant end is owned by NTPC
Beneficiary state
The states & UTs of Northern & Western regions and state of Bihar

6.  Coal before fixing in the furnace is
Pulverized.coal pulverization is required in the
whole system process not just in terms of
furnace performance and heat rate but in terms
of mechanical reliability and integrity of furnace.
 Flame is established in the furnace
Using the LDO(light diesel oil).LDO is
atomized by applying arc to it.
 Coal+air- Co2+CO+Sox+MOx+heat+ASH
Here CO2-heat carrier
CO-Acidic, danger to tubes(less air)
MOX,SOX-Acidic formation in water
bodies and atmosphere.
 To avoid the gases CO,MOX,SOX a ratio is maintained between air and coal of 1:6.It also ensures proper
combustion.The water is purified(DM water) before injunction in the furnace to prevent choking of pipes
due to the scale formation.

7. 1.BOILER
2.TURBINES
3.COOLING WATER PUMP
4.CONDENSER
5.DEAREATOR
6.REHEATER
7.AIR PREHEATER
8.PRECIPITATOR
9.ECONOMISER
10.COOLING TOWER
11.TRANSMISSION LINES(3 PHASE)
12.UNIT TRANSFORMERS(3 PHASE)
13.ELECTRIC GENERATORS(3 PHASE)
14.CONDENSATE EXTRACTION
PUMP
15. Steam governor valve
16. FEED HEATER
17.COAL CONVEYOR
18.COAL HOPPER
19.FORCED DRAUGHT FAN
20.FLUE GAS

8. Boiler is a rectangular furnace about 50 feet on side and 130 feet tall. theirs walls
are made of high pressure steel tubes about 2.3 inches in diameter which circulates
DM water to be converted into steam. The thermal radiation heats water and
changes to steam. Steam is sent to the turbine .The efficiency and technology of
boiler vary according to the operational pressures.
1. Operational pressure>221 KSC---%n=42.45%-----super critical boiler
2. 175KSC <Operational pressure<221 KSC---%n=38.42%----- critical boiler
3. Operational pressure<175KSC---%n=38%-----sub critical boiler
The turbine generator consists of a series of steam turbines interconnected to each
other and generators on a common shaft. There is a high pressure turbine at one
end, followed by intermediate pressure turbine and low pressure turbine in other
end. Steam loses pressure and temperatures as it passes through turbines and
expands in volume.
It pumps the water from the cooling tower which goes to the condenser.

9. The steam coming out from the Low Pressure Turbine
(a little above its boiling pump) is brought into thermal
contact with cold water (pumped in from the cooling
tower) in the condenser, where it condenses rapidly
back into water, creating near Vacuum-like conditions
inside the condenser chest.
A deareator is a device for air removal and used to remove
dissolved gases (an alternate would be the use of water
treatment chemicals) from boiler feed water to make it
noncorrosive. A deareator typically includes a vertical
domed deareation section as the deareation boiler feed
water tank. A Steam generating boiler requires that the
circulating steam, condensate, and feed water should be
devoid of dissolved gases, particularly corrosive ones and
dissolved or suspended solids. The gases will give rise to
corrosion of the metal.

10. Reheater is a heater which is used to raise the
temperature of steam which has fallen from the
intermediate pressure turbine.
Air preheater is a general term to describe any device
designed to heat air before another process (for example,
combustion in a boiler). The purpose of the air preheater is
to recover the heat from the boiler flue gas which
increases the thermal efficiency of the boiler by reducing
the useful heat lost in the flue gas.
An Electrostatic precipitator (ESP) or electrostatic air cleaner is a
particulate device that removes particles from a flowing gas (such as
air) using the force of an induced electrostatic charge. Electrostatic
precipitators are highly efficient filtration devices, and can easily
remove fine particulate matter such as dust and smoke from the air
steam. ESPs continue to be excellent devices for control of many
industrial particulate emissions

11.  General Voltage Level
LT – 415 V
HT – 11KV & 3.3 KV
EHT – 400KV
 Voltage generation level (NTPC Barh)
stage 1 – 24.5kv
stage 2 – 21.5kv
 voltage level ( power plant)
5.5kv, 11kv, 132kv,400kv

12. Switchyard is considered as the HEART of the Power Plant. Power generated can be worthy only if it is
successfully transmitted and received by its consumers. Switchyard plays a very important role as a junction
between the generation and transmission. It is a junction, which carries the generated power to its destination (i.e.
consumers).
Outdoor equipments
1. Bus bar
2. Lightening Arrester
3. Wavetrap
4. Breaker
5. Capacitive voltage transformer
6. Earthingrod
7. Current transformer
8. Potential transformer
9. Lightening Mask
Indoor equipments
1. Relays
2. Control panels’
3. Circuit breakers

13. 1. Bus bar
1.In electrical power distribution, a busbar is a strip
orbar of copper, brass or aluminium that conducts
electricity within a switchboard, distribution board,
substation, battery bank, or other electrical apparatus.
PICTORIAL VIEW OF BUS BAR
2.lightning arrester
A lightning arrester is a device used on electrical power
systems and telecommunications systems to protect the
insulation and conductors of the system from the
damaging effects of lightning. The typical lightning
arrester has a high-voltage terminal and a ground
terminal.
PICTORIAL VIEW OF LIGHTNING ARRESTER

14. 3.wave trap
Wave Traps are used at sub-stations using Power Line
Carrier Communication (PLCC). PLCC is used to transmit
communication and control information at a high
frequency over the power lines. This reduces need for a
separate infra for communication between sub-stations.
4 .Breaker
A circuit breaker is an automatically operated electrical
switch designed to protect an electrical circuit from
damage caused by overload or short circuit. Its basic
function is to detect a fault condition and interrupt current
flow.

15. Depending on the arc quenching medium being used C.B.s can be categorizedinto various types. In
BSTPP for 400 KV/132 KV switchyard only one type is being used
ACB (Air break circuit breaker):-
operated as well asarc quenched through air.
BOCB (Bulk oil circuit breaker):-
arc quenching done through oil(Aerosol fluid oil).
MOCB (Minimum oil circuit breaker):-
arc quenching done through oil(Aerosol fluid oil).
ABCB (Air Blast Circuit Breaker):-
arc quenching done by blast of air
SF6 circuit breaker:-
arc quenching done through SF6 gas.

16. 5. CAPACITIVE VOLTAGE TRANSFORMER
A capacitor voltage transformer (CVT), or capacitance-coupled
voltage transformer (CCVT), is a transformer used
in power systems to step down extra high voltage signals
and provide a low voltage signal, for metering or
operating a protective relay.
6.CURRENT TRANSFORMER
The current transformer is a step up transformer , it means
current is steppeddown to a very low value (generally 1 A
or 5 A) so that it can be used for measuring and protection
purposes .C.T is designed in such a way its Core Material
could give high accuracy withlow saturation factor. Core
Material is generally made of CRGO Silicon steelFor very
low loss characteristics, μ material (Alloy of Ni-Fe) is used.

17. Current Transformer is used for basically two major functions: -
1 .Metering
which means current measurement.
2. Protection
such as over current protection, overload earth faultprotection, Bus-bar protection, Bus differential
protection.CT is typically described by its current ratio from primary to secondary. Thereis not more
difference between 132 KV and 400 KV C.T , only current ratio differ

18. SPECIFICATIONS OF 132 KV C.T
Standard IS2705
Highest System Voltage 145 KV
Insulation Level 275/650 KV
Frequency 50 Hz
Short Time Current 31.5 KA for 1 sec
Rated Primary Current 1200 A
Extended Current 120

19. SPECIFICATIONS OF 400 KV C.T
Standard IS2705
Rated Voltage 420 KV
Insulation Level 275/650 KV
Frequency 50 Hz
Short Time Current 31.5 KA for 1 sec
Rated Continous normal Current 2000 A
Extended Current 200/120%
Oil weight 750 Kg
Total weight 2500 K

20. ISOLATOR
An isolator is one, which can break an electrical circuit when the circuit is to beswitched on no load. These are
normally used in various circuits for the purposes of isolating a certain portion when required for maintenance
etc.
It isalways used in OFF-LOAD condition."Switching isolators" are capable of
•
Interrupting transformer magnetized currents;
•
Interrupting line charging current; and
•
Load transfer switching

21. In BSTPP there are two switchyards:-
(i) 400KV SWITCHYARD
(ii) 132KV SWITCHYARD
.400 KV SWITCHYARD
There are total 22 bay in 400 KV switchyard. A Bay is basically
a way for the incoming power from generator as well as
outgoing power for distribution.
 5 Bay for each generating transformer
 3 Bay for ICT(Inter Connecting Transformer)
 2 Bay for PATNA line
 2 Bay for KAHALGAON line
 2 Bay for BALIA line
 7 for FUTURE line
 1 Bay for SHUNT REACTOR
There are four main buses in 400 KV switchyard.
 Main bus – 1& 2
 Main bus – 3&4
132 KV SWITCHYARD
There are total 11 Bay in 132 KV switchyard.
 3 Bay for ICT (Inter Connecting Transformer)
 5 Bay for S.T (Station Transformer)
 2 Bay for MST (Miscellaneous Service Transformer)
 1 Bay for Bus Coupler
There are two main buses in 132 KV switchyard.
 Main bus - 1
 Main bus - 2

22. It is a static machine which increases or decreases the AC voltage without changing the frequency of the supply. It is a
device that:
 Transfers electric power from one circuit to another.
 It accomplishes this by electromagnetic induction.
 In this the two electric circuits are in mutual inductive influence of each other.
WORKING PRINCIPLE: It works on FARADAY‟S LAW OF ELECTROMAGNETIC INDUCTION (self or
mutual induction depending on the type of transformer).
CLASSIFICATION:
(I) ACCORDING TO THE CORE: a) Core type transformer b) shell type transformer c) Berry type transformer
(II) ACCORDING TO PHASES: a) 1phase transformer b) 3phase transformer
(III) ACCORDING TO THE PURPOSE FOR WHICH USED : a) Distribution transformer b) Transmission
transformer c) Generator transformer d) Station transformer e) Unit Auxiliary transformer (UAT)

23. GENERATING TRANSFORMER
A generating transformer is a single – phase power transformer(3 single phaseunits shall form a bank) .
Generating Transformer steps–up the generatedvoltage of 24 KV by alternator to a higher voltage of 400 KV
(hence, workingas a step-up Transformer).This voltage of 400 KV is then transmitted to
switchyard

24. SPECIFICATIONS
HV Nominal Voltage 420/sqrt(3) KV
LV Nominal Voltage 24 KV
Rated Power 260 MVA
HV Nominal Current 1072.22 A
LV Nominal Current 10833.33 A
Frequency 50 Hz
Phases single phase *
Lightning impulse withstand voltage 1425 kVp(HV)170 kVp(LV)95 kVp(HVn
Tap range ± 5% in steps of 2.5%on HV neutral side
Oil weight 60430 Kg
Total weight 250930K

25. INTER CONNECTING TRANSFORMER
An ICT is a 3-phase auto transformer used to interconnect 400 KVswitchyard and 132 KV switchyard.
SPECIFICATIONS
Standard IS:2026
Type Auto Transformer
Rated power 200 MVA(HV)200 MVA(MV)67 MVA(LV)Reactive5 MVA Active
Current rating of different cooling 40% /60%/100% (A)

26. Winding connection star(HV)star(MV)delta(LV)solidlygrounded(HVn)
Core and winding mass 115600 Kgs
Oil mass 81880 Kgs
Total oil quantity 92000 litr

27. STATION TRANSFORMER
Station Transformer is
used only for initializing the start-up of the station (MainPlant).It
is very beneficial during emergency situations such as tripping of Units, shut-down etc. Station transformers is
used to start
Station auxiliaries awhich are required for generating services such as coal and ash handlingsystem, lighting
system, water purifying system etc.It gets the supply in its primary from 132 KV switchyard, stepsdown it to
11.5KV which is used for starting various equipments & devices used in the Main power plant

28. SPCIFICATIONS
Standard IS:2026/77-81
Type Three Winding
Rated outpu t90/45/45 MVA
Cooling ONAN/ONAF
Rated voltage 132 KV (HV)11.5 KV(LV1 & LV2)
Core & coil mass 60500 Kg
Oil quantity 33700 Litre
Total mass 121500 K

29. UNIT TRANSFORMER
Unit transformer is directly coupled to the unit itself so when
that unit is inrunning condition it supplies power to which are
coupled to auxiliaries directlyor through unit auxiliary
transformer depending upon load. Unit auxiliaries arethose
which are directly associated with the generating unit such as ID
and FDfans, Boiler feed pumps, coal mills, fans, circulating water
pumps etc

30. SPECIFICATION
Rated output 35 MVA
Cooling ONAN/ONAF
Voltage ratio 24 / 11.5 KV
Frequency 50 Hz
Phases Three
ONAN ratingmin 80% of rated MVA

31. MISCELLANEOUS SERVICE TRANSFORMER
Miscellaneous service transformer are used to supply
miscellaneous loads of plant. It is a two winding
transformer connected to 132 KV switchyard.

32. SPECIFICATION
Standard IS:2026/77-81
Rated output 16 MVA
Full load rated current 69.98 A803.27 A
Cooling ONAN
Type Two winding
Voltage ratio 132 / 11.5 KV
Frequency 50 Hz
Phase Thre
Core & coil mass 17650 Kg
Oil quantity 10400 litre
Total mass 37600 kG

33. Turbo generators are used in thermal power stations because of the steam energy to mechanical energy
conversion, turbo generators are more efficient.
GENERATOR SPECIFICATIONS-KVA
247000
Pf 0.85
Volts of stator 15750
Amperes of stator 9050
Volts of rotor 310
Amperes of rotor 2600
Rpm 3000
Hz 50
Phase 3
Connection YY
Coolant water(stator)&hydrogen(rotor)
Gas pressure 3.5kg/cm-sq.
Insulation class B