MHPS(DVC) PROJECT REPORT

BY
ABHINAW KUMAR RAI
ADITYA MISHRA
VISHAL SINGH
SAMBUJ KUMAR
SONA JAMAL HUSSAIN
NANDLAL MANDAL
AJAY KUMAR
RAHUL RANJAN
ELECTRICAL ENGINEERING
BANKURA UNNAYANI INSTITUTE OF
ENGINEERING

2
ACKNOWLEDGEMENT
The dissertation has been prepared based on the vocational
training undergone in a highly esteemed organization of
Eastern region, Maithon Hydel Power Station (MHPS) is located
on the river Barakar about 12.9 km above its confluence with
the Damodar near the border of Dhanbad & Burdwan districts
of the states of Jharkhand & West Bengal respectively. The
unique feature of this is that it is located underground in the
left bank of the river and is the first of its kind in India. The
power station has a total generating capacity of 60 MW with 3
units of 20 MW each. MHPS is located at almost 1000 feet
below the water level,and is the first of its kind, in South East
Asia. I would like to express my heartfelt gratitude to the
authorities of MAITHON HYDEL POWER STATION
and BANKURA UNNAYANI INSTITUTE OF
ENGINEERING for providing me such an opportunity to
undergo training in the Hydel power plant of DVC, MHPS. I
would also like to thank the Engineers, highly experienced
without whom such type of concept building in respect of
Hydel power plantwould not have been possible.
Some of them are:
1: P.GHOSH (Assistant Engineer CLD,DVC MAITHON)
2:NAUSAD HUSSAIN(Chief Engineer G.M.O.D-II KALYANESWARI 220KV SUBSTAION)

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CONTENT
 TRAINING REPORT FOR PUBLIC RELATION OFFICE 5-20
 DAMODAR VALLEY CORPORATION
 MISSION & VISION
 PIONEERING ROLE
 DVC INFRASTRUCTURES
 DVC POWER STATION
 POWER MAP
 DAMS & BARAGES
 INITIATIVES FOR SOCIAL SECTOR DEVLOPMENT
 TRAINING REPORT FOR CENTRAL LOAD DISPATCH 21-31
 NATIONAL LOAD DISPATCH CENTRE
 THERMAL GENERATION
 CLD MAITHON
 DEMAND FORECASTING & SHEDULING
 HYDEL GENERATION
 TIE LINES
 POWER SYSTEM OPERATION CORPORATON
 SINGLE LINE DAIGRAM OF 220/132KV DVC GRID
 SCADA
 TRAINING REPORT FOR TRANSMISSION DEPARTMENT 32-53
 220 KV KALYANESWARI SUBSTATION
 SINGLE LINE DAIGRAM OF 220 KV
 KALYANESWARI SUB STATION G.O.M.D –II, D.V.C
 RATINGS
 220 KV KALYANESWARI SUBSTATION
 BASIC COMPONENTS OF SUBSTATION
 TRANSMISSION SYSTEM
 GRIDMAP
 SUBSTATION
 ELECTRICAL SUBSTATION MODEL(SIDE VIEW)
 REPORT FOR TRANSMISSION 54-73
SYSTEM CONSTRUCTION
 PROCEDURE OF TSC
 TRANSMISSION ROUTE
 SUREVY OF LINES
 APPROVAL REQUIREMENT
 MINIMUM CLEARANCE
 APPLICATION OF SAG TEMPLATE ON PROFILE
 TOWER CONSTRUCTION : EXCAVATION
MARKING CHART
 TOWER FOUNDATION : PYRAMID
CHIMNEY TYPE
 STRINGING OF CONDUCTORS AND EARTHWIRE
 MINIMUM CLEARANCE : IS: 5613 (Part II/Sec-1)-1976
 TOWER USED FOR TRANSMISSION LINE

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 TOWER CONSTRUCTION : EXCAVATION MARKING CHART
 STRINGING OF CONDUCTORS AND EARTHWIRE
 Substation construction
 EARTHING OF SUB STATION-
 TRAINING REPORT FOR CENTRAL TESTING CENTER 75-87
 Central Testing Center
 TRANSFORMER OIL
 On-site testing
 DGA or Dissolved Gas Analysis of Transformer Oil
 DGA TESTING OF TRNSFORMERS OF DVC
 MINIMUM DETECTION LIMIT
 ADVANTAGES THAT DGA CAN PROVIDE
 Protective Relay
-.-.-.-.-.-.-.-.-.-.-.-.-.-

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TRAINING REPORT FOR
PROGRAMME NO. 1 - P.R.O
PUBLIC RELATION OFFICE
06/07/2015 TO 07/07/2015
PRO office,Combined Administrative Building (2nd Floor),Area-6
Damodar Valley Corporation

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DAMODAR VALLEY CORPORATION
Damodar Valley Corporation is the first ever multipurpose river valley
project of independent India which came into being on July 7, 1948 by an Act
of the constituent Assembly ( Act no. Xiv, 1948).Having command area of 24,325
sq.kms spreading across the damodar basin , boundaries of which transcends
the state of Jharkhand & West Bengal . The upper valley consists of two
entirely districts ( Dhanbad & Bokaro) & eight districts partly ( Hazaribagh,
Koderma, Giridih, chhatra, Palamu, Ranchi, Lohardaga & dumka) in the state of
Jharkhand .The lower valley on the other hand consist of five districts partly
( Burdwan & Hoogly, Howrah,Bankura,& purulia) in the state of West Bengal.Since
the beginning, DVC has given due emphasis on power generation & distribution,
besides flood control and irrigation, eco conservation & socio- economic
development.
Today DVC power is a vital input to core sectors including Steel plants , Railways,
collieries along with State Electricity Boards of Jharkhand & West Bengal, big &
medium industries within & beyond the Damodar Valley.
DVC was set up with the intent of promoting & operating the schemes which may
cause social and economic uplift in the valley region. DVC has already established
it existence in discharging its obligations for more than five decades in perfect
harmony. The difficult but effective water management by Corporation has
turned the devastating river Damodar from ‘River of Sorrow’ to ‘River of
Prospects and opportunities’.Proficient management of water resources through
dams ,canals & barrage, DVC facilitates irrigation as well as industrial & domestic
water supply which at large benefited the region as a whole. It has also
contributed significantly in conservation of soil & promotion of schemes of social
integration in valley area.

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MISSION & VISION
THE MISSION
The mission at the time of its inception was :
 Flood control
 Promotion & operation of schemes for irrigation
 Water supply for industrial& domestic use
 Navigation & drainage
 Generation , Transmission & Distribution of electrical energy
 Promotion of a forestation and control of soil erosion in valley area
 Promotion of public health , agriculture, industrial, economic & general
well-being in damodar valley
In keeping with industrialisation in DVC command area ,power generation ,
transmission & distribution gained priority for providing electricity to the
core industries like steel , railways , coal & other industrial& consumers
through respective State Electricity Boards .
However other mandated objectives also received equal importance as
part of overallresponsibility and commitment of DVC.
Capacity addition programmefor power generation gained a new direction
when ministry of power, Govt. Of India started advocating for setting up of
thermal power plants at or near pit heads & transmitpower rather than
transporting coal and advising DVC to world towards adequate capacity
addition during the Tenth and Eleventh plan in order to meet the power
vision. In addition to programmeof capacity addition of 1210MW in Tenth
Five year plan and 6000MW in Eleventh plan , DVC has decided to
rejuvenatethe existing unit through comprehensiveoverhauling and
refurbishment. Besides this , extension and augmentation of transmission
network of DVC, devised with the assistanceof CEA and also strengthening
of existing transmission and distribution network are also under process
of implementation. DVCis implementing ruralelectrification project in
states of West Bengal & Jharkhand under “ Rajiv Gandhi Grameen
vidyutikaran yojna ”

8
THE VISION
To establish DVC as one of the largest power majors of Eastern India while
discharging the responsibilities of its other objects adequately .
In order to achieve this goal against the backdrop of competitive market scenario
in the power sector, the objectives of the corporation havebeen redefined.
CORPORATE OBJECTIVES
 Generate more power at lowest possible costby improving
operational efficiencies of the existing plants, rejuvenating old
generating units through comprehensiveoverhauling as well as by
installing new generating plants
 Transmit , distribute and supply reliable and quality power at
competitive tariff.
 Improvethefinancial health of corporation by adoption of efficient
industrial , commercial and human resourcemanagement practices.
 Ensureoptimum utilization of available water resources through
effective and
 Efficient management and harness theremaining potential of
Damodar basin to extent possible.
 Fortify measures for environmentalprotection at plant levels and to
continue with activities of conservation in the valley area.
 Strengthen socio-economic development for the inhabitants of
villages neighbouring major projects of DVC.

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PIONEERING ROLE
 First multipurpose river valley project of Governmentof India .
 A Govt. Of India organisation generating power utilizing two sources –
Coal and water
 FirstGovt. Of India projectmanaging generation transmission and
distribution of electricity
 Firstunderground hydel station at Maithon
 Bokaro Thermal Power station , biggest thermal power plant of the nation
in 50’s of last century
 Bokaro Thermal Power Station boilers, first to burn pulverized coal in India.
 Firstre-heat units in India utilizing high steam parameter at Chandrapura
Thermal Power station
 Mejia Thermal Power Station , first in eastern India for the application of
Direct Ignition of Pulverized coal (DIPC) systemfor reducing oil
consumption in the boiler.
 Mejia Thermal Power Station , Firstof its kind in eastern India with tube
mills

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DVC INFRASTRUCTURES
With the time DVC developed and expanded its infrastructure Five
thermal power stations with a capacity of 2570 MW, three hydro-
electric power stations with a capacity of 144 MW and one gas
turbine station with a capacity of 82.5 MW contribute to a total
installed capacity of 2796.5 MW. Presently DVC has 60 sub-
stations and receiving stations more than 5500-circuit km of
transmission and distribution lines. DVC has also four dams, a
barrage and a network of canals that play an effective role in
water management. The construction of check dams,
development of forests and farms and upland and wasteland
treatment developed by DVC play a vital role in eco conservation.
DVC Command Area 24,235 Sq. Kms
POWER MANAGEMENT
Total Installed Capacity 2796.5 MW
Thermal Power Stations Five Capacity 2570 MW
Hydel Power Stations Three Capacity 144 MW
Gas Turbine Station One Capacity 82.5 MW
Sub-stations and Receiving
Stations
At 220 KV– 11 nos.
At 132 KV– 33 nos.
At 33 KV– 16 nos.
Transmission Lines
220 KV– 1500 ckt kms

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Water Management
Major Dams and Barrage
Tilaiya,Konar, Maithon
Panchet dams and Durgapur
Barrage
Irrigation Command Area
(gross)
5.69 lakh hectares
Irrigation Potential Created 3.64 lakh hectares
Flood Reserve Capacity 1292 millionCu.m.
Canals 2494 kms
Soil Conservation
Forests, Farms, Upland and
Wasteland Treatment
4 lakh hectares (approx)
Check Dams 16,000 (approx)

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DVC POWER STATION
Name Location Capacity Commissioning
THERMAL
Bokaro 'B' Dist- Bokaro
State- Jharkhand
630 MW
(3 X 210 MW)
U-I Mar 86
U-II Nov90
U-IIIAug 93
Chandrapura Dist- Bokaro
State- Jharkhand
890 MW
(3 X 130 MW)+
(2 X 250 MW)
U-I Oct 64
U-II May 65
U-IIIJuly68
U-VIINov11
U-VIIIJul 11
Durgapur Dist.- Barddhaman
State- WestBengal
350 MW
(1X140 MW)+
(1X210 MW)
U-IIIDec 66
U-IV Sept82
Mejia Dist.- Bankura
State- WestBengal
2340 MW
(4 X 210 MW) +
(2 X 250 MW)+
(2 X 500 MW)
U-I Mar 96
U-II Mar 98
U-IIISept99
U-IV Feb05
U-V Feb08
U-VISept08
U-VIIAug11
U-VIIIAug12
DSTPS Dist.- Bardhaman
State- WestBengal
1000 MW
(2 X 500 MW)
U-I May 12
U-II Mar 13
KTPS Dist.- Koderma
State- Jharkhand
500 MW
(1 X 500 MW)
U-I July13
Total Thermal 5710 MW
Name Location Capacity Commissioning
HYDEL
Tilaiya River- Barakar
Dist.-Hazaribagh
State- Jharkhand
4 MW
(2 X 2 MW)
U-I Feb’53
U-II July’53
Maithon River- Barakar
Dist.- Burdhaman
State- West Bengal
63.2 MW
(2 X 20 MW)
+
(1 X 23.2 MW)
U-I Oct’57
U-II Mar’58
U-II Dec’58
Panchet River- Damodar
Dist.- Dhanbad
State -Jhankhand
80 MW
(2 X 40 MW)
U-I Dec’59
U-II Mar’91
Total Hydel . 147.2 MW
GRAND TOTAL 5857.2 MW

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DAMS & BARAGES
FRONT VIEW OF SPILLWAYS OF MAITHON DAM
Tilaiya Konar Maithon Panchet
Inauguration 21.02.53 15.10.55 27.09.57 06.12.59
On River Barakar Konar Barakar Damodar
District Hazaribagh Hazaribagh Dhanbad Dhanbad
State Jharkhand Jharkhand Jharkhand
/W.B
Jharkhand
/W.B
Height above river bed (meters) 30.18 48.77 50.00* 40.84*
44.00** 45.00**
Length (meters) 366 4535 4860 6777
Width of roadway (meters) 3.81 5.79 6.78 10.67
Power generating capacity 2 x 2 MW - 3 x 20
MW
2 x 40
MW
Storage capacity (million cu.m.)
To dead storage 75.25 60.4 207.24 170.37
To top of gates 394.74 336.76 1361.84 1497.54
Allocation of storage capacities (MCM)
For irrigation & power 141.86 220.81 611.84 228.21
For flood control 177.63 55.51 542.76 1086.76
Drainage area (sq. km.) 984.2 997.1 6293.17 10966.1
Reservoir (sq. km.)
At dead storage level 15.38 7.49 24.28 27.92
At maximum conservation pool 38.45 23.15 71.35 121.81
Area top of gates 74.46 27.92 107.16 153.38

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Durgapur Barrage
Details of Canal Network.
Length
(Km)
Discharge at Head
Regulator (Cumec)
LBMC (Left Bank Main Canal)(Canal
originating from Durgapur Barrage)
136.8 260
RBMC (Right Bank Main Canal) (Canal
originating from Durgapur Barrage)
88.5 64.3
Total length of main and branch canals 2494
DURGAPUR BARRAGE
Year of construction 1955
Length 692 m
Number of gates 34 (including under sluice)
Size of gates 18.3m x 4.9m [60 ft x 16 ft]
Left & right under sluice 18.3m x 5.5 m [60 ft x 18 ft]
Operating levels
Between RL. 64.5 m [211.5 ft] to RL. 63.4
m [208.0 ft]

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INITIATIVES FOR SOCIAL SECTOR DEVLOPMENT
Social Integration Programme
DVC launched its Social Integration Programme(SIP) in 1981.SIP is basically an
expression of DVC’s deep commitment to socio-economic and infrastructural
development of the communities residing within a 10 Km radius of its main
projects.
The programmestarted with 25 villages. At presentit operates in 375 villages
covering 70 Panchayats in 12 blocks of Dhanbad, Giridih, Bokaro and Hazaribagh
districts of Jharkhand and Barddhaman, Purulia and Bankura districts of West
Bengal.
Areascovered under the programme:
·Education
·Agriculture
·Health
·InfrastructuralDevelopment
·Sportsand Culture
·RuralElectrification
·Self- employment
·SocialForestry
EDUCATION
DVC’s Social IntegrationProgramme (SIP) offers the following facilities:
 Non-formaladult education centers, rurallibraries and community centers
run by DVCto help spread literacy among the communities residing within
a 10 km radius of DVC’s main projects. All inputs are fed by DVC
 DVCruns 43 Sishu Siksha Kendras for imparting primary level education to
children of economically disadvantaged families and also to dropouts and
those over aged. At present 1200-1300students aregetting free primary
education.
 In these Kendras students get reading and writing materials free of cost.
Even Keroseneoil is provided to run these Kendras in the remote areas of
Panchet, Konar and Tilaiya projects.

17
 Children belonging to SIP villages are eligible to study in the schools meant
for the children of DVC’s employees.
Social Development
DVC implements integrated social development work in villages situated with in
10 km area of it's major projects through it's social integration programme.
Environment Management
The Environment Management work of DVC consists of two parts the firstpart
DVC is installing proper equipment and augmenting majors to follow the
pollution norms in it's thermal power plants the second part consists of a
forestations and other conservation work for preservation of eco systemof
Damodar Valley area.
Soil Conservation
Soil Conservation work of DVCaims to check soil erosion, and siltation of dams,
improveagricultural production, afforestation and reserves ecological balance.
Rural Electrification
DVC has been entrusted with the responsibility of implementing rural
electrification projectin selected district of West Bengal and Jharkhand
under'RAJIV GANDHI GRAMINVIDYUTIKARANYOJANA'.
Welfare
DVC provides various facilities for the well being of it's employees and their
dependents. Some of the facilities are also being extended to the villagers
covered under the social integration programme

18
AGRCULTURAL
DVC is engagedin the following activities toincrease agricultural yieldfrom
fields:
 Initiation of micro-lift irrigation programmes in the upper valley
 Digging of irrigation wells
 Construction of check dams
 Renovation of ponds
 Arranging training programmes for farmers
DVC has constructedmore than16,000 check dams
Farmers of the local villages are encouraged to adoptmodern scientific farming
practices, Experts fromKVK, Sindri, Holy Cross KrishiVigyan Kendra, Hazaribagh
and Birsa Agricultural University, Ranchiand R.K. Mission of Amarkanan Sewa
Ashram, Purulia impart training in this regard.
HEALTH
DVC’s health programmes under SIP are basically preventive as well as
curative in nature
Preventive Health Services:
DVC organizes from time to time various camps
 Pulse-polio immunization camp.
 Family welfare and operation camp.
 Anti-malaria camp.
 Aids and HIV awareness camp.
 Anti-diarrhea camp.
 Eye (cataract) operation camp.
 TB awareness and detection camp.

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INFRASTRUCTURAL
DEVLOPMENT
Infrastructural development worksareessentially need-based activities:
 Drinking water
Safe drinking water facilities through tap points, hand pumps and wells.
 Communication
Construction of roads (WBM/ bituminous / PCC), culverts, drainage
system, passenger shelters etc.
 Education and HealthCare
Construction of schoolbuildings along with boundary walls, community
buildings, adult education centers and dispensary buildings
 IrrigationFacilities
Installation of micro lift irrigation/RL
Renovation and construction of ponds
Construction of check dams and irrigation wells.
 Others
Construction of toilets, urinals, washing and bathing ghats and burning
ghats.
SELF EMPLOYMENT
Training Programme and Self-employment
DVC is actively engaged in helping local unemployed youths find meaningful
occupations. For this the following facilities are offered:
 Training centers at Maithon, CTPS, BTPS, DTPS and Panchet.
 Youths sent to differentcentres run by outside organizations for training
on poultry, duckary, goattery, para-veterinary,plantpropagation, dairy,
diesel pump mechanic, mushroomcultivation, piggery etc.
 Firsttime assistanceby DVCin terms of raw materials and kits to help
trained youths set up their own business/enterprises.

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ENVIROMENT MAMAGEMENT
We care for the Earth
DVC strongly believes that excellence in the environmental fields is of prime
importance. DVCstrives to work with environmental issues in a consistentand
systematic manner.
DVC’s environmentalmanagement programmeconsists of
 Pollution control at its thermal power stations and
 Combating soil erosion and soil decay in order to restoreand preserve
the quality of the land.
PollutionControl
Pollutants in the formof ash and emissions fromstack arethe major sources
of pollution at coal-based thermal power stations. In old units, of DVC, at
Bokaro, Chandrapura and Durgapur, which werecommissioned, before
pollution control standards becamestringent, the following measures have
been taken to bring the pollutants within the limits:
 Initiation / installation of ESPs with additional fields to bring down
emission within limits.
 Renovation of de-ashing and ash handling system.
 Installation of oil and grease separator.
 Plantation in and around plant areas, ash disposalareas and outside the
projectareas.
Modern units at MTPS, commissioned during 1990s, comply with latest
pollution control norms, including the provision of reuse and recycling of
maximum affluent to conserveland and water.
DVC’s solid wastemanagement systemconsists of evacuation of ash
fromthe ash ponds at BTPS, CTPS and DTPS, transported in protective
manner and dumped into abandoned open castcoal mines of CCL, BCCL
and ECL respectively. After filling up of the mines is over, the top surface
is covered with earth of sufficientthickness to facilitate growth of
vegetation

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TRAINING REPORT FOR
PROGRAMME NO. 2 - C.L.D
CENTRAL LOAD DISPATCH
08/07/2015 TO 10/07/2015
CLD office, Combined Administrative Building (2nd Floor)
Area-6

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NATIONAL LOAD DISPATCH CENTRE
supervise regional load dispatch centres according to Sec-26(2)- act of Ministry of Power
(2005).
These five regions are
NATIONAL LOAD DISPATCH CENTER
ER-EAST REGION WR-WESTREGION NR-NORTH REGION SR-SOUTH REGION NER-NORTH EASTREGION
Bihar Chhattisgarh Punjab Andhra
Pradesh
Arunachal
Pradesh
DVC Gujarat Haryana Telangana Assam
Jharkhand MP Rajasthan Karnataka Manipur
Odisha Maharashtra Delhi Kerala Meghalaya
W.B Goa U.P Tamil Nadu Mizoram
Sikkim DD Uttarakhand Pondy Nagaland
DNH H.P Tripura
Essar steel J&K
Chandigarh
CLD- MAITHON comes under ER

23
CLD MAITHON IS RESPONSIBLE FOR :
 Optimum Scheduling and dispatch of Electricity within the
region.
 Monitor grid operation.
 Accounts of quantity of electricity transmitted through the
regional grid.
 Supervise & control over Inter-State Transmission System.
 Real Time Operation of grid control & dispatch of electricity
through secure & economic operations according with grid
standard & grid code.
A ULDC/load Dispatch Centre of Damodar Valley Corporation is the
ModernComputerized on-line data monitoring system of DVC.
Main Display at Central Load Dispatch
Date 08-JUL-2015 TIME 11:50:52

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DEMAND FORECASTING & SHEDULING
08-JUL-2015
SUMMARY DAIGRAM-DVC 08-JUL-2015 11:50:52
FREQUENCY 50.05 UI RATE(PAISE) 261.36
DEV(MW) 33 TOTAL SCHEDULED 571
MAX. ADDITIONAL RATE/PENALTY RATE(OVER INJECTION)-0
BSEB JSEB DVC GRIDCO WBSEB SIKKIM
GENERATION 1 0 2711 1857 3311
DRWL SCHD -2050 -482 571 -848 -2081
ACT. DRAWL -2385 -87 604 6397 -2068
DEMAND 2385 87 2107 -4540 5379
ACTUAL GEN. SHARE OF DVC
RANGIT 61 6
CHUKHA 251 26
TEESTA 515 44
TALA 1079 60
KURICHU 38 19
FARAKKA 326 25
TALCHER 470 1
ACTUAL CONTROL ERROR = 36 K▲F= -2.63
VOL.BTW 12%-15% = 0.00
VOL.BTW 15%-20% = 0.00
VOL. BEYOND 20 % = 0.00
DVC GENERATION MW
THERMAL GEN 2635
HYDRO GEN 76
TOTAL GEN 2711TOTAL CS GEN :- 6220
NET EXPORT =1199
EXPORT RATE (PAISE/kwh)=101
CONSR CD(MVA) ACT(MW
NET IMPORT = -103
IMPORT RATE (PAISE/kwh)= 218
BSL
TISCO
DSP
IISCO
200
120
190
100
126
-30
WL 27
55
NET UI (mwh) = 1096
[ COMULATIVE SINCE 00:00 HRS]

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HYDEL GENERATION
MHS PHS TILAIYA TIME BLOCK AVG.
FREQ(HZ)
RATE
(PAISE/KWH
)
UI(m
wh)
TSL
UNIT 1 15 28 2 1100-1115 49.99 220 2 -34
UNIT 2 17 0 0 1115-1130 49.92 366 7 -33
UNIT 3 14 -- -- 1130-1145 50.08 71 0 -35
TOTAL 46 28 2 1145-1150 50.02 107 1 -32
THERMAL GENERATION
DSTPS BOKARO-
B
MEJIA WARIA CTPS132 CTPS
B
KTPS RTPS
GEN. GEN. GEN. GEN. GEN. GEN. GEN. GEN.
U#1 386 0 151 0 --- 0 0
U#2 0 0 165 84 --- 376 0
U#3 --- 0 152 87 91 ---
U#4 --- --- 0 0 0 ---
U#5 --- --- 0 --- --- ---
U#6 --- --- 182 --- --- ---
U#7 --- --- 372 --- --- 0
U#8 --- --- 383 --- --- 206
TOTAL
386 0 1405 87 175 206 376 0

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TIE LINES
Lines MW Lines MW
CENTRAL SECTOR GRIDCO
PURLIA-PURLIA PG-I -84 JAMSHEDP-JODA -39
PURLIA-PURLIA PG-I -76 TOTAL 39
KALYA-MAITHON PG-I -71 WBSEB
KALYA-MAITHON PG-II -70 WARIA-BIDHAN’R-I 34
DHN-MATHN-PG-I -112 WARIA-BIDHAN’R-II 33
DHN-MATHN-PG-II -117 KOLAG-KOLAG 0
MEJIA B-JAM’PUR PG 190 TOTAL 67
DSTPS- JAM’PUR PG –I 146 JSEB
DSTPS- JAM’PUR PG –II 140 PATRATU- PATRATU TPS -1 0
MEJIA B- MAITHON PG-I 210 PATRATU- PATRATU TPS -2 0
MEJIA B- MAITHON PG-II 209 CHANDIL –MAINIKUI 0
MEJIA B- MAITHON PG-III 140 MAITTHON- JAMTARA 39
TISCO(DVC)-BARIPADA 206 TOTAL 39
TISCO(DVC)- JAM’PUR PG -347
BSEB
KODERMA-B’SARIF-PG-I -65 BARHI – B’SHARIF 0
KODERMA-B’SARIF-PG-II -64 BARHI - RAJGIR 0
KODERMA-GAYA-I 0 TOTAL 0
KODERMA-GAYA-II 224 NET INTERCHANGE 604
RTPS-RANCHI-PG-I 41
RTPS-MAITHON-PG 36
TOTAL 530

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IMPORTANT LINES MW
JAMALPUR –MEJIA B1 -178
DURGAPUR- JAMALPUR -44
MAITHON- KHSTPP-I -76
MAITHON - KHSTPP -II -79
DURGAPUR-FSTPP- I -278
DURGAPUR- FSTPP-II -281
MAITHON-JAMALPUR-I -178
MAITHON-JAMALPUR-II -48
PURULIYA-JAMALPUR -44
JAMALPUR- ROURKELA-II I
ROURKELA-RAIGHAR- I -41
ROURKELA- TSTPP –I I
ROURKELA-TSTPP-II 0
KHSTPP- B’SHARIF- I 46
KHSTPP –B’SHARIF-II I
B’SHARIF-SASARAM-1 I
B’SHARIF-SHASARAM-II I
SASARAM- ALLAHABAD-I 193
SASARAM-ALLAHABAD- II 138
RENGALI-TSTPP-I 150
RENGALI-TSTPP-II -283
RENGALI- INDRAVATI -283
INDRAVATI- JAYPORE 290
JAYPORE-GAJUWAKA-I 394
JAYPORE-GAJUWAKA-II 27
MAITHON-RANCHI-I -34
RANCHI-ROURKELA-I -34
RANCHI- ROURKELA-II 282

28
DEMANDFORE CAST
(FOR TODAY) 08 jul 2015
TIME
BLOCK
DEMAND
1130-1145 2253
1145-1200 2256
1200-1215 2255
1215-1230 2268
1230-1245 2209
1245-1300 2215
1300-1315 2228
1315-1330 2243
1330-1345 2235
1345-1400 2226
1400-1415 2188
1415-1430 2194
REGION UI RATE(PAIS) FREQ
SR/WR/WR 261 50.11
INTER REG. EXCHANGE
ACTUAL SCHEDULED
ER-WR 365
651 ER-SR 2686
2633 ER-NER
-300 81
ER-NR 1838
1614
DSTPS-RTPS-I 38
DSTPS-RTPS-II 38
KTPS-BOKARO-I 90
KTPS-BOKARO-II 89
DVC BUS VOLTAGE
KV
MEJIA B 420
DSTPS 420
KODERMA 412
TISCO 413
RTPS 467
BOKARO B 220
CTPS 220 218
JAMSHEDPUR 222
KALYANESHWARI 225
MEJIA- TPS 229
PURULIYA 229
WARIA 227
ASP 139
CTPS 132 133
MAITHON (H) 137
MOSABANI 131
PANCHET 135

29
Power System Operation Corporation
Power System Operation Corporation Limited (POSOCO) is a wholly owned subsidiary of Power Grid Corporation of
India Limited (PGCIL). It was formed in March 2010 to handle the power management functions of PGCIL. It is
responsible to ensure the integrated operation of the Grid in a reliable, efficient and secure manner. It consists of
5 Regional Load Despatch Centres and a National Load Despatch Centre (NLDC). The subsidiary may eventually be
made a separate company, leaving the parent firm with only the task of setting up transmission links. The load
despatch functions,earlier handled by PGCIL, will now come up to POSOCO.
Power Grid Corporation ofIndiaLimited (aGovernment Company)shall operate National Load Despatch Centre and thefive Regional Load
Despatch Centers, with effect from October 1, 2010.

30
SINGLE LINE DAIGRAM OF 220/132KV DVC GRID

31
SCADA
Supervisory control and data acquisition (SCADA) systems have traditionally
played a vital role by providing utilities with valuable knowledge and capabilities
that are key to a primary business function – delivering power in a reliable and
safe manner. A quality SCADA solution is central to effective operation of a
utility's most critical and costly distribution, transmission, and generation assets.
The challenging issues for SCADA systems and projects today are not the same as
they were a few years ago. Today, there is much more importance placed on
integration, use of new communication and network technologies, access to
information by more users, and other purposes.
Today’s SCADA systems, in response to changing business needs, have added new
functionalities and are aids for strategic advancements towards interactive, self
healing smart grids of the future. A modern SCADA system is also a strategic
investment which is a must-have for utilities of all sizes facing the challenges of
the competitive market and increased levels of real time data exchange that
comes with it (independent market operator, regional transmission operator,
major C&I establishments, etc.). A well planned and implemented SCADA system
not only helps utilities deliver power reliably and safely to their customers but
also helps to lower costs and achieve higher customer satisfaction and retention.
Modern SCADA systems are already contributing and playing a key role at many
utilities towards achieving:
 New levels in electric grid reliability
 Increased revenue.
 Proactiveproblem detection and resolution
 Higher reliability.
 Meeting the mandated power quality requirements
 Increased customer satisfaction.
 Real time strategic decision making costreductions and increased revenue.

32
TRAINING REPORT FOR
PROGRAMME NO. 3 - TRANS.
TRANSMISSION DEPARTMENT
13/07/2015 TO 16/07/2015
220 KV KALYANESWARI SUB-STATION

33
220 KV KALYANESWARI SUB-STATION
Substation
 An Electrical Substation is a subsidiary station of an electricity Generation , Transmission
And Distribution System where voltage is transformed high to low or reverse using
transformer.
 Examples of Substation:-
 400kV/220kV substation
 33kV/.4kV substation

34
220 KV KALYANESWARI SUBSTATION
201 202 228 229 239 240 237 238
C T P S
M T P S
VIA BURNPUR
PGCIL
220 KV
ATR 1
150 MVA
ATR 2
160 MVA
ATR 3
150 MVA
18 19
KLP
MHS
132 KV
68 69
MAL
PWR TR
50 MVA
PWR TR
50 MVA
33 KV
0.415 KV
250 KVA 250 KVAANP1 HIRA UM NKITA BMA MPLANP2
AUX PWR

35
SINGLE LINE DAIGRAM OF 220 KV KALYANESWARI SUB STATION G.O.M.D –II, D.V.C

36
Ratings
ATR 1 BHEL
SCHEMATIC DAIGRAM
VECTOR DAIGRAM

38
The basic components of a substation are
as follows:
AUTO TRANSFORMER
An autotransformer (sometimes called autostep down transformer) is an
electrical transformer with only one winding. The "auto" (Greek for "self") prefix
refers to the single coil acting on itself and not to any kind of automatic
mechanism. In an autotransformer portions of the same winding act as both the
primary and secondary transformer. The winding has at least three taps where
electrical connections are made. Autotransformers have the advantages of often
being smaller, lighter, and cheaper than typical dual-winding transformers, but
autotransformers havethedisadvantageof not providing electrical isolation.
WORKING
The primary voltage is applied across two of the terminals, and the secondary
voltage taken from two terminals, almost always having one terminal in common
with the primary voltage. The primary and secondary circuits therefore have a
number of windings turns in common. Since the volts-per-turn is the same in both
windings, each develops a voltage in proportion to its number of turns. In an
autotransformer part of the current flows directly from the input to the output,
and only part is transferred inductively, allowing a smaller, lighter, cheaper core
to be used as well as requiring only a single winding. One end of the winding is
usually connected in common to both the voltage source and the electrical load.
The other end of the sourceand load are connected to taps along the winding.
Different taps on the winding correspond to different voltages, measured from
the common end. In a step-down transformer the source is usually connected
across the entire winding while the load is connected by a tap across only a
portion of the winding. In a step up transformer, conversely, the load is attached
across the full winding while the source is connected to a tap across a portion of
the winding.

39
POWER TRANSFORMER:
The use of power transformer in a switchyard is to change the voltage level. At the sending and
usually step up transformers are used to evacuate power at transmission voltage level. On
the other hand at the receiving end step down transformers are installed to match the voltage
to sub transmission or distribution level. In many switchyards autotransformers are used
widely for interconnecting two switchyards with different voltage level (such as 132 and 220
KV)
1-Main tank 2-Radiator 3-Reservoir tank 4-Bushing 5-WTI & OTI Index 6-Breather 7-Buccholz relay
CIRCUIT BREAKER
A circuit breaker is an equipment that breaks a circuit either manually or
automatically under all conditions at no load, full load or short circuit. Oil circuit
breakers, vacuum circuit breakers and SF6 circuit breakers are a few types of
circuit breakers.

40
ISOLATOR
Isolators are switches which isolate the circuit at times and thus serve the
purposeof protection during off load operation.
CURRENT TRANSFORMER
These transformers used serve the purpose of protection and metering.
Generally the same transformer can be used as a current or potential
transformer depending on the type of connection with the main circuit that is
series or parallel respectively. In electrical system it is necessary to
a) Read current and power factor
b) Meter power consumption.
c) Detect abnormalities and feed impulse to protective devices.
POTENTIAL TRANSFORMER
In any electrical power system it is necessary to
a) Monitor voltage and power factor,
b) Meter power consumption,
c) Feed power to control and indication circuit and
d) Detect abnormalities

41
(i.e. under/over voltage, direction of power flow etc) and feed impulse to
protective device/alarm circuit. Standard relay and metering equipments does not
permit them to be connected directly to the high voltage system.Potential
transformers therefore play a key role by performing the following functions.
a) Electrically isolating the instruments and relays fromHV side.
b) By transferring voltage from higher values to proportional standardized lower
values.
CONDUCTORS
Steel cored Aluminium (A.C.S.R)
Aluminium has low tensile strength, as a result produce greater sag which
prohibits their use for longer spans and makes them unsuitable for long distance
transmissions. So in order to increase the tensile strength of the aluminium
conductor, it is used with a core of galvanized steel wires. The combinational
conductor thus obtained is called as A.C.S.R. (Aluminium Conductor Steel
Reinforced)

42
The above figure shows, one steel cored conductor wire surrounded by 18 wires
of aluminium. The aluminium carries bulk of current while the steel core takes a
greater percentage of mechanical stress.
 Produces smalllag and therefore can be used for longer spans.
 A.C.S.R. Conductor gets deteriorated in service due to atmospheric
corrosion.
Cadmium copper
Sometimes copper alloyed with cadmium is used. When 1 or 2 percentage of
cadmium is added to copper it increases the tensile strength by about 40
percentages but reduces the conductivity only by 17 percentages. Cadmium
copper is expensive than copper.
 Economical for a line with long spans and small crosssection.

43
Insulator
The live equipments are mounted over the steel structures or suspended
from gantries with sufficient insulation in between them. In outdoor use
electrical porcelain insulators are most widely used.
Types of insulators
(a)Pin type insulators. (b)Suspension type insulators. (c)Strain typeinsulators.
(d)Shackleinsulators.
(a)Pin type insulators A pin type insulator is designed to be mounted on a pin,
which in turn is installed on cross-armof thepole. The insulator on the pin and
electrical conductor is placed in the grooveat the top of the insulator and soft
aluminium binding wire according to the material of the conductor.
 Pin type insulators made of glass aregenerally used for low voltages.
 Pin type insulators made of porcelain can be used up to 90kV but are rarely
used on lines above60kV
Suspension type insulators
 In a pin type insulator its cost is increased rapidly as the working voltageis
increased. Therefore pin type insulator is not economical beyond 33kV. So
it is as usualpractice to use suspension typeinsulators for voltagehigher
than 33kV.
 A pin type insulator sits on top of the cross arm, whereas a suspension
insulator hangs fromthe cross arm. The line conductor is attached to its

44
lower end. Few advantages of suspension typeinsulators over Pin type
insulators are:
 Usually cheaper in cost for operating voltage above 50kV.
 Flexibility is increased with suspension insulators.
 If line insulation needs to be increased, the additional insulators can be
easily added to the string. In casethere is damage in any insulator, the
damaged insulator can be easily replaced.

45
Bushing
A bushing is a hollow insulating liner through which a conductor maypass.
Bushings appear on switchgear, transformers, circuitbreakers and other high
voltage equipment .The bushing is a hollow insulator, allowing a conductor to
pass along its center and connect at both ends to other equipment. Bushings are
often made of wet-process fired porcelain, and may be coated with
semiconducting gglaze to assistin equalizing the electrical stress along the
length of the bushing. The inside of the bushing may contain paper insulation and
the bushing is often filled with oil to provideadditional insulation. Bushings for
medium-voltage and low-voltageapparatus may be made of resins reinforced
with paper. The useof polymer bushings for high voltage applications is becoming
more common.

46
Capacitor voltage transformer
A capacitor voltagetransformer (CVT or 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 aprotective relay.
CVTs in combinationwith wave traps are used for filtering high-frequency
communication signals from power frequency.
WAVE TRAP
Wave Traps areused at sub-stations using Power Line Carrier Communication
(PLCC). PLCCis used to transmitcommunication and control information at a high
frequency over the power lines. This reduces need for a separate infra for
communication between sub-stations.
The Wave Traps extract the high frequency information fromthe power lines and
route it to the telecomm panels. They also block any surges frompassing through.
Wave Traps aresimply resonantcircuits that producea high impedance against
PLCC carrier frequencies (24kHz - 500kHz) whileallowing power frequency (50Hz -
60Hz).

47
Pebbles flat flooring at substation
Two terms defined regarding floor of earthing system
 Touch potential(potb/w hand and structurals (gnd) when a person is
touching a grounded body like structure in switchyard.
 Steppotential(potdiff b/w the feet of a person walking in the switchyard)
now to minimize these potentials we put pebbles in place of flat flooring.
 To reduce the magnatic field in between ground and conductor.
 To reduce the growth of gress.
 To aviod entry of animals like Rats, snakes etc
 To reduce water storagein the yard in the rainy season.
Lighting Arrestor
Lightning arresters areprotective devices for limiting surgevoltages due
to lightning strikes or equipment faults or other events, to prevent
damage to equipment and disruption of service. Also called surge
arresters.
Lightning arresters areinstalled on many different pieces of equipment
such as power poles and towers, power transformers,circuitbreakers,
bus structures, and steel superstructures in substations

48
Substation Batteries
The heart of a substation is the battery bank. If this were to fail, an electric utility
could expose all feeders associated with the station to a condition where they
could not ever trip in a fault. Not only that, but any backup devices, such as the
main breaker on the low-voltage side or the high-voltage side protection of the
power transformer, would all be inoperative, leaving the transmission grid
protection as the only possiblebackup.
In many cases, however, the transmission grid cannot perform this function
because a fault on the low-voltage side of a Delta Wye transformer, especially a
phase-to-ground fault, will convert to a phase-to-phase fault on the high side. This
would be particularly true if the fault was out a few miles from the station. This
could then cause such catastrophic consequences as burning wire down across
town and eventually destroying the substation transformer. After the smoke
clears, much of the substation could be heavily damaged and the power
transformer could be in flames. This is not to mention the hazard it would cause
to the public.

49
TRANSMISSION SYSTEM
Charged with the responsibilities of providing electricity, the vital input for industrial growth
inthe resource-rich Damodar Valley region, DVC over the last 60 years has developed a big
androbust transmission network consisting of 132 KV and 220 KV grids. DVC grids operates
inunison with the eastern regional grid through 132 KV and 220 KV tie lines. All the power
stationsand substations of DVC are connected with the DVC grids. DVC power consumers are
providedsupply at 25 KV, 33 KV, 132 KV and 220 KV pressure.
DVC Transmission Lines in service at a glance
Interconnecting Tie Lines with DVC Network
*Out of service.
DVC Substations in service (Nos.) at a glance

50
Transmission & Distribution Projects
New Projects under construction
New Projects being taken up for construction

52
Substations
At 33KV Receiving Stations

53
Electrical substation model (side view)

54
TRAINING REPORT FOR
PROGRAMME NO. 4 – TSC
TRANSMISSION SYSTEM CONSTRUCTION
17/07/2015 TO 20/07/1015

55
PROCEDURE OF TSC
PRELIMINARY WORKS
 Selection of Route
 ReconnaissanceSurvey
 Preliminary Survey
 Approvals & Clearances for the Line Route
CONSTRUCTION ACTIVITIES
 Detailed Survey & Plotting of Profile
 Tower Spotting & Tower Schedule
 Check Survey & Location Marking
 Stub Setting
 Erection of Towers & Fixing of Accessories
 Stringing of Conductors & Earth Wire
 Earthing
 Protection of Tower Footings
 Clearing of Right of Way
 Final Checking
 Testing & Commissioning

56
TRANSMISSION ROUTE
The route of a transmission line is decided from the following main
considerations:
 Shortestlength, hence least capital cost.
 Route near roads for easy approach & accessibility during construction and
maintenance.
 Requirement of future loads near the proposed routeso that the line can
easily be connected to the loads and optimal use of line.
 Required separation distance fromparallel communication lines (P&T,
Railways, etc.) for meeting the conditions of induced voltage for obtaining
PTCC approval.
 Avoiding of forestareas as well as wild life sanctuaries as far as possible.
 Cost of securing and clearing right of way (ROW).
 Maintaining statutory distances fromAirports / Helipads
AVOID
 Tough inaccessibleareas
 Towns and villages, leaving sufficient margin for their growth
 Swamps and shallow lands subjectto flood, marshy areas, low lying
lands, river beds and land slide zones, etc. involving risk of stability for
foundations
 Rifle shooting areas and other protected areas such as army / defence
installations and ammunition depots.
 Buildings / Storage areas for explosives or inflammable materials, bulk
oil storagetanks, oil or gas pipelines etc.

57
SUREVY OF LINES
 METHOD : Theodolite , Total Station ,SatellitewithTotal Station
 PLOTTING OF ROUTE PROFILE: Manual , PLSCAD
APPROVAL REQUIREMENT
 Forestclearance
 Railway clearance
 Clearance frommining authority
 NH Clearance
 Power and Telecommunication Coordination Committee (PTCC)
clearance
 CEA Clearance
MINIMUM CLEARANCE

58
MINIMUM CLEARANCE : IS: 5613 (Part II/Sec-1)-1976
MINIMUM CLEARANCE : AS PER - IS :5613 (PART II/SEC I) -
1976

59
APPLICATION OF SAG TEMPLATE ON PROFILE

60
TOWER USED FOR TRANSMISSION LINE
 Lattice type tower
 A2, S15, B30, C60, D90 –132&220KV line
 A2, B15, C30, D60 – 400KV line
 Wide base tower
 Narrow basetower
 Multi circuit Tower
 Special Crossing Tower
TOWER CONSTRUCTION : EXCAVATION
MARKING CHART

61
 The excavation pit marking drawing indicates the distance of centres, sides
and corners of the pits with reference to the centre point of the tower
 From the dimensions shown in the drawing, the triangle ABC is first
marked with the help of a measuring tape. The distance CD, equal to F
(width of the pit) is marked on the ground.
The triangle AB'C is then marked by shifting the point B and without changing the
points A and C. The distance CD', equal to F, is then marked. The sides DE and D'E,
both equal to F, are then marked. The procedure is repeated for marking the
other three pits.
 The dimension G shown in the drawing is the centre to centre distance
between stubs of the tower at their lowest point. The dimension M is the
diagonal distance between the ends of the stubs of the tower. The
excavation pit marking drawing is prepared on the basis of these
dimensions.
TOWER FOUNDATION : PYRAMID CHIMNEY TYPE

64
FOLLOW THE STEPS TO ERECT THE TOWER
 Erection of Tower body - first story
 Erection of Tower body - second story upwards
 Erection of cross arms
Conclusion: Pulley and guy ropes are the minimum accessories to erect a
tower.

65
STRINGING OF CONDUCTORS AND
EARTHWIRE
HOSTING OF INSULATOR STRING
 Single / Doublesuspension insulator strings areused on suspension towers
and single / double tension insulator strings are used on angle and dead
end towers. This is indicated in the tower schedule.
 Before hoisting, all insulators are cleaned in a manner that will not spoil,
injureor scratch the surfaceof the insulator, but in no caseshall any oil be
used for the purpose.
 Disc insulators shall be examined for any cracks / chipping, etc. Disc
insulators having any hair cracks or chipping or defective glazing or any
other defect shall not be used .
NO. OF DISC / E&M STRENGTH (KN)
400kv 220kv 132kv
single suspension –I
string
1 X 23 120 KN 1 X 13 70 KN 1 X 9 45 KN
Double suspension-I
String
2 X 24 120 KN 2 X 13 70KN 2 X 9 45 KN
Single suspension- v
string
2 X 23 120 KN N.A N.A
Double suspension v
string
2 X 2 X 23 120KN N.A N.A
Single tension string 1 X 23 120 KN 1 X 14 120 KN 1 X 10 120KN
Double tension string 2 X 23 160KN 2 X 14 120KN 2 X 10 120KN
Single suspension pilot
string
2 X 23 120KN 1 X 13 70KN 1 X 9 45KN

69
Substation construction
Selectionofsite
 As near the load centre as possible.
 As far as possiblerectangular or squarein shapefor ease of proper
orientation of bus – bars and feeders.
 Far away from obstructions, to permit easy and safe approach / termination
of high voltage overhead transmission lines.
 Free frommaster plans / layouts or future development activities to have
free line corridors for the presentand in future.
 Easily accessibleto the public road to facilitate transportof material
 As far as possiblenear a town and away frommunicipal dumping grounds,
burial grounds, tanneries and other obnoxious areas.
 Preferably fairly leveled ground. This facilitates reduction in leveling
expenditure.
 Abovehighest flood level (HFL) so that there is no water logging.
 Sufficiently away fromareas wherepolice and military rifle practices are
held.

70
Main Equipments of Sub-station:
 Transformer
 LA
 CVT/PT
 Isolator
 CT
 Circuit Breaker
 Control & Relay Panel
Sub station layout

71
Note : These layouts were essentially used in
220kv/ 132kv/ 33kv Dhanbad sub station
( TSE VT – 09-01-2014 AT D.S.S , DVC )

72
SECTION 132KV & 220KV TRANSFORMER
BAY,DHANBAD S/S

73
BAY LAYOUTS OF 132KV AND 220 KV , DHANBAD S/S

75
TRAINING REPORT FOR
PROGRAMME NO. 5 – CTC
CENTRAL TESTING CENTER
CRITL MAITHON

76
Central Testing Center at Maithon
has two distinct divisions namely
1.Central Relay and Instrument Testing Laboratory
(CRITL) and
2.Central Relay and Instrument Testing Mobile
(CRITM).
The above two divisionstake care of commissioning and proper
maintenanceof the entire protection and metering system,
fault analysisas well as periodicaltesting of all types of relays
and meters includingtariff meters of the entire DVC network
includingpower houses.

77
TRANSFORMER OIL
Transformer oil or insulating oil is usually a highly refined mineral oil that is stable
at high temperatures and has excellent electrical insulating properties. It is used
in oil filled transformers, some types of high voltage capacitors, fluorescent lamp
ballasts, and some types of high voltage switches and circuit breakers .Its
functions are to insulate, suppress corona and arcing, and to serveas a coolant.
On-site testing
Some transformer oil tests can be carried out in the field, using portable test
apparatus. Other tests, such as dissolved gas, normally require a sample to be
sent to a laboratory. Electronic on-line dissolved gas detectors can be
connected to important or distressed transformers to continually monitor gas
generation trends.To determine the insulating property of the dielectric oil, an
oil sample is taken from the device under test, and its breakdown voltage is
measured on-site according the following test sequence:
 In the vessel, two standard-compliant test electrodes with a typical
clearance of 2.5 mm are surrounded by the insulating oil.
 During the test, a test voltage is applied to the electrodes. The test voltage
is continuously increased up to the breakdown voltage with a constant slew
rate of e.g. 2 kV/s.
 Breakdown occurs in an electric arc, leading to a collapse of the test
voltage.
 Immediately after ignition of the arc, the test voltage is switched off
automatically.
 Ultra fast switch off is crucial, as the energy that is brought into the oil and
is burning it during the breakdown, must be limited to keep the additional
pollution by carbonisation as low as possible.
 The root mean square value of the test voltage is measured at the very
instant of the breakdown andis reported as the breakdown voltage.
 After the test is completed, the insulating oil is stirred automatically and
the test sequence isperformed repeatedly.
 The resulting breakdown voltage is calculated as mean value of the
individual measurements.

78
DGA or Dissolved Gas Analysis of
Transformer Oil
Whenever electrical power transformer goes under abnormal thermal
and electrical stresses, certain gases are produced due to
decomposition of transformer insulating oil, when the fault is major,
the production of decomposed gases are more and they get collected in
Buchholz relay. But when abnormal thermal and electrical stresses are
not significantly high the gasses due to decomposition of transformer
insulating oil will get enough time to dissolve in the oil. Hence by only
monitoring the Buchholz relay it is not possible to predict the condition
of the total internal healthiness of electrical power transformer. That is
why it becomes necessary to analyse the quantity of different gasses
dissolved in transformer oil in service. From dissolved gas analysis of
transformer Oil or DGA of transformer oil, one can predict the actual
condition of internal health of a transformer. It is preferable to conduct
the DGA test of transformer oil in routine manner to get prior
information about the trend of deterioration of transformer health and
life.
Actually in dissolved gas analysis of transformer oil or DGA of
transformer oil test, the gases in oil are extracted from oil and analyze
the quantity of gasses in a specific amount of oil. By observing
percentages of different gasses present in the oil, one can predict the
internal condition of transformer.
Generally the gasses found in the oil in service are hydrogen (H2),
methane (CH4), Ethane (C2H6), ethylene (C2H4), acetylene (C2H3), carbon
monoxide (CO), carbon dioxide (CO2), nitrogen(N2) and oxygen(O2).
Generally it is found that hydrogen and methane are produced in large
quantity if internal temperature of power transformer rises up to 150°C
to 300°C due to abnormal thermal stresses. If temperature goes above
300°C, ethylene (C2H4) are produced in large quantity. At the

79
temperature is higher than 700°C large amount of hydrogen (H2) and
ethylene (C2H4) are produced.
DGA TESTING OF TRNSFORMERS OF DVC
DGA 3 STEPS
 OIL SAMPLE EXTRACTION as per standard IS 9434: 1992 and ASTM
3613.
 EXTRACTION OF THE GASES (fully computerized ALIGENT
TECHNOLOGIES U.S.A made using the Agilent 7697A Headspace
Sampler.)
 GAS SEPERATION AND MEASURMENT (GAS CHROMATOGRAPHY)
ALIGENT TECHNOLOGIES

80
MINIMUM DETECTION LIMIT
ADVANTAGES THAT DGA CAN PROVIDE
 Advance warning of developing faults
 Determining warning of the improper use of units
 Statuschecks on new and repaired units
 Convenient scheduling of repairs
 Monitoring of units under overload
GAS DETECTION LIMIT in
ppm
HYDROGENH2 0.60
OXYGEN02 11.0
NITROGENN2 11.2
MEATHANE CH4 0.50
CARBON MONO OXIDE
CO
0.10
CARBON DIOXIDECO2 0.10
ACETYLENE C2H2 0.05
ETHYLENE C2H4 0.04
ETHANE C2H6 0.04
PROPANEC3H8 0.20

81
Losses of Transformers
The transformers aremade of 2 types of materials: Iron and Copper. The core of a
transformer is made of Iron whereas thewinding which is wrapped over the iron
core is made up of Copper.
Correspondingly there are 2 types of losses: Iron Loss and Copper Loss. Iron and
Copper losses are measuredby open circuit andshort circuit tests.
TESTS OF DISTRIBUTION TRANSFORMERS
Two tests are conducted for testing transformers. These tests are known by
different names as describedinthe table below.

82
Protective Relay
A relay is automatic device which senses an abnormal condition of electrical
circuit and closes its contacts. These contacts in turns close and complete the
circuit breaker trip coil circuit hence make the circuit breaker tripped for
disconnecting the faulty portion of the electrical circuit from rest of the healthy
circuit.
Types of Relays
Types of protection relays are mainly based on their characteristic, logic, on
actuating parameter and operation mechanism.
Based on operation mechanism protection relay can be categorized as
electromagnetic relay, static relay and mechanical relay. Actually relay is nothing
but a combination of one or more open or closed contacts. These all or some
specific contacts the relay change their state when actuating parameters are
applied to the relay. That means open contacts become closed and closed
contacts become open. In electromagnetic relay these closing and opening of
relay contacts are done by electromagnetic action of a solenoid.
In mechanical relay these closing and opening of relay contacts are done by
mechanical displacement of different gear level system.
In static relay it is mainly done by semiconductor switches like thyristor. In digital
relay on and off state can be referred as 1 and 0 state.
Basedon Characteristic the protectionrelay canbe categorizedas-
 Definite time relays
 Inversetime relays with definite minimum time(IDMT)
 Instantaneous relays.
 IDMTwith inst.
 Stepped characteristic.
 Programmed switches.
 Voltage restraint over current relay.

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Basedon of logic the protectionrelay canbe categorizedas-
Differential.
 Unbalance.
 Neutral displacement.
 Directional.
 Restricted earth fault.
 Over fluxing.
 Distance schemes.
 Bus bar protection.
 Reversepower relays.
 Loss of excitation.
 Negative phasesequence relays etc.
Basedon actuating parameter the protectionrelay canbe categorizedas-
 Currentrelays.
 Voltage relays.
 Frequency relays.
 Power relays etc.
Basedon applicationthe protectionrelay canbe categorizedas-
 Primary relay.
 Backup relay. Primary relay or primary protection relay is the first line of
power system protection whereas backup relay is operated only when
primary relay fails to be operated during fault. Hence backup relay is slower
in action than primary relay. Any relay may fail to be operated due to any of
the following reasons,
 The protective relay itself is defective.
 DC Trip voltage supply to the relay is unavailable.
 Trip lead from relay panel to circuit breaker is disconnected.
 Trip coil in the circuit breaker is disconnected or defective.
 Currentor voltage signals fromCT or PT respectively is unavailable.
As because backup relay operates only when primary relay fails, backup
protection relay should not have anything common with primary protection relay.

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Some examples of Mechanical Relay are-
 Thermal
 OT trip (Oil Temperature Trip)
 WT trip (Winding Temperature Trip)
 Bearing temp trip etc.
 Float type
 Buchholz
 OSR
 PRV
 Water level Controls etc.
 Pressureswitches.
 Mechanical interlocks.
 Pole discrepancy relay.

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List Different Protective Relays are used for
Different Power System Equipment Protection
Now let’s have a look on which different protective relays are used in different
power systemequipment protection schemes.
Relays for Transmission& DistributionLines Protection
Relays for Transformer Protection

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 No Buchholz relay for transformers below500 KVA capacity.
 Transformers upto 1500 KVA shall have only Horn gap protection.
 Transformers above 1500 KVA and upto 8000 KVA of 33/11KV ratio shall
have one group control breaker on HV side and individual LV breakers if
there is more than one transformer.
 Transformers above 8000 KVA shall have individual HV and LV circuit
breakers.
 The relays indicate above shall be providedon HV and LV.

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 LAs to be provided on HV & LV for transformers of all capacities and
voltage class.
 OLTC out of step protection is to be provided where master follower
scheme is in operation.
 Fans failure and pumps failure alarms tobe connected.
 Alarms for O.T., W.T., Buchholz (Maintank & OLTC) should be connected.
TAP CHANGER
A tap changer is a connection point selection mechanism along a
power transformer winding that allows a variable number of turns to be selected in
discrete steps. A transformer with a variable turns ratio is produced, enabling
stepped voltage regulation of the output. The tap selection may be made via an
automatic or manual tap changer mechanism.
TAP CHANGING
Off-circuit designs (NLTC or DETC)
Also called No-Load Tap Changer (NLTC), off-circuit tap changer, or De-
Energized Tap Changer (DETC).
In low power, low voltage transformers, the tap point can take the form of a
connection terminal, requiring a power lead to be disconnected by hand and
connected to the new terminal. Alternatively, the process may be assisted by
means of a rotary or slider switch.
Since the different tap points are at different voltages, the two connections can
not be made simultaneously, as this would short-circuit a number of turns in the
winding and produce excessive circulating current. Consequently, the power to
the device must be interrupted during the switchover event. Off-circuit or de-
energized tap changing (DETC) is sometimes employed in high voltage
transformer designs, although for regular use, it is only applicable to installations

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in which the loss of supply can be tolerated. In power distribution networks,
transformers commonly include an off-circuit tap changer on the primary winding
to accommodate system variations within a narrow band around the nominal
rating. The tap changer will often be set just once, at the time of installation,
although it may be changed later during a scheduled outage to accommodate a
long-term change in the system voltage profile.
On-load designs (OLTC)
Also called on circuit tap changer or On Load Tap Changer (OLTC)
For many power transformer applications, a supply interruption during a tap
change is unacceptable, and the transformer is often fitted with a more expensive
and complex on-load tap-changing (OLTC, sometimes LTC) mechanism. On-
load tap changers may be generally classified as either mechanical,
electronically assisted, or fully electronic.

MHPS(DVC) PROJECT REPORT

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