mhps(dvc) project report
TRANSCRIPT
BYABHINAW KUMAR RAI
ADITYA MISHRA VISHAL SINGH
SAMBUJ KUMAR SONA JAMAL HUSSAIN
NANDLAL MANDAL AJAY KUMAR RAHUL
RANJAN
ELECTRICAL ENGINEERING
BANKURA UNNAYANI INSTITUTE OF ENGINEERING
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 plant would 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)
CONTENT TRAINING REPORT FOR PUBLIC RELATION OFFICE 5-20
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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 54-73SYSTEM 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 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
DAMODAR VALLEY CORPORATION
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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.
MISSION & VISION
THE MISSION
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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 overall responsibility and commitment of DVC. Capacity addition programme for 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 & transmit power 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 programme of capacity addition of 1210MW in Tenth Five year plan and 6000MW in Eleventh plan , DVC has decided to rejuvenate the existing unit through comprehensive overhauling and refurbishment . Besides this , extension and augmentation of transmission network of DVC , devised with the assistance of CEA and also strengthening of existing transmission and distribution network are also under process of implementation. DVC is implementing rural electrification project in states of West Bengal & Jharkhand under “ Rajiv Gandhi Grameen vidyutikaran yojna ”
THE VISION
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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 have been redefined.
CORPORATE OBJECTIVES Generate more power at lowest possible cost by improving
operational efficiencies of the existing plants, rejuvenating old generating units through comprehensive overhauling as well as by installing new generating plants
Transmit , distribute and supply reliable and quality power at competitive tariff.
Improve the financial health of corporation by adoption of efficient industrial , commercial and human resource management practices.
Ensure optimum utilization of available water resources through effective and
Efficient management and harness the remaining potential of Damodar basin to extent possible.
Fortify measures for environmental protection 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.
PIONEERING ROLE
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First multipurpose river valley project of Government of India . A Govt. Of India organisation generating power utilizing two sources –
Coal and water First Govt. Of India project managing generation transmission and
distribution of electricity First underground 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. First re-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) system for reducing oil consumption in the boiler.
Mejia Thermal Power Station , First of its kind in eastern India with tube mills
DVC INFRASTRUCTURES9
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.
Soil Conservation
Forests, Farms, Upland and Wasteland Treatment
4 lakh hectares (approx)
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DVC Command Area 24,235 Sq. Kms
POWER MANAGEMENT
Total Installed Capacity 2796.5 MWThermal Power Stations Five Capacity 2570 MWHydel Power Stations Three Capacity 144 MWGas 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 Lines220 KV– 1500 ckt kms 132 KV– 3415 ckt kms33 KV– 1070 ckt kms
Water Management
Major Dams and BarrageTilaiya, Konar, Maithon Panchet dams and Durgapur Barrage
Irrigation Command Area (gross)
5.69 lakh hectares
Irrigation Potential Created 3.64 lakh hectaresFlood Reserve Capacity 1292 million Cu.m.Canals 2494 kms
Check Dams 16,000 (approx)
DVC POWER STATIONName Location Capacity Commissionin
g THERMAL
Bokaro 'B' Dist- BokaroState- Jharkhand
630 MW(3 X 210 MW)
U-I Mar 86U-II Nov 90U-III Aug 93
Chandrapura Dist- BokaroState- Jharkhand
890 MW(3 X 130 MW)+(2 X 250 MW)
U-I Oct 64U-II May 65U-III July 68U-VII Nov 11U-VIII Jul 11
Durgapur Dist.- BarddhamanState- WestBengal
350 MW(1X140 MW)+(1X210 MW)
U-III Dec 66U-IV Sept 82
Mejia Dist.- BankuraState- WestBengal
2340 MW(4 X 210 MW) +(2 X 250 MW)+
U-I Mar 96U-II Mar 98U-III Sept 99
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(2 X 500 MW) U-IV Feb 05U-V Feb 08U-VI Sept 08 U-VII Aug 11U-VIII Aug 12
DSTPS Dist.- BardhamanState- WestBengal
1000 MW(2 X 500 MW)
U-I May 12U-II Mar 13
KTPS Dist.- KodermaState- Jharkhand
500 MW(1 X 500 MW)
U-I July 13
Total Thermal 5710 MW
Name Location Capacity Commissioning
HYDELTilaiya River- Barakar
Dist.-HazaribaghState- Jharkhand
4 MW (2 X 2 MW)
U-I Feb’53U-II July’53
Maithon River- BarakarDist.- BurdhamanState- West Bengal
63.2 MW(2 X 20 MW)+(1 X 23.2 MW)
U-I Oct’57U-II Mar’58U-II Dec’58
Panchet River- DamodarDist.- DhanbadState -Jhankhand
80 MW(2 X 40 MW)
U-I Dec’59U-II Mar’91
Total Hydel . 147.2 MW
GRAND TOTAL 5857.2 MW
POWER MAP
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DAMS & BARAGESTilaiya Konar Maithon Panchet
Inauguration 21.02.53 15.10.55 27.09.57 06.12.59
On River Barakar Konar Barakar DamodarDistrict 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 6777Width of roadway (meters) 3.81 5.79 6.78 10.67Power generating capacity 2 x 2 MW - 3 x 20 MW 2 x 40
MWStorage 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 71.35 121.81Area top of gates 74.46 27.92 107.16 153.38
FRONT VIEW OF SPILLWAYS OF MAITHON DAM
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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]
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
INITIATIVES FOR SOCIAL SECTOR DEVLOPMENT
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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 programme started with 25 villages. At present it 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.
Areas covered under the programme:
·Education·Agriculture·Health·Infrastructural Development·Sports and Culture·Rural Electrification·Self- employment·Social Forestry
EDUCATIONDVC’s Social Integration Programme (SIP) offers the following facilities:
Non-formal adult education centers, rural libraries and community centers run by DVC to help spread literacy among the communities residing within a 10 km radius of DVC’s main projects. All inputs are fed by DVC
DVC runs 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 1200-1300 students are getting free primary education.
In these Kendras students get reading and writing materials free of cost. Even Kerosene oil is provided to run these Kendras in the remote areas of Panchet, Konar and Tilaiya projects.
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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 first part 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 system of Damodar Valley area.
Soil Conservation
Soil Conservation work of DVC aims to check soil erosion, and siltation of dams, improve agricultural production, afforestation and reserves ecological balance.
Rural Electrification
DVC has been entrusted with the responsibility of implementing rural electrification project in selected district of West Bengal and Jharkhand under'RAJIV GANDHI GRAMIN VIDYUTIKARAN YOJANA'.
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
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AGRCULTURALDVC is engaged in the following activities to increase agricultural yield from 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 constructed more than 16,000 check dams
Farmers of the local villages are encouraged to adopt modern scientific farming practices, Experts from KVK, Sindri, Holy Cross Krishi Vigyan Kendra, Hazaribagh and Birsa Agricultural University, Ranchi and R.K. Mission of Amarkanan Sewa Ashram, Purulia impart training in this regard.
HEALTHDVC’s health programmes under SIP are basically preventive as well as curative in naturePreventive 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.
INFRASTRUCTURAL DEVLOPMENT
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Infrastructural development works are essentially need-based activities:
Drinking waterSafe drinking water facilities through tap points, hand pumps and wells.
CommunicationConstruction of roads (WBM / bituminous / PCC), culverts, drainage system, passenger shelters etc.
Education and Health CareConstruction of school buildings along with boundary walls, community buildings, adult education centers and dispensary buildings
Irrigation FacilitiesInstallation of micro lift irrigation/RLRenovation and construction of pondsConstruction of check dams and irrigation wells.
OthersConstruction 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 different centres run by outside organizations for training on
poultry, duckary, goattery, para-veterinary, plant propagation, dairy, diesel pump mechanic, mushroom cultivation, piggery etc.
First time assistance by DVC in terms of raw materials and kits to help trained youths set up their own business/ enterprises.
ENVIROMENT MAMAGEMENT
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We care for the Earth
DVC strongly believes that excellence in the environmental fields is of prime importance. DVC strives to work with environmental issues in a consistent and systematic manner.
DVC’s environmental management programme consists of
Pollution control at its thermal power stations and Combating soil erosion and soil decay in order to restore and preserve the
quality of the land.
Pollution ControlPollutants in the form of ash and emissions from stack are the major sources of pollution at coal-based thermal power stations. In old units, of DVC, at Bokaro, Chandrapura and Durgapur, which were commissioned, before pollution control standards became stringent, 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 disposal areas and outside the
project areas.Modern units at MTPS, commissioned during 1990s, comply with latest pollution control norms, including the provision of reuse and recycling of maximum affluent to conserve land and water.DVC’s solid waste management system consists of evacuation of ash from the ash ponds at BTPS, CTPS and DTPS, transported in protective manner and dumped into abandoned open cast coal mines of CCL, BCCL and ECL respectively. After filling up of the mines is over, the top surface is covered with earth of sufficient thickness 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
Damodar Valley Corporation
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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-WEST REGION NR-NORTH REGION SR-SOUTH REGION NER-NORTH EAST REGION
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
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Chandigarh
CLD- MAITHON comes under ER
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 DispatchDate 08-JUL-2015 TIME 11:50:52
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DEMAND FORECASTING & SHEDULING
08-JUL-2015SUMMARY 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
ACTUAL CONTROL ERROR = 36 K▲F= -2.63
VOL.BTW 12%-15% = 0.00 VOL.BTW 15%-20% = 0.00
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TEESTA 515 44
TALA 1079 60
KURICHU 38 19
FARAKKA 326 25
TALCHER 470 1
VOL. BEYOND 20 % = 0.00
DVC GENERATION MW
THERMAL GEN 2635 HYDRO GEN 76 TOTAL GEN 2711
TOTAL 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]
HYDEL GENERATION
MHS PHS TILAIYA TIME BLOCK AVG. FREQ(HZ)
RATE (PAISE/KWH)
UI(mwh)
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
25
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
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
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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
IMPORTANT LINES MW JAMALPUR –MEJIA B1 -178DURGAPUR- JAMALPUR -44MAITHON- KHSTPP-I -76MAITHON - KHSTPP -II -79DURGAPUR-FSTPP- I -278DURGAPUR- FSTPP-II -281MAITHON-JAMALPUR-I -178MAITHON-JAMALPUR-II -48PURULIYA-JAMALPUR -44JAMALPUR- ROURKELA-II IROURKELA-RAIGHAR- I -41ROURKELA- TSTPP –I IROURKELA-TSTPP-II 0KHSTPP- B’SHARIF- I 46KHSTPP –B’SHARIF-II IB’SHARIF-SASARAM-1 IB’SHARIF-SHASARAM-II ISASARAM- ALLAHABAD-I 193SASARAM-ALLAHABAD- II 138
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RENGALI-TSTPP-I 150RENGALI-TSTPP-II -283RENGALI- INDRAVATI -283INDRAVATI- JAYPORE 290JAYPORE-GAJUWAKA-I 394JAYPORE-GAJUWAKA-II 27MAITHON-RANCHI-I -34RANCHI-ROURKELA-I -34RANCHI- ROURKELA-II 282
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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 KVMEJIA B 420DSTPS 420KODERMA 412TISCO 413RTPS 467BOKARO B 220CTPS 220 218JAMSHEDPUR 222KALYANESHWARI 225MEJIA- TPS 229PURULIYA 229WARIA 227ASP 139CTPS 132 133MAITHON (H) 137MOSABANI 131PANCHET 135
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 of India Limited (a Government Company) shall operate National Load Despatch Centre and the five Regional Load Despatch Centers, with effect from October 1, 2010.
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SINGLE LINE DAIGRAM OF 220/132KV DVC GRID
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. Proactive problem detection and resolution Higher reliability. Meeting the mandated power quality requirements Increased customer satisfaction. Real time strategic decision making cost reductions and increased revenue.
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TRAINING REPORT FOR
PROGRAMME NO. 3 - TRANS.
TRANSMISSION DEPARTMENT
13/07/2015 TO 16/07/2015
220 KV KALYANESWARI SUB-STATION
Damodar Valley Corporation
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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
220kV/132kV substation
132kV/33kV substation
33kV/11kV substation
33kV/.4kV substation
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220 KV KALYANESWARI SUBSTATION
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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
AUTO TRANSFORMERAn 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 have the disadvantage of 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 source and 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.
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
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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.
ISOLATOR
Isolators are switches which isolate the circuit at times and thus serve the purpose of protection during off load operation.
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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
(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.
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a) Electrically isolating the instruments and relays from HV 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)
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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 small lag 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.
\
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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 type insulators. (d)Shackle insulators. (a)Pin type insulators A pin type insulator is designed to be mounted on a pin, which in turn is installed on cross-arm of the pole. The insulator on the pin and electrical conductor is placed in the groove at the top of the insulator and soft aluminium binding wire according to the material of the conductor.
Pin type insulators made of glass are generally used for low voltages. Pin type insulators made of porcelain can be used up to 90kV but are rarely
used on lines above 60kV
Suspension type insulators
In a pin type insulator its cost is increased rapidly as the working voltage is increased. Therefore pin type insulator is not economical beyond 33kV. So it is as usual practice to use suspension type insulators for voltage higher than 33kV.
A pin type insulator sits on top of the cross arm, whereas a suspension insulator hangs from the cross arm. The line conductor is attached to its
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lower end. Few advantages of suspension type insulators 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 case there is damage in any insulator, the damaged insulator can be easily replaced.
Bushing
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A bushing is a hollow insulating liner through which a conductor maypass. Bushings appear on switchgear, transformers, circuit breakers 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 assist in 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 provide additional insulation. Bushings for medium-voltage and low-voltage apparatus may be made of resins reinforced with paper. The use of polymer bushings for high voltage applications is becoming more common.
Capacitor voltage transformer
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A capacitor voltage transformer (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 combination with wave traps are used for filtering high-frequency communication signals from power frequency.
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.The Wave Traps extract the high frequency information from the power lines and route it to the telecomm panels. They also block any surges from passing through.Wave Traps are simply resonant circuits that produce a high impedance against PLCC carrier frequencies (24kHz - 500kHz) while allowing power frequency (50Hz - 60Hz).
Pebbles flat flooring at substation
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Two terms defined regarding floor of earthing system
Touch potential(pot b/w hand and structurals (gnd) when a person is touching a grounded body like structure in switchyard.
Step potential(pot diff 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 storage in the yard in the rainy season.
Lighting Arrestor
Lightning arresters are protective devices for limiting surge voltages dueto lightning strikes or equipment faults or other events, to preventdamage to equipment and disruption of service. Also called surgearresters.Lightning arresters are installed on many different pieces of equipmentsuch as power poles and towers, power transformers, circuit breakers,bus structures, and steel superstructures in substations
Substation Batteries
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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 possible backup.
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.
TRANSMISSION SYSTEM
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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
Transmission & Distribution Projects
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TRAINING REPORT FOR PROGRAMME NO. 4 – TSC
TRANSMISSION SYSTEM CONSTRUCTION
17/07/2015 TO 20/07/1015
Damodar Valley Corporation
PROCEDURE OF TSC
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PRELIMINARY WORKS
Selection of Route
Reconnaissance Survey
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
TRANSMISSION ROUTE
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The route of a transmission line is decided from the following main considerations:
Shortest length, hence least capital cost. Route near roads for easy approach & accessibility during construction and
maintenance. Requirement of future loads near the proposed route so that the line can
easily be connected to the loads and optimal use of line. Required separation distance from parallel communication lines (P&T,
Railways, etc.) for meeting the conditions of induced voltage for obtaining PTCC approval.
Avoiding of forest areas as well as wild life sanctuaries as far as possible. Cost of securing and clearing right of way (ROW). Maintaining statutory distances from Airports / Helipads
AVOID Tough inaccessible areas Towns and villages, leaving sufficient margin for their growth Swamps and shallow lands subject to 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 storage tanks, oil or gas pipelines etc.
SUREVY OF LINES
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METHOD : Theodolite , Total Station ,Satellite with Total Station PLOTTING OF ROUTE PROFILE : Manual , PLSCAD
APPROVAL REQUIREMENT
Forest clearance Railway clearance Clearance from mining authority NH Clearance Power and Telecommunication Coordination Committee (PTCC) clearance CEA Clearance
MINIMUM CLEARANCE
MINIMUM CLEARANCE : IS: 5613 (Part II/Sec-1)-1976
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MINIMUM CLEARANCE : AS PER - IS :5613 (PART II/SEC I) -1976
APPLICATION OF SAG TEMPLATE ON PROFILE
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Lattice type tower A2, S15, B30, C60, D90 – 132&220KV line A2, B15, C30, D60 – 400KV line Wide base tower Narrow base tower Multi circuit Tower Special Crossing Tower
TOWER CONSTRUCTION : EXCAVATION MARKING CHART
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
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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
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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.
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STRINGING OF CONDUCTORS AND EARTHWIRE
HOSTING OF INSULATOR STRING
Single / Double suspension insulator strings are used 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, injure or scratch the surface of the insulator, but in no case shall 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-IString
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
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Substation construction
Selection of site
As near the load centre as possible.
As far as possible rectangular or square in shape for 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 from master plans / layouts or future development activities to have free line corridors for the present and in future.
Easily accessible to the public road to facilitate transport of material
As far as possible near a town and away from municipal dumping grounds, burial grounds, tanneries and other obnoxious areas.
Preferably fairly leveled ground. This facilitates reduction in leveling expenditure.
Above highest flood level (HFL) so that there is no water logging.
Sufficiently away from areas where police and military rifle practices are held.
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Main Equipments of Sub-station:
Transformer LA CVT/PT Isolator CT Circuit Breaker Control & Relay Panel
Sub station layout
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Note : These layouts were essentially used in 220kv/ 132kv/ 33kv Dhanbad sub station ( TSE VT – 09-01-2014 AT D.S.S , DVC )
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TRAINING REPORT FOR
PROGRAMME NO. 5 – CTC
CENTRAL TESTING CENTERCRITL MAITHON
Damodar Valley Corporation
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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 divisions take care of commissioning and proper maintenance of the entire protection and metering system, fault analysis as well as periodical testing of all types of relays and meters including tariff meters of the entire DVC network including power houses.
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
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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 serve as 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.
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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
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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
MINIMUM DETECTION LIMIT
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GAS DETECTION LIMIT in ppm
HYDROGEN H2 0.60OXYGEN 02 11.0NITROGEN N2 11.2MEATHANE CH4 0.50CARBON MONO OXIDE CO
0.10
CARBON DIOXIDE CO2 0.10ACETYLENE C2H2 0.05ETHYLENE C2H4 0.04ETHANE C2H6 0.04PROPANE C3H8 0.20
ADVANTAGES THAT DGA CAN PROVIDE
Advance warning of developing faultsDetermining warning of the improper use of units Status checks on new and repaired unitsConvenient scheduling of repairsMonitoring of units under overload
Losses of TransformersThe transformers are made of 2 types of materials: Iron and Copper. The core of a transformer is made of Iron whereas the winding 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 measured by open circuit and short circuit tests.
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TESTS OF DISTRIBUTION TRANSFORMERS
Two tests are conducted for testing transformers. These tests are known by different names as described in the table below.
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 RelaysTypes 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.
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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.
Based on Characteristic the protection relay can be categorized as-
Definite time relays Inverse time relays with definite minimum time(IDMT) Instantaneous relays. IDMT with inst. Stepped characteristic. Programmed switches. Voltage restraint over current relay.
Based on of logic the protection relay can be categorized as-Differential.
Unbalance. Neutral displacement. Directional. Restricted earth fault. Over fluxing. Distance schemes. Bus bar protection. Reverse power relays. Loss of excitation. Negative phase sequence relays etc.
Based on actuating parameter the protection relay can be categorized as-
Current relays. Voltage relays. Frequency relays. Power relays etc.
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Based on application the protection relay can be categorized as-
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. Current or voltage signals from CT 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.
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.
Pressure switches. Mechanical interlocks. Pole discrepancy relay.
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List Different Protective Relays are used for Different Power System Equipment ProtectionNow let’s have a look on which different protective relays are used in different power system equipment protection schemes.
Relays for Transmission & Distribution Lines Protection
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No Buchholz relay for transformers below 500 KVA capacity.
Transformers up to 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 provided on 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 to be connected.
Alarms for O.T., W.T., Buchholz (Main tank & 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.
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