1. POWER DISTRIBUTION SYSTEM FOR
2.0 MTPA INTEGRATED STEEL PLANT
VOCATIONAL TRAINING
(23rd
May,2016 - 2nd
July,2016)
AT MECON LIMITED,RANCHI
SUBMITTED BY:
PRAJNA PRAKASH GIRI
6th SEMESTER,ELECTRICAL ENGINEERING
NIT,ROURKELA
Dt-02/07/2016
2. P a g e 1 | 35
Acknowledgement
The satisfaction and euphoria that successfulcompletion of any task would be
incomplete without the mention of the people who made it possible, and whose constant
guidance and encouragement helped in completing the project successfully.
I consider it a privilege to express gratitude and respect to all those who guided me
throughout the course of the completion of the project.
I express my gratitude to G. Dewan, DGM I/c, Electrical & Mr. V. Kapila, DGM,
Department of Electrical(Power).
I extend my sincere thanks to Mr. Ashok Pandey, DGM, Electrical(Power) and Ms.
Chenna V. Murmu, Sr.Manager, Electrical(Power) and my project guide Ms.
Maheshwari Paikra, D.E., Electrical(Power) and all other staffs of the department for their
constant guidance, encouragement, support and invaluable knowledge that they shared with
us without which this project would not have become a reality.
Prajna Prakash Giri
3. P a g e 2 | 35
Contents: Page No.
Introduction: MECON
Area of Activities
Steel Making Plant
Process:An Overview
Raw material handling plant
Steel Making Units
Sinter Plant
Blast Furnace
Pellet Plant
Electric Arc Furnace
Desulphurization Unit
Pig Casting Machine(PCM)
Oxygen Plant
Ladle Furnace
Various Rolling Mills
Power Generation Plant: An Overview
Activities of Power
Activities of PT&Ddepartment
Preparation of Feasibility Report
Basis of Design
Preparation of TEFR
Load Chart
Feasibility Reportof 2.0Mt/yr integrated steel plant
Basic Design Parameters
Major Facilities
Power Distribution System
Single Line Diagram for Power Distribution scheme
04
05
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Type PSU
Industry Consulting
Founded 1973
Headquarter
s
Vivekanand Path,Ranchi,
Jharkhand, India
Key people Shri A K Tyagi
(Chairman-cum-Managing Director)
Website http://www.meconlimited.co.in
Employees 2057
Introduction:MECON
MECON LIMITED is a public sector undertaking under the Ministry of Steel, Government of India,
enterprise was set up in 1959 under the aegis of Central Engineering & Design Bureau (CEDB), for design
and consultancy services to the upcoming various
metallurgical industries like iron and steel, copper,
aluminum industries etc. in India under the different
five years plan being implemented by Govt. of
India. With headquarters at Ranchi, Jharkhand the
organization, over the last five decades, has been
intensively associated and has been synonymous
with the development on the country’s fast changing
industrial front. It has emerged as India’s frontline
design, engineering, consultancy and contracting
organization, handling numerous prestigious
consultancy assignments and turnkey contracts at
home and abroad.
MECON is the first engineering consultancy
organization in India to be accredited with the ISO
9001 certification. MECON has played a significant
role in the development and expansion of Indian
Industries. MECON is an ISO: 9001:2008 company
and is registered with international financial institutions like WB, ADB, AFDB and has technological tie-
ups with world leaders.
MECON is a multi- disciplinary firm with 1285 experienced & dedicated engineers, scientists and
technologists, having a network of offices spread all over the country, experienced in handling consultancy
assignments and EPC Projects.
Keeping space with constantly changing demand of the free Indian market, MECON has diversified far
beyond ferrous metallurgy to encompass non-ferrous metals, coal carbonization, chemicals and
petrochemicals, oil and gas including pipelines, power projects, ocean engineering, environmental
engineering, water supply, roads, ports, computer, software development and host of other fields. In recent
years, it has identified petrochemicals, oil and gas pipelines, power and infrastructure as major thrust areas
and achieved considerable success in procuring jobs from these potential sectors and executing them
successfully.
6. P a g e 5 | 35
Metals:
Iron making
Steel making
Rolling mills
Non-ferrous(Cu, Al, Zn)
By-products & chemicals
Raw materials & mineral beneficiation
Refractories
Research & development
Power:
Power plant-thermal & Hydel
Transmission and distribution
Non-conventional energy resources
Energy management & audit
RLA(residual life analysis)&RMU studies
Oil & Gas:
Oil & Gas pipelines
Petrochemical & refineries
CNG stations & city gas distribution
POL depots
LPG bulk storage, handling, bottling & transportation
Group gathering station
Off-shore platforms & marine pipelines
Retail outlets
Currency Project:
New Note Press and Coin Plant
Infrastructure:
Civil & structural Engineering
Architecture and town planning
Ports & material handling
Defense related projects
Environmental engineering
Hydro engineering
Information technology
Health sector
Range of services:
Planning, analysis, feasibility reports
Market survey, site selection
Basic & project engineering
Design and detailed engineering
7. P a g e 6 | 35
Inspection & expediting
Project monitoring and control
EIA/EMP reports
Clean development mechanism
ISO 9001:2000 quality system implementation
Software design & development
Health studies & asset evaluation
Plant relocation & rehabilitation
EPC/turnkey execution of project
Equipment/System design and supply:
Blast furnace
Coke ovens
Gas cleaning plant
Basic oxygen furnace
Continuous casting plant
Reheating furnaces
Power plants
Hot and cold rolling mills, material handling systems.
Steel Making Plant:
Steel plants products are of two types:
1. Carbon steel plant
2. Stainless steel product
Stainless steel
Ferro-Chromium steel
Ferro-Manganese steel
Silico-Manganese steel
Carbon Steel (MS) product
Long –product steel plant
Beams
Angles
Channels
I-sections
H-sections
Flat-products
HR coil(hot roll)
CR coil(cold roll)
Galvanized sheet
Corrugated sheet
Plane sheet
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Schematic Diagram of Iron & Steel Making
10. P a g e 9 | 35
Steel making units:
Blast Furnace
Pellet Plant
Sinter Plant
Electric Arc Furnace
Desulphurization Unit
Pig casting machine
Oxygen Plant
Ladle Furnace
Calcination plant
Basic Oxygen Furnace
Casting Plant
Direct Reduction plant (DR)
Various Rolling Mills
11. P a g e 10 | 35
Others are:
Water supply(demineralized water, industrial water and drinking water)
Gas supply (oxygen supply and nitrogen supply and its flow chart)
Sinter Plant
Sinter plant agglomerates iron ore fines with other materials(limestone, lime & dolo fines, dolomite
and coke breeze) at high temperature , such that constituent materials fuse together to make a single
porous mass without much change in the chemical properties of each ingredient.
Sinter -Making Process:
Charge material is put on a sinter machine in two layers. In the first layer of 30 mm (may vary from
30 to 75 mm) thickness, 12 mm-20 mm sinter fraction is used (It is also called the hearth layer). Over this
comes a second layer of mixed material making for a total bed height up to 600 mm (bed height may vary
350-660 mm), applied with the help of a drum feeder and nine roll feeders . The upper layer furnace,
where there are two rows of multislit burners. The first zone of the ignition furnace where eleven burners
are installed and is called the ignition zone, and the next part of the ignition furnace where twelve burners
are installed is called the soaking zone (annealing zone). +5 mm from screens of screen house 2 goes to
conveyor carrying sinter for blast furnace and along with BF grade sinter either goes to sinter storage
bunkers or to BF bunkers.
Functional Diagram of a Sinter Making Plant
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Blast Furnace:
Diagram Showing constructional
Details of a Blast Furnace
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Blast Furnace is a type of metallurgical furnace used for smelting to produce industrial metals,
generally iron. In a blast furnace, fuel and ore and flux(limestone) are continuously supplied through the
top of the furnace ,while air(sometimes with oxygen enrichment) is blown into the bottom of the chamber,
so that the chemical reactions take place throughout the furnace as the material moves downward .The
end products are usually molten metal and slag phases tapped from the bottom, and flue gases exiting
from the top if the furnace .The downward flow of the ore and flux in contact with an up flow of hot,
carbon monoxide rich combustion gases is a counter current exchange process.
Pellet Plant:
“Pellets” are small particles typically created by compressing an original material. Palletizing is the
industrial process used to create pellets, using a pellet mill, equipment for extrusion. Palletizing processes
very fine grained iron ore into balls of a certain diameter, also known as pellets which are suitable for
blast furnace and direct reduction. Pellet plants can be located at mines, near harbors or be attached to
steel mills.
Equipped with advanced environmental technology they are virtually pollution free, generating no
solid or liquid residues.
It comprises three steps:
1. Raw Material Preparation.
2. Formation of Green Pellets.
3. Pallet Hardening.
Needof pelletize:
In the face of shrinking world reserve of high-grade ores, ores must now be concentrated before
further processing. Pellets form one of the best options thanks to their excellent physical and
metallurgical properties. Moreover, due to high strength and suitability for storage, pellets can be easily
transported over long distances, with repeated transshipment, if necessary.
Here, we use sinter plant not pellet plant.
Functional Diagram of a Pellet Plant
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ElectricArc Furnace:
An electric arc furnace (EAF) is a furnace that heats charged material by means of electric arc. It
is under steel making shop (SMS). Arc furnaces range from small units of approximately one ton
capacity (used in foundries for producing cast iron products) up to about 400 ton units used for secondary
steel making. It is operated at 33kV.
Direct reduced Iron, burnt lime, burnt dolomite, ferro-alloys and return scrap are charged and the
product is liquid steel which is sent to oxygen furnace.
Scrap Metal is delivered to scrap bay, located next to the melt shop. Scrap generally comes in two
main grades, Shred (White goods, cars and other objects made of similar light gauge steel) and heavy
melt (large slabs and beams), along with some direct reduced iron (DRI) or pig iron for chemical balance.
Some furnaces melt almost 100% DRI. The Scrap is loaded into large buckets called baskets, with “clam
shell” doors for a base. Care is taken to layer the scrap in the basket to ensure good furnace operation;
heavy melt is placed on top of a light layer of protective shred, on top of which is placed more shred.
These layers should be present in the furnace after charging. After loading, the basket may pass to a scrap
pre-heater, which uses hot furnace off – gases to heat the scrap and recover energy, increasing plant
efficiency.
. For a 90 ton, medium power furnace, the whole process will usually take about 60-70 minutes from
the tapping of one heat to the tapping of the next(the tap to tap time).
Desulphurization Unit:
Sulphur dioxide is one of the three elements
forming acid rain. Tall flue gas stacks disperse
emissions by diluting the pollutants in ambient air and
transporting them to other areas. Flue gas
Desulphurisation (FGD) is a technology used to remove
sulfur dioxide (SO2) from the exhaust flue gases of
fossil fuel power plants burn coal or oil to produce
steam for steam turbines, which in turn drive electrical
generators.
Most FGD systems employ two stages:
1. Fly Ash Removal.
2. SO2 Removal.
Functional Diagram
of a Desulphurization Unit
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Pig Casting Machine (PCM):
Pig Iron is the intermediate product of smelting iron ore with
a high carbon flux such as coke, usually with limestone as a
flux. Charcoal and anthracite have also been used as fuel. Pig
iron has a very high carbon content, typically 3.5-4.5%, which
makes it very brittle and not useful directly as a material for
limited applications.
Pig Casting machine (PCM) is used for molten iron
continuous casting into a slab in a BF iron making or non BF
iron making.
The motor adopts three-phase alternating current variable
frequency speed control, so the chain belt speed can be
regulated by frequency variation which is advantageous for
adjusting and controlling casting speed of molten iron.
Oxygen Plant:
A high -speed method of steel making in which oxygen is
blown through an oxygen lance at high velocity onto the
surface of a bath containing steel scrap and molten pig iron
within a vessel with a basic lining.
Basic Oxygen Process method is producing steel from
a charge consisting mostly of pig iron. The charge is a placed
in a furnace similar to the one used in the Bessemer's Process
of steel making except that pure oxygen instead of air is
blown into the charge to oxidize the impurities present . One
desirable feature of this process is that it takes less than an
hour, and is thus much faster than the open-hearth process, another important method of steel making. A
second advantage is that a major byproduct is carbon monoxide, which can be used a fuel or in producing
various chemicals, such as acetic acid. The basic oxygen process also produces less air pollution than
methods using air.
Ladle Furnace:
Ladle furnace is included in SMS shop. The main function of ladle furnace treatment is to ensure that
the molten steel has the required temperature when the ladle is taken over at downstream secondary
metallurgy units or at a continuous caster.
A dynamic process model has been developed for the on-line calculation of the temperature during
the treatment and for the controlling the electrical energy input.
The remaining temperature and time of takeover is noted at the downstream unit.
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Various Rolling Machine:
They are of two types: hot roll mills and cold strip mills.
In hot roll mills slabs are converted to sheets and in cold roll mills sheets are converted to long or flat
products accordingly.
Here we use hot strip mills.
Power Generation:
POWER ENGINEERING
One of the Strategic Business Unit (SBU) of MECON, the Power Group renders total engineering
consultancy from concept to commissioning and project management services for captive as well as utility
power projects. For over four decades, we are associated with power projects both in India as well asabroad
and is providing expertise for any type, size and technology.
In this section only electrically equipped auxiliaries used in various section in power plant are
considered
Electrical system for the Turbo Generator & Auxiliaries, Boilers & their auxiliaries of the
2x500MWPower Plant are as follows:-
TG and auxiliaries
All electrical equipment related to the TGs & their auxiliaries are
1) 11KV unit boards & station boards, 3.3KV unit boards & station boards, 11 KV and 3.3kv bus ducts,
LT board(415V)
2) Various MCCs like Turbine Aux. MCC, Turbine Valve MCC, Emergency MCC, DCDBs, ACDBs,
control station etc.
3) Transformers(unit service transformers, station service transformers, lighting transformers,
transformers for A/C & ventilation, bus ducts & switchgears.
4) Neutral Grounding resistors for the transformers.
5) HT & LT motors for all the drives of TGs & auxiliaries. DC batteries and chargers.
6) UPS system with DB.
7) All electrics related with the TGs & auxiliaries like excitation system, VTs,CTs, surge protection,
Generator circuit breaker etc.
8) Control, protection & metering system for the TGs etc.
9) Protection of Generators & Generator transformers, control, protection & metering for the TGs,
synchronizing panels, UAT protection, fast change over scheme, under voltage scheme,
synchronizing scheme etc.
10) Generator busducts with tap off.
11) Neutral Grounding transformers, resistors etc. for the TGs.
12) Power & control cables from the HT boards to 11KV and 3.3KV motors.
13) Power & control cables from LT board to large capacity motors.
14) Power & control cables from LT boards to various MCCs.
17. P a g e 16 | 35
15) Power & control cables from various MCCs to the individual drives.
16) Various DC motors and their starter panels.
17) Local Push button stations
18) Cable trenches/tunnels, Cable trays, cable racks, supporting structure/ cable trestles etc. for all
cables.
19) Under ground earthing and earthing of all electrical equipment.
20) Welding sockets, 240V industrial sockets for maintenance work, 24V sockets for hand lamps etc.
21) Fire proof sealing system.
22) All electrics related to the compressors and Air drying plant.
23) Electrics related to EOT cranes, lifts & hoists.
24) Electrics for Air conditioning & ventilation system for the TG area.
25) Electrics for chilled water plant.
26) Illumination of all premises
27) Fire detection and alarm system.
Boilers & their auxiliaries
1) 3.3KV board, LT board(415V)
2) Various MCCs like Boiler Aux. MCC, Valve MCC, Soot Blower MCC, FOPH MCC etc.
3) Motors for all the drives of Boiler & auxiliaries.
4) Power & control cables from the HT boards to 11KV and 3.3KV motors.
5) Power & control cables from LT board to large capacity motors (those motors which are directly
controlled from LT board)
6) Power & control cables from LT boards to various MCCs.
7) Power & control cables from various MCCs to the individual drives.
8) Various DC motors and their starter panels.
9) DC distribution boards for distribution of DC power to various loads of Boiler & Auxiliaries.
10) Under ground earthing and earthing of all electrical equipment.
11) Lightning protection system for the buildings/structures.
12) Electrics related to cranes, hoists etc. wherever applicable.
13) Electrics for the AHUs for the Boiler & ESP area. Electrics for the ventilation of various premises in
the Boiler & ESP area.
14) Electrics related to Coal feeding system to Boilers
15) Electrics related to the bottom ash conveyors
16) Electrics related to the ESP and its control.
17) Electrics of Fuel oil pumps and fuel oil unloading system.
18) Cable trenches/tunnels, Cable trays, cable racks, supporting structure/ cable trestles etc.
19) Welding sockets, 240V industrial sockets for maintenance work, 24V sockets for hand lamps etc.
20) Fire proof sealing system.
21) Local Push button stations.
22) Illumination of all premises.
23) Voice communication facility.
Three voltage levels (11kv,3.3kv and 415V) are considered for the Boiler area.
All the motors related to the process (Boiler) shall be normally controlled from the control room through
the DDC, even though provision shall be kept for local starting through local push button stations. This local
option shall be mainly meant for maintenance work. For local starting of these motors, permission will have
to be issued from the control room through mouse click.
ESP related equipment shall be controlled from the ESP control room.
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Activities of Power Department:
ACTIVITIES OF PT&D Department
1. Feasibility studies: A study is done to enquire upon viability of any project from electrical point of
view. Here, the type of project and its capacity is decided beforehand after discussion with client and
our technologist.
2. Detail project report: This is done after feasibility study or, perspective plan report is fine-tuned
and final decision is taken on plant configuration. The brief specification and quantity of electrical
components to be used in the proposed plant is also prepared.
19. P a g e 18 | 35
For all above, following is submitted by various sections:
A. Product flow chart which shows various plants.
B. General layout of plant showing various shop locations,Roads, railway tracks etc.
C. Electrical load details i.e. connected load, working load,standby load etc.
D. Power plant configuration and power evacuation scheme.
From the above following is submitted to the project Coordinator:
a) Single line diagram
b) Electrical write up
c) Composite cost and volume of work
d) Civil building requirement
e) Space requirement for outdoor switchyard, sub-station, cable tunnels/ Galleries, etc.
f) Air conditioning and ventilation requirement
3. Site selection: Based on plant configuration under study, this activity is done for preparation of
FR/DPR/perspective plans. Alternatively, this may be finalized by clients site visit is done and a
report is submitted to the project coordinator giving location of power, quality of power, estimated
maximum demand and viability of project from electrical point of view base on load and source.
4. Details engineering: Subsequent to finalization of FR/DPR/perspective plan, various technological
and services equipment order is placed. This involved hard core engineering to the maximum extent
to actualize any industry in operational form.
5. System study: Wherever various load flow analysis are conducted. This mainly conveys technical
viability of any power distribution scheme design. Particularly, in tie line bus connections, these
studies are must. Though these studies can be done in conventional methods of system study viz.
Gauss-Siedal, Newton-Raphson method etc. these are iterative in nature and thus time consuming if
done manually.
Preparation of Feasibility Report.
Introduction to Feasibility Report.
Preparation of Feasibility Report.
Calculation of Maximum Demand & Annual Energy Consumption.
Power Requirement
Sources of Power Supply.
System Earthing.
Major Facilities.
20. P a g e 19 | 35
Basis of Design:
The design done at electrical dept. has following basis:
Theory of Electrical Engineering
Advancement in electrical engineering
Indian Standards/IPSS
Indian Electricity rules/Indian electricity act
IEC (International Standards for Electrical Components)
IEEE (International standards wherein, design basis and formulae’s are given for
engineering like earthing, busbar sizing, etc.)
Central Bureau of Irrigation & Power reports
Industrial norms
Mecon Norms
Common Sense
Feasibility studies
A study is done to enquire upon viability of any project from electrical point of view. Here, the
type of project/plant and its capacity is decided beforehand after discussion with client and our
Technologist. This may be a green field/ brown field.
Perspective Plans
A study is done to finalise the type of the plant and its configuration. Keeping in view of market
scenario, demand of product mis, raw material availablity and various options are studied and the
most economical and technically viable solution is rendered.
Detail Project reports
This may or may not be done after feasibility study or perspective plan report is fine tuned
and final decision is taken on plant configuration. Here, the brief specification and quantity of
electrical components to be used in proposed plant prepared.
Electrical Section is a service section and involved mainly in the electrical aspects of
engineering activities undertaken by technological section.
Power transmission and distribution section carries out the engineering of systems of the plant
which includes high & medium voltage, main receiving sub stations and HT& LT substations inter shop
power distribution, power system analysis and power factor compensation.
21. P a g e 20 | 35
What is Feasibility Report?
In layman's terms , it is a study done to inquire upon the viability of any project from electrical
point of view . Type of project/plant and its capacity is decided beforehand after discussion with client.
There are different types of data submitted by the client like product flowchart which show a
various plant/shop and their interconnection , electrical load details etc. and is called assignments.
Basedon the assignments , following activity is done
• Calculation of connected load, maximum demand, annual energy consumption (AEC) of each
shop with the help of assignments.
There are some defined formulas to calculate the given factors which are used in calculating the
above values,
• Connected Load: The sum of the continuous ratings of all electrical equipment connected to the
power supply system is known as the connected load.
Or Connected Load=Working Load + Standby Load
This is calculated for each shop separately.
• Maximum Demand: The maximum value of the apparent power or current consumed by a plant.
It may be noted that it is not necessary that all the connected loads are always in working mode.
Also , there are some loads which work in Intermittent Duty Cycle,for example Stacker-Reclaimer ,
Wagon Tippler,Conveyors,Heaters etc and hence maximum demand is always less than connected
load.
Or M D = Demand Factor x Connected Load
Demand Factor may be different for different shops . It is always less than unity.
Further, all shops of a plant do not have the same demand factor, So.
• Annual Energy Consumption: It is a product of total MD for each shop in KW, average Load
Factor, Working Hrs per Day and Working Days Per Annum.
Or AEC= [MD(in KW) x Working Hrs/Day x Working Days/yr x Average Load Factor x
Power factor]
• Average Load Factor is a factor associated with converting MD value to an average load value so
that Net Energy (KW*Time) can be calculated in a rectangular area model.
Or AEC (for plant) = ∑ AEC (of individual shops)
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Steps for Making a Feasibility Report
1. Note the HT and LT Load in KW.
2. Note the HT and LT working load in KW.
3. Calculate the maximum demand for each plant.
4. Calculate the energy in MU.
5. Calculate the AEC.
6. Finalize the load centers.
7. Decision on voltage levels at sources , primary distribution and utilization.
8. Bus Bar scheme design was finalized.
9. Power Distribution scheme based on load centers was drawn.
10. Short Circuit Level Calculation and deciding on bus bar/breaker short circuit level capacity and
duration.
11. Finalization of main receiving station , HT and LT sub stations locations.
12. Transformer sizing & Breaker ratings.
13. Design a composite single line diagram showing electrical interconnection.
14. Preparation of cable schedule and cable engineering estimate.
15. Cost estimation of illumination , shop electrics , earthing & lightning protection.
16. Preparation of composite cost estimate and volume of work of electrical part of project comprising
of power distribution , shop electrics and illumination.
17. Preparation of electrical write up for feasibility report.
18. Preparation of civil building assignments for HT & LT substations and preparation of ventilation&
air conditioning for HT & LT substations.
19. Estimation of heat load in each case HT & LT substations.
From the above the following is prepared for the project coordinator:
• Single Line Diagram.
• Electrical write-up.
• Composite cost and volume of work.
• Civil building requirements.
• Space requirements in case of switch yards etc.
• Air conditioning and ventilation requirement.
Selectionofsite:
Selection of a location of plant is important from techno economic point of view. The process of site
selection starts with a selection team visiting the different sites proposed and making an on spot study.
Before the selection of site must observe following points:
1) Market Survey.
• Demand.
• Required Product.
• Future Project.
• Scope for experts.
• Capacity.
23. P a g e 22 | 35
• Location of plant.
• Raw material
• Transportation.
• Government Policy.
2) Raw Material Survey:
• Location of Plant nearer to the sources of raw materials.
• Transportation facility because huge amount of raw materials are needed as compared to finished
product.
• Position nearer to consumer point.
3) Land:
• Availability of area as well as topography.
• The soil condition of strata, water level, availability of land for future expansion.
• Area accommodated for present plant and future expansion.
• Welfare and township facilities.
• Sufficient area of waste dumping.
• Topography is natural and artificial obstruction should be normally avoided.
4) Water Supply:
Proper source of water available near the plant.
Consumption of water varies with scale of work, product or site condition.
Necessary to secure sufficient quantity of water for construction of reservoirs, dam, township etc.
5) Power Supply:
Nearest to the power station.
Power consumption in every plant should be proper.
6) Man Power:
Various types of workers needed.
Skilled, semiskilled, unskilled and supervisors, engineers, scientists etc.
Preparationof TEFR:
There are various in a steel plant and each of the shop is having certain load & loads are mainly
distributed in four major parts for each shop,viz,:
1. Process Load
2. Dedusting & heating ventilation and air conditioning (HVAC) load.
3. Water supply.
4. Material handling.
Out of all these water supply contributes major load in the system . All the above loads are classified
into 2 major types:
1. LT loads.(all loads upto 200 KW)
2. HT loads.(all loads above 200 KW)
24. P a g e 23 | 35
Process of Preparation:
• Now for all the shops total LT and HT loads are calculated. These total loads consist of (process load
+ dedusting & HVAC + Water supply + MH loads).
• Out of these loads working load and connected load is separated.
• Now the maximum demand (MD) is calculated using the formulas:
MD = Working Load (WL) x K
Where K>= Load Factor (or)
Utilization factor
Average load can be calculated as:
Avg. Load = MD x Avg. Load Factor.
o Average load factor dependsupon type of shops.
The costing of energy consumption is also a major consideration hence annual energy
consumption (AEC)is calculated as :
AEC =MD load Factor x No .of Days Plant/yr.*24hrs
Load chart:
sl. Name of unit Power
Requirement in MW
DF Max.
Demand(MVA)
HT LT Total
1 coal handling
plant
3.
2
1.
25
4.45 0.6 2.67
2
(i)
coke sorting
plant
6.
8
6.8 0.6 4.08
25. P a g e 24 | 35
After receiving the assignment, we calculate the demand and prepare the following
chart as given:
(
ii)
coke oven
battery
5 5 0.6 3
(
iii)
by product plant 2 4.
5
6.5 0.7 4.55
3 lime plant 3.
25
3.25 0.6 1.95
4 sinter
plant(1*500)
7.
8
3.
2
11 0.7 7.7
5 oxygen
plant(1*600)
30 2.
5
32.5 0.7 22.75
6 hot strip mill 75 1
8
93 0.5 46.5
7 DR
plant(6*500t/d)
4 8.
2
12.2 0.6 7.32
8 blast
furnace(1*150)
20 1
3
33 0.7 23.1
9
(i)
EAF and LAF
(
ii)
EAF(2*140T) 16
0
1.
6
161.6 0.7 113.12
(
iii)
LHF 44
.8
1.
9
46.7 0.7 32.69
CCP 3.
5
4.
6
8.1 0.6 4.86
1
0
Power Plant 8 6 14 0.6 8.4
1
1
RMHS 8 7 15 0.6 9
36
6.3
8
6.8
291.69
26. P a g e 25 | 35
Sample for Preparation of Feasibility Report of 2.0MTPA Integrated Steel
Plant:
2.0 Mt/yr. Integrated steel plant
Power Requirement
The estimated power requirement of the proposed steel plant is :
Maximum demand: 291.69MVA
Annual energy consumption:1433.714MkWh
(291.69 x0 .8x0.8 x 1000 x 24 x 320)
Sources of Power Supply: The power supply for the proposed project shall be made available from 220
KV Grid sub-station. The power shall be received through two numbers of 220 kV feeders drawn over
single tower double circuit lines. The 220kV source grid substation is located at a distance of approximately
3 km from the proposed project site.
Power distribution scheme: The power required for the plant shall be received at 220 kV main receiving
station (MRS). A capacitive power plant (CPP) consisting of 4 nos. of 50 MW turbo-generators have also
been envisaged to meet the power requirement of the plant. A separate 220 kV switchyard has also been
planned at CPP to which all these four generations will be connected through 63MVA step up transformers.
This switchyard will also be interconnected with MRS through a double circuit transmission lines.
Main furnace loads and rolling mill loads will be fed from the MRS other process/emergency loads like
B.F., Sinter Plant, C.O. & B.P.P, Oxygen Plant, Water Supply, RMHS,DR Plants etc. will receive power
from 220kV, CPP switchyard.
Power from 220 kV level at MRS & CPP switchyard shall be stepped down to 33kV level, which will
serve as the primary distribution level in the plant. 33kV will be further stepped down to 6.6kV level at
various load centres to meet the voltage requirements at the plant. LT power requirement shall be met at
415V level by stepping down the power from 6.6kV to 415 kV as per the requirement at the respective load
centres.
Two nos. of 140 MVA, 220/34.5kV power transformers with a 33 kV switchboard
have been envisaged to cater the main furnace loads (2nos. 100MVA EAFs & 2 nos.28MVA LFs and
their auxiliaries). Bulk load of Hot strip Mill shall be fed by two nos. 50/63MVA, 220/34.5kV transformers.
These 140 MVA and 50/63MVA, 220/34.5kV transformers shall be installed in 220kV switchyard of MRS.
Two nos. of 80MVA, 220/34.5kV transformers have been envisaged at CPP, 220kV switchyard to cater
the other plants like B.F., water supply, sinter plant, oxygen plant, C.O.& BPP, DR plant, RMHS etc.
A number of 33/6.6kV sub-station have also been envisaged at different load centres, which will be fed
from main 33kV switchboards of MRS & CPP through underground cables.
It was observed during the visit to the proposed plant site that a number of EHV/HV transmission lines
27. P a g e 26 | 35
are crossing over the site. The diversion would be needed during the execution of the project cost.
Power distribution scheme envisaged for the proposed plant is shown I enclosed SLD.
DesignConsiderations:
The power distribution network has been designed as a simple radial system with two alternative supply
feeders to each load center.
The design of power distribution system and selection of equipment shall be based on the main
consideration of simplicity, safety, reliability, ease of operation & maintenance as well as convenience of
future expansion.
The equipment shall conform to relevant IS/IEC specification and code of practice to meet the
operational requirements and to ensure reliable and trouble free service in the plant.
Basic Design Parameters: (As per the plant philosophy )
Incoming Power Supply 220 KV , 3ø , 50 Hz
Primary Distribution 33 KV , 3 ø , 50 Hz
Secondary Distribution & Drives rated above
1000 KW
11 KV , 3 ø , 50 Hz
Secondary Distribution & Drives below 1500
KW
6.6 KV , 3 ø , 50 Hz
Motor rated 200 KW & below and other LT
Consumers
415 V , 3 ø , 50 Hz
Illumination and small power 240 V , 1 ø , 50 Hz
Control Power AC 240 V , 1 ø , 50 Hz
Control Power DC 220 V
System Earthling:
• 220 KV : Effectively Earthed
• 33 KV : Effectively Earthed
• 6.6 KV : Resistance Earthed
• 415 V : Effectively Earthed
Maximum Symmetrical Short Circuit Level:
(Considered for the System)
• 220 KV bus : 40 KA , 3 sec
• 33 KV bus : 31.5 KA , 3 sec
• 6.6 KV bus : 40 KA , 3 sec
• 415 V bus : 50 KA , 1 sec
28. P a g e 27 | 35
MajorFacilities:
220 KV MSDS:
Both the MRS and CPP 220kV switchyards have been envisaged with double bus and
transfer bus configuration with maximum symmetrical short circuit level of 40 KA at 220 KV bus.
Necessary protections such as distance protection, bus differential, transformer differential, over current,
earth fault etc. have been foreseen. ACSR
‘MOOSE’ conductor in different configurations (twin, quad) has been considered for busbars and
interconnection.
HT SwitchGear:
The circuit breaker is a device which can make, break the circuit and also can carry the
load current. The 33KV and 6.6 KV switch gear envisaged shall be indoor type sheet metal clad , drawn
out type with VCB/SF6 CB(circuit breaker) and shall be provided with necessary protection, control
gear, metering and audio visual alarm system, the circuit breakers shall be mechanically and electrically
trip free. Generally vacuum circuit breakers(VCB) are used in HT upto 33kV, but beyond 33kV
SF6(sulfur hexafluoride) CB are used. Actually vacuum and SF6 are used only for quenching the arc.
Circuit breakers are operated by getting signals from relays, and the relay sense the condition of circuit
i.e. normal or faulty by getting data from CTs and PTs. Now a days GIS(gas insulated switchgears) are
used.
Previously bulk oil circuit breakers(BOCB) and minimum oil circuit breakers(MOCB) were used,
but now a days these are discarded due to their severity. The circuit breakers shall be electrically
operated , stored energy type and shall be operated on 220 V DC control power supply.
415 V SwitchGear:
It comprises of air circuit breakers, in draw out design and multi-tier formation. The
switchboard should have two bus sections and a bus coupler breaker with option for auto change over in
the event of loss of power on any bus section.
The CB shall be electrically operated and equipped with microprocessor for over load and
short circuit as well as earth fault protection.
In LT large varieties of switch gears are used such as mcb(miniature circuit breaker ),
mccb(moulded case circuit breaker), elcb(earth leakage circuit breaker), rccb(residual current circuit
breaker), acb(air circuit breaker) etc. In mcb the rated current is not more than 100A. In mccb the rated
current is upto 1000A. Both mcb and mccb are thermal-magnetically operated. In acb the rated current is
upto 10000A. RCCB trips the circuit within 30 miliseconds when there is earth fault current.
All motor control centers, large drives starter panel (above 90 kW and upto 200kV) and
29. P a g e 28 | 35
PDB's shall be supplied power from the 415 V switchboards
LT Switch Gear Layout
HT/LT Transformers:
The transformer is a device that transfers electrical energy from one electrical circuit to
another electrical circuit through the medium of magnetic field and without change in the frequency .
Transformer cores are made of low loss CRGO(cold rolled grain oriented) silicon steel sheet. maximum
temperature at the rated output and at principal tap shall be 85 degree Celsius for top oil thermometer
method and 95 degree Celsius for winding by resistance method. The transformers can be dry type or oil
type. Distribution transformer of smaller ratings i.e. upto 3000kVA are usually dry type transformers. Oil
type transformers usually use cooling method. The power transformers of higher ratings have oil inside
the tank for cooling purpose. The oil type transformers shall be ONAN(Oil Natural Air
Natural)/ONAF(Oil Natural Air Forced) /OFAF(Oil Forced Air Forced), oil immersed, three phases,
copper wound. The Transformers shall be capable of withstanding 40% over fluxing corresponding to
rated voltage.
Various standard norms of transformer in India are: IS11171, IEC60076, IS2026 etc.
The factors required for the selection of the transformer are:
Application (i: e Oil or Dry Type)
Reference Standard
Rated Voltage
Rated Power
Type of Cooling
Insulation Class
Temperature Rise
30. P a g e 29 | 35
Type of tapes (ON load tape or OFF load tape changer)
Load Requirements
The winding shall be made of electrolytic grade copper and shall be vacuum dried. Inter
turn and inter coil insulation shall be so designed that the dielectric stress is distributed uniformly
throughout the winding under all operating conditions. Impregnated paper insulations are provided
between hv and lv windings. To ensure reliable and trouble free operation, the transformers shall be
designed to withstand short circuit current on the lv side for duration of 5 seconds without any damage.
Off-circuit tap-changers are provided in the distribution transformers and OLTCs(on load tap changers)
with local & remote control cubical have been foreseen for the power transformers. All the standard
accessories such as conservator , breather , buchholz relay ,OTI(oil temp. indicator) ,WTI(winding temp.
indicator),PRV(pressure releasing valve),oil level gauge ,valves ,explosion shall be provided for all
transformers. Differential protection is the main protection for transformers which protect the
transformer in fault/short circuit condition. Other protections are there as back up to the differential
protection. Before installation of a transformer different types of routine tests and type tests are done by
the manufacturer. These tests include short circuit(SC) test, open circuit(OC) test, sumpner's test,
impulse withstand test, temperature rise test etc.
Minimum Transformer FeederProtection:
Three phase over current and earth fault protection(50 & 50 N1/50 N2)
31. P a g e 30 | 35
The over current element should have the minimum setting adjustable between 250-2000% of
CT secondary rated current. The earth fault element should be suitable for both residually
connected CT input as well as CBCT input .With the CBCT the relay shall be suitable for earth
fault currents in the range of 10mA secondary.
Restricted earth fault protection(64R)
The restricted earth fault protection connected between CTs of LT incomer and neutral of
transformer.
Stand by earth fault protection(51N)
The stand by earth fault protection should be of definite time delay type provided having a pick
up setting range of 10% to 40% with a timer delay of 0.3sec to 3sec.
Transformer differential protection(87T)
Differential protection for transformer equal and above 5 MVA be provided with stabilized
biased differential relays. It shall be suitable to achieve harmonic restraint during switching
and over fluxing condition.
For more reliability two or more transformers are connected in parallel, so that each
transformer divides the load and hence transformer overloading can be avoided and also the transformer
life can be increased. But for parallel operation of two transformers these conditions must be satisfied
like both the transformers have same turns ratio, same voltage ratio, same KVA/MVA ratings, same
vector group, same percentage impedance and X/R ratio, same polarity, same phase sequence etc.
Instrument Transformers:
The transformer which supplies power to measuring instruments, meters, relays is known
as instrument transformer. It is of two types such as current transformer and voltage/potential
transformer. Current transformer(CT) measures the current by converting the high current in the primary
upto 1A/5A in the secondary. The maximum burden of a CT shall be 100VA. PT/VT gets used in
electrical power system for stepping down the system voltage to safe value which can be fed to low
ratings meters and relays. Generally in India the stepped down voltage is 110V. The CTs and PTs are
used for both measuring and protection purpose.
Cables:
Power inside the plant shall be distributed through cable to various cables to various
premises. Wherever necessary and where the cables are in small nos. , they will be directly buried
underground .Whenever cables are in large number, concrete cable tunnels will be used.Cables will be
laid in cable tray.
There are four essentials of cables. These are:
The conductor, solid or stranded, providing an electrical conducting path. Generally
ACSR(Aluminum conductor steel reinforced) conductors are used for cable core.
The insulation, which is a dielectric material, which isolates the conductors from one another and
from their surroundings
A sheath and/or some protective armour, around the conductors and their insulation, to protect them
against mechanical damage.
An oversheath or protective finish around the complete cable to protect it against abrasion, water or
other external influences.
Inside the substation and covered premises , the cables shall be laid in basement or in
concrete tunnels or on columns and available structures , power cables shall be laid on ladder type GI
cable trays , whereas control cable shall be laid on perforated cable trays.
32. P a g e 31 | 35
All 33KV , 11KV , 6.6 KV cables shall be heavy duty , PVC sheeted multi-core ,
aluminum conductor steel wire armored .11 kV and 6.6 KV cable shall be unearthed type suitable for
solidly earthed system . Cables for 415 V systems shall be heavy duty, 1.1 KV grades, PVC sheathed
aluminum conductors, armored/unarmored as required.
The control cables shall be multi strand copper conductor, PVC insulated and PVC
sheathed with minimum cross-section of 2.5mm2 for control voltage circuit and 4mm2 for power circuit.
Typical 132kV cable layout
Shop Electrics:
Power supply to all drives up to 90 KW and other loads operating at 415 V, 3ῴ, 50 Hz
system is envisaged through motor control centers (MCC's). Drives beyond 90 KW shall be supplied
power from 415 V switchboards comprising of air circuit breakers (ACB's) (Through single direct feed
starter panel).The MCC's/PDB's shall be sheet steel enclosed and of modular, multi-tier design. MCC's
shall be in draw out execution whereas PDB's shall be in non-drawn out execution. The enclosure class
shall be IP-42 for switchboards.
HT/LT Motors:
All motors shall have TEFC construction and provided with class F insulation with
temperature rise limited to that permissible for class B insulation with enclosures. The motor generally
shall be squirrel cage type suitable for direct on line starting. Slip Ring induction motors shall be
considered for intermittent duty drives requiring frequent switching operations and for heavy duty
applications requiring speed control DC motors will be used for drives requiring frequent reversals, high
starting torque wide range of speed and precise speed control. Use of energy efficient drive motors shall
be preferred in general. Before installation of any motor different types of routine tests and type tests
should be done. In AC motors speed control is quite difficult so VFD (Variable Frequency Drives) are
used so that we can control the speed and also the power consumption is minimized though the
installation cost is very high. The starting current is very high i.e. about 6 times the FL current that can
damage the system. So different types of starting methods are adopted like DOLstarting, RDOLstarting,
33. P a g e 32 | 35
full voltage starting (for small motors) method etc. In DOL and RDOL starting method we usually
supply reduced voltage through different methods like stator resistance method, autotransformer starting,
star-delta starting etc.
Various motors used for industrial application for steel industries/power sectors are as follows:
ID(Induced Draft) Fan Motor
PA(Primary Air) Fan Motor
SA(Secondary Air) Fan Motor
BFP(Boiler Feed Pump) Motor
CW(Circulating Water) Feed Pump Motor
Motor Feeder Protection:
ACB Motor Feeders
Protections: Metering:
Composite motor protection to cover a
minimum of protections such as over
current, short circuit, earth fault, locked
rotor, negative phase sequence, thermal
alarm etc.(for large motors>=90kW)
Current
Voltage
kW
kWh
(SFU with Contractors) Motor feeders:
Protections: Metering:
Bimetallic thermal overload relay (with
single phase preventer), short circuit
protection (through fuse/MCCB)
Phase Current (for motors of rating above
15kW)
Automation:
The automation of operations shall be achieved through HMI(Human Machine Interface)
systems using Programmable Logic Controllers (PLC's) from the central control room of each unit, it
shall be possible to operate any motor in remote mode from the control room. Where, HMI is a
programmable operated interface and PLC is basically I/O with programming as well as HMI facility. To
monitor the status of various drive motors , VDU's shall be provided in the control room, where
VDU(Visible Display Unit) is a large electronic screen for display. Distributed control system(DCS) shall
be provided for controlling various drives equipments and processes and its sequence shall also be
displayed on operator work station(OWS) and engineering work station(EWS). EWS is the master work
station for centralized work station and OWS is basically for controlling small part of plant/process.
Substation atomization system shall be provided for controlling the switchyard power transmission and
distribution system.
The technological drives shall be grouped in logical control blocks , for the purpose of
sequence of operations , monitoring and fault annunciation.
34. P a g e 33 | 35
Automation System
Illumination:
For supply of various illumination loads in the plant, provision of lightening distribution
boards (LDB's) has been considered. These LDB's shall be installed in L.T substations/MCC room and
shall be fed from 415 V switchboards. LDB's shall supply power to the various sub-lightening
distribution boards (SLDB's) installed in various buildings.
The internal illumination of low roof buildings shall be fluorescent tube light fittings.
Whereas for shops as well as high building shall be illuminated with HPSV lamp fittings. Whenever high
color rendering is required, metal halide lamp fittings shall be used. Average illumination inside the shop
building shall be 100-150 lux; however the illumination level shall be 300 lux. Illumination in open yard
and area illumination shall be provided with HPSV flood fittings. The average illumination level shall be
15 to 30 lux for outdoor illumination. The use of energy saving high power factor shall be preferred.
35. P a g e 34 | 35
Power distributionsystem:
Quantity estimation of 2.0Mt of integrated steel plant
S.No
.
Description Unit Qty.
1. 220 kv switchyard with double bus & transferconfig as per
details in SLD.
a) MRS bays 11
b) Power plant bays 11
2. Power transformers
a) 140MVA,220/34.5kV Nos. 2
b) 80 MVA,220/34.5kV Nos. 2
c) 63MVA,220/34.5kV Nos. 2
d) 25 MVA,33/6.9kV Nos. 2
e) 16 MVA,33/6.9kV Nos. 10
f) 12 MVA,33/6.9kV Nos. 3
g) 10MVA,33/6.9kV Nos. 4
h) 8MVA,33/6.9kV Nos. 4
3. 33 kV switchboards consist of
a) Panels Nos. 64
b) Static VAR compensation equipment lot 1
4. 11kV CICO for O2 motor Nos. 1
5. 6.6/.433kV,2MVA LT Nos. 60
6. 415V switchboards consisting of 12 panels Nos. 30
7. 6.6 kV switchboards consisting of
a) 30 panels Nos. 8
8. 33 kV, 3C x 300sqmmXLPE cables km 50
9. 33kV cable termination kits
a) End terminations Nos. 150
b) Straight through joints Nos. 110
10. 11kV 3C x 300sqmm XLPE cables km 1.5
a) End terminations Nos. 6
b) Straight through joints Nos. 3
11. 6.6kV,3C x 300sqmm XLPE cables Km 86
12. 6.6kV cable termination kits
a) End terminations Nos. 344
36. P a g e 35 | 35
b) Straight through joints Nos. 175
13. Control cable km 400
14. Busduct
a) .415kV,4000A Set 60
15. Earthing
a) HT sub-stations Nos. 13
b) LT sub-stations Nos. 30
16. Battery charger-cumDCDB etc. set 13
17. Cable supporting structure Lot 45
Sub-total(PD)
Shop electrics, instrumentation and automation kW 2000
0
Illuminations Nos.
Typical Single Line Diagram(SLD) For Power Distribution Scheme:
