KAKINADA INSTITUTE OF ENGINEERING & TECHNOLOGY

KORANGI,KAKINADA,EAST GODAVARI(Dist)

A MINI PROJECT report ONSCADA in VSP

INRASHTRIYA ISPAT NIGAM LIMITED

(STEEL PLANT) – VISAKHAPATNAM

A Project work done in partial fulfillment for the award of

BACHELOR OF TECHNOLOGYIN

ELECTRONICS & COMMUNICATION

Submitted by: Boorugu.Neelima Ippili.Sameera

Vatada.Venkata Lakshmi B.S.S.S.L.D.Sindhu

III/IV - B.Tech.

CERTIFICATE

This is to certify that the mini project work entitled “SCADA SYSTEM IN VSP” is a bonafied record of work done by Boorugu.Neelima, Ippili.Sameera,Vatada.Venkata Lakshmi, B.S.S.S.L.D.Sindhu students of KAKINADA INSTITUTE OF ENGINEERING & TECHNOLOGY have been sincere, dedicated and the conduct throughout the study has been excellent in partial fulfillment of the requirement for the award of degree in BACHELOR OF TECHNOLOGY under the guidance and supervision in VISAKHAPATNAM STEEL PLANT.

Visakhapatnam Signature of Guide

DATE: M. SRINIVASU

Jr.Mgr (TELECOM)

ACKNOWLEDGEMENT

I hereby take this opportunity to express my sincere gratitude to the

following eminent personalities whose aid and advice helped me to complete

this project work successfully without any difficulty.

I am thankful to Mr. M SRINIVASU, Jr.mgr (Telecom) who has been

with me all through the project to spend his valuable time and to share his

knowledge.

As a token of my feeling, I would like to acknowledge my

sincere regards to Mr. K. Iyapillai, DGM I/c (Telecom), Mr. S. Prasada Rao,

DGM (Telecom) and each and every person of the telecom department who has

directly or indirectly helped me in completing this project.

INDEX

Abstract

Introduction

Major Department in VSP

Communication Systems in VSP

Introduction to SCADA System.

Supervisory Control And Data Acquisition System

Architecture

Remote Terminal Unit (RTU)/PLC

DSL using LAN Extenders

Cables

Master Server

Display units (HMI/Engg Stations)

Conclusion

ABSTRACT

In this modern world of Industrialization and automation, energy plays a major role in

the growth of any organization. The utilization of energy plays an impacting and direct role

in the growth of organizations like Visakhapatnam Steel Plant.

The Telecommunication department plays a vital role in providing & maintaining

different electronic communication systems in various departments to achieve the assigned

targets and accomplishing the desired performance in VSP.

In Vizag Steel Plant, The supervisory control and data acquisition system (SCADA)

is implemented to monitoring the energy network. The objective of this SCADA system is to

monitor the energy usage and demands of various consumers of the plant and exercise

effective control over their energy consumption and optimum utilization of in-house energy

resources.

INTRODUCTION

INTRODUCTION

Visakhapatnam Steel Plant, an integrated steel plant under the corporate entity of

Rashtriya Ispat Nigam Limited (RINL), is the first shore based integrated Steel

Plant in the country, constructed with the then latest state of the art technology.

The Plant with a rated capacity of 3.0 Mt is a producer of steel products in the

longs category like wire rods, re-bars, angles, channels, blooms and billets.

2.                 EVOLUTION

Visakhapatnam Steel Plant was conceived in the year 1970 as a unit of Steel

Authority of India Limited (SAIL) to augment its long products capacity and to

service the southern markets. Announcement for Visakhapatnam Steel Plant was

made in the Parliament in the year 1970 and the foundation stone was laid in

1971 by the late Prime Minister Smt. Indira Gandhi. The feasibility report of the

plant was made in 1973 and the Indo-Soviet Agreement was signed in 1979. The

comprehensive detailed project report was made in 1980 and the project was

sanctioned by Government of India in 1982. In the same year, a separate

company called Rashtriya Ispat Nigam Limited was formed.

The plant was to be commissioned by 1986 as per original schedule. However,

because of severe cash crunch, in the year 1986, a rationalized concept was

adopted to lower the capital costs. Some of the envisaged facilities were dropped

and the nameplate capacities of steel making and rolling mills were increased for

making revenue generation more attractive.

Finally, the plant was fully commissioned in the year 1992. Due to the long

gestation period of 22 years from concept to commissioning stage, the capital

cost of the project went up from original estimate of Rs.2256 crs in 1979 to

Rs.8594 crs in 1992. As a result of high capital cost and large borrowings the

company had to bear high interest and depreciation burden resulting in

continuous losses. This has resulted in huge cost over runs and high capital

related charges and Visakhapatnam Steel Plant at the time of commissioning

itself had a net loss of over Rs.2000 crs.

While the plant was picking up production, the South East Asian financial crisis

severely affected the steel market which led to continuous drop in steel prices

both in domestic and international markets. Also from 1998, the steel industry,

worldwide, was affected by recession. Steel demand declined, forcing the steel

producers to throttle production levels. Many unviable production units in the

world had to close down. India’s exports were hit adversely and domestic

consumption remained almost stagnant. Sales realizations plummeted and

profitability of the Indian steel producers was adversely affected. All these

conditions brought a tremendous pressure on the financials of the company.

3.                 THE TURN-AROUND

Despite these adverse conditions, the Vizag Steel collective rose to the occasion

and over the last few years Vizag Steel’s performance has improved on all fronts

including production, techno-economics, marketing and financials. The emphasis

initially had been towards total employee involvement, then to technology up

gradation and process management and then to managing external environment.

At this juncture, the leadership played a crucial role in providing direction focusing

on critical issues and empowering employees. A number of sustenance and

performance improvement programmes were initiated to put the company on the

growth trajectory. The emphasis was on attaining rated capacity at the earliest,

improving techno-economic performance, improving health of equipment, cost

reduction and process innovations. Systematic and standard operation practices

and structured systems were developed and Vizag Steel was the first integrated

steel plant in the country to be accredited with all the three International

Standards for Quality (ISO 9001), for Environment Management (ISO 14001) and

for Occupational Health and Safety (OHSAS-18001).

All these initiatives gave positive results and the company started its journey

to excellence by crossing its rated capacity levels in the year 2001-02.

Since then the company has been operating consistently beyond the

rated capacities. Currently, the plant is operating at 120% of its rated

capacity.

The Plant turned around in the year 2002-03 by achieving for the first

time a net profit of Rs.521 crs. The improved performance saw Vizag Steel

become a Zero debt company and is a net positive company today having

wiped off all its accumulated losses.

All these efforts of Vizag Steel were well recognised by one and all. For its

excellent performance in the year 2002-03, Vizag Steel was conferred with the

Prime Minister’s trophy for the best Integrated steel plant in the

country. During the year 2002, Vizag Steel was awarded with `SCOPE’

excellence award for turnaround for its outstanding performance. Vizag Steel has

been winning the National Energy Conservation award for the last seven years

and has also won the Special Prize for National Energy Conservation for

successfully annexing the first prize for three consecutive years. Vizag Steel has

been constantly achieving excellent MOU rating from the government for its

excellent performance. It was bestowed with the World Quality Commitment

Award at Paris. In 2005, Vizag Steel bagged six Vishwakarma Rashtriya Puraskar

Awards out of the 28 awards announced by Ministry of Labour, a tribute to the

involvement of its employees and participatory approach of the management.

Best Water Management, Best Financial Management and Best Safety &

Occupational health awards from Confederation of Indian Industries are some of

the prestigious awards received.

4.                 VIZAG STEEL TOMORROW:

Armed with a vision to become world class integrated steel plant, the Vizag Steel

Collective is charged with a steely resolve to face a challenging tomorrow. Some

of the initiatives taken to make Vizag Steel a world class organization are:

                     Adoption of business excellence through CII-Exim Business Excellence Model.

                     Initiation for BPR & ERP.

                     Implementation of Six Sigma methodology.

                     Implementation of ‘5S’ for outstanding housekeeping.

                     Bench marking with world class companies.

                     Introduction of Knowledge Management to harness the inner potential of employees.

                     Introduction of e-commerce.

                     Acquisition of captive mines in India and abroad through joint venture, so as to have a level playing field with its competitors.

In line with its vision to become a continuously growing company, Vizag Steel

recast its expansion plan to double its capacity from its present 3 mT to 6.3 mT by

2008-09. The approval for its recast expansion plan was obtained on 28th Oct ’05

in a record time of 10 months. The expansion has been planned to further

strengthen its long product leadership in the country through production of

special bars, wire rods and structurals, in view of its high brand image and also

envisaged demand in line with the infrastructure growth of the country. A

seamless tube plant has been planned for the first time in an integrated steel

plant to cater to the growing oil and gas industry and reduce dependence on

imports of seamless tubes. The next phase of expansion to 10 mT is planned for

completion by 2012-13 which will include flat products also to provide a rich

product mix.

With excellent performance levels continuing during the current year also and the

ensuing expansion wherein Vizag Steel has set up an ambitious target of

completion of its expansion in a record 36 months at international standards,

Vizag Steel looks to new horizons. Vizag Steel collective has proved its mettle

time and again and is all set to take up new challenges and soar to new heights to

emerge as a World Class steel plant.

MAJOR DEPARTMENTS IN VSP

RAW MATERIAL HANDLING PLANT (RMHP) :

The RMHP receives the basic materials iron ore, fluxes (lime stone, dolomite),coking

and non coking coals etc. required for the steel making process from various sources through

wagons which are stacked and reclaimed by stackers-cum reclaimers and distributed to

various departments of Visakhapatnam steel plant through conveyor systems.

COKE OVENS (CO):

Blast furnaces, the mother units of any steel plant require huge quantities of strong,

hard and porous solid fuel in the form of hard metallurgical coke for supplying necessary heat

for carrying of the reduction and refining reactions besides acting as a reducing agent.

Coke is manufactured by heating of crushed coking coal (below 3mm) is in the

absence of air at a temperature of 1000deg centigrade and above for period of 16 hrs to 18

hrs. A coke oven comprises of two hollow chambers namely coal chamber and heating

chamber in the heating chamber a gaseous fuel such as blast furnace gas, coke oven gas etc.

is burnt. The heat so generated is conducted through the common wall to heat and carbonize

the coking coal placed into adjacent coal chamber. Number of ovens built in series one after

the other form a coke oven battery.

At VSP there are three coke oven batteries, 7 meter tall and having 67 ovens each.

Each oven is having volume of 41.6 cu meters and can hold up to 31.6 tonnes of dry coal

charge. The carbonization takes place at 1000 to 1050 deg centigrade in the absence of air for

16 to 18 hours.

Red hot coke is pushed out of the oven and sent to coke dry cooling plants for

cooling to avoid its combustion. There are three coke dry cooling plants (CDCP) each having

four cooling chambers. The capacity of each cooling chamber is 50 to 52 TPH. Nitrogen gas

is used as the cooling medium. The heat recovery from nitrogen is done by generating steam

and expanding in two back pressure turbines to produce 7.5 power each.

The coal chemicals such as benzol, tar, ammonium sulphate etc. are extracted in

coal chemical plant from co gas. After recovering the coal chemicals the gas is used as a

byprioduct fuel by mixing it with gases such as BF gas, LD gas etc. A mechanical, biological

and chemical treatment plant takes care of the effluents.

SINTER PLANT :

Sintering is one of the most widely used and economic agglomeration techniques. Sinter

is a hard and porous lump obtained by agglomeration of fines of iron ore, coke, limestone ,

and metallurgical waste. Sinter increases the productivity of blast furnace, improves the

quality of pig iron and decreases the consumption of coke rate .Two 312 square meter sinter

machines with 420 square meter straight stand type coolers for annual production of 5.26 MT

sinter.

BLAST FURNACE (BF) :

Pig iron or hot metal is produced in the Blast Furnace .The furnace is named as BF as

it is run with blast at high temperature and pressure of 1500 deg. C. Raw materials required

for pig iron and iron are iron making ore, sinter, coke, and lime stone. There are two 3200

cubic meter blast furnace to meet 3.0 MT annual metal requirement. with bell- Each furnace

is provided with a set of four hot blast furnace stoves designed for supplying air blast up to

1300 deg .C. Three turbo blowers, one for each furnace and one stand by common to both

furnaces are provided with 12 MW top pressure recovery turbo generating power. BF gas is

produced from each furnace is being cleaned in gas cleaning plant comprising dust catcher,

high pressure scrubber and is distributed through out the plant as a fuel.

STEEL MELT SHOP (SMS) :

Steel is an alloy iron and carbon, where carbon should be less than 2%. Hot metal

produced in B.F contains impurities like carbon, sulphur, phosphorous, silicon etc., these

impurities will be removed in steel making by oxidation process. These are the three L.D

converters to convert hot metal in to steel. The steel melt shop complex comprising two

1300-ton hot metal mixers, three 130-ton LD converters (two operating) and six 4-stand

bloom casters. Each converter is being provided with gas cleaning plant for cleaning and

recovery of LD gas, which will be used as fuel in plant.

ROLLING MILLS (RM):

Blooms cannot be used as they are in daily like. These blooms have to be reduced in

size and properly shaped to fit for various jobs. Rolling is one of the mechanical processes to

reduce large size sections in to smaller ones. The cast blooms from CCM are heated and

rolled in to long products of different specifications like high capacity, sophisticated high-

speed rolling mills. The rolling mill complex comprises:

Light and medium merchant mill (LMMM)

Wire rod mill (WRM)

Medium merchant and structured mill (MMSM).

Each mill is well equipped with required number of walking beam furnaces for

heating of walking beam furnaces for heating of blooms or billets and except for wire rod

mills, each furnace is provided with evaporative cooling system for generation of steel for

plant consumption.

THERMAL POWER PLANT (TPP) :

The estimated power requirement for V.S.P in 280 at 3.0 MT stages, the peak load

being 292 MW essential loads being 49 MW. The generating capacities 286.5 MW. A

captive power having 3x60 MW turbo-generator sets and 5x330 ton/hr steam generators. In

this plant, 6000 Nm^3/min turbo blowers are being provided for supplying cold air blast

furnaces.

MAIN PRODUCTS OF VSP( PRODUCT MIX)

Unlike many other steel plants VSP is an integrated steel plant , producing many

products like Blooms,Channels,Angles etc., other than these VSP also produces many by-

products that are derived during the production of coke and iron .The main products and the

by-products that are produced are shown in the table below :

TABLE –1 :

Steel products By-Products

Angles Nut coke Granulated slag

Billets Coke dust Lime fines

Channels Coal tar Ammonium sulphatnut

Beams Anthracene oil

Squares HP napthalence

Flats Benzene

Rounds Toluene

Re-bars Zylene

Wire rods Wash oil

COMMUNICATION SYSTEMS IN

VSP

In this modern age of industrialization telecommunications plays a very important

role in coordinating the activities of various departments / sections and in achieving the set

targets and also in improving the performance of the organization. In Visakhapatnam Steel

Plant, different types of communication systems are being used to meet the internal and

external communication needs. These are broadly classified as follow:

a. General purpose communication systems.

b. Process communication systems.

c. Monitoring & Signaling Systems.

Apart from the above facilities Telecom department maintains the following cable

networks also

a) DATACOM cable network.

b) Telephone cable network in plant and township

GENERAL PURPOSE COMMUNICATION SYSTEMS:

The following facilities are provided under category of general purpose communication

systems:

4000 lines IP based Telephone in Plant.

3000 lines Electronic Exchange in Township.

100 lines Electronic Exchange in Visakha Steel General Hospital.

44 lines Electronic exchange in Hill Top Guest House

2500 Lines Electronic Exchange of Bharat Sanchar Nigam ltd (BSNL) in Project

Office is catering to the needs of Plant area and Sectors-I to VII in township. Another 2000

Lines Electronic Exchange of Bharat Sanchar Nigam ltd (BSNL) in Township is catering to

the needs of Sectors-VIII to XI in Township.

The 3000 Lines electronic exchange in plant and 3000 lines exchange in township are

having the following facilities:

Extension (subscriber) to extension call, Auto call back, Hot lines, Music on hold,

Reminder Alarm, Automatic line testing facility, Faults man ring back, Call consult facility,

Malicious call tracing facility, 3 party conference Facility and Howler Tone alert etc. All

exchanges working in the steel plant are interconnected by means of junction lines and have

closed numbering scheme.

The 3000 lines exchange in township is interconnected to the BSNL network. Due to

this interconnection all the subscribers of this exchange can receive incoming calls from any

part of the world. A few subscribers are provided with facility to contact subscribers

connected to the BSNL network and cellular and mobile phones in and around

Visakhapatnam.

PROCESS COMMUNICATION SYSTEMS:

To facilitate coordination, operation & management activities of production,

maintenance & service departments, the following process communication systems are

provided:

a) Dispatcher communication system

b) Loudspeaker intercom systems

c) Loudspeaker broadcasting systems

d) Loudspeaker conference communication system

e) Industrial public address system

f) Hotline communication systems

g) VHF communication systems

A) DISPATCHER COMMUNICATION SYSTEMS :

Initially dispatcher communication is provided with a cordless switch board type

manual exchanges of electromechanical. Since manufacture of such systems and their spares

is discontinued in the country, these dispatcher systems are being replaced by Electronic

exchanges progressively. Except the ones in CCCP other systems have been replaced. These

would also be replaced very soon.

Production coordination at plant level being conducted by ED (Works) with all HOD

s in the morning every day is facilitated with the help of the digital EXCOM system provided

in the plant control room.

B) LOUD SPEAKER INTERCOM SYSTEMS :

Loudspeaker intercom systems are working LMMM & WRM. These systems are used

for communication between various sections of the same production shop. Communication is

made possible using microphones and loudspeakers provided in the subscriber stations. This

system is very useful in noisy environment where conventional telephones are ineffective.

This system helps to establish communication between any two stations having

interconnectivity on selection basis. By using group call facility it is possible to

communicate to all the subscribers in the group at a time.

C) LOUDSPEAKER BROADCASTING SYSTEMS:

This system consists of centralized amplifier rack with amplifiers, desktop micro

phone with press to talk switch and a network of loud speakers connected to the

amplifiers .this is useful to make general announcements to the entire working area as to pass

on important instruction from the control room.

Loudspeaker broad casting systems are provided in C&CCD, BF, SP and SMS

departments.

D) LOUDSPEAKER CONFERENCE COMMUNICATION SYSTEMS:

Loudspeaker conference communication systems are working in CCCP. These

systems are provided with both paging and private channel communication facilities. In case

of paging a general announcement can be made which is heard on all the stations. In the

private mode communication is possible between two selected stations only. Here also

communication is carried out by means of microphones and loudspeakers provided in the

subscriber stations.

E) INDUSTRIAL PUBLIC ADDRESS SYSTEM:

Industrial Public Address System is working in TPP. It is a combination of

loudspeaker broadcasting system and conference communication system. From the main

control room it is possible to make announcements which are heard on the shop floor. From

certain locations the communication can also be established through handsets in private mode

with the main control room.

F) HOTLINE COMMUNICATION SYSTEMS:

To ensure direct telephone communication between closely related critical locations

hot lines are provided. By using the hot lines specified locations are connected permanently.

Communication is possible only between these two locations. When one subscriber lifts his

telephone the other will immediately get a ring and communication can be had without any

loss of time.

This is useful to pass-on urgent messages. These hot lines are initially provided with

direct line communication systems which are electro mechanical systems. Due to

obsolescence electronic systems are now being used for most of the locations. Hot lines are

working in CCCP, BF, SMS, LMMM, WRM, MMSM, TPP, PPM, DNW and WMD

departments.

G) VHF COMMUNICATION SYSTEMS:

VHF communication systems are used in VSP to establish two way communications

between two or more when either or one of them is moving. There are three models working

in our plant. They are hand-held units (Walkie-talkie), vehicle mounted – mobile units and

base station units.

Walkie-talkies are used by operation and service personnel in almost all of the

production shops. Vehicle mounted units are being used by DNW, CISF (Fire) and CISF

(security). Base station units are used by CISF (fire), CISF (Security), Administration, DNW

and largely by CCCP departments. In CCCP these can be seen in pusher cars, charging cars,

door extractors, electric locos, lifters and CDCP areas. These sets are very essential and

useful in answering proper communication and coordination during alignment of oven

machines while charging and pushing the ovens and carrying out these operations safely.

Handheld VHF sets are extensively used for establishing instantaneous

communication and ordination of operation or maintenance activities on different

departments throughout the steel plant.

MONITORING AND SIGNALING SYSTEMS:

To facilitate monitoring production, maintenance & service activities, the following

monitoring and signaling systems are provided:

a) Closed Circuit Television Systems (CCTV)

b) Central fire alarm signaling system

c) SCADA system

d) Shift change Announcement Siren System

A) CLOSED CIRCUIT TELEVISION SYSTEMS (CCTV):

For monitoring critical operations in different production units continuously from the

concerned control rooms / pulpits CCTV systems are used in SP, BF, SMS, LMMM, WRM

and MMSM departments. CCTV system comprises of CCTV camera with a lens and a CCTV

monitor.

In some cases a video switcher, a central control console, pan and tilt head and zoom

lens are also used. These are interconnected by means of control cables and / or coaxial

cables. Necessary protection is provided for the CCTV equipment depending on the locations

where they are used.

B) CENTRAL FIRE ALARM SIGNALING SYSTEM :

The central fire alarm system is provided for communicating the exact location of

outbreak of fire in any part of the steel plant complex to the central fire station and

simultaneous actuation of sirens to alert personnel of the affected plant zone. The system

employs manual call points located all over the plant.

C) SCADA SYSTEM :

To monitor the generation and consumption of various energies by various users in

the plant the SCADA system is provided. Scada system is located at Energy and Telecom

centre.

The system comprises of a master servers ,23 Remote Terminal Units (RTUs)

installed in different plant units and display units. The RTUs will collect the signals from the

tranducers& electrical systems and transmitting to the master servers by means of

cocommunication channel. The RTUs are connected to the master servers by under ground

laid telephone cables.

D) SHIFT CHANGE ANNOUNCEMENT SIREN SYSTEM:

The shift change announcement siren system is provided for ensuring uniform and

accurate shift timings throughout the plant. This system consists of two quartz crystal

controlled master clocks in the Energy & Telecom Centre. The shift timings are programmed

in the Master Clock. At the specified time, the signal will be transmitted for energizing the

sirens located at strategic points in plant area simultaneously at the preset timings.

INTRODUCTION

SCADA SYSTEM:

SCADA is an acronym for Supervisory Control and Data Acquisition system, a computer system for gathering and analyzing real time data. SCADA systems are used to monitor and control a plant or equipment in industries such as water and waste control, energy, oil and gas refining and transportation. A SCADA system gathers information, such as where a leak on a pipeline has occurred, transfers the information back to a central site, alerting the home station that the leak

has occurred, carrying out necessary analysis and control, such as determining if the leak is critical, and displaying the information in a logical and organized fashion. SCADA systems can be relatively simple, such as one that monitors environmental conditions of a small office building, or incredibly complex, such as a system that monitors all the activity in a nuclear power plant or the activity of a municipal water system.

SCADA systems were first invented in the 1960s.

The signals for a plant unit will normally be concentrated in the control room of the unit from where the unit is being operated. PLCs/RTUs of the SCADA will be installed in these main control rooms and the tele- transmission signals identified for the units will be wired to the PLCs/RTUS .

The PLCs/RTUs are micro processor based intelligent units , responsible for Acquisition of inputs from the plant units and convert them in to digital code for Tele -- transmission to the Master station computer of SCADA through the 5 pair telephone cable . Some plant unit where few signals are available for tele – transmission , A junction box will be installed in the control room ( instead of an PLCs) for the termination of inputs and these inputs are further connected to the nearest PLCs through the multi – core control cables.

. The 23 PLC s are located in different parts of the plant are connected to the center Master station through modems. The Master station located in the E&T centre of the Visakhapatnam steel plant will acquire all Information through PLC and LAN and Process the information for displays and report generation .

The SCADA system acquires various electrical & utility parameters for effective monitoring & control operation. The various parameters acquired are electric power , voltages , currents , etc… under electrical monitoring and parameters such as flows , temperatures, pressures , etc

CATEGORY OF ENERGY FORMS IN VSP

Utility systems Electrical systems WATER

UTILITY SYSTEMS:

The utility system covers the services like fuel , gases , stream , compressed air, water etc…. The services covered by the utility systems of CSCS are broadly classified in to following groups.

Fuel gases system : CO, BF ,Mixed & converter gases. Process gas system : Nitrogen, Oxygen ,Argon, Acetylene. Steam Distribution system: Steam at 40 KSCG,13 KSCG. Compressed air system: Compressed air and instrumentation grade air

Chilled water system: Chilled water. Fuel oil system : LSHS,LDO and LTF.

water Water systems: make up water, fire and drinking water

ELECTRICALSYSTEM:

The electrical system covers the complete electrical distribution network inside the Visakhapatnam Steel Plant like 220 KV ,11 KV, 6.6 KV systems in MRS,

LBSS , 1, 2 , 3 , 4 and 5 , LBDSS.For centralized supervisory of above services in utility and electrical systems and also to

exercise control over their optimum utilization, following types of signals are considered for the users.

Analog input (AI) Digital input (DI) EM SIGNALS The input signals acquired by the PLCs are tele-transmitted to the Master station and

are sorted out according to the above subsystem division i.e utility and electrical.

SCADA systems monitor a total of 4000 different signals originating at different depts. in VSP. Among these 4 000 signals, 150 0 signals are catered to monitor utility system and 2 500 signals are electrical system .

ARCHITECTURE OF THE SCADA

ARCHIECTURE OF THE FIELD PLC/RTU’S

PLC – Architecture:

The selected PLC has got powerful processor to take care of the data acquisition

requirements of the VSP. The PLC interfaces with field to acquire the data from various field

instruments. The offered PLC system supports maintenance from the Engineering station

in master station. The PLC will be supplied with ladder programming language for

building local automation sequences. The offered PLC is fully modular and supports

distributed I/O for future expansion. The PLC supports a total of 20,000 I/O ports.

The functional architecture of the PLC system will be as follows. The offered

architecture is latest state-of-the-art in which the PLC processor communicates with

individual I/O stations over a highly reliable Ethernet ring. The extension racks will be

available for any more expansion in I/Os. The system will support a total of 20,000I/O’s.

The PLC presented above shall have the following characteristics: High capacity controller for I/O signals High memory capacity and expandable Input digital signals cards Input analog signal cards Galvanic isolation for the signal. Empty slots for future expansions Ports to connect to field buses (RS232C/RS485) Configurable to standard protocols (MODBUS RTU / Profibus DP) Comprehensive self testing and diagnostic facilities SCADA Master Station over dedicated telephone cables.

HARDWARE COMPONENTS OF THE PLC : 1. Power Supply Unit.2. Programming Unit.3. Central Processing Unit.4. Bus Controller Unit.5. Communication unit to Interface with External Programming unit.6. Input and Output modules.

1.POWER SUPPLY UNIT :

The power supply modules provide the power supply for each rack.

The required power supply standard format or double format model. The mains

electrical supply ~200..240V

Description of the Power Supply Unit:

1. Display blocks comprising. OK lamp (GREEN), if voltages are present and correct. BAT lamp (RED), if the battery is faulty or missing. 24V lamp (GREEN) when sensor voltage is present

2. RESET pencil-point push button causing a warm restart of the application.

3. Slot for a battery which protects the internal RAM memory of the processor.

4. Cover to protect the front panel of the module.

5. Screw terminal for connecting: To mains supply. The alarms relay contact. The sensors power supply for a.c supplies.

6. Opening for cable clamp.

7. Fuse located beneath the module and protecting.

8. 24VR voltage on the non-isolated d.c supply. Primary voltage on the other power supplies.

9. 110/220 voltage selector

CHARACTERISTICS OF THE POWER SUPPLY

The characteristics of the power supply module are

Primary Power supply Module:

Voltage (in V)

Nominal ~100…240

Limit ~85..264

Frequency (in Hz)

Nominal /limit 50…60/47..63

Current (in A)

Nominal input 1ms 0.5 at ~100v0.3 at ~240V

Secondary power supply Module:

OutputNominal voltage 5V

Nominal current 5A

Power 25W

OutputNominal voltage 24V

Nominal current 0.6A

Power (typical) 15 W

Description of the 12 slot Rack Power Supply Unit :

It is possible to constitute a PLC station with premium processors with just a single rack. These racks are connected to each other.

The Racks comprise :

1. Metal frame.2. Slots for anchoring the Module pins.3. 48-way female ½ DIN connectors for module-rack connections4. Locating slot for the power supply module.5. Trapped holes for mounting the module.6. Four holes for mounting the rack.7. Position for rack address label.8. Position for station network address label.9. Two earth terminals for earthing the rack.10. Micro switches for coding the rack address 11. Two 9-way female SUB-D connectors for the remote connection of bus X to another

rack.Rack address :

Address 0: This address is always assigned to the rack which holds the processor.This rack can be located in any position on the line.Adresses 1to 7: These can be assigned in any order to all other extendable racks of the

station.As the two racks with 4,6 or 8 slots which make up each pair can have the same address on

the bus X , position numbers are defined as follows: Rack n “ less- significant “: position 00 to xx; Rack n “ most-significant “; position 08 to yy; Each rack with 12 slots holds an address Specifications of power supply :

Type ModularNo.of Slots 12 slots inclusive of power supply slotDimensions in mm 482.6(W) x 151.5 (H)Reserved slots Slot-1 for power supply

Slot -2,3 for processor

Functions of the power supply module:

Alarm Relay:

The alarm relay located in each power supply module has a volt-free contact which

can be accessed on the connection screw terminal of the module.

Principle:

Module alarm relay on the processor rack (rack 0): In normal operation, PLC in RUN, the alarm relay is activated and its contact is closed. Whenever the application stops, even partially, occurrence of a blocking fault, incorrect output voltages or loss of mains power, the relay de-energizes and the associated contact opens(state 0).

Alarm relay of power supply modules located on the other racks(racks 1to 7).when the module is powered up and if the output voltages are correct, the relay is activated and its contact is closed (state 1).when the mains power is lost or if the output voltages are incorrect, the relay de-energizes (state 0).

Back-up battery:

Each power supply module has a slot reserved for a battery which provides the power

supply to the internal RAM memory located in the processors, in order to ensure that data is

saved when the PLC is switched off. The duration of data back-up is one year. The battery

must be changed as soon as the BAT lamp(RED) on the front panel lights up.

RESET Push button:

Pressing this push button, which located on the front panel of the power supply

module, triggers a sequence of service signals which is the same as that for:

A power breaks when the push button is pressed. A power up when the push button is released.

Sensor power supply:

The sensor power supply (a.c) modules have an integrated power supply which

provides a voltage of 24V to supply the input sensors. Connection to this sensor power supply

can be accessed via module screw terminal.

2. PLC PROGRAMMING

PLC acronym for Programmable Logic Controller is an industrial computer control

system that continuously monitors the input devices and performs a sequence of operations

depending of inputs. The output is user defined through a set of instructions, integrating the

process sequences and interlocks.

Programmable Logic Controller is a solid state device, basically designed to perform

logic decision making for industrial control applications. Sincere their development in early

1970’s PLC have evolved to challenge not only relays but also other discrete control devices

such as stepping switches, drum sequencers etc.

The PLC is composed of electric circuit with a microcomputer centered. However , it

can be equivalently regarded as an integrated body of ordinary relay, timer, counter etc.

There are different methods of programming PLC’s .They are

1. Ladder diagram programming.2. Function blocks programming.3. Instruction list programming.4. Structure text programming.Ladder diagram: It is graphic and very easy to understand. It closely resembles the old

relay logic diagram. Generally shop floor maintenance people easily understand and prefer it. The drawback of this language is, occupies more memory space and slow.

Function diagram: It is also easy to understand and pictorial representation. It closely

resembles the controller programming. This is also very slow. Most of the PLC’s use a combination of ladder and function block programming.

Instruction List: It uses he mnemonic codes of a microprocessor. It is very fast but it

requires familiarity with assembly language programming of microprocessor.Structured text: It is nothing but C language programming. It is a fastest of all languages.

But it requires through knowledge of ‘C’ language programming.

Function of the PLC:

HOUSE KEEPING

INPUT SCAN

LOGIC SCAN

OUTPUT SCAN

SERVICE COMMUNICATIONS

House Keeping: It consists of internal checksums and diagnostics that the processor

executes every scan cycle. These can be done at the beginning or the end of the scan cycle or both depending upon the PLC.

Input Scan: It consists of reading the current state for each input connected to the PLC

system and updating the input memory tables.

Logic Scan: It consists of reading the use program that ahs been stored in the PLC

memory. These programs can be written in ladder logic, instruction list, sequential flow charts, function block, structure test, c code or state logic depending upon their manufacturer of the system. Some system supports programming using combination of languages within the same program.

Output scan: It consists of adjusting the values of outputs connected to the system based

upon the status of inputs and execution of the logic.

Service communications : It consists of opening the window of time for the processor to

communicate to other devices. These can be programming devices, operator interface devices, remote IO controllers, other PLC’s or any devices having communication capability that is compatible with the PLC system.

3. CENTRAL PROCESSING UNIT:

This CPU is a double format high performance processor.

Figure 1

The CPU displays 6 additional display lamps1. RUN lamp (GREEN) : Ethernet TCP/IP port ready. ERR lamp (RED) : Ethernet port fault COL lamp (RED) : Collision detection. STS lamp (YELLOW) : Ethernet link diagnostics. 2, TX and Rx lamp (YELLOW) : Tx/Rx activity.

2. A “Memory Extract” button for extracting the PCMMCIA memory extension card. The associated “Memory extract ready” display lamp indicates that this card can be

extracted safely.

3. RESET button causing a cold restart of the PLC when it is activated.

4.An 8-way female mini-DIN connector marked AUX for connecting a programming adjustment.

5.A USB type connector marked TER for connecting a programming terminal.

6. A PCM CIA slot (no.0) for a memory extension card.

7.A PCM CIA slot (no.1) for a communication card or memory Extension card for storing additional data.

8. NOT APPLICABLE FOR THIS MODEL.

9. An RJ 45 type connector for connection to the Ethernet TCP/IP 10BASE-T/100 BASE-Tx network.

MEMORY STRUCTURE

The application memory is divided into memory areas physically distributed in the internal RAM memory and on 0, 1 or 2 PCMCIA memory extension cards.

1. The application data area, which may be one of 2 possible types, is always in the internal RAM.

Located Data: It is defined by an address (e.g. %MW237) which a symbol may be associated.

Unlocated Data: It is defined by the symbol. This type of symbol addressing removes the memory “memory management” constraints because address is assigned automatically.

2. Area in internal RAM or PCMCIA memory card for the program and symbols. In the event of this area being in internal RAM.

It also supports the area for modifying the program in online mode. This area contains the program’s executable binary code and IEC source code. The user selects the type of information to be stored in the PLC memory.

3. Constants area in the internal RAM or the PCMCIA memory card (slot no .0)

4. Storage area for additional data (slot no. 0 or no.1)Ex: For production data and manufacturing recipes.

Application of the internal RAM: In this case, the application is entirely loaded in the

processor’s internal battery-backed RAM(2). It varies at 96 to 640 Kb.

Application in PCMCIA card: IN this case, the internal RAM is reserved for the

application data. The PCMCIA memory card (slotno.1) contains the program space (programs, symbols and constants areas). It varies at 224 to 7168 Kb.

The internal RAM memory is backed up by an optional battery (3 year’s life) located in the power supply module.

Extension of data storage area : Memory cards reserved for data storage (4096 or 8192 Kb) are used to:

Access the data storage area when the application is entirely supported by the internal RAM. In this case, the data storage memory card is inserted into PCMCIA slot no.0

Free up memory space to provide additional program space when the application is in the PCMCIA card (slot no.0).In this case, the data storage memory card is inserted into PCMCIA slot no.1.

Protecting the application: Regardless of the PLC memory structure (whether it is located in the internal RAM or

in the PCMCIA memory card), it is possible to protect this order to prevent it being accessed (read or modify program) by only loading the executable code on the PLC.

A memory protection bit, set in configuration mode, is also available to prevent any program modification (via the programming terminal or downloads).

Program modification in online mode: The function of this PLC is, it allows program code and data in different parts of the

application to be added or modified in a single modification session. Any program modification made in online mode.

CHARACTERISTICS AND PERFORMANCE

The characteristics and performance are

Functions:

Max No. in Rack

Discrete I/O 2048

Analog I/O 256

Process control channels 20 (up to 60 simple loops)

Application- specific channels (counter, serial links)

64

Integrated ConnectionsEthernet TCP/IP 1

Serial link 1x12 Mbps USB link(TER)1x19.2 Kbps (AUX) link

Maximum no. of connections

Network (Ethernet,TCP/IP,Fipway,Ethway,ModbusPlus)

4;3if integrated Ethernet is used

Memories:

Maximum capacity

Without PCMCIA card (in Kb) 320prog + data

With PCMCIA card (in Kb) 2048 prog, 440 data

Data Storage 16,384 Kb

Execution time: 11.4 Instructions /MsExecution time for 1K instructions: 1/11.4 =0.0877msTotal memory: 324 kb (with CPU) +256kb (with PCMICA memory Card) = 580kbAssuming 50% Program memory loading =290kbScan time 290*0.0877 = 25.433ms Communication protocol with Scada: Modbus TCP/IP.Communication with SCADA: Built –in-Ethernet module

INPUT AND OUTPUT MODULES:

1. Analog Module2. Digital Module

Analog Module : The front panels of analog module comprise

i. A display and module diagnostics block.ii. A connector for receiving the screw terminal block.

iii. A rotating supports containing the module locating device.iv. A removable screw terminal for direct connection of the I/O to the sensors and

preactutators.v. A pivoting cover for accessing the terminal block screws and holding the identification

label.vi. A screw terminal blocks encoder.

vii. A 25-way SUB-D connector for connecting the sensors.

Functions of Analog Module:

1. Scanning of input channels, protection against over voltages, adaptation of signals by analog filtering, scanning by solid state multiplexing.

2. Adaptation to input signals: Gain selection, drift compensation.3. Digitization of signals: 12-bit analog/digital conversion.4. Converting input measurements to user format: recalibration coefficient, filtering,

scaling.5. Module monitoring: conversion circuit test, range overshoot test, terminal block

presence test, “watch dog “test.& fast processing inputsSpecifications:

Channels 16channels

Isolation Between Bus and channelsBetween channels and earth

1000 v RMS1000 v RMS

Resolution 12 bits

Input operating range +/-10 V DC,0-10V,0-5V,1-5V,0-20mA,4-20mA

Maximum Over Voltage +/- 30 V

Maximum Over current +/- 30 Ma

Digital Module :

The front panels of Digital module comprise

Functions of the Digital Module :

I/O assignment : Each module is functionally organized into groups of 8 channels. Each group of channels can

be assigned a specific application task.

Reactivation of Outputs : If a fault has caused an output to trip, output can be reactivated if no other terminal

fault is present. The reactivation command, defined during configuration, can be automatic or

controlled via program. Reactivation is carried out in groups of 8 channels. This function can

be accessed on modules with solid state d.c outputs. For relay and triac output modules

protected by fuse, the same type of reactivation is necessary after replacement of one or more

fuses.

RUN /STOP command : An input can be configured to control the Run /STOP mode for the PLC.

The command is accepted on a rising edge. A STOP command via an input takes priority

over a change to RUN via the terminal or via a network command.

Output Fallback:

When an application is placed in STOP mode, Outputs must be set to a state which is

not harmful to the application. This state known as the fallback position is defined for each

module when its outputs are configured.

This configuration enables the choice between:

Fall back: channels are set to state 0 or 1 depending on the fallback value entered.

Maintain: outputs retain the state they were in before the PLC stopped.

Diagnostic functions:

Module diagnostics: Any exchange fault preventing normal operation of an output module or fast input mode is signaled. Similarly, any internal module fault is signalled. Process diagnostics: Sensor/procurator voltage check, terminal blocks presence check, short –circuit and overload check, preactuator voltage check.

Specification:

Nominal Input Voltage 24 VDCInput characteristics Input voltage On state voltage Off state current On state voltage Off state current

24 V DC>=11 V>= 3mA=<5 V =<1.5 mA

On response time Off response time

4ms

Web servers: The web server module is a stand alone TCP/IP –module gateway module used

to connect a Modbus device to a TCP/IP network. It is a standard device. It has a built in RS 232 serial link which can be used to connect an external modem.

Mainly this module is used to perform the following functions: Modbus messaging over TCP/IP, SMTP service SNMP service. Embedded Web server. Option of having a user web site.

Specifications:

Functions Embedded web server ,Option of having a user websiteModbus messaging over TCP/IP

SMTP serviceSNMP service

No. of Ports 1-RJ 45 connector1-RJ 45 connector for RS 485 linkA 9-pin SUB D connector for a modem link

No. of simultaneous connections 16 Internet browsers

Energy Meters:

The energy meter portable working is a 3 phase portable electronic meter test unit for

use as a working standard to test both single and 3 phase electricity meters on site. This

device allows checking of all meter installation parameters and associated circuits. The

energy meters is available in accuracy classes 0.1.The unit can be used either with a direct

connection in the range 1mA..12A.

Function:

Active, reactive and apparent energy measurement for single phase and 3 phase, 3 or 4 wire circuits with integrated error calculator.

Advantages:

Wide measuring range with auto ranging. Display of vector diagram for analysis of mains conditions and meter connections. Measurements of wave from and harmonics with display. Easy detection of circuit connection faults. Data memory. Small dimensions and light in weight. Serial interface for data transfer.

Application: On site test of electricity meters.

Specifications:

Power consumption 10VACurrent range 1mA….12AVoltage range 10V…..300V

CABLES

In both interrogation and broadcasting mode there is a continuous

transfer of information between the PLC and the MS so there is a necessity of a

physical medium to facilitate the flow of information( Electrical Signal). Cables

perform the job of interconnected the field PLCs and MS.

The inter- connecting cables required for connecting various terminals can be

classified in to 3 categories and the technical specification of various cables are

also given below .

CATEGORY – I :Telephone cables required for inter connection of PLCs and the MS. 5Pair Petroleum jelly filled. Armored. Over all polythene packed. Solid annealed high conductivity copper. Diameter 0.633mm. Resistance 57 ohm /KM.

CATEGORY—II: Twisted pair cables required for the inter connection of remote video terminal

to the master stations . 5Pair. Diameter 7/ 0.2 mm. Individually and over all shielded. Armored cables.

CATEGORY – III :Control cables required for the inter connection of signals from plant units and

junction boxes to the PLCs . # Size 1.5 mm. # Solid annealed copper conductor. # Multi core control cable. # Armored and unarmored. # Thickness 0.8 mm. # Resistance 12.1 ohm / KM. # PVC Insulated.

The cables will be laid partly on cable trays in cable tunnels and balance the directly buried under ground .

LAN EXTENDERS

The RTU’s are connected to the MS by under ground telephone cables with one pair of Lan extenders.Descriptions of Modems.

The SHDSL (Single-Paired High Speed Digital Subscriber Loop) routers/lan

extenders comply with10/100 Base-T auto-negotiation. It provides business-class, multi-

range form64Kbps to 2.304Mbps (for 2-wire mode) or 128kbps to 4.608Mbps (for 4-wire

mode) payload rates over exiting single-pair copper wire. The SHDSL routers are designed

not only to optimize the service bit rate from central office to customer premises also it

integrates high-end Bridging/Routing. Because of rapid growth of network, virtual LAN has

become one of the major new areas in Internetworking industry. The SHDSL routers support

port-based and IEEE 802.1q VLAN over ATM network.

The firewall routers provide not only advanced functions, Multi-DMZ, virtual server

mapping and VPN pass-through but advanced firewall, SPI, NAT, DoS protection serving as

a powerful firewall to protect from outside intruders of secure connection.

The SHDSL routers allow customers to leverage the latest in broadband technologies

to meet their growing data communication needs. Through the power of SHDSL products,

you can access superior manageability and reliability.

Features:1. Easy configuration and management with password control for various applicationEnvironments2. Efficient IP routing and transparent learning bridge to support broadband Internet services3. VPN pass-through for safeguarded connections4. Virtual LANs (VLANs) offer significant benefit in terms of efficient use of bandwidth, flexibility, performance and security.5. Build-in advanced firewall (Firewall router)6. Four 10/100Mbps network connectivity (4-port router)7. Getting enhancements and new features via Internet software upgrade.Specification

Bridging:1. IEEE 802.1D transparent learning bridge2. IEEE 802.1q VLAN3. Port-based VLAN (4-port router)4. Spanning tree protocol

Management:1. Easy-to-use web-based GUI for quick setup, configuration and management2. Menu-driven interface/Command-line interface (CLI) for local console and TelnetAccess3. Password protected management and access control list for administration4. Software upgrade via web-browser/TFTP server

LAN Interface:1. 4-ports switching hub (4-port router)2. 10/100 Base-T auto-sensing and auto-negotiation

LAN –LAN Connection:

Communication Types :

Citect SCADA supports four types of I/O device communication:1. Serial communication2. PLC interface board3. Data acquisition board4. Dynamic data exchange (DDE) Server

Whether the I/O device is local or remote, communicating with I/O devices isusually via a simple serial connection using the RS-232or RS-485 standard .

With Citect SCADA there are many I/O device communications options, through

Citect SCADA computer's COM port, through a high-speed serial board, or through a

communications board supplied by the I/O device manufacturer.

Advantages:1. Flexible.2. Scalable.3. Reliable, low cost.

MASTER STATION/Master server

SERVERS:

WINDOWS based operating software shall be considered as SCADA servers. Servers

shall work on hot redundant server configuration. All the PLCs shall be communicating

directly to both the servers. The data updates taking place in any of the PLCs shall be updated

in both the servers automatically and simultaneously. In the other HMI stations, only client

software shall be loaded. Both servers shall update relevant data (process, configurations,

history etc.) continuously. Necessary

dual redundant network interface modules shall be provided for communication with

PLCs and other peripherals. Other operator station, shall log on to these servers for system &

process operation, data access and other operations. Servers shall be considered with Oracle

database. The system software shall support 10000 tags.

HUMAN MACHINE INTERFACE (HMI) STATIONS:

PC BASED SYSTEMS:

1.2 nos PC based system HMI stations shall be provided for operator interface, data logging,

trending, alarm & graphic generation and Management information system,

Suitable dual redundant network interface units shall be provided for necessary

communication with Ethernet. The SCADA system software offered shall support 10000

tags.

2. 1 HMI shall be provided for connecting to plasma board for the purpose of video mimic.3. 5 nos remote HMIs (work stations) Each HMI shall have high resolution color Flat screen,

which can be chosen, designed to any parameters during formatting. It shall be on line, real

time system for remote operations, control and monitoring of process

functions with facilities for mimic and graphic displays (over view, group, loop, alarms etc.),

data acquisition and logging, trending (real time and historical), realtime report generation,

alarm handling, etc. Client software shall be loaded in all the HMIs. The MRS- HMI station

shall be equipped with dual monitors for simultaneous data monitoring and report browsing /

printing etc. The following shall be the minimum system requirement. The HMIs shall be

supplied with latest configuration at

the time of supply. The HMI shall be mounted in a stand alone metallic desk

HMI SOFTWARE:

Required licensed operating software’s, client software’s for downloading the screens

developed at Servers for day to day monitoring, operation etc., shall be provided.

ENGINEERING STATIONS:

1 no Engineering station shall be provided at the Master Station along with licensed

software for the system administration/database administration/HMI functions. The same

shall be connected on the ETHERNET communication network. The Engineering station

shall be supplied with suitable metallic enclosure.

LAP TOP PC :

LAPTOP PC shall be supplied with latest configuration at the time of supply. It shall

be supplied along with required licensed softwares and all accessories as

required.

PROGRAMMING SOFTWARE :

Each LAP TOP PC shall be loaded with licensed programming software. All software

shall be licensed version. The programming software shall be windows based and shall be

compatible with the systems proposed. The Programming software shall be suitable to

program all the RTUs. In addition to above one licensed RTU/PLC programming software

shall be loaded in the HMI (Telecom) also. It shall be ensured that the healthiness and fault

diagnosis of PLC/RTU cards can be checked / accessed from HMI (Telecom) only.

60” PLASMA Screen:

The HMI shall connect to the 60” PLASMA screen (Video mimic) for viewing of

mimic pages in the control room. The offered mimic screen shall be self-standing type.

INTELLIGENT COMMUNICATION INTERFACE UNIT :

The intelligent communication interface unit shall be serving the purpose of

interfacing between Master station and PLCs with high speed.

The PLCs shall be connected to the Master station utilizing existing telephone cables

with modems at the RTU/PLC end and at Master station end. In the control room of E&T

centre the modems shall be connected to the Intelligent Communication Interface unit. The

data of the PLCs shall be transferred by the intelligent Interface unit to the server without

affecting the process requirement. The communication

from each RTU shall be connected to the Intelligent Interface unit through separate module.

The retrieval of data from the PLCs shall be configured by the servers of Master station.The

intelligent communication interface unit shall be connected to the dual ETHERNET. The

offered interface unit shall connect to all RTUs and 3 nos work station. Over and above the

above 20% spare cards to be provided for future expansion. If the offered interface unit is not

capable of handling all the cards then required number of Intelligent Interface units shall be

included in the scope of work. All the interface units to be connected to the dual ETEHRNET

switch.

ETHERNET SWITCH:

The ETEHRNET SWITCHES shall be redundant. It shall have 24 ports in each

switch. Layer-3 Ethernet switch supporting 10/100/1000 MBPS shall be considered. It shall

be mounted in suitable metallic enclosure.

DIGITAL ENERGY METERS :

The digital Energy Meters shall be with serial interface (RS485) to connect to the

PLC. The energy meters shall be mounted in the field and the maximum distance shall be

considered from the RTU location

This covers design, engineering, manufacture,assemble, inspection and testing before

supply of 110V, 5A/1A and 3 element 4 wire CT

Meters of accuracy class 0.5 capable of performing the functions of metering in all 4

quadrants .The scope also includes commissioning of the meters by dismantling the existing

electromechanical meters, TTB and suitably installing, wiring new meter and commissioning

of the meters at VSP site. Connection to RTU for SCADA connectivity using MODBUS

protocol or otherwise by ensuring 10 meters per serial loop also is included in the scope of

the supplier. The supplier is expected to bring all tools/tackles and instrument etc. required

for commissioning as mentioned in the

specifications.

MODEMS:

The modems located at site shall be suitable for interfacing the PLCs to Master

Station over existing telephone cables. The selected Modem shall be able to send the signals

up to a distance of 15 KM over telephone cables. For this purpose the existing 5 pair PJF

telephone cables of RTUs shall be utilized for connecting the modems as well. Point to point

modems shall be considered. The modems shall be housed in suitable metallic enclosure and

mounted in the RTU/PLC panel in the field and separate panel in E&T centre. The modems

shall be duplex type The modems shall be suitable for the ambient temperature of 45 Deg C

and shall be UL certified. The modems shall be dedicated line type for industrial applications.

The interface shall be as required to connect to the RTU. The modems shall be suitable for

SCADA applications.

UPS SYSTEM:

For RTUs and remote work stations separate UPS systems shall be provided. Total 26

nos UPS systems shall be provided. A feeder with 230V +10% / - 10%,1Phase,

50Hz+/-3% will be made available. UPS rating shall be as per the requirement of

complete equipment covered in tenderer scope + 25% spare capacity. In the proposed UPS

system the batteries should be sealed maintenance free lead acid type. In case of power

failure the backup time of the UPS to be 30 minutes with resistive load (Unity Power factor).

The AH rating of the offered batteries shall be selected accordingly. The batteries shall be

mounted in a suitable metallic enclosure.

COMMUNICATION CABLES:

The communication cables like ETHERNET bus network and Modbus cable shall be

industry standard for process control. All these communication cables shall be routed through

suitable size GI conduits and GI conduits to be included in the scope of work. The OFC cable

between proposed SCADA server and the existing IBM server shall support 1Gbps data

transfer. Same shall be single mode, 6-core armored type. The specifications of PJF armored

cables shall be same as the existing cables.

CONTROL CABLES:

All the control cables shall have spare cores of 20%. The control cable shall be of 1.5

sq.mm size, 1100 V grade,Annealed tinned Copper core, multistrand conductor, PVC

insulated, PVC sheathed, un-armoured cables conforming to IS 1554.

The size of the cables/wires considered for the internal wiring of the PLC panels unto

the terminal blocks shall be as per the PLC manufacturer's standard only.

POWER CABLES:

The power cables shall be ATC copper core, multistrand,PVC insulated, PVC sheathed, un-armoured cables conforming to IS 1554. The size and voltage grade of power cables shall be done as per the requirement and PLC manufacturer's standard only.

CONCLUSION

Supervisory control and data acquisition system is a versatile network of intelligent sub systems, which has brought revolution in the field of monitoring and controlling systems. Further it was a very time consuming process to undo the effect causing the problem (only after making sure the data received is correct). In the mean time a lot of energy is waste and sometimes even unacceptable hazards also used to take place. Also there was no privilege to track the position that is responsible for the error.

The supervisory control and data acquisition system over comes all the above bottlenecks. It has host computer in the master station to store the data for a long period of time so that it can be sued to take strategic decisions sat the time of crisis.

The SCADA System for Vizag Steel Plant shall acquire various electrical and utility parameters for effective monitoring and control operations. The various parameters acquired shall be such as electric power, voltages, currents,flow, temperatures pressures, etc.

These parameters are logged into the system using a suitable database management system. The data is processed and presented in the plant to the concerned officials and operators using user-friendly graphical interfaces.

Advantages of SCADA system are:

High availability of front-end processors to dual access hardware. Scalability due to provision for expansion for Field Remote terminal units, front end

processors, intermediate serial port cards and memory / processors of the host and other computer systems.

Upgradability of hardware and software Standard interfaces like RS 232, LAN etc are provided for interfacing with other

systems and applications. Availability of standard interfaces for interoperability with other systems like central

computer, power plant computer, etc.

Thus SCADA is system has proven that a better technology establishment is a one – time cost but the fruits we see from this are continuous and encouraging.