Transcript SCADA system has three layers

Implementation Of SCADA In Power
Plant
Presented by
Muhammad Usman
tee-307-206
What Is SCADA?
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SCADA stands for supervisory control and data
acquisition. It generally refers to a computer system
monitoring and controlling a process.
Why SCADA is Needed
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Reduce the needs for field travel
Faster indication on field problems
Higher reliability of supply
Lower cost maintenance
Higher customer satisfaction
Reduce risk
1950’s – 1970’s Control room
1970’s : Improved Control manual systems
1970’s Onward : Mixed auto/manual
systems
1980’s : SCADA systems appear
Present SCADA system
Basic SCADA System Structure
SCADA
•HMI
SCADA
Modem
PLC
Versatile
Interface
Comm.-
Progr. Tool
Comm.
•Interface
Progr. Tool
RTU
• Local Control
Data Terminal
•Local Display
RTU
• Local Control
SCADA system has three layers
1.
2.
3.
SCADA master
communication media
local control system
SCADA Master
SCADA master consists of three
main parts
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SCADA console
The console is HMI
SCADA server
The server contains database for historical trends
of relevant data.
MTU (Master Terminal Unit).
MTU is a terminal that communicates with
RTU’s at local site.
Human Machine Interface (HMI)
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This is the Heart of the System
 Operator receives information via the HMI
 System functions are initiated via the HMI
Architecture of the HMI
 Single PC up to Hierarchical PC Network
 Standby to assure reliability
Services of HMI Layer Wise
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Higher Management
 Information and Finance
 Planning and Engineering
Mid Control Systems
 Real time network management
Low Control System
 Remote monitoring and Control
 Alarm management
Human Machine Interface
SCADA HMI Provides:
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Monitoring of Parameters and Status
 Pressures Flow Levels
 Pump Operation status
 Power consumption
Control of remote sites
 Pump operation
 Dynamic pressure control
Historical data collection and analysis
 Trending on past demand and parameters
 Fault events
Communication Media
Communication media
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For the data communication between MTU and
RTU, communication media will be chosen from
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leased line
microwave radio
fiber optic transmission
satellite communication
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Redundant Source for back-up
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What is protocol?
A protocol is a set of rules that governs how message containing
data and control information are assembled at a source for their
transmission across the network and then dissembled when they
reach their destination.
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IEC 60850-5-101
IEC 60850-5-103
DNP3
Elcom-90
TCP/IP and SLIP
ABB - RP570/571
ABB - INDACTIC 2033
GI74
TG709/E & TG809
Data Communication Network
RTU
RTU
RTU
Site 2
RTU
Site 1
Remote
Programming
SCADA
Local Control System
Remote Terminal Units
An RTU converts the electrical signals from the equipment to
digital values such as the open/closed status for a switch,
Valve or pump etc. By sending and receiving these electrical
signal RTU can control equipment.
Reliable and Secure
 Very Low Failure rate
 Secure and Reliable messages
 Expandable and Upgradeable
 Provides platform for growth and enhancement
 Modular concept allows simple modifications
 Friendly to Operate and Maintain
What to Look for in a SCADA-RTU
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Sufficient capacity to support the equipment
at your site
Rugged construction
Secure, redundant power supply.
Redundant communication ports.
NVRAM
Watchdog timer
Intelligent control.
Remote Terminal Units
Housing &
Chassis
Power Supply
CPU
Frames
I/O Modules
Radios
Software
Dynamic Pressure Control
Antenna
Optional
Solar
Panel
RTU
Monitor and
Control
Q
Flow
Power Consumption Reduction 1/2
Pressure
/ flow
Sensors
Pump
Power
Main valve
Start/Stop
Controls
Interface between HMI and RTU
Different RTU’s
Case Study
CRITICAL CONTROL Of BOILER
Manual Control
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Human Errors
Hard Wired Logic Control (Contactors & relay's
together with timers and counters)
Bulky and complex wiring
The work can be started only when the task is fully
defined and this leads to longer project time.
Scada Environment
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Advantages
Reduced Space
Higher productivity
Superior quality of end product
Efficient usage of raw materials and
Energy
Easy trouble shooting
Improved safety in working condition
Reduce Human Error
CRITICAL CONTROL PARAMETERS IN
BOILER
Level Control
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Steam Drum level
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De-aerator level
Pressure Control
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Steam pressure
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drum pressure
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De-aerator pressure
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Turbine inlet pressure
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Flow Control
Air flow
Steam flow
Water flow
Temperature Control
De-aerator temperature
Steam drum temperature
Turbine inlet steam temperature
Flue gas temperature
Flow Chart Of PLC-Scada
Purpose of PLC works ?
Basics of a PLC function are continual scanning of a
program. The scanning process involves three basic
steps.
1.
2.
3.
Testing input status
Programming execution
Checking and Correcting of output status
Scanning time = Time for performing step 1+ Time
for performing step 2+ Time for performing step 3.
PLC Working
At the beginning of each cycle the CPU brings in all
the field input signals from the input signals and store
into internal memory of CPU is called as process input
image (PII).
User program will be available in CPU program
memory. Once PII is read, CPU pointer moves in ladder
program from left to right and from top to bottom. CPU
takes status of input from PII and user program. The
result of scan is stored in the internal memory of CPU
called process output image or POI and Is sent to the
field control.
I/O driver (SCADA) picks up PII and POI and transfers
the image to database and this image is called driver
image. This driver image available in SCADA database
is used for graphical view of process monitoring from
operator station (OS) in the central control room.
PID Controller-SCADA
Flow chart of Boiler Operation
Any Questions?