1. EDM NATIONAL & REGIONAL CONTROL
CENTERS FEASIBILITY STUDY
Introduction to SCADA systemsIntroduction to SCADA systems
and Power Control Centresand Power Control Centres

2. EDM NATIONAL & REGIONAL CONTROL
CENTERS FEASIBILITY STUDY
A dAgenda
 Definitions
 Objectives & main features of SCADA systems
 Different generations of SCADA systems
 Components of Power Control Centres Components of Power Control Centres
 Major requirements of Power Control Centres
 Standardisation process

3. EDM NATIONAL & REGIONAL CONTROL
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S i C t l A d D t A i iti (SCADA)Supervisory Control And Data Acquisition (SCADA)
 Set of computerized systems communicating through ap y g g
telecommunication network that allow operators from a
central location to remotely monitor and control plant
iequipment
 Allows monitoring and control of geographically dispersedg g g p y p
assets from a central location
 Extensively used in electricity power grids but also in gas and Extensively used in electricity power grids but also in gas and
oil industry, water utilities, railway transportation systems,
buildings and factory automationg y

4. EDM NATIONAL & REGIONAL CONTROL
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Monitor
 Critical operational data
 Events
 Alarms
 …
Control
 Generator set points
 Switching devices
 Device automation
 …
Control Centre /
Master station
Power stations and
Substations / Remote
stations
Telecommunication systems
 Fiber optic
 Power line carrier
 Microwave
 Radio
Leased line
 …

5. EDM NATIONAL & REGIONAL CONTROL
CENTERS FEASIBILITY STUDY
 Power control centre
S i t l d d t i iti (SCADA)– Supervisory control and data acquisition (SCADA)
– Balance generation and demand
– Monitor flows and observe system limits
– Coordinate maintenance activities
– Emergency response functions
– Advanced Generation / Transmission (EMS) / Distribution (DMS)( ) ( )
applications
 Power stations and substations
– Feedback controls (governors, voltage regulators, …)
– Protection (protective relays, circuit breakers, …)
 K P i i i Key Priorities
– Safety
– Protect equipment from damageq p g
– Reliability
– Economics

6. EDM NATIONAL & REGIONAL CONTROL
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 Main features of SCADA systems for power gridy p g
‒ Covers wide geographical area
‒ Predominantly open-loop control
‒ Operators play central role
Event driven‒ Event driven
‒ Designed for secure data and control communication
‒ No loss of data
‒ Operators continuously aware of data quality

7. EDM NATIONAL & REGIONAL CONTROL
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 Early generation of SCADA systemsy g y
‒ Facilitate central control and monitoring
‒ Hardwired system
‒ Mimic panel with switches and gauges

8. EDM NATIONAL & REGIONAL CONTROL
CENTERS FEASIBILITY STUDY
 First generation of computer base SCADA systemsg p y
‒ Modern SCADA systems came with introduction of computers
‒ Based on stand-alone mainframe computers
‒ Computers and software purpose-built by SCADA vendors
SCADA slow and noisy communication network‒ SCADA slow and noisy communication network
‒ Proprietary protocols but efficient and reliable communication
‒ Remote station equipment with small I/O density.q p y
‒ Single vendor

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 Local Area Network based SCADA systemsy
‒ Technological advances
 Local Area Network (LAN)
Miniaturization of electronic components and devices
 Computer to computer communication Computer to computer communication
‒ Mini computers
‒ Distributed processing over LANp g
‒ Redundancy and increased reliability
‒ “Open” systems by using third-party hardware and software
l i l i i l‒ Multiple communication protocols
‒ Sharing of information with other information systems

10. EDM NATIONAL & REGIONAL CONTROL
CENTERS FEASIBILITY STUDY
 Wide Area Network based SCADA systemsy
‒ Takes advantage of further advances in computer and
communications technology
‒ Adoption of international standards
Distribution of SCADA functionality across WAN‒ Distribution of SCADA functionality across WAN
– More flexible architecture
– Cost effective Redundancyy
– Greater operational flexibility
‒ Sharing of information with various information systems

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 Control centre / Master station
‒ Located centrally at the Control Center
‒ Network of computer subsystems with various functions to
support the operation of the SCADA based control centersupport the operation of the SCADA based control center
‒ 3 main functional subsystems:y
• Front end subsystem
i & b k / db b• Main & backup / Hot standby subsystem
• Human Machine Interface (HMI) subsystem

12. EDM NATIONAL & REGIONAL CONTROL
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 Front end subsystemy
‒ Manages communication with the remote stations
‒ Responsible for the transmission and reception of raw data
to/from the remote stationsto/from the remote stations
‒ Receives data from remote stations, pre-process them and, p p
send to main computer subsystem
i l f i b d‒ Receives control requests from main computer subsystem and
sends to the remote stations

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 Main & backup / Hot standby subsystemp y y
‒ Contains main SCADA applications & databases
‒ Database holds information of all points
‒ Processes control commands received from MMI, packages
it and sends to front end subsystemy
‒ Process data received from front end subsystem and sends to
bHMI subsystem

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 Human Machine Interface (HMI) subsystem( ) y
‒ Allows operators to interface with SCADA system
‒ Processes operator commands and send to main & backup /
hot standby subsystemhot standby subsystem
‒ Receives information from main & backup / hot standbyp y
subsystem and presents it to operators visually on video
display units, display walls and printers
‒ Receives alarms and alerts operators visually and in audible
wayway

15. EDM NATIONAL & REGIONAL CONTROL
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 Major Power Control Centre requirements Major Power Control Centre requirements
‒ Monitoring of power system real time information
C i l li bl d i li d i f i• Correct, timely, reliable and time-aligned information
• Available to enterprise-wide business operations
• Customized and tailored to each business unit needs
‒ Control operations
• Fast and reliable remote control actions
• Coordinate actions over geographical dispersed and large areas
• Coordinate autonomous staff in decentralized and distributed environment
S t‒ Systems
• Flexible
• Scalable
• Interoperable
• Maintainable

16. EDM NATIONAL & REGIONAL CONTROL
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 Data processing system major components of a Power Controlp g y j p
Centre
S t hit t‒ System architecture
‒ Basic software system
‒ SCADA functions
‒ EMS functions
‒ DMS functions
I t f ith t IT t‒ Interfaces with corporate IT systems
‒ Interfaces with systems of external entities

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 Standardisation process
International standards (IEC, ISO)
National standards (AFNOR, DIN, ANSI, …)
Industry standards (Formalized practice)Industry standards (Formalized practice)
Industry practice (Informal practice)
Proprietary systems (Vendor specific)