SCADA Supervisory Control And Data Acquisition
System for National Power Control Center
NTDC, WAPDA Islamabad
Data Acquisition System
Data/Voice Transmission Channel
PLC, Microwave, Satellite, PTCL, Mobile
Two Computer Systems
- One at NPCC Islamabad both for NCC Islamabad & Regional Control Center North
- One at Regional Control Center Jamshoro
Computers are based on Computers are based on 1980’s1980’s technology Memory of the computer technology Memory of the computer
at NPCC/RCC is at NPCC/RCC is 4 Mbytes4 Mbytes. . Secondary Secondary
memory(H.D) memory(H.D) 340 Mbytes 340 Mbytes
Both Systems Linked via 6 Channels through Wapda’s Analoge Microwave
system
PresentNPCC, NTDC SCADA System
• NPCC Computer system connected with 25 RTUs– Regional Control center (North) is Using same computer .
• Regional Control Center (south) heaving separate computer system connected with 11 RTUs
– It has a Front end to Front end link with NPCC (subscription link)
• In-plant SCADA system at Tarbela further connected with 11 RTUs
– It has a Front end to Front end link with NPCC only for selected values ( due to less memory of NPCC SCADA system) from selected RTUs via single subscription link through PLC.
Network Configuration
Point to Point
Multi Drop
Series
Star
Series loop
Subordinate terminals
Limitations for RTU interfacing 40 channels were
designed 34 already allocated.
Data acquisition Facilities 1/2
Analogue Values– MW– MVAR – Voltages– Frequency– Tap position
Data acquisition Facilities page 2/2
Status ( Indications )• Breaker Open / Close and error Status (X)• Isolator Open / Close and error Status (X)• Protection signals (only for IPPs)• Synchro-check Signals ( Freq, Phase and Voltage difference)• AGC signals
Remote Control FacilitiesRemote Control Facilities
Remote Control OperationRemote Control Operation – Breaker Open / Close (Only for 500Kv breakers)– Tap regulation (Only for 500/220 Kv Transformers.)
– Automatic Generation Control (Facility limited due to poor communication and limited interfacing )
Remote Control OperationRemote Control Operation – Breaker Open / Close (Only for 500Kv breakers)– Tap regulation (Only for 500/220 Kv Transformers.)
– Automatic Generation Control (Facility limited due to poor communication and limited interfacing )
Operation Pages
Display types– Single line diagrams– Curves– Events– Alarms– Reports, power system– Post mortem review (only for analogue
values on 30 Seconds Resolution)
Storage Capacities
Values and indication Storages
Values: Storage
Time
• 10 Seconds Instant values only for AGC = 250 : (45 min)
• 30 Seconds Instant =1000 : ( 1Hrs )
• 15 Minutes Instant = 650 : (5 days)
• One Hour Instant ALL : (5 days)
• One Hour Indications ALL : (5 days)
1. How can load Despatch system sustain and ensure !Optimization of costs of GenerationMinimization of transmission lossesQuick restoration of supply Minimization of outages Avoiding major collapseQuality and reliability of supply Voltage and frequency control By upgrading existing SCADA & Tele-communication with latest version
Technical Features(SCADA Hardware)
Existing System Proposed New System
Make : Modcomp USA /ABB Latest Available At the time of Procurement
Operating System MAX-IV
( DOS environment)
Window Based
(User Friendly)
Capacity : 4 MB Latest Available At the time of Procurement
Present day PC RAM : 1000 MB
Hard Disk Space : 340MB Latest Available At the time of Procurement
PC Hard Disk : 40000- 80000 MB
Speed : 30 MHz Normal PC Speed > 2000 MHz
VDUs are of special design,
Replacement of VDU is due ( Life was 10 years)
Cost is very High, being of special design
VDU are of common design.
Easy replacement being readily available.
Low Cost.
Interfacing with PC is not provided in the system. Can be easily Interfaced with PC.
Spares no longer manufactured becoming difficult to maintain
Technical support from manufacturer if required may not be available in future.
In new system this problem will be solved.
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Technical Features(SCADA Software)
Existing System Proposed New System
New application Software cannot be used due to less memory and speed.
New Software would be easy to run.
The following new software are proposed which are essential for NPCC.
i. Unit Commitment and economic despatch.
ii. Automatic Generation control.
iii. Optimal Power flow.
iv. Load Forecasting Software.
v. Training Simulator software.
vi. On line Load flow studies.
vii. Contingency Analysis
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Technical Features(Remote Terminal Units - RTUs )
Existing System Proposed New System
Only ABB Collector 300 and Collector 400 RTUs can be Interfaced
RTUs of any make & type can be interfaced.
Cost Per RTU : Rs 12.5 Mln.
Existing Stations( without RTUs) : 9
Future stations up to 2008 : 17
Cost of 26 RTUs ( 9 + 17) : Rs. 325 Mln.
Rs. 3 Mln.
Rs. 78 Mln.
Expensive Transducers are required due to software limitation and is proprietary item of ABB
Low cost transducers can be used.
Expensive spares have to be purchased from manufacturer being proprietary item of ABB
Cheap Spares can be purchased from open market.
Limit to interface number of RTUs is 40, which is about to exhaust.
Communication Lines Interfacing Limit of both RTUs and Lines would be enhanced.
Globel Positioning system ( GPS ) for time clock cannot be interfaced.
GPS is easy to interface.
Only 6 – channels for interfacing with other system.
Enhanced number of channels.
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Technical Features(Telecommunications)
Existing System Proposed New System
Analogue Microwave backbone from Islamabad to Jamshoro
Digital Microwave communication highway from Islamabad to Jamshoro.
Number of Channels : 60 Number of Channels : 630
Channels Capacity already saturated Channels capacity enhancement possible up to 1890 Channels.
Spares no longer manufactured, Becoming difficult to maintain.
Spare availability shall be ensured for about 15 years.
Failure rate of system is on increasing trend. --
System is working in 1 + 0 configuration at several points instead of 1 + 1 requirement.
--
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Status of RTUs
(Installed)500 kV ( 13 Stations )
Tarbela Guddu Ghazi Barotha ( Not Comissioned )
New Rewat Dadu Hubco
Lahore Jamshoro Rousch
Gatti Muzzafar Garh ( Not Comissioned )
New Multan Shaikh Mohammedi ( Not Comissioned)
220 kV ( 21 Stations )
Mardan Nishatabad Islamabad Pesh Road ( Not Comissioned)
Burhan Kala Shah Kaku Daud Khail ( Not Comissioned )
Gakhar Bund Road AES Lal pir
Mangle NGPS Multan AES Pakgen
New Kot Lakhpat Sibbi KAPCO
Yousaf Wala Hala Road Uch Power
Jaranwala Road Sialkot ( Not Comissioned ) Chashnup
132kV (11 Stations )
Warsak GTPS Faisalabad Fuji Kabirwala
Kel Saba Power Liberty Power
Kotri Chasma Hydro Power ( Not Comissioned) Habibullah coastal
Sepcol Japan ( Not Comissioned )
1/2
Status of RTUs
(Additional Requirement upto year 2008 )
Existing Stations without RTUs
220 kV ( 8 Stations )
Bahawalpur Bannu Ludewwala
Quetta Industrial Ravi Sumundri Road
Sarfraz Nager Vehari
132 kV
Lakhra
Future Stations to be commissioned upto 2008
500 kV ( 4 Stations)
Gujranwala Sahiwal Rahim Yar Khan
KESC
220kV ( 13 Stations )
Shahi Bagh Fateh Garh Islamabad University
Nowshera Indutrial Mansehra Mustung
Ghazi Road Lahore Chiniot Road Kharian
Shikar Pur T.M Khan (Hydrabad)
Chichawatni D.G Khan
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