1. COMMUNICATION REQUIREMENTS FOR SCADA Communication media should have: Communication media should have: * High Reliability * High Reliability * High Availability * High Availability * Rapid Response * Rapid Response * Transparency * Transparency * Economy * Economy * Flexibility * Flexibility * Maintainability * Maintainability

2. Modes of Communication Modes of Communication PLCC PLCC PLCC Leased Telephone circuits Leased Telephone circuits Leased Telephone circuits Leased Telephone circuits Microwave Communication Microwave Communication Microwave Communication Microwave Communication Fibre Optics Communication Fibre Optics Communication Fibre Optics Communication Fibre Optics Communication Satellite Communication Satellite Communication Satellite Communication Satellite Communication

3. PLCC High voltage lines themselves are used as communication links. High voltage lines themselves are used as communication links. Carrier Frequency: 50-300 KHz. Carrier Frequency: 50-300 KHz. 3 channels are used generally: 3 channels are used generally: Main-Channel -> Main-Channel -> speech channel – 300 Hz to 2000 Hz speech channel – 300 Hz to 2000 Hz Telemetring- 2000 Hz to 3400 Hz Telemetring- 2000 Hz to 3400 Hz Protection-Channel-I -> Protection-Channel-I -> speech channel – 300 Hz to 2000 Hz speech channel – 300 Hz to 2000 Hz Teleprotection- 2000 Hz to 3400 Hz Teleprotection- 2000 Hz to 3400 Hz Protection-Channel-II (Backup-Protection)-> Protection-Channel-II (Backup-Protection)-> speech channel – 300 Hz to 2000 Hz speech channel – 300 Hz to 2000 Hz Teleprotection- 2000 Hz to 3400 Hz Teleprotection- 2000 Hz to 3400 Hz

4. PLCC Advantages: 1. High reliability 2. All channels are available for dedicated use by power-utility alone power-utility aloneDisadvantages: 1. Cost of insulating communication equipment is high 2. High noise level due to Corona 3. High speed data-transfer not possible because of Bandwidth limitations. Bandwidth limitations.

5. Microwave Communication Line-of-sight communication Line-of-sight communication Requires repeaters at 50-60 kms. Intervals Requires repeaters at 50-60 kms. Intervals Provides sufficient bandwidth to meet the needs of power utility Provides sufficient bandwidth to meet the needs of power utility Higher availability than PLCC, availablity not affected by maintenance or faults on the power lines Higher availability than PLCC, availablity not affected by maintenance or faults on the power lines Suffers from multipath-fading effect Suffers from multipath-fading effect In India, WPC (wireless planning & co-ordination) wing has assigned 2.3-2.5 GHz and 2.8-5 GHz bands to power sector usage. In India, WPC (wireless planning & co-ordination) wing has assigned 2.3-2.5 GHz and 2.8-5 GHz bands to power sector usage.

6. Digital Microwave Systems

7. Leased Telephone Circuits Simple solution, no need to develop own dedicated communication facility by power utility Availability of this mode of communication at remotely located substations is the deciding factor

8. Fiber-Optic Communication Fiber-optic communication is a method of transmitting information from one place to another by sending light through an optical fiber. The light forms an electromagnetic carrier wave that is modulated to carry information Fiber-optic communication is a method of transmitting information from one place to another by sending light through an optical fiber. The light forms an electromagnetic carrier wave that is modulated to carry information The process of communicating using fiber-optics involves the following basic steps: Creating the optical signal using a transmitter Relaying the signal along the fiber, ensuring that the signal does not become too distorted or weak Receiving the optical signal and converting it into an electrical signal Analog/Digital Interface Voltage to Current converter Light Source Source to Fiber Interface Fiber to Light Detector Interface Light Detector Current to Voltage converter Analog/Digital Interface OUTPUT INPUT Optical Fiber

9. Fiber Optic Communication Advantages: Advantages: The ability to carry much more information and deliver it with greater fidelity than either copper wire or coaxial cable. The ability to carry much more information and deliver it with greater fidelity than either copper wire or coaxial cable. Fiber optic cable can support much higher data rates, and at greater distances Fiber optic cable can support much higher data rates, and at greater distances The fiber is totally immune to virtually all kinds of interference, including lightning, and will not conduct electricity. It can therefore come in direct contact with high voltage electrical equipment and power lines. The fiber is totally immune to virtually all kinds of interference, including lightning, and will not conduct electricity. It can therefore come in direct contact with high voltage electrical equipment and power lines. POWERGRID uses overhead fiber optic communication: POWERGRID uses overhead fiber optic communication: OPGW (optical ground wire cable) OPGW (optical ground wire cable)OPGW ADSS (all dielectric self supporting cable) ADSS (all dielectric self supporting cable)ADSS WRAP AROUND WRAP AROUNDWRAP AROUNDWRAP AROUND

10. Fibre Optic Systems

11. OPGW FODP OLTE ADD DROP MUX 2 MB/S MICROWAVE RADIO TERMINAL 2 MB/S INTEGRATION OF DIGITAL & ANALOG NETWORKS PLCC VOICE CARD DATA CARD

12. OPGW OPGW (optical ground wire) replaces shield wires OPGW (optical ground wire) replaces shield wires Provides lightning protection Provides lightning protection Provides communication Provides communication Lightning short circuit damage Lightning short circuit damage Installation requires long term outage Installation requires long term outage Expensive Expensive Superior performance Superior performance

13. ADSS F.O ADSS (all dielectric self supporting) which ADSS (all dielectric self supporting) which is mounted at various locations, typically 3 is mounted at various locations, typically 3 to 10 meters below the phase conductors. to 10 meters below the phase conductors. ADSS costs less than OPGW ADSS costs less than OPGW Higher fiber count than Wrap type. Higher fiber count than Wrap type. Can be installed on towers not designed for shield wires. Can be installed on towers not designed for shield wires. Suitable for hot line installation Suitable for hot line installation

14. WRAP AROUND F.O Wrap-type which is wound around shield wires and, in some instances, around energized conductors Wrap-type which is wound around shield wires and, in some instances, around energized conductors Hot-line installation is difficult Hot-line installation is difficult Cost more than ADSS, but less than OPGW Cost more than ADSS, but less than OPGW Need a shield wire Need a shield wire No operation problem is observed No operation problem is observed

15. OPGW WRAP ADSS OVERHEAD CABLES FOR POWER UTILITIES

17. FIBRE OPTIC CABLE INSTALLATION OPGW WRAP AROUND ADSS AD\AS\RKG\JP\FIBINST

18. SATELLITE COMMUNICATION A geostationary satellite is used as an active repeater. A geostationary satellite is used as an active repeater. Modulated signals are send from earth VSATs in 6 GHz band to the satellite. Modulated signals are send from earth VSATs in 6 GHz band to the satellite. Signals are beamed back to earth in 4 GHz band. Signals are beamed back to earth in 4 GHz band. Roundtime propagation delay of 540ms exists Roundtime propagation delay of 540ms exists Communication is interrupted during eclipses. Communication is interrupted during eclipses.

19. Lingasugur

21. WRLDC Borivalli Vav Haldarwa Jambuva Gotri SLDC Asoj Itarsi Indore Sub-LDC Itarsi V’chal Korba STPP Raipur Bhilai-400 (SLDC) Jabalpur-400 Asoj WRTCC Indore Dhule Vindhyanchal Chandrapur Phadge Kalwa Tarapur 1&2 Itarsi-220 Bina-400 Bhopal-400 Sub-LDC Satna-220 Katni-220 Jabalpur-220 SLDC- Jabalpur Korba-West Korba-East Kalwa Kawas Rajgarh Khandwa Sipat Raigarh Bhatapara Seoni Bhilai-220 Vadodara POP Gandhar Kakrapar Dehgam Tarapur 3&4 Phadge Bhadrawati Satna Bina Gwalior Vapi Boiser LEGENDS Green - ULDC Wideband Link BLUE - PDT Link Black - PLCC Link Main Data PLCC Channel St. By Data PLCC Channel Both Main and Std. By Data PLCC Channel HaldarwaJambuva Asoj 62 Nos. PLCC Equipment 109 Nos. Wideband ULDC Eqpt MPSEB Sector CSEB Sector GEB Sector WR-SC&C Communication system ILA-387 ILA-174 ILA-311 ILA-194ILA-362ILA-702 ILA-368 KR-13 Raipur B’Vati SEB’s Wideband Equipment and OFC OPGW U/G – OFC SLDC GOA Leased Link Ponda Mapusa

22. Sembatti Madurai 400 Trichy 400 Paramakudi Samayapuram Madurai North Kodayar PH2 Madurai Sub LDC Karaikudi Tanjore 230 S R Pudur Pariyar PH Theni Kayathar E Sathur TTPS Podukotta C Echengodu Adanakottai Peramballur Kovilvenni Pugalur Thiruvarur Tuticorin Auto Trichy 230 Chennai Sub-LDC (NLC TS-I) Erode Sub-LDC (Erode) Wideband Channel Routing for Madurai Sub-LDC Orthonadu Sivagangai Existing RTU – 9 nos. Existing RTU integrated New RTUs – 13 nos. PLCC Link MW Link

23. ChalakudyT. NorthKozhikode -BKannur-B Kalamassery Pallom KayamkulamKundraParipallyTrivendrum North Vidyuthi Bhavanam RSCC,Bangalore (Udumalpet) Wideband Routing from Sub-LDC to SLDC,(Kalamassery) COMMUNICATION NETWORK FOR KERALA MW Link FO Link