Cigre 2013 Colloquium
INFORMATION SYSTEMS AND
TELECOMMUNICATION
COMMUNICATION SYSTEM FOR SMART
TRANSMISSION
(D2-01_01)
Authors: N S Sodha
H H Sharan
Sheela Rani
Load Despatch & Communication Department
Power Grid Corporation of India Limited
Saudamini, Plot No. 02, Sector-29, Gurgaon
122001(HARYANA)
New Delhi
INDIAN POWER SECTOR – AT A GLANCE

Indian Power Sector has grown at a rapid pace from 1.3 GW in 1947 to around 170
GW as on date geographically spread over about 3.3 million sq. kms

Generation Mix comprises





Thermal – 111294 MW (65.4%)
Hydro – 37367 MW (22.0%)
Nuclear – 4780 MW (2.8%)
RES – 16787 MW (9.9%)
Transmission Grid Comprises
 765kV/400kV Lines - 1,07,953 ckt. Kms
 220 kV Lines – 1,33,262 ckt. Kms
 ± 500 kV HVDC Lines – 8,234 ckt. Kms

At current 8-10% of economic growth the installed Capacity requirement of the
country shall be around 575 GW by the year 2027

POWERGRID Carries about 50% of Generated Power Across Country with
Transmission System as on 31 August 2012, comprising of 95,846 Ckt. kms
Tansmission line, 1,44,303 MVA Transformation Capacity, 157 EHVAC/HVDC
Substations, 28,000 MW(Approx) Inter-regional Power Transfer Capacity.
POWERGRID EXPERIENCE IN COMMUNICATION
SYSTEM FOR SMART TRANSMISSION




Establishment of Unified
Load
Despatch
&
Communication (ULDC)
schemes in all Five (5)
regions of country
Each project comprises of
EMS/SCADA
&
Associated
Communication System
based on Fiber Optics/
Digital Microwave/PLCC.
SCADA/EMS Project of
Northern Region of India
is the World’s Largest of
its kind with 33 Control
Centers, 369 RTUs &
more than 3500 Km wide
band
communication
Network.
National Load Despatch
Center
(NLDC)
established in 2008.
Present Hierarchical LD& C System
Unified Load
Despatch &
Communication
5 Nos.
34
Nos.
51
Nos.
1322 Nos.
National
Level
NLDC
Region
Level
RLDC
State HQ
Level
SLDC
Group of
District
Level
SUB LDC
Plant/Sub
Station RTU
Level
POWER SYSTEM HIERARCHY
NLDC:
Ensure integrated operation of
National Grid
5
31
RLDC:
Ensure integrated operation of
Regional Grid
SLDC:
Ensure integrated operation of State
Grid
ESTABLISHED ULDC SYSTEM
Hierarchical system for Load Dispatch were
installed between 2000-2005:
•
•
•
•
•
•
NLDC: National Load Dispatch Centre
RLDC: Regional LDC (5 Nos.)
SLDC: State LDC (31 Nos.)
Sub LDC: 51 Nos.
RTU: More than 1200 RTUs reporting
Communication Media
– Fibre Optic
– Microwave
– PLCC
– VSAT
ULDC PROJECTS – BENEFITS
• Centralised monitoring
• Minimized grid disturbance
• Quick restorations
• Optimized scheduling of generation
• Development & Implementation of Effective Grid Code
and Operational Standards for Grid Security and Reliable
Grid Operation.
• Manning of Load Despatch Centers with trained
personnel
• Facilitation of Availability Based Tariff (ABT)
Monitoring.
COMMUNICATION SYSTEM IMPLEMENDTED
UNDER
ULDC PROJECTS
From RTU to Control Centre : Mostly PLCC
Between Control Centre :
Wideband Communication
(Mix of Fibre Optic & Digital
Microwave)
Technology :
Mix of PDH & SDH
CONSIDERATION FOR COMMUNICATION SYSTEM
IMPLEMENDTED UNDER ULDC PROJECTS
PLCC SYSTEM
Main Consideration:
To cater for Low data requirement between RTU and Sub-LDC
Low Cost
System availability in India
Extensive experience on the system
Limitations:
Low capacity
Low performance in long connections consisting of several hops
Low frequencies
Contd.
CONSIDERATION FOR COMMUNICATION SYSTEM
IMPLEMENDTED UNDER ULDC PROJECTS
Digital Microwave System
Main Consideration:
For providing communication connectivity
centres
Independence from power line
Low Cost compared to cable system
between control
Limitations:
Suitable frequency assignment (Frequency band between 2.3
GHz to 2.5 GHz allocated to Power Sector. This frequency band has
been withdrawn by Ministry of Communication now.)
Line of sight requirement
Susceptible of fading
Contd.
COMMUNICATION SYSTEM IMPLEMENDTED UNDER
ULDC PROJECTS
Fibre Optic System
Mostly OPGW with terminal equipment based on SDH
(STM-1, 155mbps bit rate) technology installed
 Ready infrastructure
 ROW available
Repeater less links distances up to 150km
Centralized NMS
COMPARISION – COMMUNICATION TECHNOLOGIES
COMPARISON OF DIFFERENT COMMUNICATION MEDIA
PARAMETERS
FIBRE
OPTICS
MICROWAVE
PLCC
Bandwidth
Very high
High
Low
Installation cost
Very High
High
Low
Expandability
Easy
Difficult
Not possible
Repeater distance
(typical)
80-90 KM
40-50 KM
Not
applicable
Immunity to
interference
Very High
Prone to
interference
Prone to
interference
Reliability
Very high
High
Low
Frequency
clearance
NA
Required
Required
WIDEBAND COMMUNICATION UNDER ULDC
PROJECTS
Region
Fibre Optic Cable Microwave Hops
Aerial
Northern
2142 Km
78
Southern
2324 Km
35
North Eastern
964 Km
12
Eastern
1520 Km
40
Western
2561 Km
0
9511 Km
165
Total
WIDEBAND COMMUNICATION UNDER ULDC
PROJECTS – CONTD/POWERGRID established Wideband Communication Network
as a part of Unified Load Despatch and Communication
(ULDC) Project in all the Regions.
Wideband Communication Network comprising of Fiber Optic
Communication and Digital microwave Communication
System.
Fiber Optic Communication System was based primarily on
Aerial Cables i.e. OPGW cable and few links on ADSS and
Wrap Around Cable technology.
Majority of the installations of Aerial Cables was carried out
using Live Line Installation Technique.
NEW TECHNOLOGIES IN TRANSMISSION
 Use of Flexible AC Transmission system like Series
Compensation, TCSC, SVC etc. for increase in power
transfer capacity & maintaining critical grid parameters
 Wide Area Monitoring (WAMS), PMUs for real time
monitoring & visualisation.
 Adaptive Islanding, Self Healing
 HVDC Transmission
 Substation Automation
 UHVAC
 SPS (Special Protection Scheme)/SIPS (System Integrated
Protection Scheme) using PMU data
 Remedial Action Schemes (RAS)
COMMUNICATION SYSTEM REQUIREMENT FOR
SMART TRANSMISSION
High Bandwidth
High Reliability
High Availability
Security of highest order
Least latency
15
CHALLANGES FOR COMMUNICATION SYSTEM
Need for Strong Communication Network in order to handle
mass information
Communication channel has to support emerging technology
– WAMS, PMU
Different Networking Environments
16
SMART TRANSMISSION - COMMUNICATION SYSTEM
OPGW PROJECTS
Project status
Sl. No.
OPGW
(in Kms)
A.
OPGW UNDER ULDC PROJECTS
9511
B.
OPGW PROJECTS AWARDED
34602
C.
OPGW UNDER AWARD
8115
D.
OPGW PROJECTS APPROVED
RECENTLY
9159
SUB-TOTAL
61387
OPGW PROJECT UNDER APPROVAL
42667
TOTAL OPGW
104054
E.
SMART TRANSMISSION-COMMUNICATION SYSTEM
OPGW
Implementing OPGW based Communication System under various
project such as Microwave Replacement Project (MRP), Fibre Optic
Expansion Projects (FEP) and other projects
 Around 35000kms of OPGW under implementation
Around 65000kms of OPGW network to be implemented to
meet the requirement
COMMUNICATION EQUIPMENT
Communication equipment with minimum bit rate of 622mbps
being implemented as part of expansion
Provision for both E1 & Ethernet interface in the OLTE equipment
Both equipment protection as well as path protection
NETWORK FOR FUTURE
OPGW based communication network best suited to meet the
communication requirement of Power System
Implementation of ring network wherever feasible
SDH based communication network to
communication requirement of new technologies
meet
the
Provision of both E1 & Ethernet interfaces
Ethernet based backbone with speed ranging from 1 to 10
GBPS