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.

RTU

SUB LDC

SLDC

RLDC

NLDC

34Nos.

51 Nos.

1322 Nos.

5 Nos.

Plant/Sub Station Level

Group of District Level

State HQ Level

Region Level

National Level

Unified Load Despatch &

Communication

Present Hierarchical LD& C System

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.

POWERGRID EXPERIENCE IN COMMUNICATION SYSTEM FOR SMART TRANSMISSION

NLDC:Ensure integrated operation of National Grid

RLDC:Ensure integrated operation of Regional Grid

SLDC:Ensure integrated operation of State Grid

31

5

POWER SYSTEM HIERARCHY

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

ESTABLISHED ULDC SYSTEM

ULDC PROJECTS – BENEFITSULDC PROJECTS – BENEFITS

• Centralised monitoring Centralised monitoring

• Minimized grid disturbance Minimized grid disturbance

• Quick restorationsQuick restorations

• Optimized scheduling of generation Optimized scheduling of generation

• Development & Implementation of Effective Grid Code Development & Implementation of Effective Grid Code and Operational Standards for Grid Security and Reliable and Operational Standards for Grid Security and Reliable Grid Operation.Grid Operation.

• Manning of Load Despatch Centers with trained Manning of Load Despatch Centers with trained personnel personnel

• Facilitation of Availability Based Tariff (ABT) Facilitation of Availability Based Tariff (ABT) MonitoringMonitoring..

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-LDCLow CostSystem availability in IndiaExtensive experience on the system

Limitations:Low capacityLow performance in long connections consisting of several hopsLow frequencies

Contd.

Digital Microwave System

Main Consideration:For providing communication connectivity between control

centresIndependence from power lineLow Cost compared to cable system

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 requirementSusceptible of fading

Contd.

CONSIDERATION FOR 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

COMMUNICATION SYSTEM IMPLEMENDTED UNDER ULDC PROJECTS

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

COMPARISION – COMMUNICATION TECHNOLOGIES

Region Fibre Optic Cable Aerial

Microwave Hops

Northern 2142 Km 78

Southern 2324 Km 35

North Eastern 964 Km 12

Eastern 1520 Km 40

Western 2561 Km 0

Total 9511 Km 165

WIDEBAND COMMUNICATION UNDER ULDC WIDEBAND COMMUNICATION UNDER ULDC PROJECTSPROJECTS

WIDEBAND COMMUNICATION UNDER ULDC WIDEBAND COMMUNICATION UNDER ULDC PROJECTSPROJECTS

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.

WIDEBAND COMMUNICATION UNDER ULDC WIDEBAND COMMUNICATION UNDER ULDC PROJECTS – CONTD/-PROJECTS – CONTD/-

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

15

High Bandwidth

High Reliability

High Availability

Security of highest order

Least latency

CHALLANGES FOR COMMUNICATION SYSTEM

16

Need for Strong Communication Network in order to handle mass information

Communication channel has to support emerging technology – WAMS, PMU

Different Networking Environments

SMART TRANSMISSION - COMMUNICATION SYSTEM

OPGW PROJECTS

Sl. No.Project status OPGW

(in Kms)

A. OPGW UNDER ULDC PROJECTS 9511

B. OPGW PROJECTS AWARDED 34602

C. OPGW UNDER AWARD 8115

D.OPGW PROJECTS APPROVED

RECENTLY9159

SUB-TOTAL 61387

E. OPGW PROJECT UNDER APPROVAL 42667

TOTAL OPGW 104054

SMART TRANSMISSION-COMMUNICATION SYSTEM

OPGWImplementing 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 implementationAround 65000kms of OPGW network to be implemented to meet the requirement

COMMUNICATION EQUIPMENTCommunication equipment with minimum bit rate of 622mbps being implemented as part of expansionProvision for both E1 & Ethernet interface in the OLTE equipmentBoth 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 meet the communication requirement of new technologies

Provision of both E1 & Ethernet interfaces

Ethernet based backbone with speed ranging from 1 to 10 GBPS