POWER
REPUBLIC DAY 2009
DEVELOPMENT OF NATIONAL GRID
India is endowed with rich and abundant natural resources. However, these energy
resources are unevenly distributed such as, coal resources are abundant in Bihar/Jharkhand,
Orissa, West Bengal, hydro resources are mainly concentrated in Northern and North-Eastern
Region, etc. But the demand for power continues to grow all over the country.
Creation of a strong “National Power Grid” has been recognized as a flagship endeavor to
steer the development of power system on a planned path leading to a cost effective fulfillment of
the objective of ‘Electricity to All’.
Establishment of a strong National Grid has been planned in a phased manner to ensure
optimum utilization of generating resources and bringing security & reliability in power system
operation. Towards this, a perspective transmission plan has been evolved for strengthening the
regional grids and to support the generation capacity addition in the country. In line with this
plan, various inter-regional transmission schemes have been commissioned/ undertaken for
implementation/ commissioned.
During the 1990s and early 200s considering the then prevailing operational regime, to
start with, it was decided to establish asynchronous connections between the Regional Grids to
enable exchange of regulated quantum of power. Accordingly, a synchronous HVDC back-toback links of 500MW at Vindhyachal between the Northern and Western Region, 1000 MW at
Bhadrawati between Western and Southern Region, 1000MW at Gazuwaka between Eastern and
Southern Region and 500MW at Sasaram between Eastern and Northern Region were
established.
Several other milestones have been achieved as a part of development of National Grid
such as implementation of Asia’s longest Talcher-Kolar HVDC Bipole link including its
upgradation, Sasaram HVDC back-to-back link, 400 kV D/C Synchronous interconnection
between Eastern and Western Region including series compensation, Muzaffarpur-Gorakhpur400
kV D/c line under Tala Transmission System, Agra-Gwalior 765 kV S/C line (operating at 400
kV), Patna-Balia 400 kV D/c line, Biharshariff-Balia 400 kV D/c line, etc.
At present, National Grid with inter-regional power transfer capacity of about 17,000
MW has been established. Presently, the Northern, Western, Eastern and North-Eastern regions
are operating as one synchronous grid. Southern Region is interconnected with this large grid
(ER-WR-NR-NER) mainly through asynchronous links viz., HVDC back-to-back and HVDC
bipole lines.
Strong transmission network established in the country and modernised Regional Load
Despatch Centres (RLDCs) have facilitated manifold growth in inter-regional power exchanges
across the country on real-time basis. During FY 2007-08, about 43,000 MUs of inter-regional
energy transfer was facilitated across the country, an increase of about 13% compared to previous
year (about 38,000 MU). Growth of inter-regional power exchange helped in meeting more
demand in energy deficit regions besides achieving overall economy.
Further strengthening of this National Grid is being undertaken through implementation
of various inter-regional links as a part of planned generation projects. Accordingly, the Interregional power transfer capacity of National Grid is envisaged to be enhanced to more than
37,000 MW by year 2012.
Several technological innovations aimed at conserving Right of Way (RoW), minimizing
impact on natural resources & human habitat and cost effectiveness in evacuation of power from
the future generation projects were undertaken in the country. For transfer of bulk power over
long distances, initiatives were under taken for development of major transmission highways
using higher transmission voltage levels, i.e. at 765 kV EHV AC and ±500 kV HVDC to achieve
efficient utilisation of existing RoW and increased power transfer capability. During financial
year 2007-08, next higher transmission voltage, i.e. 765 kV was introduced in the country by
commissioning and operating country’s 1st 765 kV transmission line, namely Sipat-Seoni line,
alongwith 765/ 400/ 220 kV Seoni Sub-station at 765 kV at its rated voltage, in October’07. This
is a major milestone in the process of gearing ourselves in meeting the future requirement.
With a focus on long term sustainability and to serve the growing energy needs, efforts
are under way towards introducing 1200 kV AC voltage in India. POWERGRID is establishing a
1200kV Ultra High Voltage AC Test Station at Bina (WR) as a collaborative effort with
manufacturers for indigenous development of 1200KV equipment. Besides, action plan was also
formulated to implement +800kV, 6000 MW HVDC Bi-pole line from North Eastern region to
Northern Region (Agra). This link shall pass through the North Eastern Region, transferring large
quantum of power over more than 2000 Kms. These technologies are pioneering efforts even
globally. Other transmission technologies envisaged for future include, High Surge Impedance
Loading (HSIL) line, Large scale automation of Sub-stations, High Temperature Conductors for
increased loading (INVAR, GAP, ACCC, ACCR), etc. (PIB Features)
CAPACITY (MW)
MW
37,000
14,100
17,000
11,500
5,000
500
1993
2002
2006
2007
2008
YEAR
Graph: Growth of National Grid capacity
*Inputs from the Ministry of Power
RTS/VN
2012