• Power sector across the world is undergoing a lot of
restructuring; India is no exception to this.
• In some States of India there are multiple private
utilities, which are technically and financially in a
position to enter the phase of a competitive
SARAVANAN SIVAMANI 2
What is a “Grid” ?
WHAT IS AN “INTER-CONNECTION” ?
WHY DO WE NEED THIS INTER-CONNECTION ?
3)Proper Load Sharing
Two or more generating stations are interconnected by tie lines.
Interconnection provides the best use of power resources and
ensures greater security of supply.
An Interconnected power system covering a major portion of a
country’s territory (or state) is called a Grid. The different state grids
may be a interconnected through transmission lines to form a Grid.
SARAVANAN SIVAMANI 3
All Power-Grid equipments used
Lightning Arrestor Power Transformer
Current Transformer/Potential Transformer
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NEED FOR RESTRUCTURING
• The need for restructuring the power sector was felt
due to the scarcity of financial resources available
with Central and State Governments.
• Necessity of improving the technical and commercial
SARAVANAN SIVAMANI 6
PROPOSED MODEL FOR
RESTRUCTURING IN INDIA
• In many parts of the world wherever unbundling, i.e.
separation of generation, transmission and
distribution has taken place, the two models are more
prevalent for system operation.
• Independent System Operator (ISO) model
• Transmission System Operator (TSO) model.
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ISO AND TSO MODELS
• . In ISO model, transmission companies are also
permitted to own, manage and control generation and
distribution companies, an independent system operator is
created to facilitate open access and competitive markets.
• In TSO model, operation of the grid and ownership of the
grid are integrated in a single entity, which is responsible
for development of transmission system and to provide
non-discriminatory open access to all eligible market
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TO BE CONTINUED….
• TSO model seems to be most suitable for future
restructured electricity market in India.
• This is because the government owned transmission
company is merely responsible to provide non-
discriminatory open access.
SARAVANAN SIVAMANI 9
ELECTRICITY ACT 2003
• This act consolidates all the existing laws and
introduces provisions with respect to new
developments in the sector. It focuses on
creating competition, protecting consumer interests,
rationalizing tariff, etc.
• All the necessary powers including issue of licenses
are given to the regulators which
are made independent entities from the government.
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• Open access in transmission with provision of surcharge
for cross subsidy and this surcharge
will be gradually phased out.
• Distribution licensees are free to undertake generation
and generating companies are free to take up distribution
• For rural and remote areas stand alone systems for
generation and distribution would be permitted.
• State Governments can convert State Electricity Boards
(SEBs) into companies or continue them as distribution
SARAVANAN SIVAMANI 122
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(EX NR, ER,NER)
REGIONAL (SYNCHRONOUS GRID)
LOAD DESPATCH CENTRE
GENERATION OF ELECTRICITY
• The generating company should establish, operate and
maintain generating stations, tie-lines, substations and
dedicated transmission lines.
• According to the 16th Electric Power survey conducted
by CEA, the country has energy shortage of 7.8 % and
peaking shortage of 13 % (100GW).
• As per the reports published by Oxford Institute for
Energy Studies (OIES)  the Indian Government should
do more to encourage and facilitate local private
investment in small-scale distributed electricity
SARAVANAN SIVAMANI 144
Central Authority System (contd.)
•The Central Electricity Authority of India (CEA) is a
statutory organisation constituted under section 3(1) of
Electricity Supply Act 1948
•To develop a sound adequate and uniform national power
policy, formulate short-term and perspective plans for power
development and co-ordinate the activities of planning
agencies in relation to the control and utilisation of national
•To collect and record the data concerning generation,
distribution and utilisation of power and carry out studies
relating to cost, efficiency, losses, benefits and such like
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What is a National load Dispatch Centre ?
The main functions assigned to NLDC are:
• Supervision Over the Regional Load Dispatch Centers.
• Scheduling and dispatch of electricity over the inter-regional
links in accordance with grid standards specified by the
authority and grid code specified by Central Commission in
coordination with Regional Load Dispatch Centers.
• Coordination with Regional Load Dispatch Centers for
achieving maximum economy and efficiency in the operation
of National Grid.
• Monitoring of operations and grid security of the National
• Coordination for restoration of synchronous operation of
national grid with Regional Load Despatch Centres.
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Sharing Of Transmission Charges
•Wheeling is the transportation of electric power (megawatts
or megavolt-amperes) over transmission lines.
•An entity that generates power does not have to own
power transmission lines
•The entity then pays the owner of the transmission line
based on how much power is being moved and how
congested the line is.
•Charges for inter-regional lines may be shared by two
contiguous regions on 50 : 50 basis.
•Charges for the regional assets may be shared by the regional
•If an inter regional asset is used for wheeling by a third party
the balance transmission charges may be shared by the
beneficiaries of the contiguous region on 50 : 50 basis.
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Ownership and Coordination
• Inter-State and other transmission links may be owned
by other independent entity (Ex: PGCIL).
• State Electricity Boards can Import or Export a pre
decided amount of power from neighboring states or
generators owned by other entities like National
Thermal Power Corporation.
• State Electricity Boards are divided into
1) Generation companies (GENCOs)
2) Distribution Companies (DISCOs)
3) Transmission Companies(TRANSCOs)
• Overall coordination is done by a Load Dispatch
SARAVANAN SIVAMANI 188
The companies which are responsible for power generation are
called as Generation Companies(GENCOs) ex: NTPC
The companies which are responsible for transmission of large
amounts of power are called as Transmission
companies(TRANSCOs) Ex: PowerGrid
The companies which are responsible for Distribution of the
large amounts of power to the general public are called as
Distribution Companies(DISCOs) Ex: UP-RVVNL
SARAVANAN SIVAMANI 199
Transmission of Electricity
• The RLDC will work as per the Indian Electricity Grid Code
(IEGC) to ensure integrated operation of the power system in
the concerned regions.
• It has to monitor grid operations, keep accounts of
the quantity of electricity transmitted through the regional
grids, exercise supervision and control over the Intra-State
• It will be responsible for carrying out real time operations for
grid control and dispatch of electricity within the state through
secure and economic operation of the state grid in accordance
with grid standards and the state grid code.
SARAVANAN SIVAMANI 20
Distribution of Electricity
• State Commission permits a consumer or class of
consumers to receive supply of electricity from a person
other than the distribution licensee of his area of
supply, such consumer shall be liable to pay an
additional surcharge on the charges of wheeling, as may
be specified by the State Commission, to meet the fixed
cost of such distribution licensee arising out of his
obligation to supply.
• Distribution companies have been given mandate for
achieving complete metering within two years from the
enactment of the law.
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Different grids of India
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Some Landmark Events Of Power Grid
• 1948 - Growth of supply systems
• 1962- First 220KV Voltage level
• 1967- Interconnection Of state Grids to form
• 1975- First 400Kv Voltage level
• 1989- HVDC Back to Back
• 1998- Installation of 765 Kv line(Charged at 400Kv)
• 2006- Synchronisation of NR with ER-NER-WR
• 2007- Transmission at 765 Kv
• 2010/11- Installation of 800Kv HVDC Bi-pole Line
SARAVANAN SIVAMANI 23