Restructuring of power grid

RESTRUCTURING OF GRID

SARAVANAN SIVAMANI 1

INTRODUCTION

• 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

electricity market.


What is a “Grid” ?

WHAT IS AN “INTER-CONNECTION” ?

WHY DO WE NEED THIS INTER-CONNECTION ?

1)Reliability

2)Economy

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.


All Power-Grid equipments used

Lightning Arrestor Power Transformer

Current Transformer/Potential Transformer


Circuit Breakers Insulators Isolators

Wave Trap


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

efficiency.


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.


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 participants.


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.


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.



SALIENT FEATURES

• 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 licensees.

• 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 licensees.


CENTRAL AUTHORITY SYSTEM


COORDINATE WITH

OTHER

SYSNCHRONOUS GRIDS

(EX NR, ER,NER)

REGIONAL (SYNCHRONOUS GRID)

LOAD DESPATCH CENTRE

STATE LOAD

DESPATCH

CENTRES

CENTRALLY

OWNED LINESCENTRALLY

OWNED PLANTS

INTER-STATE TIE

LINES

STATE OWNED

HVDC LINESDISTRIBUTION

SUBSTATION

POWERPLANT

OPERATORS

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) [6] the Indian Government should do more to encourage and facilitate local private investment in small-scale distributed electricity generation capacity.


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

power resources.

•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

matters.


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

Grid.

• Coordination for restoration of synchronous operation of

national grid with Regional Load Despatch Centres.


Sharing Of Transmission Charges

WHEELING 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 twocontiguous regions on 50 : 50 basis.•Charges for the regional assets may be shared by the regionalbeneficiaries•If an inter regional asset is used for wheeling by a third partythe balance transmission charges may be shared by thebeneficiaries of the contiguous region on 50 : 50 basis.


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 Centre.


TRANSCOs:

DISCOS:

GENCOS:

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


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 transmission.

• 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.


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.


Different grids of India


Some Landmark Events Of Power Grid

• 1948 - Growth of supply systems

• 1962- First 220KV Voltage level

• 1967- Interconnection Of state Grids to form

Regional Grids

• 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


Thank You…


Engineering

Restructuring of power grid