POWER GRID OPERATION IN INDIA

PREPARED BY:-MAHIM SRIVASTAVAEN-3RD YEAR

WHAT IS A “GRID” ?

WHAT IS AN “INTER-CONNECTION” ?

WHY DO WE NEED THIS INTER-CONNECTION ?

1)Reliability2)Economy3)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

LAYOUT DESIGNING – BUS BAR SCHEMES

Single Bus Bar Scheme Main & Auxiliary Bus Bar

Scheme

Double Bus Bar Scheme Double main &

Aux Bus Bar Scheme

LAYOUT DESIGNING – BUS BAR SCHEMES

THE ELECTRICITY ACT (OVERVIEW)

•The electricity Act, 2003 provides for open access. •This would create demand from third party for wheeling of Power.•No additional wheeling charges unless any new system is added•The Electricity (Supply) Act, 1948 was amended in 1991 to provide for creation of private generating companies for setting up power generating facilities and selling the power in bulk to the grid or other persons.

CENTRAL AUTHORITY SYSTEM

COORDINATE WITH

OTHER

SYSNCHRONOUS GRIDS (EX NR, ER,NER)

REGIONAL (SYNCHRONOUS GRID)

LOAD DESPATCH CENTRE

REGIONAL (SYNCHRONOUS GRID)

LOAD DESPATCH CENTRE

STATE LOAD DESPATCH CENTRES

STATE LOAD DESPATCH CENTRES

CENTRALLY OWNED LINES

CENTRALLY OWNED PLANTS

INTER-STATE TIE LINES

STATE OWNED HVDC LINES DISTRIBUTION

SUBSTATION

POWERPLANT OPERATORS

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 DESPATCH CENTRE ?

The main functions assigned to NLDC are:

Supervision Over the Regional Load Despatch Centres. 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 Despatch Centres.

Coordination with Regional Load Despatch Centres 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 two contiguous regions on 50 : 50 basis.•Charges for the regional assets may be shared by the regional beneficiaries•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.

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

NEW DELHI POWER DISTRIBUTION SYSTEM

All three companies mentioned are Distribution Companies

DIFFERENT GRIDS OF INDIA

SOME LANDMARK EVENTS OF POWERGRID

• 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

ANY QUESTIONS ???

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