Transmission network

PRESENTAION ON GRID SUB-STATION By Avdhesh kumar meena B.Tech 4th Year Electrical BranchNIET Alwar Rajasthan avdheshkumarmeena10@gmail.com

SMART GRID

TRANSMISSION NETWORK

Generating Station

Transmission Line

Sub-Stations

TYPES OF SUBSTATION

Classification based on voltage levels, e.g. : A.C. Substation : EHV, HV, MV, LV; HVDC Substation.

Classification based on Outdoor or Indoor : Outdoor substation is under open sky. Indoor substation is inside a building.

PRIMARY/SECONDARY/DISTRIBUTION SUBSTATION

Primary Substations receive power from EHV lines at 400KV, 220KV, 132KV and transform the voltage to 66KV, 33KV or 22KV to suit the local requirements .

Secondary Substations receive power at 66/33KV which is stepped down usually to 11KV.

Distribution Substations receive power at 11KV, 6.6 KV and step down to a volt suitable for LV distribution purposes, normally at 415 volts

Generating Station

ELECTRICAL TRANSMISSION LINE

DEFINATION Electrical transmission system is the means of transmitting power from generating station to different load centres.

Component of Transmission Line

Conductor Earth wire Insulator Transmission Tower Wave trap and other hardware(Clamp,

Spacer, Vibration dampers, connectors etc.

Tower Grounding

Used to reduce earth wire potential

and stress on insulators at the time of

stroke and also for safety

Earth resistance depend upon soil

resistivity(general 100 Ω-m)

EARTHING It provides a surface under the

substation which has uniform potential nearly equal to zero or Absolute Earth Potential.

It is of two typeso Neutral Earthingo Equipment Body Earthing

EARTHING

EARTH WIRE Earth wire provided above the

phase conductor across the line

and grounded at every tower.

Optical Ground Wire

Advantages : Serves the dual purpose of ground wire and communication.

High speed data transmission.

Optical Ground Wire

Earth Resistance Major power station= 0.5 Ohm. Major Sub-stations= 1.0 Ohm Minor Sub-station = 2 Ohm Neutral Bushing. =2 Ohm Service connection = 4 Ohm Medium Voltage Network =2 Ohm L.T.Lightening Arrestor= 4 Ohm L.T.Pole= 5 Ohm H.T.Pole =10 Ohm Tower =20-30 Ohm

CONDUCTOR

Selection of Conductor Size

Mechanical Requirement

Electrical Requirement Mechanical Requirement Tensile Strength(For Tension)

Strain Strength(For Vibration)

Cable end termination

INSULATOR Insulator are required to

support the line conductor and provide clearance from ground and structure.

TRANSFORMERS A Transformer is a static device

that transfers Electrical energy from one Electrical circuit to another Electrical circuit by means of a common Magnetic Circuit.

TRANSFORMER USED IN GSS

POWER X-MER

C.T.

P.T.

STATION X-MER

POWER TRANSFORMER

To step-down the voltage and transfer power from one A.C voltage to another A.C Voltage at same frequency

Current transformer

Potential transformer

Normally Transformer cooling

C.V.T. (capacitor voltage transformer) :-

Control room

THANK YOU