This document provides an overview of grid substations. It discusses how substations receive power from generating stations and transmission lines and transform voltages to suitable levels for distribution. It also describes the key components of substations, including transformers, circuit breakers, and earthing systems. Classification of substations by voltage level and indoor/outdoor design is covered. The purpose and components of transmission lines, including conductors, insulators, towers, and earth wires, are summarized as well.

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

3.  Generating Station
 Transmission Line
 Sub-Stations

4.  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.

5.  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 .


6.  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

8. ELECTRICAL
TRANSMISSION
LINE

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

11.  Conductor
 Earth wire
 Insulator
 Transmission Tower
 Wave trap and other hardware(Clamp,
Spacer, Vibration dampers, connectors etc.

13.  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)

14.  It provides a surface under the
substation which has uniform potential
nearly equal to zero or Absolute Earth
Potential.
 It is of two types
o Neutral Earthing
o Equipment Body Earthing

15. EARTHING

16.  Earth wire provided above the
phase conductor across the line
and grounded at every tower.

17. Optical Ground Wire

18. Advantages :
Serves the dual purpose of
ground wire and
communication.
High speed data transmission.
Optical Ground Wire

20.  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

23.  Mechanical Requirement
 Electrical Requirement
 Mechanical Requirement
 Tensile Strength(For Tension)
 Strain Strength(For Vibration)

25.  Insulator are required to
support the line conductor and
provide clearance from ground
and structure.

29.  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.

30. TRANSFORMER USED IN GSS
 POWER X-MER
 C.T.
 P.T.
 STATION X-MER

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

41. THANK YOU