Components of an electrical sub-station and their functions. i.e. What are the basic components of an electrical sub station or a grid station and how they contribute in supplying, transformation and transmitting power?

1. Electrical Substation
(Grid Station)
SUFI NOUMAN RIAZ

2. Substation
A substation is a part of an electrical
generation, transmission, and
distribution system. Substations
transform voltage from high to low,
or the reverse, or perform any of
several other important functions

3. Elements of a Substation
A: Primary power lines' side B: Secondary power lines' side
1. Primary power lines
2. Ground wire
3. Overhead lines
4. Transformer for measurement of electric voltage
5. Disconnect switch
6. Circuit breaker
7. Current transformer
8. Lightning arrester
9. Main transformer
10. Control building
11. Security fence 12. Secondary power lines

4. Elements of substation

5. Transformer
A substation may include
transformers to change
voltage levels between
high transmission
voltages and lower
distribution voltages, or
at the interconnection of
two different transmission
voltages.

6. Disconnect Switch
In electrical engineering, a
disconnector, disconnect
switch or isolator switch is
used to ensure that an
electrical circuit is completely
de-energized for service or
maintenance. Disconnectors
can be operated either
manually or automatically.

7. Circuit Breaker
A circuit breaker is an
automatically-operated electrical
switch designed to protect an
electrical circuit from damage
caused by overload of electricity
or short circuit. A circuit breakers
function is to detect a fault
condition and, by interrupting
continuity, to immediately
discontinue electrical flow.

8. Lightning Arrester
A lightning arrester is a
device used on electrical
power systems and
telecommunications systems
to protect the insulation and
conductors of the system
from the damaging effects
of lightning. The typical
lightning arrester has a
high-voltage terminal and a
ground terminal.

9. CT and PT
While a potential transformer(PT)
used to reduce the voltage to
lower values and to provide
isolation between high voltage
power network and the relays
and the other instruments that
are connected to their
secondaries. CT is used for
current measurement and PT is
used for voltage measurement.