A substation is part of an electrical distribution system that converts electric power from high transmission voltages to lower distribution voltages. It collects and distributes power to homes, offices, factories and other facilities. A substation contains transformers to step down transmission voltages to distribution voltages, circuit breakers and switches to control equipment and protect electrical lines, and other devices. Substations allow for the efficient transmission of power over long distances at high voltages and distribution over shorter distances at lower voltages that are safer and more suitable for end use.

1. Working model of step down sub station
and its knowledge of switch gear
GUIDED BY PREPAID BY
PROF. VIMAL TANK ACHARYA SURAJ
BHATT ABHAY
JADAV PRAFUL
SAVSANI DEEP
DR.SUBHASH TECHNICAL CAMPUS- JUNAGADH[362001]

2. OUTLINE
• project definition
• A quick picture of how substation works
• Lay out & explanation
• Single line diagram
• Circuit diagram & explanation
• Components list & explanation
• Advantages & application
• Future scope
• Conclusion
• reference

3. Definition of sub-station
A substation is a part of an electrical generation, transmission,
and distribution system.
The assembly of apparatus used to change some characteristic
of electric supply is called a sub-station

4. Lay out of substation

5. Single line diagram

6. Working of sub- station
• Electrical power is transmitted at high voltage using
transmission line and brought to the placed of utilization.
• But the power is not utilized at high voltage. For this it is
converted to the required form and voltage.
• This is because power is utilized in different forms and at
different voltages.
• In big industries power is delivered at 11kv. For domestic use
230v a.c. supply.

7. List of substation Components :-
 Power transformer
 Current transformer
 Potential transformer
 Isolator
 Circuit breaker
 Battery
 Relay
 Earth wire
 Lighting arrestors
 P.L.C.C.

8. Power transformer
It Can transfer voltage from low to
high or high to low at required
level.

9. Current transformer and Potential
transformer:-
It can be used for purpose of
metering and relying and
protection also.

10. Isolator
it would be used to
isolate equipments
to live electricity.

11. Circuit breaker
It would be used as a on-off switch
in substation

12. Battery
It would be used to supply the d.c
power for control system of
substation

13. Relay
It would be used for protection
purpose of sub-station
Equipment .

14. Earth switch
it should be used for
maintenance
purpose.

15. Lighting arrestors
Protect Equipment from line surges
and Lightening discharge.

16. wave trap
it should be used as
communication
device.

17. Application of Sub-Station
 we know the electrical power is generated at around 11kv
and this voltage is stepped up to high voltage and brought to
the place of utilization.
 Now electrical power is not used at this high voltage.
 So this high voltage is stepped down to the required voltage
and power is distributed in different area.
 This task is performed by using sub-station. In this unit ,we
shall obtain information about different type of substation .

18. Reference
v.k. mehta
j.b. gupta
www.circuit study.com
www.Wikipedia.com
Electric study for u & other net