Government polytechnic pune-16
Presentation on inplant training at sub-
station
Jawale sushant vikas
2St shift Electrical engineering
3Rd year K3
2022022

Points
1. What is sub station
2. Use of sub station
3. Info. Of my training sub station
4. Equipment used in sub-station in short
5. Maintenance of sub station
6. Precaution taken in sub-station
7. conclusion

1. What is Sub-station .
A substation is a part of an electrical generation, transmission, and distribution system
Sub-station is an arrangement of equipments for changings some properties of electrical
supply.

• Basically a sub-station is a place where the power of supply changes, voltage
level change, current level change,power factor chage also conversion of
power takes place.
• 33/11kV sub station is substation that convert high level voltage to low level
voltage for convenience of power transmission or distribution.
• Further voltage which is step down in Sub-station with improved power factor
sent to distribute via. Distribution transformer.
• The purpose of a substation is to ‘step down’ high voltage electricity from the
transmission system to lower voltage electricity so it can be easily supplied to
homes and businesses through our distribution lines.
2. What is use Of sub station ?

3.Info. Of sub-station
• I have completed my implant training at the 33/11kV Sub-station of TER
• Where the I have completed training under the operating staff
• The incoming supply fed to sub station by 220/33kV sub station.
• 33 kV voltage is step down to 11 kV with the help of huge transformers .
• 2 transformers of rating 5 MVA 33/11kV are used in sub station.
• With help of different devices & equipment we monitor the voltage, current, power
factor, frequency,ect.

4. Equipments used in Sub-station in short.
Sub station uses many equipment as a need of suppling suitable power to consumer
We are going to see some of them.
1. Lighting arrestor
most primary part is safty under it’s consideretion first thing you will notice is
arrestor
It’s function is to protect the sub station equipment from Lighting bolts.

2.Insulators:-
Insulation is required for avoiding connection between
current carrying conductor to ground , in two different phases.
Insulation is dependent upon the voltage & current carried
by it.
Mostly now days the Insulators made up of porcelain or
composite polymer materials

3. Conductor & Cable
conductor is used to carrying current. For better transmission ACSR conductor is
used.
4. Transformer.
transformer is used to step down the current & voltage. Used transformer is of 5MVA
33/11kV.

1. Transformer tank
2. HV bushing
Breather
3. LV bushing
4. Radiator/cooling fins
5. Cooling fans
6. Conservator tank
7. Explosion vent
8. Drain valve
9. Breather
10. Temperature indicator/ oil level indicator
temp. Indicator
11. CT
12. Control panel

5. Isolator
During the maintenance & repair the Isolator is used to isolate the Sub-station
from power supply as well as from consumers side.
6. Instrumental transformer
It includes CT & PT .

CURRENT TRANSFORMER POTENTIAL
TRANSFORMER
Instrument transformer is use to measure the high voltage &
current of the power system. Vai. Potential & current transformer.

7. Vaccum Circuit breaker (VCB)
• Most widely used
Circuit breaker in
sub-station is VCB
• VCB has very high
dielectric strength.
• In the 33kV Sub-
station for safty
porpose VCB is
suitable.

Capacitor bank
• Capacitor bank is
used to reduce the
phase difference
between the voltages
and current.
• Capacitor banks
provide stable voltage
level, reactive power
support , and
increasing power
transfer capability in
the power system.
• Capacitor banks are
mainly used to
enhance the electrical
supply quality and
enhance the power
systems efficiency.
• By doing power factor
correction.

Guarding wire Relay
KWH Meter
Guarding is provided to 33kV
substation incoming lines.
Relays are used for
controlling multiple circuits
For daily load
consumption

5. Maintenance of Sub-station.
• Substation maintenance is a process of periodic, planned inspection of
and, if necessary, repair, and replacement of all switchgear, buildings,
and ancillary equipment in substation installations.
• And on daily basis of inspection is done by operating staff. If any fault
occurred in sub station unexpectly the operating staff does the
maintenance.
• In maintenance first thing is shutdown work of Sub-station.
• Sub station required Routine inspection & cleaning.
• Maintenance of circuit breaker.

6. Safty precautions taken in Sub-station.
• Securing Perimeter Area.
• Restricting or Prohibiting Visitor Access
• Prohibiting Equipment Storage
• Use of rubber Gulbs , shoes, helmets during working or checking
• Displaying danger sign boards
• These are the few tricks to keep our self safe.
• Do’s
1. Wear rubber Gulbs, safety
helmet,ect
2. Please sign ‘Men working’ or
warning boards on the main
switch before commencing work.
3. Always treat the circuit alive until
you have proved them to be dead.
• Don’ts
1. Don’t Touch any live equipment
2. Do not close any switch, unless
you are familiar with the circuit
which it controls and know the
reason for it’s being opened.
3. Do not work on live circuit

Conclusion
We have seen the brief summary of Sub-station which includes work & it’s
importants.
We study the different equipment in Sub-station & structure of Sub-station.
We introduce to precaution taken in Sub-station
As a electricity is our need similarly Sub-station is important factor in power
distribution & transmission.
Thank you