The document is a presentation on grid substations that discusses their purpose and key components. It begins by defining a substation as part of an electrical generation, transmission, and distribution system that transforms voltage from high to low levels. It then outlines the main equipment found in substations, including lightening arresters, isolators, transformers, circuit breakers, busbars, and protective relays. Instrument transformers like potential and current transformers are also explained. The presentation provides diagrams and descriptions of this essential infrastructure that forms the backbone of electrical networks.

1. GUIDED BY:-
Mr. Deepak Somani
Asst. Prof. EE
PRESENTED BY:-
Ravi kant
Roll no. :-12ECOEE020
A
TRAINING SEMINAR
ON
“GRID SUB-STATION”
SESSION 2015-16
Bachelor of Technology
In
Electrical Engineering
1

2. CONTENTS
SUBSTATION.
TYPES OF SUB-STATION.
SINGLE LINE DIAGRAM.
EQUIPMENT.
• Lightening Arrester.
• Isolator.
• CVT.
• Instrument Transformer.
a. Current Transformers.
b. Potential Transformers.
• Circuit Breaker.
• Bus bars.
• Transformer.
• Protective Relaying.
• DC Power Supply.
2

3. SUB-STATION
• A substation is a part of an
electrical generation, transmission
and distribution system. Substations
transform voltage from high to low
or the reverse.
• Then that voltage we use in our
homes and industries etc.
Fig. SUB-STATION
3

4. CLASSIFICATION OF SUB-STATION
• ACCORDING TO SERVICE REQUIRMENT.
a) Transformer sub-station.
b) Switching sub-station.
c) Power factor correction sub-station.
d) Frequency changer sub-station.
e) Converting sub-station.
• ACCORDING TO CONSTRUCTIONAL FEATURE.
a) Indoor sub-station.
b) Outdoor sub-station.
c) Underground sub-station.
d) Pole-mounted sub-station.
4

5. SINGLE LINE DIAGRAM
5

6. EQUIPMENT OF SUB-STATION
• Lightening Arrester.
• Isolator.
• CVT.
• Instrument Transformer.
a. Current Transformers.
b. Potential Transformers.
• Circuit Breaker.
• Bus bars.
• Transformer.
• Protective Relaying
• DC Power Supply
6

7. LIGHTENING ARRESTER
• Lightening arrestors are the
instrument that are used to
prevent from lightening entering
the main station.
• It is also known as surge
arrester.
Fig. LIGHTENING ARRESTER
7

8. ISOLATORS
• The use of isolators is to off the
transformer and the other instrument in
the line.
• Isolators are used for maintenance
whenever fault occur.
• It is manually operated.
Fig. ISOLATORS
8

9. CVT(CAPACITOR VOLTAGE TRANSFORMER)
• A CVT is a transformer used
in GSS to step-down extra
high voltage and provide low
voltage either for
measurement or to operate a
protective relay.
Fig. CAPACITOR VOLTAGE TRANSFORMER
9

10. BUSBAR
• BUSBAR is a term we use
for a main bar or conductor
carrying electric current to
many connection.
Fig. BUSBAR
10

11. INSTRUMENT TRANSFORMER
• Current transformers are basically
used to take the readings of the
currents entering in the substation.
• The other uses of this CT.
a) Distance Protection.
b) Backup Protection.
c) Measurement.
Fig. INSTRUMENT TRANSFORMER
CURRENT TRANSFORMER
11

12. • The potential transformer uses for
Measurement and Protection.
• The main use of potential transformer
is to measure the voltage through the
Busbar.
• There are two main parts in it.
a) Measurement.
b) Protection.
POTENTIAL TRANSFORMER
Fig. POTENTIAL TRANSFORMER
12

13. PROTECTIVE RELAYS
• Relay is a device which sense the
fault and send message signal to
circuit breaker to trip the coil.
• It used for transformer protection.
Fig. PROTECTIVE RELAYS
13

14. CIRCUIT BREAKER
• A circuit breaker is used to receive
the fault message signal from the
relay and trip the coil.
TYPES:-
a) AIR CIRCUIT BREAKER.
b) OIL CIRCUIT BREAKER.
c) VACCUM CIRCUIT BREAKER.
d) SF6 CIRCUIT BREAKER.
Fig. CIRCUIT BREAKER
14

15. TRANSFORMERS
• Transformer is a static device by
which Transform AC electrical
power from one voltage level into
other level by keeping same
frequency.
• Transformer used in GSS is
called Power Transformer.
Fig. TRANSFORMERS
15

16. DC POWER SUPPLY
• DC power supply is used for
operate Circuit Breaker and
control room operation.
• 110V dc power supply is
used.
Fig. DC POWER SUPPLY
16

17. GRID SUB-STATION AT A GLANCE
17

18. 18