it has components and equipment used in the substation like feeders,circuit breakers,transformer parts etc..

1. STUDY OF SUBSTATION
COMPONENTS
UNDER THE GUIDENCE OF
Mr. PAVAN KUMR
BALA KRISHNA

2. SUBSTATION COMPONENTS
 A substation is a part of an electrical generation, transmission,
and distribution system.
 Between the generating station and consumer, electric power may flow
through several substations at different voltage levels.

3. CLASSIFICATION
 Transmission substation
 Distribution substation
 Converter substations
 Switching substation
 Classification by insulation
 Classification by structure

4. MAIN COMPONENTS
TRANSFORMER
CIRCUIT BREAKER
CURRENT TRANSFORMER LIGHTING ARRESTER

5. BUS BAR ISOLATOR
POTENTIAL TRANSFORMER WAVE TRAP

6. INSULATOR EARTH SWITCH
EARTHING SYSTEM
CONTROL PANEL

7. CABLES CABLE PARTS
TYPES OF CABLES
TWISTED CABLES

8. TRANSFORMER
• Power transformers are used in transmission network of higher voltages for step-up
and step down application (400 kV, 200 kV, 110 kV, 66 kV, 33kV) and are
generally rated above 200MVA.
• Distribution transformers are used for lower voltage distribution networks as a
means to end user connectivity. (11kV, 6.6 kV, 3.3 kV, 440V, 230V) and are
generally rated less than 200 MVA.

9. PARTS OF
TRANSFORMER
Main tank
Primary winding
Secondary winding
Buchholz relay
Oil level indicator
Breather
Radiator
L T & HT bushes
Tap changer
Air release plug

10. Buchholz relays
Buchholz relays are used in most
oil insulated electric transformers
where there is an expansion tank.
 Buchholz relays are particularly
efficient in detecting and
capturing gases that may form
inside the transformers and for
instant system shut down in case
of a serious defect.
CONSERVATOR
 The conservator provides space
for the expansion of oil .
BUCHHOLZ RELAY
CONSERVATOR

11. BREATHER
The breather filled with silica gels
are provided to separate moisture from
the aspirated air.
The silica gel turns blue when it
becomes saturated with moisture
after which it needs to be replaced.
AIR RELEASE PLUGS
 These air releasing plugs are made
from very excellent quality raw
material which ensure hassle free
work performance. These plugs finds
its applications in various industrial
sectors. We are able to customized
these plugs as per customer
requirement with market competitive
rates
BREATHER
AIR RELEASE PLUGS

12. TERMINAL BOX
 A terminal box is designed to
enable the electrical connection
of the elements within a
transformer to the external
elements in an airtight and
reliable manner that ensures
years of trouble-free operation.
COOLING FANS
 They are used for cooling of
the transformer when there is a
temperature raise in the
transformer.
TERMINAL BOX
COOLING FANS

13. RADIATORS
 The radiator of transformer
accelerates the cooling rate of
transformer. Thus, it plays a vital role
in increasing loading capacity of
an electrical transformer. This is basic
function of radiator of an electrical
power.
TRANSFORMER RATING
RADIATORS

14. TAP CHANGER
 A tap changer is a connection point
selection mechanism along a power
T/F winding that allows a variable
number of turns to be selected in
discrete steps. A T/F with a variable
turns ratio is produced, enabling
stepped voltage regulation of the
output. The tap selection may be
made via an automatic or manual tap .
BHUSHINGS OF T/F
The oil impregnated paper insulated
bushings arc used to connect over
head lines to T/F. These are mounted
on t/f in vertical or inclined position
at a maximum inclnation of 30° from
the verticaL.
TAP CHANGER
BUSHINGS OF T/F

15. BUS BARS
• a bus bar is a thick strip of copper or aluminium that conducts electricity.
• Bus bars are used to carry very large currents, or to distribute current to
multiple devices within switchgear or equipment.

16. CIRCUIT BREAKER
•It designed to protect an electrical
circuit from damage caused by
overload or short circuit.
•Its basic function is to detect a fault
condition and discontinue the
electric flow
.

17. BULK OIL CB
BULK OIL CB
It uses a large quantity of oil
The oil serves two purposes.
Firstly ,it extinguishes the arc during
opening of contacts.
Secondly ,it insulates the current
conduting parts from one anthor and
from the earthed tank.
AIR BLAST CB
The CB in which high pressure air
blast is used for extinguishing the arc.
The arcing products are completely
removed by the blast whereas the oil
deteriorates with successive
operations.
The expense of regular oil
replacement is avoided
AIR BLAST

18. MINIMUM OIL CB
•These types of circuit breakers utilize oil
as the interrupting media. However,
unlike bulk oil circuit breaker, a minimum
oil circuit breaker places the interrupting
unit in insulating chamber at live potential.
• The insulating oil is available only in
interrupting chamber. The features of
designing MOCB is to reduce requirement
of oil, and hence these breaker are
called minimum oil circuit breaker.
CROSS BLAST CB
The CB in which the air blast is directed
right angles to the arc path.
The splitters serve to increase the arc
length of the arc and baffles give improved
cooling resulting in extinguished arc.
MINIMUM OIL
CROSS BLAST

19. AUXIAL BLAST CB
The circuit breaker in which
the air blast is directed long
the arc path
When the fault occurs the arc
is extinguished and current
flow is interrupted.
SF6 CB
The circuit breaker in which
sulphur dioxide (SF6)gas is
used for arc extinction.
Due to superior arc quenching
property of SF6 ,such circuit
breakers have short arcing
time.
AUXIAL BLAST
SF 6

20. 1. Actuator lever - used to manually
trip and reset the circuit breaker.
2. Actuator mechanism - forces the
contacts together or apart
3. Contacts - Allow current when
touching and break the current when
moved apart
4. Terminals
5. Bimetallic strip.
6. Calibration screw - allows the
manufacturer to precisely adjust the
trip current of the device after
assembly.
7. Solenoid
8. Arc divider/extinguisher
CIRCUIT BREAKER

21. ISOLATOR
•It is a disconnection
switch and to be operated
on no load.
•It is used to make sure
that an electrical circuit can
be completely de-energized
for service or maintenance.
• It provide electrical
isolation of the equipment .

22. CURRENT TRANSFORMER
•CT is a type of instrument transformer
that is used in power system for
measurement, detection, protection of the
system.
•Current transformers are used extensively
for measuring current and monitoring the
operation of the power grid.

23. POTENTIAL TRANSFORMER
 Potential transformers are instrument
transformers. They have a large number of
primary turns and a few number of
secondary turns.
 It converts voltages from high to low. It
will take the thousands of volts behind
power transmission systems and step the
voltage down to something that meters can
handle.

24. LIGHTING ARRESTER
It discharge the over voltage surges to earth
and protect the equipment insulation from
switching surges and lightning surges.
It located at the starting of the substation as
seen from incoming transmission lines and is
the first equipment of the substation

25. INSULATOR
 An insulator, also called a dielectric,
is a material that resists the flow of
electric current.
Insulators are used in electrical
equipment to support and separate
electrical conductors without allowing
current through themselves.

26. PIN TYPE
SUSPENSION TYPE
PIN TYPE
Pin type insulators are used for transmission
and distribution of electric power at voltages
up to 33 kV. Beyond operating voltage of 33
kV, the pin type insulators become too bulky
and hence uneconomical.
SUSPENISION TYPE
For high voltages (>33 kV), we use
suspension type insulators. Each unit or disc
is designed for low voltage, say 11 kV.
For instance, if the working voltage is 66 kV,
then six discs in series will be provided on
the string.
STRAIN TYPE
When there is a dead end of the line or there
is corner or sharp curve, the line is subjected
to greater tension.
 In order to relieve the line of excessive
tension, strain insulators are used. For low
voltage lines (< 11 kV), shackle insulators are
used as strain insulators.
STRAIN TYPE

27. STRAIN TYPE
SHACKLE TYPE
STRAIN TYPE
When there is a dead end of the line or there is
corner or sharp curve, the line is subjected to
greater tension. In order to relieve the line of
excessive tension, strain insulators are used. For
low voltage lines (< 11 kV), shackle insulators
are used as strain insulators.
However, for high voltage transmission lines,
strain insulator consists of an assembly of
suspension insulators as shown in Figure.
The discs of strain insulators are used in the
vertical plane. When the tension in lines is
exceedingly high, at long river spans, two or
more strings are used in parallel.
SHACKLE TYPE
In early days, the shackle insulators were used
as strain insulators. But now a day, they are
frequently used for low voltage distribution
lines.
 Such insulators can be used either in a
horizontal position or in a vertical position.
They can be directly fixed to the pole with a
bolt or to the cross arm.

28. WAVE TRAP
 It trap the high frequency communication
signals sent on the line from the remote
substation and diverting them to the telecom/
teleprotection panel in the substation control
room .
 The Line trap offers high impedance to the
high frequency communication signals thus
obstructs the flow of these signals in to the
substation bus bars.
 The signals are primarily teleprotection
signals and in addition, voice and data
communication signals.

29. EARTH SWITCH
 Earth Switch is used to discharge the voltage on the circuit to
the earth for safety.
 Earth switch is mounted on the frame of the isolators.
 Earth Switch is located for each incomer transmission line and
each side of the bus-bar section

30. EARTHING SYSTEM
 Station Earthing System includes Earth Mat and Earth electrodes placed
below ground level
Function earthing system is to provide low resistance earthing for
 Discharging currents from the surge arresters, overhead shielding,
earthing switches
 For equipment body earthing
 For safe touch potential and step potential in substation.

31. METERING, CONTROL AND
RELAY PANELS
To house various measuring Instruments, control Instruments, Protective relays.
They are located in air-conditioned building. Control Cables are laid between
Switchyard equipment and these panels.

32. RELAYS TYPES
Electromagnetic relays
•These are those relays which are operated by
electromagnetic action. Modern electrical
protection relays are mainly micro processor
based, but still electromagnetic relay holds its
place. It will take much longer time to be
replaced the all electromagnetic relays by micro
processor based static relays.
Induction relay
•This relay in nothing but one version of
induction disc relay. Induction cup relay work in
same principle of induction disc relay. The basis
construction of this relay is just like four poles
or eight pole induction motor. The number of
poles in the protective relay depends upon the
number of winding to be accommodated.

33. CABLES STRUCTURE & CONSTRUCTION

34. THREE CORE CABLES TYPES