This document provides information about a 132/33 kv sub-station, including a single line diagram and descriptions of its main components. It discusses the transformer, types of transformers, lightning arresters, relays, circuit breakers and their operating principles. The transformer uses electromagnetic induction to transfer energy between coils. Lightning arresters protect equipment from surges, while relays and circuit breakers detect faults and interrupt current flow to protect circuits.

1. 132/33 kv
SUB-STATION

2. SUB-STATION

3. Content
• Introduction
• Single Line Diagram
• Transformer
• Types of Transformer
• Lightning Arrester
• Circuit Breaker
• Relays
• Control Pannel

4. INTRODUCTION
Uttarakhand Power Corporation Ltd (UPCL), formerly
Uttaranchal Power Corporation Ltd was incorporated under
the Companies Act, 1956 on February 12, 2001 consequent
upon the formation of the State of Uttarachal. UPCL, has
been entrusted to cater to the Transmission & Distribution
Sectors inherited after the de merger from UPPCL (erstwhile
UPSEB) since 1st April 2001. The Electricity Act. 2003
mandated the separation of Transmission functions under
Power Sector Reforms. On 1st June 2004, the Power
Transmission Corporation Limited (PTCUL) was formed to
maintain & operate 132 KV & above Transmission Lines &
substations in the State. Today UPCL, the State Power
Distribution Utility of the Government of Uttaranchal (GoU)
caters to the Sub –Transmission & Distribution Secondary
Substations & Distribution Lines 66 KV & below in the State

5. UPCL - the Frontline State Power Distribution Utility & service
provider of QUALITY & RELIABLE POWER SUPPLY to over
1.59 million consumers of electricity spread over the 13 Districts
of Uttarakhand i.e Dehradun, Pauri, Tehri, Haridwar,
Pithoragarh, Almora, Nainital, Uttarkashi, Udhamsingh Nagar,
Rudraprayag, Chamoli, Bageshwar & Champawat.
The Corporate and Registered Office is at Vidyut bhawan, Near
ISBT Crossing, Saharanpur Road, Majra, Dehradun. The
Company is managed by the Board of Directors who meet
frequently and atleast once in every quarter. The day to day
management of the Company is looked after by the Managing
Director and other officers of the Company.

6. Single Line Diagram

7. TRANSFORMER

8. • A transformer is a static electrical device that
transfers energy by inductive coupling between
its winding circuits. A varying current in
the primary winding creates a varying magnetic
flux in the transformer's core and thus a varying
magnetic flux through the secondary winding.
This varying magnetic flux induces a
varyingelectromotive force (emf) or voltage in
the secondary winding.
• Transformers range in size from thumbnail-sized
used in microphones to units weighing hundreds
of tons interconnecting the power grid. A wide
range of transformer designs are used in
electronic and electric power applications.
Transformers are essential for
the transmission, distribution, and utilization
of electrical energy.

9. • The transformer is based on two
principles:-
• first, that an electric current can produce
a magnetic field
• second, that a changing magnetic field
within a coil of wire induces a voltage
across the ends of the coil
(electromagnetic induction). Changing the
current in the primary coil changes the
magnetic flux that is developed. The
changing magnetic flux induces a voltage
in the secondary coil.

10. • Referring to the two
figures here, current
passing through the
primary coil creates a
magnetic field. The
primary and secondary
coils are wrapped around
a core of very
high magnetic
permeability,
usually iron, so that most
of the magnetic flux
passes through both the
primary and secondary
coils. Any secondary
winding connected load
causes current and
voltage induction from
primary to secondary
circuits in indicated
directions.

11. Types Of Tranformers
1. Autotransformer :-
Transformer in
which part of the
winding is common
to both primary and
secondary circuits.

12. 2. Power Tranformer
:-
Transformers being
used to transfer
electric energy
between the
generator and
distribution primary
circuits.

13. 3. Capacitor voltage
transformer :-
Transformer in
which capacitor
divider is used to
reduce high
voltage before
application to the
primary winding.

14. 4. Instrumental
transformer :-
Potential or current
transformer used
to accurately and
safely represent
voltage, current or
phase position of
high voltage or
high power circuits.

15. Instrumental Transformer are of
two types :-
• Current Transformer :- A current transformer (CT) is a series
connected measurement device designed to provide a current in its
secondary coil proportional to the current flowing in its primary.
Current transformers are commonly used inmetering and protective
relays in the electrical power industry.
• Potential Transformer :- Voltage transformers (VT) (also called
potential transformers (PT)) are a parallel connected type of
instrument transformer, used for metering and protection in high-
voltage circuits or phasor phase shift isolation. They are designed to
present negligible load to the supply being measured and to have an
accurate voltage ratio to enable accurate metering.

16. 5. R.F. Transformer :-
Transformers are
sometimes made
from configurations of
transmission line,
sometimes bifilar or
coaxial cable, wound
around ferrite or other
types of core. This
style of transformer
gives an extremely
wide bandwidth.

17. Lightining Arrester

18. 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. When a lightning surge (or
switching surge, which is very similar)
travels along the power line to the arrester,
the current from the surge is diverted
through the arrestor

19. Types of Lightning Arrester
• Rod arrester
• Horn gap arrester
• Expulsion type lightning arrester
• Valve type lightning arrester
• Silicon Carbide Arrestors
• Metal Oxide Arrestors

20. Relays
Basic design
Simple electromechanical relay
Small "cradle" relay

21. A relay is an electrically operated switch. Many
relays use an electromagnet to operate a
switching mechanism mechanically, but other
operating principles are also used. Relays are
used where it is necessary to control a circuit by
a low-power signal (with complete electrical
isolation between control and controlled circuits),
or where several circuits must be controlled by
one signal. The first relays were used in long
distance telegraph circuits, repeating the signal
coming in from one circuit and re-transmitting it
to another. Relays were used extensively in
telephone exchanges and early computers to
perform logical operations.

22. Types Of Relays
1. Induction Relay :-
These are the most
widely used relays for
protective relaying
purposes involving
only a.c quantities.
These relays operate
on the simple
principle of split-
phase induction
motor.

23. 2. Thermal Relay :-
These relays
operate on the
principle of thermal
effects of electric
current.
Mostly used for
protection of low
voltage suirrel
cage induction
motor.

24. 3. Buchholz relay :- A
Buchholz relay is a
safety device sensing
the accumulation of
gas in large oil-filled
transformers, which will
alarm on slow
accumulation of gas or
shut down the
transformer if gas is
produced rapidly in the
transformer oil.

25. 4. Over Load Protection
Relay :-
Electric motors need overcurrent
protection to prevent damage from
over-loading the motor, or to protect
against short circuits in connecting
cables or internal faults in the motor
windings.The overload sensing
devices are a form of heat operated
relay where a coil heats a Bimettalic
strip, or where a solder pot melts,
releasing a spring to operate
auxiliary contacts. These auxiliary
contacts are in series with the coil. If
the overload senses excess current in
the load, the coil is de-energized.

26. Other Types of Relays are :-
• Latching relay
• Reed relay
• Mercury relay
• Polarized relay
• Ratchet relay
• Coaxial relay

27. CIRCUIT BREAKER
A circuit breaker is an automatically
operated electrical switch designed to protect
an electrical circuit from damage caused
by overload or short circuit. Its basic function is
to detect a fault condition and interrupt current
flow. Unlike a fuse, which operates once and
then must be replaced, a circuit breaker can be
reset (either manually or automatically) to
resume normal operation. Circuit breakers are
made in varying sizes, from small devices that
protect an individual household appliance up to
large switchgear designed to protect high-
voltage circuits feeding an entire city.

28. Types of Circuit Breaker
1. Oil Circuit Breaker :-

29. In an oil circuit breaker with simple interruption
under oil, the duration of arcing is 0.02-0.05 sec.
To extinguish the arc more efficiently, arc-
quenching chambers are used. In a longitudinal
blast chamber the vapors and gases evolved
travel upward along the arc, thus cooling it. In
addition, the arc is in contact with the cold oil
that fills the annular slots of the chamber, which
also accelerates cooling of the arc. In a
transverse blast chamber a drastic pressure
increase within the gas bubble causes a stream
of oil and gases to flow across the arc, thus
accelerating the cooling process.

30. 2. Air Blast Circuit Breaker :-

31. High pressure air at a pressure between 20 to 30
kg/ cm2 stored in the air reservoir. Air is taken
from the compressed air system. Three hollow
insulator columns are mounted on the reservoir
with valves at their basis. The double arc
extinguished chambers are mounted on the top
of the hollow insulator chambers. The current
carrying parts connect the three arc extinction
chambers to each other in series and the pole to
the neighbouring equipment. Since there exists
a very high voltage between the conductor and
the air reservoir, the entire arc extinction
chambers assembly is mounted on insulators.

32. 3. Vaccum Circuit Breaker:-

33. A vacuum circuit breaker is such kind of circuit
breaker where the arc quenching takes place in
vacuum. The technology is suitable for mainly
medium voltage application. For higher voltage
Vacuum technology has been developed but not
commercially viable. The operation of opening
and closing of current carrying contacts and
associated arc interruption take place in a
vacuum chamber in the breaker which is called
vacuum interrupter. The vacuum interrupter
consists of a steel arc chamber in the centre
symmetrically arranged ceramic
insulators.Service life of Vacuum Circuit Breaker
is much longer than other types of circuit
breakers.

34. 4. SF6 Circuit Breaker :-

35. A circuit breaker in which the current carrying contacts operate in Sulphur
Hexafluoride or SF6 gas is known as an SF6 Circuit Breaker.
SF6 has excellent insulating property. SF6 has high electro-negativity. That
means it has high affinity of absorbing free electron. Whenever a free
electron collides with the SF6 gas molecule, it is absorbed by that gas
molecule and forms a negative ion.
The attachment of electron with SF6 gas molecules may occur in tow different
ways,
1) SF6 + e = SF6 -
2) SF6 + e = SF5 - + F
These negative ions obviously much heavier than a free electron and therefore
over all mobility of the charged particle in the SF6 gas is much less as
compared other common gases. We know that mobility of charged particle
is majorly responsible for conducting current through a gas.

36. CONTROL PANEL

37. • Control panel is most important equipment of the
substation as it work as shield guard for all substation
equipments and electrical network. Moreover, these
panels are useful to control the flow of electricity as
per the Voltage class and detect the faults in
transmission lines.
• Designing and manufacturing of Control panel
depend on the requirement of utilities and these can
broadly be classified as follows;
- Line Protection
- Transformer Protection
- Bus Bar Protection
- Tie Breaker
- Bus Coupler
- Reactor

38. • In this panel, varieties of numerical & electromechanical
relays are installed to provide damage protection to
equipments. Meters, Semaphore indicators, Control
Switches, Indicating lamps, Push Buttons, Annunciator,
Test Blocks and Test Plugs are among of major
equipments installed as per designing requirements.
• The Control & relay panels are designed & manufactured
as per voltage class of substations like 11KV, 33KV,
66KV, 132KV, 220KV and 400KV etc. However DC
voltage or supply voltage may differ according to the
panel requirement such as 30V DC, 110V DC, 220V DC
etc. Use of Control & relay panel is not only limited in
Substations owned and operated by electrical utilities,
but also essential in industrial and commercial sector
where power consumption is very high.

39. TECHNICAL SPECIFICATION OF
CONTROL PANEL AND RELAY
• FEEDER METER- it consists of ammeter (2), voltmeter (2),
and solid state buzzer (2).
• Further ammeter switch, voltmeter switch and neutral switch
are directly connected through feeder panel.
• ANNUNCIATOR- this consists of :-
• Master trip relay operated
• Trip circuit
• Low oil level alarm
• Over current relay operated
• Winding temp alarm
• Earth fault relay operated
• Differential relay operated
• Isolator connected indicator

40. • SWITCH BOARD :- it consists of :-
• Bus coupler: it acts as a intermediate
switch board which couple two incoming
source generation. A bus coupler is also
used in case of fault occurrence. Each
time the bus coupler is engaged for the
faulty condition of one side of bus bar so
as to provide supply to the feeders from
the other side. Thus protecting the system.

41. • INCOMING SUPPLY
Rishikesh
kulhal
Purkul
Bindal

42. • OUTGOING SUPPLY
Ajabpur
Niranjanpur
Araghar
Doiwala
I.M.A.
Sahastradhara

43. Fire alarm panel
• In large buildings, a central fire alarm
annunciator panel is located where it is
accessible to fire-fighting crews. The
annunciator panel will indicate the zone and
approximate physical location of the source of a
fire alarm in the building. The annunciator will
also include lamps and audible warning devices
to indicate failures of alarm circuits. In a large
building such as an office tower or hotel, the fire
annunciator may also be associated with a
control panel for building ventilation systems,
and may also include emergency
communication systems for the building.

44. Thanking you