SUBMITTED BY :-

MANISH GUPTA

1006421045

NEHA SINGH

1006421059

PUNEET DHINGRA

1006421066

UZMA UDDIN

1006421108

• Introduction

• Single Line Diagram

•Power Transformer

• A Quick Picture Of How Substation Works

• Lightening Arrestor

• Wave Trap

• Current Transformer

• Potential Transformer

• Circuit Breaker

• Isolator & Earth Switch

• New Instruments

• Conclusion

Electric power is produced at the power generating

stations, which are generally located far away from the

load centers. High voltage transmission lines are used to

transmit the electric power from the generating stations to

the load centers. Between the power generating station and

consumers a number of transformations and switching

stations are required. These are generally known as

substations.

Substations are important part of power system and form a

link between generating stations, transmission systems and

distribution systems.

The generation, transmission and distribution system of

electrical power is called the electrical power supply

system.

Substation is an assembly of electrical components such as bus-

bars, switchgear apparatus, power transformers etc.

In 400 KV substations, there is three yard:

400 KV yard

220 KV yard

132 KV yard

Some of the important components of substation in above yard

are.

1. POWER TRANSFORMER

2. CURRENT TRANSFORMER

3. CIRCUIT BREAKER

4. POTENTIAL TRANSFORMER

5. BUS BAR

6. LIGHTENING ARRESTERS

7. ISOLATORS

8. EARTH SWITCHES

WHAT IS POWER TRANSOFRMER

WORKING PRINCIPLE

PRACTICAL WORKING

MAIN CONSTRUCTION PARTS

PRIMARY WINDING

MAGNETIC CORE

SECONDARY WINDING

• TAP CHANGER

• TANK

• CONSERVATOR

• SILICA GEL BREATHER

• BCHHOLZ RELAY

• DOUBLE DIAPHRANGM EXPLOSION

VENT

• OIL LEVEL INDICATOR

• WINDING TEPERATURE INDICATOR

Lightning Arrestor

Lightening arresters discharge the

over voltage surges to earth and

protect the equipment insulation

from switching surges & lightening

surges. surge arresters are generally

connected between phase conductor

and ground. In a substation surge

arrester is located at the starting of

the substation as seen from

incoming transmission lines and is

the first equipment of the

substation. Surge arrester are also

provided near the transformer

terminals phase to ground

Wave trap is a PLCC (power line

carrier communication)

communication in power system

which block the outer frequency of

other power station these are

installed in switch yard. It is also

known as line trap.

This equipment is installed in the

substation for trapping the high

frequency communication signals

sent on the line from remote

substation and diverting them to

the telecom panel in the substation

control room.

A current transformer (CT) is

used for measurement of

alternating electric currents.

Current transformer, together

with voltage VT is known as

instrument transformers.

The lines in substations carry currents in the order of thousands

of amperes. The measuring instruments are designed for low

value of currents. Current transformers are connected in lines to

supply measuring instruments and protective relays.When current

in a circuit is too high to direct apply to measuring instruments, a

CT produces a reduced current accurately proportional to the

current in the circuit, which can be conveniently connected to

measuring and recording instruments.

The lines in substations operate at high

voltages. The measuring instruments are

designed for low value of voltages.

Potential transformers are connected in

lines to supply measuring instruments

and protective relays. These

transformers make the low voltage

instruments suitable for measurement of

high voltages.

Potential transformer

Circuit breakers are used for

opening or closing a circuit under

normal as well as abnormal

(faulty) conditions.

Different types of CBs which are

generally used are oil circuit

breaker, air-blast circuit breaker,

vacuum circuit breaker and SF6

circuit breaker.

of a short circuit.

SF6 CIRCUIT BREAKER

Isolators are employed in substations

to isolate a part of the system for

general maintenance. Isolator

switches are operated only under no

load condition. They are provided on

each side of every circuit breaker.

Earth switch is used to discharge the

voltage in the circuit to earth for

safety. It is located for each incoming

transmission line and each side of the

bulbar section.

Isolators

Earth switch

When number of lines operating at

the same voltage levels needs to be

connected electrically, bus-bars are

used. Bus-bars are conductors

made of copper or aluminium, with

very low impedance and high

current carrying capacity.

Different types of bus-bar

arrangements are…

single bus bar arrangements, single

bus-bar with sectionalisation,

double bus-bar arrangements, and

ring bus-bar scheme and etc.

500mva transformer750 mva transformer

Now from this report we can conclude that electricity

plays an important role in our life, we made aware of

how the transmission of electricity is done. We also

came to know about the various parts of the substations

system.