The 220kV power substation in Muradnagar has a capacity of 2*160MVA and 1*100MVA. It receives power from three 220kV transmission lines and two 400kV lines, which it steps down to lower voltages of 132kV, 66kV, 33kV and 11kV. The substation contains various equipment like circuit breakers, isolators, transformers, lightning arrestors, current and potential transformers, and wave traps to distribute, monitor and protect the flow of electricity. It utilizes equipment like oil and air-blast circuit breakers, vacuum and SF6 gas circuit breakers, and oil and air-cooled power transformers in its operations.

1. UTTAR PRADESH POWER C0RPORATION LTD
K AL M T
AM
IT AL
E 4th YE
NAR

2. DESCRIPTION OF 220KV SUBSTATION,
MURADNAGAR
The 220KV power substation has the capacity(2*160MVA+1*100MVA).
It receives three 220kv lines from Sikandrabad,
Loni and Dadri and two 400kv lines from
Modipuram (circuit 1) and a newly installed circuit
2. It steps down this supply to 132kv, 66kv, 33kv
and 11kv. 132kv line gives supply to Lalkuan,
Morta, Newari, Modisteel, Hapur and Dasna, 33kv
line to Rawli, Noorpur, Goelispat, and 11kv to New
substation.

3. SINGLE LINE DIAGRAM 220KV SUBSTATION
MURADNAGAR

4. MAIN EQUIPMENTS AT MURADNAGAR
SUBSTATION 220KV
LIGHTINING ARRESTER
Used for protecting the
equipment from surge
voltages
CIRCUIT BREAKER
used to protect the
eqiupment by opening the
circuit for over current
and over voltages
ISOLATORS
Used for maintenance of the
circuit in no load condition
TRANSFORMERS
Also known as the heart of
substations. These are
used to reduce the
voltages at appropriate
levels
CURRENT VOLTAGE
TRANSFORMERS
It is a used in power
systems to step downextra
high voltage signals and
provide a low voltage signal,
for measurement or to
operate a protective relay
WAVETRAP
Traps the high frequency
signals

5. LIGHTNING ARRESTER
DEFINATION
A lightning arrester is a device used on
electrical power systems to protect the
insulation on the system from the
damaging effect of lightning.

6. L.A CIRCUIT DIAGRAM
ALSO KNOWN AS SURGE ARRESTER
USED IN THE POWER SYSTEMS TO
PROTECT FROM LIGHTNING
WHEN SUURGE TRAVELS ALONG
THE LINE , THE ARRESTOR DIVERTS IT
TO THE EARTH
1.Rod arrester
2.Horn gap arrester
3.Multi gap arrester
4.Expulsion type lightning arrester
5.Valve type lightning arrester
6. Silicon Carbide Arrestors
7. Metal Oxide Arrestors
At MURAD NAGAR substation we use
ZINC OXIDE ARRESTOR GAPLESS

7. CURRENT VOLTAGE TRANSFORMER
A capacitor voltage transformer (CVT),
or capacitance coupled voltage
transformer (CCVT) is a transformer used
in power systems to step down extra high
voltage signals and provide a low
voltage signal, for measurement or to
operate a protective relay.
In its most basic form the device consists
of three parts: two capacitors across which
the transmission line signal is split,
an inductive element to tune the device to
the line frequency, and a transformer to
isolate and further step down the voltage
for the instrumentation or protective relay.

8. CURRENT VOLTAGE TRANSFORMER
CVTs are typically single-phase devices used
for measuring voltages in excess of one
hundred kilovolts where the use of wound
primary voltage transformers would be
uneconomical. In practice, capacitor C1 is
often constructed as a stack of smaller
capacitors connected in series. This provides
a large voltage drop across C1 and a relatively
small voltage drop across C2.

9. WAVE TRAP
Reliable & fast communication is
necessary
for safe efficient &
economical power supply . To
reduce the power failure in extent &
time, to maintain the interconnected
grid system in optimum working
condition to
coordinate the
operation of various generating unit
communication
network
is
indispensable for state electricity
board.

10. CURRENT VOLTAGE TRANSFORMER
Wave trap is an instrument using for trapping of
the wave. The function of this trap is that it traps
the unwanted waves. Its function is of trapping
wave. Its shape is like a drum. It is connected to
the main incoming feeder so that it can trap the
waves which may be dangerous to the instruments
here in the substation. Low pass filter when power
frequency currents are passed to switch yard and
high frequency signals are blocked.
It is used for communication purpose.

11. ISOLATOR
Isolator
Used to ensure that an electrical circuit is
completely de-energised for service or
maintenance. Such switches are often
found in electrical distribution
and industrial applications, where
machinery must have its source of driving
power removed for adjustment or repair.
High-voltage isolation switches are used in
electrical substations to allow isolation of
apparatus such as circuit
breakers, transformers, and transmission
lines, for maintenance. The disconnector is
usually not intended for normal control of
the circuit, but only for safety isolation.
Disconnector can be operated either
manually or automatically (motorized
disconnector)

12. STEPS OF OPERATION OF ISOLATOR
SEQUENCE OF STEPS FOR ATTENDING
MAINTENANCE:
1.Open CB on no load or full load
2.Open the isolator on no load
3.Close the earth switch
SEQUENCE OF STEPS FOR KEPT IN
SERVICE
1.Open the earth switch
2.Close the isolator
3.Close the CB

13. CIRCUIT BREAKER
A circuit breaker is equipment, which can
open or close a circuit under normal as well as
fault condition. These circuit breaker breaks
for a fault which can damage other instrument
in the station. It is so designed that it can be
operated manually (or by remote control)
under normal conditions and automatically
under fault condition. Whenever a fault
occurs trip coil gets energized, the moving
contacts are pulled by some mechanism &
therefore the circuit is opened or circuit
breaks.

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

15. DIFFERENT CIRCUIT BREAKERS
Oil circuit breaker
A high-voltage circuit
breaker in which the
arc is drawn in oil to
dissipate the heat and
extinguish the arc; the
intense heat of the arc
decomposes the oil .
Air-blast circuit breaker
Fast operations ,suitability for repeated
operation , auto reclosure , unit type
multi break constructions ,simple
assembly , modest maintenance are
some of the main features of air blast
circuit breakers. A compressors plant
necessary to maintain high air pressure in
the air receiver.
Sulpar hexafluoride
circuit breaker (SF6)
Sulphar hexa fluoride (SF6)
gas is used as the arc
quenching medium . The SF6
is an electronegative gas and
has a strong tendency to
absorb free electrons. Circuit
breakers have been developed
for voltage 115KV to
230KV , power rating10
MVA
Vacuum circuit breakers
Vacuum circuit breakers are
circuit breakers which are
used to protect medium and
high voltage circuits from
dangerous electrical
situations

16. 2OIL CIRCUIT
BREAKERS
Air-blast circuit breaker
Vacuum circuit breakers
CIRCUIT BREAKER
Oil circuit breaker
Sulpar hexafluoride circuit breaker (SF6)

17. TRANSFORMERS
POWER TRANSFORMERS
Transformer is a static machine, which transforms
the potential of alternating current at same
frequency. It means the transformer transforms the
low voltage into high voltage & high voltage to low
voltage at same frequency. It works on the principle
of mutual inductance.
When the energy is transformed to a higher voltage,
the transformer is called step up transformer and
then it is transmitted at lower voltage it is called
step down transformer.
There are 3 transformers in the substation:
160MVA, 220/132 KV (2nos.)
100 MVA TRANSFORMER(1)

18. Power Transformer feeding
160 MVA transformers are manufactured by
ADITYA and by TRM. These are the power
transformers and , there efficiency is high.
Primary side is star connected while secondary is
delta connected.
There are seventeen tapping in it.
Every transformer has OLTC to change the tap
for controlling voltage.
TYPES OF COOLING:
AIR NATURAL COOLING
AIR BLAST COOLING
OIL NATURAL COOLING
OIL BLAST COOLING etc.

19. SOME IMPORTANT COMPONENTS
Earth switch: It is a switch normally kept open and connected between earth and conductor. If the
switch is closed it discharges the electric charge to ground, available on the uncharged line.
Bus-bar: 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 aluminum, with very low
impedance and high current carrying capacity.
Current transformers (CT): 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.
Insulators They support the conductor (or bus bar) and confine the current to the conductor. The
most commonly used material for the manufactures of insulators is porcelain. There are several
type of insulator (i.e. pine type, suspension type , strain type ,shackle types etc.) and there used in
Sub-Station will depend upon the service requirement
Potential transformers (PT): 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.

20. THANKS