2. INTRODUCTION
In India Electrical power is Generated at a voltage of 11kv to
33kv ,which is taken stepped up to the transmission level in the
range of 132kv or 220kv member of transmission and switching
have to be created these are known as ”Substation”.
Substation is an assembly of apparatus ,which transform the
characteristics of electrical energy from one form to another say
from one voltage level to another level. hence a substation is an
Intermediate link between the Generating station and consumer
3. FUNCTION OF THE SUBSTATION
The sub-station receives power from the generating station by a single or more
feeders at a high voltage, transform the same to the different distribution
voltages and sends to different consumers through distribution network.
4. 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
ISOLATORS
Used for maintenance of
the circuit in no load
condition
CIRCUIT BREAKER
used to protect the
eqiupment by opening
the circuit for over
current and over voltages
LIGHTINING ARRESTER
Used for protecting the
equipment from surge
voltages
MAIN EQUIPMENTS AT SUBSTATIONS
5. 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 2 transformers in the ROBERTSGANJ
substation: 60MVA & 40 MVA ( 132/33 KV)
6. LIGHTNING ARRESTER
A lightning arrester is a device
used on electrical power systems
to protect the insulation on the
system from the damaging effect
of lightning.
7. L.A CIRCUIT DIAGRAM
ALSO KNOWN AS SURGE
ARRESTER
USED IN THE POWER SYSTEMS
TO PROTECT FROM LIGHTNING
8. 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.
9. 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.
10. 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)
