tcl project report
TRANSCRIPT
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Introduction
The Subhasgram substation under WBSETCL is situated a few km away fromthe Subhasgram station on the way to Champahati. It is a 220/132/33 kv
substation. It is stretched over 22.59 acres of land. It was commissioned at
18th August 2009. At present the 132 kV feeders are still under construction.
Currently it feeds 220 kV to Lakshmikantapur & KLC and 33 kV to
Madarhat.
The substation has 8 transformers:
160 MVA, 220/132 kv Autotransformer 2 31.5MVA, 132/33 kv Double Winding Transformer 2 630KVA, 33/0.4 kv Station Service Transformer 2 100KVA, 33/0.4 kv Earthing Transformer 2
Incoming Voltage: - 220 kV
Outgoing voltage: - 132 kV & 33 kV
Power source: - Nearby Power Grid Corporation of India Limited (PGCIL)
400/220 kV substation.
Sub-Station type: - Outdoor Primary Grid Sub-Station
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Sub-station
Definition of sub-station:
The assembly of apparatus used to change some characteristics of electric
supply is called sub-station.
Introduction:
The present day electrical power is generated, transmitted, and distributed
in the form of AC. The electric power is produce at the power station, which
are located at favorable places, generally quite away from the consumers. It
is delivered to the consumer through a large network of transmission and
distribution. At many place in the line of power system, it may be desirable
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and necessary to change some characteristic (e.g. Voltage, ac to dc,
frequency p.f. etc.) of electric supply. This is accomplished by suitable
apparatus called sub-station for example, generation voltage (11KV or
6.6KV) at the power station is stepped up to high voltage (Say 220KV to
132KV) for transmission of electrical power. Similarly, near the consumers
localities, the voltage may have to be stepped down to utilization level.
Site Selection & Layout 220 KV Substation:
220KVSub-Station forms an important link between Transmission network
and Distribution network. It has a vital Influence of reliability of service.
Apart from ensuring efficient transmission and distribution of power, the
sub-station configuration should be such that it enables easy maintenance
of equipment and minimum interruptions in power supply. Sub-station is
constructed as near as possible to the load center. The voltage level of
power transmission is decided on the quantum of power to be transmitted
to the load center. Transmission is decided on the quantum of power to be
transmitted to the load center.
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Classifications of different types of substations:-
Substations are classified into the following types according to theService requirement:-
Transformer substation Switching substations Frequency Changer substations Power Factor Correction Substations Converting substations Industrial substations.
Substations are classified into the following types according to theConstructional features:-
o Indoor Substationso Outdoor Substationso
Underground Substationso Pole Mounted Substations.
Substations are classified into the following types based on thePurpose served:-
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o Step-Up Substationo Primary Grid Substationo Secondary Substationo Distribution Substation
Transformers & Its Parts
A transformer is a device that transfers electrical energy from one circuit to
another through inductively coupled conductorsthe transformer's coils. A
varying current in the first or primary winding creates a varying magnetic
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flux in the transformer's core and thus a varying magnetic field through the
secondary winding. This varying magnetic field induces a varying
electromotive force (EMF), or "voltage", in the secondary winding. This effect
is called inductive coupling.
If a load is connected to the secondary, current will flow in the secondary
winding, and electrical energy will be transferred from the primary circuit
through the transformer to the load. In an ideal transformer, the induced
voltage in the secondary winding (Vs) is in proportion to the primary
voltage (Vp) and is given by the ratio of the number of turns in the
secondary (Ns) to the number of turns in the primary (Np) as follows:
By appropriate selection of the ratio of turns, a transformer thus enables an
alternating current (AC) voltage to be "stepped up" by making Ns greater
than Np, or "stepped down" by making Ns less than Np. The windings are
coils wound around a ferromagnetic core, air-core transformers being a
notable exception.
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160 MVA transformer of Subhasgram Substation
Different parts of a transformer:-
CORE AND WINDING:-The core of the transformer may be of various
shapes i.e. core, shell. It is made by cold-rolled grain oriented silicon-steel
lamination. Laminated sheets are insulated from each other by applying a
thick layer of varnish insulation on the lamination. The core is laminated to
reduce eddy current losses. The laminations are made in steps and try to
give circular cross section. Bolts and nuts secure the lamination. The core is
placed at the bottom of the tank. The tanks are constructed from welded
sheet steel for small tanks and boiler sheet steel for large tanks. There are
thermometer pockets, radiators tubes for increasing cooling surface. A three
phase transformer has six separate windings- three primary and three
secondary wounded on iron core. Enameled copper with insulation is used
for winding. Insulated papers are used for interlayer insulation. Paper in the
form of tape may be used for taping winding leads and other parts. Press
boards are used as insulation between windings and cores. Press boards are
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also used to separate H.V. windings from L.V. windings input nearer the
core.
TRANSFORMER OIL:-The tank filled with transformer oil and tank is sealed.
It is a mineral oil obtained by refining crude petroleum. It serves the
following purposes:
the core and oils.
Good transformer oil should have:-
rm slugging under normal operating conditions. It is necessary to
check the oil in regular intervals.
Bushing: -The bushing is a hollow insulating liner that fits through a hole
in a wall or metal case, allowing a conductor to pass along its centre and
connect at both ends to other equipment. The purpose of the bushing is to
keep the conductor insulated from the surface it is passing through.
Bushings are often made of wet-process fired porcelain, and may be coated
with a semi-conducting glaze to assist in equalizing the electrical stress
along the length of the bushing.
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The inside of the bushing may contain paper insulation and the bushing is
often filled with oil to provide additional insulation. Bushings for medium-
voltage and low-voltage apparatus may be made of resins reinforced with
paper. The use of polymer bushings for high voltage applications is
becoming more common. The largest high-voltage bushings made are
usually associated with high-voltage direct-current converters.
Conservator: - To allow room for oil expansion and contraction. The
transformer is completely filled with the oil and when it heats up underload or due to ambient temperatures, the oil has to have a place to go. In
the event of colder weather or if the transformer is not under heavy load
the oil cools and contracts creating a slight vacuum inside the tank. The
conservator acts as a reservoir of oil that can then flow back into the tank
so that no air enters it.
It is connected by piping to the main transformer tank that is completely
filled with oil. The conservator also is filled with oil and contains an
expandable bladder or diaphragm between the oil and air to prevent air
from contacting the oil.
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Air enters and exits the space above the bladder/ diaphragm as the oil level
in the main tank goes up and down with temperature. Air typically enters
and exits through a desiccant-type air dryer that must have the desiccant
replaced periodically. The main parts of the system are the expansion tank,
bladder or diaphragm, breather, vent valves, liquid-level gauge and alarm
switch. Vent valves are used to vent air from the system when filling the
unit with oil. A liquid-level gauge indicates the need for adding or
removing transformer oil to maintain the proper oil level and permit flexing
of the diaphragm.
Conservator Tank Silica Gel Breather
Silica Gel Breather:-A transformer breather is an accessory of an oil filled
type transformer which is attached into the oil conservator tank; this serves
as the breathing point of the unit, that when the insulating oil of the
transformer gets heated up, it expands and goes back to the conservator
tank and subsequently pushes the dry air out of the conservator tank
through the breather which is filled with silica gel, when the oil cools down,
it retracts and sucks fresh air from the atmosphere through the breather
and from this point, the silica gel dries up the air that goes back in to the
conservator tank.
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Buccholz Relay: -It is a gas activated relay inside in oil immersedtransformers for protection against all types of fault. Any fault produces
heat and in course the evaluation of gases. It mainly consists of two float
switches and placed in the connecting pipe between he main tank and the
conservator. Under normal condition the main tank and the Buccholz relay
is completely filled up with oil and the conservator tank is half full. When
the fault occurs, it produces gas which is collected in the container. So the
oil level falls and closing the alarm circuit. If no attention is paid to it the
gas collection will be more and close another circuit, which will cut out the
transformer from the line.
Buccholz Relay
PRD (Pressure Release Device):- The pressure relief valve plays a
significant role in the protection ofPower transformer systems. As
mentioned before, a major faultinside the transformer causes instantaneous
vaporization of the oil,leading to extremely rapid build-up of gaseous
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pressure. If thispressure is not relieved within a few milliseconds, the
transformertank can get ruptured, spilling oil over a wide area. The
consequentdamage and fire hazard possibilities are obvious. A pressure
reliefdevice provides instantaneous relieving of dangerous pressure.
PRD
Radiator: - Radiators are used in a transformer to cool the transformer oil
through natural air or forced air flowing in these radiator fins. As the
transformer oil temperature goes down due to cooling it goes to the
transformer tank from bottom, cool the windings and gets heated, and then
returns to the radiator for next cooling. This cycle repeats as the oil flow is
also natural due difference in temperature of oil on bottom and top. In big
power transformers this oil circulation is forced by oil pumps for effective
cooling.
The radiator has many small fins and there are 4-10 radiator banks in a
transformer depending on capacity and make of the transformer.
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Transformer radiator
160 MVA TRANSFORMER
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31.5 MVA transformer
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630 KVA STATION SERVICE TRANSFORMER
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100 KVA EARTHING CUM STATION SERVICE TRANSFORMER
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Substation Equipments
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. Metal oxide varistors (MOVs) have been used for power
system protection since the mid 1970s. The typical lightning arrester also
known as surge arrester has a high voltage terminal and a ground terminal.When a lightning surge or switching surge travels down the power system
to the arrester, the current from the surge is diverted around the protected
insulation in most cases to earth.
The lightning arrestor protects the structure from damage by intercepting
flashes of lightning and transmitting their current to the ground. Since
lightning strikes tend to strike the highest object in the vicinity, the rod is
placed at the apex of a tall structure. It is connected to the ground by low-
resistance cables. In the case of a building, the soil is used as the ground,
and on a ship, water is used. A lightning rod provides a cone of protection,
which has a ground radius approximately, equal to its height above the
ground.
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Lightning Arrester
Isolator: - In electrical engineering is used to make sure that an electrical
circuit can be completely de-energized 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 and
transformers, and transmission lines, for maintenance. Often the isolation
switch is not intended for normal control of the circuit and is used only for
isolation; in such a case, it functions as a second, usually physically distant
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master switch (wired in series with the primary one) that can independently
disable the circuit even if the master switch used in everyday operation is
turned on.
Isolator switches have provisions for a padlock so that inadvertent operation
is not possible (see: Lockout-Tag out). In high voltage or complex systems,these padlocks may be part of a trapped-key interlock system to ensure
proper sequence of operation. In some designs the isolator switch has the
additional ability to earth the isolated circuit thereby providing additional
safety. Such an arrangement would apply to circuits which inter-connect
power distribution systems where both end of the circuit need to be
isolated.
The major difference between an isolator and a circuit breaker is that an
isolator is an off-loaddevice intended to be opened only after current has
been interrupted by some other control device. Safety regulations of the
utility must prevent any attempt to open the disconnector while it supplies
a circuit.
Standards in some countries for safety may require either local motor
isolators or lockable overloads (which can be padlocked).
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Horizontal Center Break Isolator
Pantograph Isolator
Current Transformer: - A current transformer is defined as "as aninstrument transformer in which the secondary current is substantially
proportional to the primary current (under normal conditions of operation)
and differs in phase from it by an angle which is approximately zero for an
appropriate direction of the connections." This highlights the accuracy
requirement of the current transformer but also important is the isolating
function, which means no matter what the system voltage the secondary
circuit need be insulated only for a low voltage.
The current transformer works on the principle of variable flux. In the "ideal"
current transformer, secondary current would be exactly equal (when
multiplied by the turns ratio) and opposite of the primary current. But, as in
the voltage transformer, some of the primary current or the primary
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ampere-turns are utilized for magnetizing the core, thus leaving less than
the actual primary ampere turns to be "transformed" into the secondary
ampere-turns. This naturally introduces an error in the transformation. The
error is classified into two-the current or ratio error and the phase error.
Current Transformer
Capacitor Voltage Transformer: -A capacitor voltage transformer (CVT), orcapacitance coupled voltage transformer (CCVT) is a transformer used in
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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. The tuning of the
divider to the line frequency makes the overall division ratio less sensitive to
changes in the burden of the connected metering or protection devices.
The device has at least four terminals: a terminal for connection to the high
voltage signal, a ground terminal, and two secondary terminals which
connect to the instrumentation or protective relay. 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.
The CVT is also useful in communication systems. CVTs in combination with
wave traps are used for filtering high frequency communication signals from
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power frequency. This forms a carrier communication network throughout
the transmission network.
CVT Potential Transformer
Potential Transformer:-
Potential transformers are instrument transformers. They have a large
number of primary turns and a few numbers of secondary turns. It is used
to control the large value of voltage.
The potential transformer works along the same principle of other
transformers. 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. These transformers work for
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single and three phase systems, and are attached at a point where it is
convenient to measure the voltage.
Potential Transformer is designed for monitoring single-phase and three-
phase power line voltages in power metering applications. The primary
terminals can be connected either in line-to-line or in line-to-neutral
configuration. Fused transformer models are designated by a suffix of "F"
for one fuse or "FF" for two fuses.
A Potential Transformer is a special type of transformer that allows meters
to take readings from electrical service connections with higher voltage
(potential) than the meter is normally capable of handling without at
potential transformer.
Wave Trap: - The wave traps are used to block the high frequency currents
with values of frequencies between 50 kHz and 300 kHz, but to allow the
power frequency current to pass without losses. The blocking effect
depends on the value of inductance in the wave trap. Higher the inductance
in the wave trap, the larger the blocking effect will occur. Wave traps aredesigned as resonant circuit tuned to block the carrier wave. In the wave
trap, inductance and condenser are connected in parallel. Arrangement can
be made such that a wave trap is able to tune two different earner
frequencies. The addition of a second inductance and a second condenser
can do this. The wave traps are connected directly in one phase of the
power transmission line. It is also essential to design the inductances in
such a way that they can carry the current flowing in the line. Wave traps
are standardized for currents of 200 ampere. 400 ampere and 700 ampere.
The variation in the tuning frequency in the wave trap is possible due to the
variable condensers. The inductance unit is made of copper or aluminum
windings. The condenser units arc mounted on a moisture proof casing.
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Wave Trap
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,
by interrupting continuity, to immediately discontinue electrical flow. Unlike
a fuse, which operates once and then has to 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 protectan individual household appliance up to large switchgear designed to
protect high voltage circuits feeding an entire city.
All circuit breakers have common features in their operation, although
details vary substantially depending on the voltage class, current rating and
type of the circuit breaker.
The circuit breaker must detect a fault condition; in low-voltage circuit
breakers this is usually done within the breaker enclosure. Circuit breakers
for large currents or high voltages are usually arranged with pilot devices to
sense a fault current and to operate the trip opening mechanism. The trip
solenoid that releases the latch is usually energized by a separate battery,
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although some high-voltage circuit breakers are self-contained with current
transformers, protection relays, and an internal control power source.
Once a fault is detected, contacts within the circuit breaker must open to
interrupt the circuit; some mechanically-stored energy (using something
such as springs or compressed air) contained within the breaker is used toseparate the contacts, although some of the energy required may be
obtained from the fault current itself. Small circuit breakers may be
manually operated; larger units have solenoids to trip the mechanism, and
electric motors to restore energy to the springs.
Circuit Breaker
Conductors:-
Conductor Material Properties
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Materials commonly used in conductors are aluminum, copper, and steel.
The properties of these common materials fabricated as wires are
summarized in Table 1.1. Galvanized steel wires are combined with
aluminum in the most common type of overhead conductor -- Aluminum
Conductor Steel Reinforced (ACSR). The use of copper is uncommon in
modern transmission lines since it weighs and usually costs considerably
more than aluminum conductor of the same resistance. Conductor Design
& Construction "Standard" bare overhead conductors consist of round
strands helically laid about a core in one or more layers. In a
homogeneous conductor - all aluminum conductor (AAC), hard drawn
copper conductor (CU), or all aluminum alloy conductors (AAAC5005 or
AAAC6201) - the core consists of a single strand identical to the outer
strands. Since all the strands are the same diameter, one can show that the
innermost layer always consists of 6 strands, the second layer of 12 strands,
etc., making conductors having 1, 7, 19, 37, 61, 91, or 128 strands.
In a non-homogeneous conductor - aluminum conductor steel reinforced
(ACSR), aluminum conductor alum weld steel reinforced (ACSR/AW), or hard
drawn copper conductor copper weld steel reinforced (CU/CW), or
aluminum conductor aluminum alloy reinforced - the strands in the core
may or may not be of the same diameter. In a 30/7 ACSR conductor the
aluminum and steel strands are of the same diameter. In a 30/19 ACSRthey are not. Within the core or within the outer layers, however, the
number of strands always increases by 6 in each succeeding layer. The most
common type of transmission conductor is ACSR. ACSR consists of one or
more layers of aluminum strands surrounding a core of 1, 7, 19, or 37
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galvanized steel strands. Certain strandings are stronger than others. 36/1
ACSR is the weakest stranding (1/37 of the cross-sectional area is steel).
30/7 is the strongest (7/37 of the cross-section is steel).
Conductors used in Subhasgram sub-station:-
DOG (6/7) PANTHER (30/7) DEER (30/7) MOOSE (54/7) ZEBRA (54/7)
Tower
The supporting structures for line conductors are called towers.
In general towers have the following properties:
1) High mechanical strength to withstand the weight of conductors and
wind loads.
2) Light in weight without the loss of mechanical strength.
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3) Cheap in cost.
4) Longer life
5) Easy accessibility of conductors for maintenance. For transmission
purpose we only use steel towers.
Various types of steel towers:
1)A TYPE tower: Its a suspension type tower and it has angle ofdeviation of 0-2degree between the conductors.
2)B TYPE tower: These are tension towers having an angle of deviationof 2 -15 degree.
3)C TYPE tower: These are tension towers having an angle of deviationof 15 -30degree.
4)D TYPE tower: These are also tension type tower having angle ofdeviation of 30-60 degree.
Transmission Tower
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ROW (Right Of Way)
ROW or Right Of Way is the minimum permissible distance from an
electrical tower where a building can be build.
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RELAY
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.
A type of relay that can handle the high power required to directly control
an electric motor or other loads is called a contractor. Solid-state relays
control power circuits with no moving parts, instead using a semiconductor
device to perform switching. Relays with calibrated operating characteristics
and sometimes multiple operating coils are used to protect electrical circuits
from overload or faults; in modern electric power systems these functions
are performed by digital instruments still called "protective relays".
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A simple electromagnetic relay consists of a coil of wire wrapped around a
soft iron core, an iron yoke which provides a low reluctance path for
magnetic flux, a movable iron armature, and one or more sets of contacts
(there are two in the relay pictured). The armature is hinged to the yoke
and mechanically linked to one or more sets of moving contacts. It is held
in place by a spring so that when the relay is de-energized there is an air
gap in the magnetic circuit. In this condition, one of the two sets of
contacts in the relay pictured is closed, and the other set is open. Other
relays may have more or fewer sets of contacts depending on their
function. The relay in the picture also has a wire connecting the armature to
the yoke. This ensures continuity of the circuit between the moving contacts
on the armature, and the circuit track on the printed circuit board (PCB) via
the yoke, which is soldered to the PCB.
When an electric current is passed through the coil it generates a magnetic
field that activates the armature and the consequent movement of the
movable contact either makes or breaks (depending upon construction) a
connection with a fixed contact. If the set of contacts was closed when the
relay was de-energized, then the movement opens the contacts and breaks
the connection, and vice versa if the contacts were open. When the current
to the coil is switched off, the armature is returned by a force,
approximately half as strong as the magnetic force, to its relaxed position.
Usually this force is provided by a spring, but gravity is also used commonly
in industrial motor starters. Most relays are manufactured to operate
quickly. In a low-voltage application this reduces noise; in a high voltage or
current application it reduces arcing.
When the coil is energized with direct current, a diode is often placed
across the coil to dissipate the energy from the collapsing magnetic field at
deactivation, which would otherwise generate a voltage spike dangerous to
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semiconductor circuit components. Some automotive relays include a diode
inside the relay case. Alternatively, a contact protection network consisting
of a capacitor and resistor in series (snubber circuit) may absorb the surge.
If the coil is designed to be energized with alternating current (AC), a small
copper "shading ring" can be crimped to the end of the solenoid, creating a
small out-of-phase current which increases the minimum pull on the
armature during the AC cycle.
A solid-state relay uses a thyristor or other solid-state switching device,
activated by the control signal, to switch the controlled load, instead of a
solenoid. An optocoupler (a light-emitting diode (LED) coupled with a
photo transistor) can be used to isolate control and controlled circuits
There are many types of relays:
Directional Over current Relays Auxiliary relays High Impedance Differential relay Directional relays Numerical relays
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COMMUNICATION
In Subhasgram substation, we have basically three types of communication.
They are as follows:
VHF (Very High Frequency) Communication: The frequency used for this
purpose is about 167 megahertz. It is a simple system which does not
require plcc. Communication can be done both ways but one at a time i.e.
we can either speak or listen at a single
1. Instance. It is used to connect to Madarhat substation. The signal iscommunicated through 33kv line.
2. Hotline connection through PLCC: We dont require EPAX in thissystem since the connection is made as soon as we pick up the
receiver end. This type of connection is used for high priority
communication. It is implied to connect Subhasgram substation to
power grid from where it gets the input power. The connection
sequence: phase wire (blue in general) wave trap- LMU box Carrier
(PLCC) Receiver. The incoming is done through 220kv line.
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3. PLCC connection: It is the general configuration which is used toconnect our substation to Lakshmikantapur, Kasba, Bantala substations
and the output is conveyed through 220kv line. The outline of the
communication system: phase wire (blue in general) wave trap- LMU
box Carrier (PLCC) - EPAX- Receiver end.
The Communication room which consists of Carrier, Epax and other
equipments are operated in 48 volt dc. There is a backup room
consisting of 24 batteries for backup to the communication room.
An example of frequency range for interconnection of our substation to
others:
Frequency- KASBA- SINGLE CHANNEL
TX (P) =143.57 KHz
RX (P) =147.57 KHz
Where TX represents Transmission end frequency and RX represents
receiving end frequency.
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CONCLUSION
The vocational training at WBSETCL has been a practical experience for all
of us from Subhasgram subdivision. We have been extremely fortunate to
have got a scope to learn the various intricate details of power transmission
from the engineers and the officers of WBSETCL, Subhasgram. It was a
firsthand experience for all of us to see the various transmission methods
that are employed at a transmission sub-station. We got to understand how
power from various generating station is transmitted to a transmitting sub-
station and the several processes that are undergone before transmitting
the power to a distributing sub-station. While consuming power we hardlycare about the fact that it is the effort of so many tireless people that we
get to enjoy power at our home and other commercial places.
We realize that power transmission is not an easy task and that it comes
after a lot of hard work and loss of innumerable energy. We also got to see
transformers and understand its functioning from very close quarters. We
saw the functioning of circuit breakers, isolators and capacitor banks all that
we had been only reading in textbooks. It was an enlightening experience
to interact with the engineers who has helped to enrich our knowledge.
We also learnt about PLCC and the various models of communication that
are employed in power plants and sub-stations. In all we had an overall
understanding and knowledge of the functions of a transmission sub-
stations. We as students feel proud to have been associated with the
WBSETCL and hope to strengthen our relationship in the near future.
We sincerely thank all the staff of WBSETCL, Subhasgram for making our
training a truly enriching and enjoyable. We had a wonderful time in
WBSETCL.
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Acknowledgement
I would like to thank Mr. Soumen Maity, Divisional Engineer, Mr. Bipul
singha, Assistant Engineer & other employees of Subhasgram Sub-station,
WBSETCL, for supporting me in every possible manner during my training.
Finally I would also like to thank each and everyone responsible for having
made my training days at WBSETCL, Subhasgram a pleasant learning
experience.
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