BBMB COLONY SUBDIVISION AT SUNDERNAGAR

DHEERAJ DHEERAJ SHARMASHARMAB.TECH EEE 7B.TECH EEE 7THTH SEM.SEM.

TRANSFORMERSAlso known as the heart of substations. These are used to reduce the voltages at appropriate levelsCURRENT VOLTAGE TRANSFORMERSIt 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

WAVETRAPTraps the high frequency signals

ISOLATORSUsed 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 BBMB COLONY SUBDIVISION

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

L.A CIRCUIT DIAGRAM

1.Rod arrester2.Horn gap arrester3.Multi gap arrester4.Expulsion type lightning arrester5.Valve type lightning arrester6. Silicon Carbide Arrestors7. Metal Oxide ArrestorsAt MURAD NAGAR substation we use ZINC OXIDE ARRESTOR GAPLESS

ALSO KNOWN AS SURGE ARRESTERUSED IN THE POWER SYSTEMS TO PROTECT FROM LIGHTNINGWHEN SUURGE TRAVELS ALONG THE LINE , THE ARRESTOR DIVERTS IT TO THE EARTH

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.

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.

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.

ISOLATORISOLATOR

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)

CIRCUIT BREAKERCIRCUIT BREAKERA 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.

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

Air-blast circuit breakerFast 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.

Oil circuit breakerA 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 .

DIFFERENT CIRCUIT BREAKERS

CIRCUIT BREAKERCIRCUIT BREAKER2OIL CIRCUIT BREAKERS2OIL CIRCUIT BREAKERS

Oil circuit breaker 

Air-blast circuit breaker

Sulpar hexafluoride circuit breaker (SF6)Vacuum circuit breakers

TRANSFORMERSTRANSFORMERSPOWER TRANSFORMERSTransformer 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)

Power Transformer feedingPower Transformer feeding160 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 COOLINGAIR BLAST COOLINGOIL NATURAL COOLINGOIL BLAST COOLING etc.

SOME IMPORTANT COMPONENTSSOME 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 requirementPotential 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.

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