Power Station Projecy Report

8/7/2019 Power Station Projecy Report

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A

TRAINING REPORT

AT

132 KV SUBSTATION

JIND (NEW)

(24 July 2010 to 21 August 2010)

Submitted to: Submitted by:

Mr. Jugal Kishor Vikash Singh (0805809903)

(H.O.D. of ELE Dept.) Branch ELE

SCR Polytechnic GohiyanJind (Haryana)


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FOREWORD

I was required to undergo on four weeks training during the July 2010

to September 2010 towards the partial fulfillment of my diploma Being a

student of Electrical Engineering. I choose to undertake this training at an

Electrical Engineering, since it is a highly progressive sector these days, and

the demand for power is on a rise. Therefore, I landed up at 132 KV

substation Jind one of the good substation in Northern India and a fine

source of Electric power distribution for the local areas The training was a

great learning experience and I have tried to put what I learnt, through these

pages.


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PREFACE

Electricity is one of the most convenient and important source of energy

electricity is used at home and in industry for various purposes such as

lighting, heating operating machine and so on.

Therefore, generation of electricity holds important place in our

society. The generation of electricity and its per capita consumption is an

index to the prosperity of a nation. Man has found a no. of ways to generate

electricity. He began by tapping the energy generated by chemical reaction

for e.g., in a Daniel cell. However, this form was suitable only for very small

application. In addition, large amount of electricity could not be generated

using this method and the output voltage was not suitable. Therefore, man

sought new ways of electric power generation. In this question he invented

huge power plants. The early plants used wood to generate steam for water,

which in term used to drive an electric generation. However, this quick

depletion of forests led man to look for alternative source of power. The

power of falling water was used to generate electricity. However, a need was

felt for more power generation. In addition, the Hydel-power station was

costlier and tougher to establish, even though the cost of operations was


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lower consequently, in the mid twentieth century, coal was found to be a

technologically and economically viable option for steam power generation.

Today, most of the world's electric energy needs are met using coal

Nevertheless, the progress can never stop. Even this cheap alternative has

some limitation. The greatest problem is that of ash disposal. A huge amount

of ash is generated in a coal-based station and it is highly harmful for man

and his environment. Therefore, must of the new power station coming up in

India are natural gas based. According to some experts, for sustainable

development because of its low long-term availability can only be a

transition fuel. Indeed, hydrogen is stipulated to be the fuel of the future.

Clearly, the electric power requirement of man kind is on rise and therefore

the need of looking at alternate and unconventional source of energy is being

best. There are a no. of such sources, for instance, solar, geothermal, tidal

wind etc. these source, though not sufficient all by themselves, can

contribute significantly to our power needs.

As such the consistent growth of power is vital to meet our day-to-

day- requirements and improve the living standards.


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ACKNOWLEDGEMENT

We as a group would like to express our heart filled gratitude to the various

People those who have he pad us curing the entire training period. First of all

We would spastically like to extend a word of thanks to J.E. Mr.Jyoti

Sharma, Haryana Vidyut Para saran Nigam limited 132KV substation, Jind.

It was under his able guidance and leadership that we are permitted to be a

Part of this esteemed substation.

We also would like to thanks ALM Mr.Rajbir Nain & Mr. Virender Kundu

(SA), of the substation for their Instrumental in guiding us to the various

Processes in the substation and Thus played vital role in enriching our

Knowledge in the technical field.


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CONTENTS

1. Introduction to HPGCL

2. Introduction to substation JIND

3. Switchyard

Lightening Arrestor

Capacitor Voltage Transformer

Wave trap

Current Transformer (CT)

Potential Transformer (PT)

Circuit Breaker

Isolators

Insulator

Buses

Power Transformer

Neutral Current Transformer

4. Power line Carrier Communication (PLCC)

5. Battery Room

6. Control Room

7. Substation Auxiliaries Supply

8. Earthing of Substation


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INTRODUCTIO N TO HPGCL

Haryana Power Generation Corporation Limited (HPGCL) wasincorporated as a company under companies Act 1956on 17th March 1997

and certificate for commencement of business was granted on 5 th August

1997. The business of generation of power of erstwhile Haryana State

Electrically Board was transferred to Haryana Power Generation

Corporation Limited on 14th August 1998 pursuant to the implementation of

power reforms in the state of Haryana. The main objective of HPGCL is to

generate power in the state of Haryana from the existing station in most

efficient manner on commercial lines and shell whole of the power

generated exclusively to Haryana Vidyut Parasaran Nigam Limited and to

setup new power project on the state sector.

The main objectives of HPGCL are as under:

1. To generate power from its existing Generating Stations in the

most efficient manner on commercial lines and to sell the same to

distribution companies.

2. To setup new power generation projects.

3. from June 2005 HPGCL is also responsible for the work of powertrading i.e. Procurement of power on long term and short term

basis, signing of power purchase agreements with power

producers/traders


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SUBSTATION (JIND)

Haryana Vidyut Power Generation Corporation Limited (HVPNL) 132 KV

substation Jind is an undertaking of Haryana Power Generation Corporation

Limited Panchkula (HPGCL). Substation serve as a source of energy supply

for the local areas of distribution in which these are located. Their main

functions are to receive energy transmitted at high voltage from the

generating stations, reduce the voltage to a value appropriate for local

distribution and provide facilities for switching.

It is established near milk plant on HANSI road, JIND. This substation

required area of 15 acres. The input of the substation is mainly from threesubstations which are as follows:

1. 132 KV from JHANJ

2. 132 KV from PANIPAT

3. 132 KV from SAFIDON

Then this input power is stepped down and passes to the nearest substation.

So the output of this substation is also going to the three substations which

are as follows:

1. 132 KV to JIND (OLD)

2. 132 KV to KHERI


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SWITCHYARD

Haryana Vidyut Power Generation Corporation Limited (HVPNL) 132 KV

switchyard JIND is an undertaking of Haryana Power Generation (HPGCL)

Corporation Limited Panchkula (HPGCL). Switchyard serve as a source of

energy supply for the local areas of distribution in which these are located.

Their main functions are to receive energy transmitted at high voltage from

the generating stations, reduce the voltage to a value appropriate for local

distribution and provide facilities for switching.

A Highlight of Switchyard Of substation is given in Table Below:


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LIGHTNING ARRESTER

The lightning arrester as a surge diverter is used forthe protection of power system against the high

voltage surges. It is connected between the line and

earths and so diverts the incoming high voltage wave

to the earth. Lightning arrester act as safety valves

designed to discharge electrical surges resulting from

lightening strokes, switching or other disturbances,

which would other wise flash over insulator or

puncture insulation, resulting in a line voltage and

possible failure of equipment. They are designed to

absorb enough transient energy to prevent dangerousreflection and to cut off the flow of power frequency

follow (or dynamic) current at the first current zero

after the discharge of transient. They include one or

more sets of gaps to establish the breakdown voltage,

aid in interrupting the power follow current, and prevent any follow of

current under normal condition(except that gap shunting resistor when

used ton assume equal distribution of voltage across the gap, permits a

very small leakage current). Either resistance element to limit the power

follow current of values the gap can interrupt, or an additional arcextinguishing chamber of interrupt the power follow current are

connected in series with gaps. Arresters have a short time lag of

breakdown compared with the insulation of apparatus, the breakdown

voltage nearly independent of the steepness of the wave front.

Lightning protection by means of lightning arrestors and gaps and

overhead ground wire is a mean of reducing outages and preventing

damage to station equipments from lightning disturbances.

The ground wire or earthling screen does not provide protection againstthe high voltage wave reaching the terminal equipment, so some

protective devices are necessary to provide protection of power stations,

substation and transmission line against the voltage wave reaching there.

The most common device used for the protection of power system

against the high voltage surge is sure diverter.


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CAPACITOR VOLTAGE TRANSFORMER

A capacitor voltage transformer (CVT) is a transformer used in power

system to step down extra high voltage signal and provide low voltagesignals either for measurement or to operate a protective relay. In its

basic form the device consist of three parts: two capacitor across which

the voltage signals is split, an inductive element to tune the device to the

supply frequency and a transformer used to isolate and further step down

the voltage for the instrumentation and protective relay. The device has at

least four terminals, a high voltage terminal to connection to the high

voltage signal, a ground terminal and at least one set of secondary

terminals for the connection of the instrumentation and the protective

relay. CVTs are typically single phase devices used for measuring

voltage in excess of one hundred kilovolts where the use of voltagetransformer would e uneconomical. In practice the first capacitor, C1, is

often replaced by a stack of capacitor connected in series. This result in

large voltage drop across the stacks of capacitors that replaced the first

capacitor and a comparatively small voltage drop across the second

capacitor C2, and hence the secondary terminals.


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WAVETRAP

Wave trap is a parallel tuned inductor capacitor tank Circuit made to be

resonant at the desired communication frequency. It is the effort to utilizethe same transmission line between two substations for the purpose of

communications. At these communication frequencies the tank ckt provides

high impedance and does not allow passing through them & onto the

substation bus & into transformers.

The Line trap offers high impedance to the high frequency communication

signals thus obstructs the flow of these signals in to the substation bus bars.

If there were not to be there, then signal loss is more and communication

will be ineffective/probably impossible.


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CURRENT TRANSFORMER

These instrument transformers are connected in ac power circuits to feed

the current coil of indicating and metering instrument (ammeter,wattmeter, and watt hours meter) protective relays. Thus the CTs

broaden the limit of measurements and maintain a watch over the current

flowing in the circuit and over the power loads. In high voltage

installation CTs in addition to above, also insolate the indicating and

metering instruments from high voltage. The current transformer

basically consists of an iron core on which arc wound a primary and one

or two secondary windings. The primary is directly inserted in the power

circuit (the circuit in which the current is to be measured) and ton the

secondary winding or windings the indicating and metering instruments

and relays are connected. When the rated current of CT flows through itsprimary winding a current of 5 amperes will appears in its secondary

windings. The primary windings are single turn windings and the number

of turns on secondary winding depends upon the power circuit current to

be measured. The larger current to be measured, more the number of

turns on secondary. The ratio of primary current to the secondary current

is known as the transformation ration.


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POTENTIAL TRANSFORMER (PT)

The potential transformer are employed for voltage above 380 volts to feed

the potential coils of indicating and metering instrument (voltmeter,Wattmeter, and watt hours meter) and relays. These transformers make the

ordinary low voltage instrument suitable for measurement of high voltage

and isolate them from high voltage.

The primary windings of the potential transformer is connected to the main

bus bar of the switchgear installation and to the secondary windings, various

indicating and metering instrument and relays are connected.

When rate high voltage is applied to the primary of PT the voltage of 10V

appear at the secondary windings. The ration of rated primary voltage to the

rated secondary voltage is known as turn or transformation ration.


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CIRCUIT BREAKER

A circuit breaker is a mechanical device designed to close or open

contact members, thus closing or opening an electrical circuit under

normal or abnormal conditions. It is so designed that it can be operatemanually under normal condition or automatically under faulty condition.

An automatic circuit breaker is equipped with a trip coil connected to a

relay or other means designed to open or break automatically under

abnormal condition, such as over current. When the circuit breaker is

closed considerably energy stored in the springs. The connects are held

together by means of toggles. To open the circuit breaker only a small

pressure is required to be applied on the trigger. When t6hw trigger is

actuated by the protective relay, it trips and potential energy of the

springs is released and the contacts open in the fraction of second.

HIGH VOLTAGE CIRCUIT BREAKER

High voltage circuit breakers are broadly classified by the medium used to

extinguish the arc.

Oil filled (dead tank and liver tank)

Oil filled, minimum oil volume

Air blast

SF6 Vacuum circuit breaker (manufacturing in ABB, AREVA, cutler-

hammer (Eaton), Siemens, Toshiba)

High voltage circuit breakers are routinely available up to 765 KV AC.

Live tank circuit breaker are where the enclosure that contains the breaking

mechanism is at line potential, that is, live. Dead tank circuit breaker

enclosures are at earth potential.

[Interrupting principle of high voltage circuit breakers

Current interruption in high voltage circuit breaker is obtained by separating

two contacts in a medium, such as SF6 having excellent dielectrical and arc

quenching properties.


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SULPHUR HEXAFLUORIDE (SF6) CIRCUIT BREAKER

In many type of circuit breakers the extinguishing

force built up relatively slowly after the moment of

contact separation, and hence arc is extinguishingafter a few half cycles current have passed zero. The

prevention of arc re-igintioin needs a high

dielectrical strength of the arc path and its fast

recovery current zero. In the case of high voltage

circuit breaker these properties are particularly

required to have quick arc extinction and have less

time for quick recovery voltage build up. Vacuum

circuit breaker and Sf6 circuit breaker havebetter

properties in this regard compared to conventional

bulk oil minimum oil as well as air blast circuitbreakers hence modern trend is to employ vacuum

circuit breaker and SF6 circuit breakers in HV

system.

Modern circuit breaker employs heavy gas SF6 as the medium for quenching

the arc. Sf6 gas because its excellent dielectric, arc quenching, chemical and

other physical properties, has proved its superiority over other mediums

such as oil or air for use in circuit breakers. Several types of SF6 circuit

breakers have been developed by different manufacturers during last two

decades for rated voltages 3.6 to 760 Kv.

Rated voltage 245 KV

Frequency 50 HZ

Current 200 A

Opening voltage 220 V DC

Total wt. 2400 KG

Gas wt. 21 WG

Include gas SF6

Pressure 16.5 KG/cmg

Short circuit 40 KV -3 sec.

Made by Siemens, India


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ISOLATOR

Isolator (or

disconnect switches)are not equipped with

arc quenching device

and, therefore, not

used to open circuits

carrying current. As

the name implies

isolator isolates one

portion of the circuit

from another and is

not intended to beopened while current

is flowing. Isolators

must not be opened

until the circuit is interrupted by some other means. If an isolator is

opened carelessly, when carrying a high current, the resulting arc could

easily cause a flash over the earth. This may shatter the supporting

insulator and may even cause a fatal accident to the operator, particularly

in high voltage circuits. While closing a circuit, the isolator is closing

first, then the circuit breaker. Isolators are necessary on supply side ofcircuit breaker in order to ensure isolation (disconnection) of the circuit

breaker from the live parts for the purpose of maintenance.


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INSULATOR

The porcelain insulators employed in substations

are of the post and busing type. They sever as

supports and insulation of the bus-bars.

A post insulator consists of porcelain body, cast

iron cap and flanged cast iron base, as shown in

fig. the hole in the cap is threaded so that the bus-

bar are either directly bolted to the cap or fixed by

means of bus-bar clamp. Post insulators are

available with round oval and square flanged bases

for fixing respectively, with aid of one, two or four

bolts. Each base in addition also has an earthing bolt. A bushing insulator consists of porcelain-

shell body ,upper and lower locating washers used

for fixing the position of the bus bar in shell, and

mounting flange with holes drilled for fixing bolts and supplied with an

earthing bolt, as shown in fig.

For current rating above 2,000A, the bushings are designed to allow the

main bus bars to be passed directly through them. Each phase of the bus bars

is located with paint according to a fixed color code red, yellow and blue so

that phase of main bus bars can be identified. But at Jind substation disk

type insulators are used which is shown in fig.


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BUS-BARS

Bus bar term is used for a main bar or conductor carrying an electric currentto which many connections may be made.

Bus bars are merely convenient

means of connecting switches and other equipment in to various

arrangements .the usual arrangement of connections in most of the

substations permits working on almost any piece of equipment without

interruption to incoming or outgoing feeders.

In some arrangement two

buses are provided two which the incoming or outgoing feeder and theprincipal equipment may be connected. One bus is usually called the main

bus and the other auxiliary or transfer bus. The main bus may have a more

elaborate system of measuring instruments, relay etc.associated with it. The

switches used for connecting feeders or equipment to one bus or the other

are called transfer switches.


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POWER TRANSFORMER

Power transformer are used for stepping-up the voltage for transmissionat generating stations and for stepping-down voltage for further

distribution at main step down transformer substation. Usually naturally

cooled, oil immersed, known as ON type, two winding, three

transformers are used up to the rating of 10 MVA. The transformers of

rating higher than 10MVA are usually cooled. For very high rating, the

forced oil, water cooling and air blast cooling may be used. For

regulating they voltage of transformers used are provided with on load

tap changer. They are put in operation during load hours and disconnect

during light load hours i.e. they are usually operated at approximately full

load. This is possible because they are arranged in blank and can bethrown in parallel with other units or disconnect at will. So power

transformers are designed to have maximum efficiency at or near full

load (i.e. with iron loss to full load copper loss ratio of 1:1). Power

transformer are designed to have considerable leakage reactance then is

permissible in distribution transformer because in power transformers

inherent voltage regulation is not as much important as current limiting

of the higher leakage reactance. At 132 KV substation Jind two

transformers are used for the stepping down purpose. Each of them is of

100 MVA. These transformers steps down the voltage 132 KV into 33KV. This voltage is then transmitted to the 33 KV substations of KHERI


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NEUTRAL CURRENT TRANSFORMER

This transformer is used after the power transformer. This transformer is asafety device. If there is any extra current in the transformer then this current

is taken by the neutral current transformer and this current is grounded by

the transformer. This is connected to the power transformer for grounding

the extra current. If there is any type of current that current will be grounded

by the neutral current transformer.


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CONTROL ROOMS

The control room (or the operating room) is the nerve center of the power

station. The various control performed from here are voltage adjustment,

load control, emergency tripping of turbines etc. and the equipment and

instruments housed in a control room are synchronizing equipment, voltage

regulators, relays, ammeters, voltmeters, watt meters, KWh meters, kVARh

meters, temperature gauges, water level indicator and other appliances, as

well as a mimic diagram and suitable indicating equipment to show the

opened or closed position of circuit breaker, isolators etc. the location of

control room in relation to other section of the power station is also very

important. It should be located away from the sources of noise and it should

be near the switch house so as to save multi-core cablesUsed for interconnections. Of course, if there is any fire in switch house, the

control room should remain unaffected. Also there is an access from the

control room to the turbine house. The control room should be neat and

clean, well ventilated, well lighted and free from draughts. There should be

no glare and the color scheme should be soothing to eyes. The instrument

should have scales clearly marked and properly calibrated and all the

apparatus and circuit should be labeled so that they are clearly visible.


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BATTERY ROOM

All power plant and substation require dc power supply for protection and

control purposes and dc supply is obtained from secondary or storagebatteries. Battery room is the heart of a substation. Lead acid batteries are

most commonly used in po0wer stations and substations because of their

high cell voltage and lower cost.

Station batteries are assembled of a certain number of accumulator cells

depending on the operating voltage if the respective de circuits. Storage

batteries are of two types viz lead acid and alkaline batteries. Lead acid

batteries are most commonly used in power stations and substations because

of their higher cell voltage and low cost. At substation 132KV Jind 110 cells

are used each of 2 volts. And nickel cadmium alkaline batteries are used.


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TRANSMISSION TOWER

MATERIAL USED IN LINE CONDUCTORS

Aluminum conductor steel reinforced (or

ACSR) cable is a specific type of high

capacity, high strength standard cable

used in overhead power lines. The outer

standards are aluminum, chosen for its

excellent conductivity, low weight, and

low cost. The centre strand is of steel,

providing extra strength. Simultaneously

however, the tower electricalconductivity of the steel core has only a

minimum effect on the overall current

carrying capacity of the cable. Due to a

skin effect, most of the current is carried

by the outer, aluminum portion of the

cable, so the higher Resistance of the

inner, steel strand is largely immaterial.


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POWER LINE CARRIER COMMUNICATION (PLCC)

Power line carrier communication (PLCC) is mainly used for

telecommunication, tele-protection and tele-monitoring between electrical

substations throughpower lines at high voltages, such as 110 Kv, 220 Kv,

400 Kv. PLCC integrates the transmission of communication signal and

50/60 Hz power signal through the same electric power cable. The major

benefit is the union of two important applications in a single system.

In a PLCC system the communication is established through the power line.

The audio frequency is carried by a carrier frequency and the range of carrierfrequency is from 50 kHz to 500 kHz. The modulation generally used in

these systems is amplitude modulation. The carrier frequency range is

allocated to include the audio signal, protection and the pilot frequency. The

pilot frequency is a signal in the audio range that is transmitted continuously

for failure detection.

The voice signal is converted/compressed into the 300 Hz to 4000 Hz range,

and this audio frequency is mixed with the carrier frequency. The carrier

frequency is again filtered, amplified and transmitted. The transmission of

these HF carrier frequencies will be in the range of 0 to +32db. This range isset according to the distance between substations.

PLCC can be used for interconnecting PBXs. The electricity board in India

has an internal network PLCC between PBXs.

Contents

1 Line trap

2 Coupling capacitor

3 Line matching unit 4 Digital power line carrier
http://en.wikipedia.org/wiki/Telecommunicationhttp://en.wikipedia.org/wiki/Electrical_substationhttp://en.wikipedia.org/wiki/Electrical_substationhttp://en.wikipedia.org/wiki/Power_linehttp://en.wikipedia.org/wiki/High_voltagehttp://en.wikipedia.org/wiki/Audio_frequencyhttp://en.wikipedia.org/wiki/Carrier_frequencyhttp://en.wikipedia.org/wiki/Amplitude_modulationhttp://en.wikipedia.org/wiki/Private_branch_exchangehttp://en.wikipedia.org/wiki/Power_line_carrier_communication#Line_trap%23Line_traphttp://en.wikipedia.org/wiki/Power_line_carrier_communication#Coupling_capacitor%23Coupling_capacitorhttp://en.wikipedia.org/wiki/Power_line_carrier_communication#Line_matching_unit%23Line_matching_unithttp://en.wikipedia.org/wiki/Power_line_carrier_communication#Digital_power_line_carrier%23Digital_power_line_carrierhttp://en.wikipedia.org/wiki/Electrical_substationhttp://en.wikipedia.org/wiki/Electrical_substationhttp://en.wikipedia.org/wiki/Power_linehttp://en.wikipedia.org/wiki/High_voltagehttp://en.wikipedia.org/wiki/Audio_frequencyhttp://en.wikipedia.org/wiki/Carrier_frequencyhttp://en.wikipedia.org/wiki/Amplitude_modulationhttp://en.wikipedia.org/wiki/Private_branch_exchangehttp://en.wikipedia.org/wiki/Power_line_carrier_communication#Line_trap%23Line_traphttp://en.wikipedia.org/wiki/Power_line_carrier_communication#Coupling_capacitor%23Coupling_capacitorhttp://en.wikipedia.org/wiki/Power_line_carrier_communication#Line_matching_unit%23Line_matching_unithttp://en.wikipedia.org/wiki/Power_line_carrier_communication#Digital_power_line_carrier%23Digital_power_line_carrierhttp://en.wikipedia.org/wiki/Telecommunication


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LINE TRAP

It is also called Wave trap. It is connected in series with the power

(transmission) line. It blocks the high frequency carrier waves (24 kHz to

500 kHz) and let power waves (50 Hz 60 Hz) to pass through. It is

basically an inductor of rating in mili henry.

COUPLING CAPACITOR

It provides low impedance path for carrier energy to HV line and blocks the

power frequency circuit by being a high impedance path.

LINE MATCHING UNIT

LMU is a composite unit consisting of Drain Coil, Isolation transformer with

Lightning Arrester on its both the sides, a Tuning Device and an earth

switch. Tuning Device is the combination of R-L-C circuits which act as

filter circuit. LMU is also known as Coupling Device. Together with

coupling capacitor, LMU serves the purpose of connecting effectively the

Audio/Radio frequency signals to either transmission line or PLC terminal

and protection of the PLCC unit from the over voltages caused due to

transients on power system.

DIGITAL POWER LINE CARRIER

A power line carrier using a power line as transmission media needs to

change its transmission system from analog to digital to address rapid

diffusion of IP devices and digital telecommunication devices. With this

view, digital power line carrier (DPLC) was developed featuring several

technological measures which enable digital transmission via power lines

and performed a field evaluation test. As a result, DPLC has the required

quality of bit error rate characteristics and transmission ability such as

transmitting information from monitoredelectric-supply stations and images.


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SUBSTATION AUXILIARIES SUPPLY

In small unattended substation only a small amount of power for electric

lighting during regular periods of inspection, maintenance and repair is

required. In regional substation the electric power is required for theauxiliaries:- the lighting circuit, air blast fan of transformer, battery

charging sets oil servicing facilities, compressor unit in case of air blast

circuit breakers, ventilating fans of the substation buildings water supply

and heating system equipment etc. substation incorporating synchronous

condensers the supply is also required for the operation of auxiliaries

equipment of the synchronous condensers.

At 132 KV substation Jind a stepping down transformer is used which

step down 33 KV into 11 KV which is used for the substation auxiliaries

supply. Feeders are also taken from this voltage.


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EARTHING OF SUBSTATION

The term earthing mean connecting of the non current carrying parts ofthe electrical equipment or the neutral point of the supply system to the

general mass of the earth in such a way that at all times am immediate

discharge of electrical energy take place without a danger. The earthing is

provided by the following activities:-

1. for the safety of personnel form of electrical shock- insuring

that non current carrying parts, such as equipment frames are

always safely at ground potential even though insulation fails.

2. For the safety of equipment and personnel against lightning and

voltage surges- providing the discharge path for the lightningarresters, gaps and similar devices.

3. For providing the ground connection for ground neutral system.

4. For provide a mean of positively discharging or highly de-

energizing feeders or equipment before proceeding with

maintenance of them. The station earthing system should have

low resistance.

Grounding of power system is highly important. A substational and adequate

ground that will not burn off or permit danger rise in voltage under abnormalconditions essential.

Equipment earthing also help in the earth fault protection.

Solid grounding will be done it means a direct connection of the neutral to

the earth.


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Power Station Projecy Report