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    lege.Of.Engineering,BBSR..College.Of.Engineering,BBSR.College.Of.Engineering,BBSR.College.Of.Engineeringle e.Of.En ineerin BBSR..Colle e.Of.En ineerin BBSR.Colle e.Of.En ineerin BBSR.Colle e.Of.En ineerin

    COLLEGE OF ENGINEERING, BHUBANESWAR

    CERTIFICATE

    This is to certify that the seminar report entitled SEMINAR ON ELECTRIC CAR is submitted

    in partial fulfillment of the requirements for award of degree of Bachelor of Technology in Electrical & Electronics engg. incollege of engineering, Bhubaneswar.

    It is faithful record of bonafied seminar work carried by

    SANAT KUMAR UPADHYAYA(Regd.no.0701219203)

    under my supervision & guidance. It is further certified that no part of this report has been submitted to any other University or

    institute for award of any other degree or diploma.

    Stutee soumya Pani Anshuman Nayak Dr.Amiya.Ku. Rath

    Seminar in charge H.O.D Director (A&R)

    Department Of Electrical Engg Department Of Electricall Engg. College Of Engineering, BBSR

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    COLLEGE OF ENGINEERING BHUBANESWAR

    ACKNOWLEDGEMENT

    I express my sincere thanks to my Head of the

    Department Mr. Anshuman Nayak and seminar in chargeMs Stutee soumya Pani of Electrical and Electrical Department for their valuable guidance .

    I am also grateful to the staff members of Electrical and ElectricalDepartment for their immense help and support in the making the

    seminar a success.

    SUBMITTED BY:-

    SANAT KUMAR UPADHYAYA

    REGD NO.- 0701219203

    BRANCH := EEE (1)

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    ABSTRACT

    POWER LINE CARRIER COMMUNICATION:

    Power line carrier communication(PLCC) provides significant

    services for the electric utilities in particular and to the industrial

    and consumer sectors in general. Since its inception in the early

    1920s, PLC has been used for voice communication, protective

    relaying, telemetry and supervisory control. Lately PLCC has proved to

    render the most efficient means for distribution automation & load

    management.

    PLCC is used in all power utilities as a primary

    communication service to transmit speech, telemetry and

    protection tripping command.

    PLCC system uses HV power transmission line of utility as

    a metallic medium for telecommunication. No need for

    laying separate telephone lines on the electric poles or

    hire lease lines from public telephone companies.

    This is very economic, secure communication compared to

    any other means like HF, wearless, lease line etc. It is

    feasible for line length up to 800km.

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    CONTENTS

    Sl.No. Topic Page No.

    1 Introduction 12 History 2

    3 Why electric car? 3

    4 Different parts 4

    5 Motor 56 Controller 6

    7 Batteries used in electric cars 8

    8 Obstacles 10

    9 Future 11

    10 Conclusion 12

    11 References 16

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    INTRODUCTION

    Fast and efficient communication is a pre-requisite for

    management of modern power systems. To maintain a large power

    grid in optimum working condition, the Central LoadDespatcher has

    to have at his command a large battery of communication systems.

    The load dispatcher may use the commercial P&T telephone system

    using open wires or under-ground cables for communication over

    short distances such as communications between the load dispatch

    centre and generating/receiving stations in the same city where the

    load despatch station is located. In some cases, VHF wireless

    communication may also be used. For communication over medium

    and long distances in a power network, Power Line carrier

    communication is the most economical and reliable method of

    communication, this is because of the higher mechanical strength and

    insulation level of the high voltage power lines which contribute to

    the increased reliability of communication and lower attenuation over

    the longer distances involved.

    During the last years PLC technologies have been widelydeveloped mainly due to new modulation techniques used for wireless

    telecommunication systems that can also be applied to PLC systems. The

    current state of the art of PLC communications is presents many

    possibilities and opportunities for the utilities.

    Power Line Carrier communication systems consist of a high

    frequency signal injection over the electrical power lines. This kind of

    technology has been used since the 1950 decade in order to provide

    signalling and ripple control in High Voltage lines, at transmissionlevel. In the last years the interest for this technology has suffered a

    revival because the impressing increase of the mobile

    telecommunications has brought a big development in transmission

    technologies for this kind of communications. In particular, new

    modulation technologies used for wireless communication are especially

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    suitable for PLC communication and make massive data transmissions

    possible. 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 is set according to the distance between substations.

    Bennfits:

    Power line carrier communication integrates the transmission of

    communication signal and 50/60 Hz power signal through tha same

    electric power cable. The major benefit is the union of two important

    application on a single system.

    Data link appears transparent to the user . Although devicesare connected through power line, consumer perceive that there is a

    separate link available for data communication.

    Since the existing lines are used for signal transmission, the

    initial heavy cost and investment for setting up a data communication

    system is avoided. Setting up such a communication system then involves

    installation of transmitter and/or receiver at appropriate points.

    The Challenge:Since the power line is devised for transmission of power at 50/60 Hz and

    at most 400 Hz, The use this medium forData transmission (at high

    frequencies) presents some technically challenging problems. It is one of

    the most electrically contaminated environments which makes it hostile

    for transmission of data signals. The channel is characterized by high

    noise levels and uncertain (or varying) levels of impedance and

    attenuation. In addition, the line offers limited bandwidth in comparision

    to cable or fibre optics links.

    Power line networks are generally made up of a variety of

    conductor types and cross section joined almost at random. Therefore a

    wide variety of characteristic impedances are encountered in the network.

    This imposes interesting difficulties in the designing the filters for this

    communication system. So a power line carrier communication system

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    uses its proper design and its implementation causes connection of two

    microproceesor/ microcontroller kits as also two personal computers. The

    device should be able to transfer data using power lines as their link of

    communication.

    HISTORY

    Engineers started thinking about using power lines for

    communication at the beginning of the 20th century. Practical power

    line carrier communication systems came into operation in several

    countries after 1920. In those early days antennae similar to those

    used in radio work were used to couple the telephone systems to the

    power lines. This was because capacitors capable of withstanding the

    high voltages used in power transmission had not yet been developed

    at that time. These antennae were more than 100 meters long and

    were tuned to the carrier frequencies employed. The coupling

    systems using antennae were inefficient and were affected by

    interference from nearby long wave radio transmitters.

    By about 1930, suitable paper and oil capacitors weredeveloped which could withstand high voltages and serve as effective

    coupling devices for power line carrier communication equipment.

    These early PLC Communication systems have now developed

    into extremely sophisticated and complicated systems which handle

    not only speech communication but also telemetry, tele-signalling,

    tele-control, tele-printer and tele-protection signals. Such

    comprehensive PLCC systems are now widely used in all power grids.

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    FrequencySelection:

    Selecting 24 KHZ:

    y Harmonics,switching andlightningsurge andcorona whichwillbepresentonhigh voltage powerlines allhavecomponentsinthe frequency

    bandbetween 100 Hz to 24 Khz,whichcancauseconsiderablenoiseinthe

    communicationcircuits,if frequencies. Thesignal-to-noiseinsuchcircuits

    willbequite poor.

    y Itwillbe verydifficulttoseparatethe powerfrequencyandradio

    frequencycomponentbelow24 KHz, asthedifferenceinthe frequencies

    willbesmaller, andtheunwantedpowerfrequencyvoltageswillbe very

    highcomparedtosignalvoltageswhichwillbeoftheorderofmilivolts.

    y Thecostofcouplingequipmentbecomes prohibitive below24 KHz,

    becauseof thesize andcomplexityoftheequipmentrequiredfor

    operatingefficientlyatsuchlowfrequencies.

    Selecting 500KHZ:

    * Above 500 KHz,theradiationlosses becomes veryhigh.

    * Interferenceto andfromotherservicesincreases.

    Thelowerandupperfrequencylimitsof 24 KHz and500 KHz have beendecided

    bythe CCITToftheITU forthe abovereasons.

    Inmanycountries,therangeof frequenciesusedforPLCcommunicationis

    restrictedbythegovernmentconcernedassomeoftheotherutilitiessuch as

    longwaveradiostations,navigationreasonsetc.,havetosharethe available

    frequencyband.

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    CARRIER S AND MODULATION

    CARRIERS:

    The carriers used in modern PLC communication systems are

    radio frequency currents of frequencies between 24KHz and 500KHz.

    The use of radio frequency carrier current enables several channels

    of communication to be had over a single physical circuit.

    The reasons for the low frequency limit of 24KHz are:

    1)Harmonics, Switching, lightening surges and corona will be present

    on HV power lines in thefrequency band between 100Hz and 24KHz.

    2)It will be very difficult to separate the power frequency and radio

    frequency components below 24KHz.

    3)The cost of coupling equipment becomes prohibitive below 24KHz.

    The reasons for the high frequency limit of 500KHz are:

    1)Above 500KHz, the radiation losses become very high.

    2) Interference to and from other services increases.

    MODULATION:

    In PLC telephony, the carrier currents are modulated by voice

    frequency currents and the modulated currents are transmitted over

    the power lines. Modern PLCC system use almost exclusively single

    side band amplitude modulation system for voice communication.

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    11

    RF carrier

    (40-500kHz)

    Power Line

    (50Hz)

    WT

    CC

    PAX

    RTU

    (ABB-ETL41)

    PLCC TERM NAL

    POWER FREQUENCY & CARRIER FREQUENCY

    MATERIALS REQUIRED AND SPECIFICATION

    BILL OF MATERIALS:

    1)48 Volt DC supply-> For uninterrupted power supply.

    2) PLCC Equipments-> consists of transmit and receive equipments.

    3)Co-axial Cable-> Also called Coax, is used to transmitRF signals.

    4) Line Matching Unit-> Provided for matching the characteristic

    Impedance of the power line to that of

    Co-axial cable.5)Coupling Capacitor-> U sed as a part of filter network which allows

    a fairly wide band of frequency to pass

    through to the PLC transmit-receive equipment.

    6) Wave trap-> Consists mainly of suitably designed choke coils

    connected in series with power line. It offers a suitably

    high impedance to RF carrier current.

    SPECIFICATION:

    a)Co-axial cable: 75ohmb)Coupling capacitor: (4nF-10nF)

    c)Wave trap:y 132kv (600A, 0.5 mH)

    y 220kv (800A, 1mH)

    y 400kv (1200A, 2mH)

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    10

    Components of PLCC

    Wave Trap

    H.V Line

    PLCC T minal

    Translates voice

    and data into

    Radio Freq.

    Carrier.

    LMU

    Coupling Capacito

    Coaxial

    cable

    COUPLING ARRANGEMENTS

    Since telephone communication system work at a low voltages,

    they cannot be directly connected to high voltage lines. Suitable

    coupling devices have therefore, to be employed. Those, usually,consist of HV capacitors with suitable line matching units for

    matching the impedance of the power line to that of co-axial cable

    connecting the matching unit to PLC transmit-receive equipment.

    WAVE TRAPS:The carrier currents used for PLC communication have to be

    prevented from entering the power equipment in the stations, as this

    would result in high attenuation or even complete loss of

    communication signals. For this purpose ,wave traps or line trapsare employed. What it does is trapping the high frequency

    communication signals sent on the line from the remote substation and

    diverting them to the telecom/teleprotection panel in the substation

    control room (through coupling capacitor and LMU).

    This is relevant in Power Line Carrier Communication (PLCC)

    systems for communication among various substations without

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    dependence on the telecom company network. The signals are primarily

    teleprotection signals and in addition, voice and data communication

    signals.Line trap also is known as Wave trap. What it does is trapping the

    high frequency communication signals sent on the line from the remote

    substation and diverting them to the telecom/teleprotection panel in thesubstation control room (through coupling capacitor and LMU). This is

    relevant in Power Line Carrier Communication (PLCC) systems for

    communication among various substations without dependence on the

    telecom company network. The signals are primarily teleprotection

    signals and in addition, voice and data communication signals.

    The Line trap offers high impedance to the high frequency

    communication signals thus obstructs the flow of these signals in to the

    substation busbars. If there were not to be there, then signal loss is more

    and communication will be ineffective/probably impossible.

    COUPLING CAPACITORS: A modern coupling capacitor consists of a stack of flat wound

    elements of pure cellulose paper and aluminium foil held between

    insulating rods under optimum pressure to minimize capacitance

    changes with temp and time. The interconnections are designed to

    obtain highest possible surge withstand capacity, highest cutoff

    frequency and lowest series resistance at carrier frequencies.

    Coupling capacitor is part of the tuning circuit in Power Line CarrieCommunication. It provides low impedance path for carrier energy to HV

    line and blocks the power frequency circuit by being a high impedance

    path.

    A coupling capacitor allows AC to pass but blocks DC. Like any other

    capacitor it has two conductive plates separated by an insulator. With AC,

    current flows into it during one half cycle charging the capacitor. During

    the other half cycle current flows out of it discharging it and then charging

    it it the opposite direction. With DC, the current flows in once when the

    voltage is first applied, the capacitor is charged, and then current stops.

    Anyway, a coupling capacitor is to join two circuits together. Normally

    the function is to blockDC and transmit AC signals. Typical use in a

    transistor amplifier to connect the signal from the collector of one stage to

    the base of the next stage, as they are at differentDC potentials.

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    A coupling capacitor is a capacitor used to separate the various stages

    in a circuit, for example, to separate the stages of a multistaged amplifier.

    It separates the dc and ac components and 'couples' the output of one

    stage to the input of the next stage.

    coupling capacitors are used in circuits to filter noise signals from

    passing on to the next stage. for example, a coupling capacitor is used in

    the input of an R-C coupled amplifier to filter dc noise. As u may know, the

    reactance offered by a capacitor Xc= 1/(2*pi*f*C) where f is freuency, c is

    capacitance. as d.c has 0 freq, so the reactance offered to dc by a capacitor

    is very very large.

    Coupling capacitors used in modern PLCC systems have a

    capacity between 2 and 8 nF. The units are designed to have very

    low loss (less than 0.5 dB). They are usually mounted on pedestalsbelow the line conductors where the line enters the station.

    In many cases, the capacitive voltage dividers used for

    measurement of line voltages are used as coupling capacitors for

    PLCC, thus making for economy in the installation.

    USE OF CVT AS COUPLING CAPACITORS: As capacitor voltage transformers are almost always used at the

    entry of each power line into a power station both for line alive

    Indication and for synchronizing purposes in a grid system, the idea of

    using these devices for coupling the PLCC system to the power line

    was tried and found to be successful. Their is considerable saving the

    cost of communication system with this arrangement as the use of a

    separate coupling capacitor is avoided.

    The capacitors in series act as coupling capacitors for PLCC.

    The voltage drop across C2 is applied to a suitable auxillary

    transformer to get the potential required for line alive indication,metering and synchronizing circuits. A compensating choke/reactor is

    used in series with the primary of this transformer to resonate with

    the two capacitors and make the output voltage of the auxillary

    transformer largely independent of the load. Taps on the compensating

    choke are used for the correction of phase angle error at desired volt-

    ampere borden on the CVT. Taps on the primary coil of auxiliary

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    transformer are used for getting the exact voltage desired on secondary

    side . The ferro resonance filter is provided to reduce subharmonic

    resonance under unloaded condition of CVTsince such sub-harmonic

    oscilation may cause mal operation of protection relays. The filter consists

    of a parallal resonant circuit which resonates at 50 Hz and is loaded bydamping resistor. Some manufacturers provides the damping resistor on

    a separate secondary winding of the auxiliary transformer.

    The two capacitors can be built as two separate units. This

    arrengment is usually adopted when only one of the facilities namely

    carrier communication is to be installed in the first place and the second

    facility added at a later date. In this case, the capacitor C2, the auxillary

    transformer, and the compensating choke are combined into one single

    unit constructionally.

    The two capacitors may also be built into a single porcelain bushing

    if both metering and carrier facilities are required from the beginning.

    This will ensure uniform dielectric conditions for the two capacitors and

    temperature variations will affect both the capacitors equally. This results

    in a constant voltage division ratio and thus one possible source of

    metering erroris avoided.

    LINE MATCHING AND PROTECTIVE EQUIPMENT:

    The line matching unit consists of matching transformer and

    tuning capacitor. The matching transformer performs two functions.

    Firstly, it isolates the communication equipment from the power line.

    Secondly, it serves to match the characteristic impedance of the

    power line(400-600 ohms)to that of the coaxial cable to

    communication equipment(50-150 ohms). The tuning capacitors enable

    maximum carrier energy transfer to take place between the power

    line and transmit-receive equipment.

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    17

    CVT and HF connection

    PLCC

    TERMINAL

    HF

    8800 pf

    8800 pf

    20mH

    Drain coil

    DISCONNECT

    THIS LINK

    LMU

    220kV

    CVT

    COAXIAL CABLE

    TYPES OF COUPLING

    There are three types of coupling,i.e.

    a) phase-to-ground

    b) phase-to-phase

    c) inter circuit

    PHASE -TO-GROUND COUPLING:

    Wave traps and coupling capacitors are all connected to one

    conductor of power line. Another two conductors do not have wavetraps, a portion of the carrier energy is lost. Also radiation losses

    are high as earth forms a part of the circuit. It is more economical

    as it uses only half the number of wave traps and coupling

    capacitors as compared to others.

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    PHASE-TO-PHASE COUPLING:

    Four wave traps and four coupling capacitors are used for this

    type of PLC coupling. Two power conductors are used for this

    purpose. The signal attenuation is less because two conductors areused instead of one conductor and earth. This type of coupling is

    more reliable over longer distances and is generally used in load

    dispatch work.

    INTER-CIRCUIT COUPLING:

    In this case the two conductors used for communication belong

    to two different power circuits carried on common towers. This type

    of coupling is even more reliable than phase-to-phase coupling onthe same circuit in that it permits operation with one of the two

    circuits opened out and grounded for maintainance purposes.

    21

    Inter circuit

    Phase-to-Ground

    LMU

    Cc

    LT

    PLC

    Cc

    LMDU LMUPLC

    Cc

    LT

    LT

    Cc

    LMDU LMUPLC

    Cc

    LT

    LT

    Phase-to-Phase

    HF Coupling modes

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    APPLICATIONSAND INTEREST

    As we mentioned in the introduction, the interest of PLC

    communications is growing, due to the current circumstances.

    The active grid or intelligence gridconcept will define the

    network of the future and needs of a parallel communication

    system in order to give a successful response to its problems.

    A. INDUSTRIALAUTOMATION:In an industrial environment the PLC communication networks

    can be used to give electric energy related services, such as meter

    reading,

    demand management and remote billing but also to give value addedservices like remote control and security, automation or even, education,

    information and e -business opportunities. On the other hand it can also

    offer telecommunication services such as traditional telephony and

    Internet.

    B. TELECOMMUNICATIONSERVICES:

    Current PLC networks are able to reach speeds of 200Mbps.

    Telephony and Internet services can be delivered at high speed

    through broadband PLC networks. Traditional telephony uses

    Plesiochronous Digital Hierarchy, PDH. PDH uses Time Division

    Multiplexing, TDM. One possibility is to send the TDM frame over IP,

    and the voice overTDM, VoTDM. However, this service should

    accomplish the quality and reliability criteria, like Bit Error Rate,

    timing and latency, and unfortunately the delay in VoTDM transmissions

    exceeds 25ms. Nevertheless, it is possible to give a good telephony

    service over IP. OverTCP/IP, VoIP and Internet services can be delivered

    at a 200Mbps speed, so it can be possible to compete with technologies

    such as ADSL.

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    C. SOLUTIONSFORELECTRICITYSUPPLIERS:

    c.1. Ripple Control:

    It is used for applications such as switched meters, local lightning,

    connection and disconnection of load groups, generation units and

    Individual controls. Traditionally, it has been done through a radio

    communication through an antenna covering a 500km range, which

    allows only a unidirectional communication. PLC would allow a

    bidirectional communication and makes communications more flexible

    and allows different applications.

    c.2. Transformation centres telecontrol:Transformation centres operation and control functions could be

    done via PLC. Currently, the distribution networks automation is of 2%

    but in the near future it is expected to reach50%.

    c.3 Fraud detection:

    The energy provided by the transformer and the energy reaching

    the end customer could be compared, losses more precisely calculated

    and fraud detected.

    c.4. Demand Side Management:

    Demand side management systems cover a variety of policies in

    order to decrease the customers energy consumption , increase the

    energy efficiency, reduce the energy costs, vary the energy use times and

    promote different energy sources. Instead of building new power plants,

    consumption could be reduced by implementing special programs for

    particular clients, industries and institutions.

    c.5. Distributed Generation integration:

    The distributedgeneration will grow significantly during the next

    years.In thirty years the amount of energy produce by distributed

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    generation units will equal to the conventionally produced one. To

    minimize the impact on the stability and functioning of the grid, the

    communication between installations and equipment will have to be

    guaranteed. For this purpose, PLC is a feasible technology.

    c.6. System protection:

    The communication link can be used to transit control signals that

    may be used to protect the system. For example, PLC can be successfully

    used in order to detect islanding operation ofDER units.

    c.7. Fault detection:

    The synergies between the PLC communication system could beanalyzed and used for fault detection and location and also to do

    preventive maintenance actions that can improve significantly the grid

    operation.

    Advantages:

    PLCC integrates the transmission of communication signal and 50/60 Hz power

    signal through the same electric power cable.

    Higher mechanical strength and insulation level of the high voltage power lines

    which contribute to the increased reliability of communication and lower

    attenuation over the longer distances involved.

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    CONCLUSIONThe communication flow of today is very high. Many applications are

    operating at high speed and a fixed connection is often preferred. If the power

    utilities could supply communication over the power-line to the costumers itcould make a tremendous breakthrough in communications. Every household

    would be connected at any time and services being provided at real-time. Using

    the power-line as a communication medium could also be a cost-effective way

    compared to other systems because it uses an existing infrastructure, wires

    exists to every household connected to the power-line network.

    The deregulated market has forced the power utilities to explore new

    markets to find new business opportunities, which have increased the research in

    power-line communications the last decade. The research has initially been

    focused on providing services related to power distribution such as load control,

    meter reading, tariff control, remote control and smart homes. These value-

    added services would open up new markets for the power utilities and hence

    increase the profit. The moderate demands of these applications make it easier

    to obtain reliable communication. Interested several researchers and utilities

    during the last decade, trying to achieve higher bit-rates and more reliable

    communication over the power lines.

    The electric power grid is about to face an important renewal in which the

    information and communication technologies are of vital importance. Thus, it is

    important to have a solid communication infrastructure. Currently, PLC

    networks provide a proprietary solution and enough reliability and qualityconditions.

    When designing or analyzing a PLC network, the structure and

    components of it, as well as its topology have to be taken into account. Also,

    there are different providers that use different technologies so compatibility

    is an issue. There is a narrow band standard and the broadband is very

    developed.

    The transmission quality is also an important factor. Inorder to

    characterize a PLC network, attenuation, noise, SNR, crosstalk and Delay

    Spread parameters have to be measured, analyzed and considered.

    Finally, the application range of PLC is very wide, it can provide

    telecommunication services and value added services but it can also be very

    useful for distribution and transmission system operators in order to guarantee

    the operation and control of the power grid.

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    REFERENCES

    [1] Elisa Garcia, MiguelA. Chileno, Luis Legorburu

    TheexperienceoftheIberdrola Group in Power

    Line Communications, 9 CHLIE Marbella, Spain,July2005.

    [2] Electric power systemsresearch,Volume-4,Issue 2,

    April1981, Page 85-104

    [3] The OPERA ISTIntegratedProjectNo 507667

    fundedbyEC PublicDeliverables.www.ist-opera.org

    [4] J.G. Proakis DigitalCommunication. EditionMcGraw-HillInc. 2001

    [5] Elisa Garcia, MiguelA. Chileno, Luis Legorburu

    The OPERA IST Project, 9 CHLIE Marbella,

    Spain, July2005.

    [6] O. Abarrategui,I. Zamora, DM..Larruskain, M.

    Gomez DLC Communications forIslanding

    Detectionin Systemswith DGXCLEEFunchal,Madeira, Portugal, Spain, July2007.

    [7] O. Abarrategui,I. Zamora, DM. Larruskain, M.

    Gomez SmartGrid: A GlobalVisionXCLEE

    Funchal, Madeira, Portugal, Spain, July2007.

    SPECIALREFERENCE : OPTCL, Chandaka,BBSR.

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