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8/11/2019 Aman Yugtgt

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"Energy Meters"INDUSTRIAL TRAINING REPORT

In partial ful lment f r t!e a ar# f t!e #egree$f

%a&!el r f Te&!n l gyInEle&tr ni&s an# ' mmuni&ati n Engineering

Su(mitte# (ySupriya

)))))*+$*,

'!- De.i Lal State Institute Of Engg- / Te&!n l gy

Panni ala M ta 0Sirsa1

Guru 2am(!es! ar Uni.ersityOf

S&ien&e an# Te&!n l gy 3 4isar'!- De.i Lal State Institute Of Engg- / Te&!- Panni ala M ta

0Sirsa1


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'ERTI5I'ATE This is to certify that industrial training reportentitled Energy Meters by Sanjay(1111153 1! # sub$itted in partial ful%l$ent

of the re&uire$ent of the degree of 'achelor of Technology in Electronics and o$$unicationEngineering during the acade$ic year )!1* isa bona %de record of +or, carried out underguidance and super-ision.

/.0. .Electronics and o$$unication

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ACKNOWLEDGEMENT

I take this opportunity to express my profound gratitude

and deep regards to my guide Mr. Rakesh Chanrdra

Notiyal for his exemplary and guidance, monitoring and

constant encouragement throughout the course of this

thesis. The blessing, help and guidance given by him time

to time shall carry me a long way in the journey of life on

which I am about to embark.

I am obliged to staff members of Creative Electronix , for

the valuable information provided by them in their

respective fields. I am grateful for their cooperation during

the period of my assignment.

Lastly, I thank almighty, my parents, brother, sisters and

friends for their constant encouragement without which this

assignment would not be possible.

SanjayElectronics & Communication Engg.4 th year


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TABLE OF CONTENTS T !"CS !#$E N%M ER

!"#$%&L'()'*'$T

"'+TI I"!T' -

I$T+%( "TI%$ T% T+!I$I$) /

"%*0!$1 0+% IL'

'$'+)1 *'T'+3 4Introduction to 'nergy *etersnits of *easurementT10'3 of *'T'+356

o E'ECTR (MEC)#N"C#'o E'ECTR N"C

Testing %f *etersTampering of *eters

T +' T+'$(3 /2!utomatic *eter +eading 7 #MR 8

"ommon *eter +eading Instrument 7 CMR" 8

%T9'+ 0+%( "T3 % T9' "%*0!$1 :"eiling ans*";


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'"ST * *"$%RES

Fig 1. - MetersFig 2.-electromechanical MetersFig 3.-Moving S stem

Fig !.-"egistration S stemFig #.-Electronic MetersFig $.-Bloc% &ig . o' &irect connection o' (ol (hasemeter Fig ).-Electricit Meter Bloc% &ig.Fig *.-Electricit MeterFig +.-A,tomatic metering Fig 1 .- sm mo&emFig 11.-o,tla 'or sm mo&emFig 12.-A"M architect,reFig 13.-/ata connector

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'"ST * T# 'ESTa+le ,.( Some Ty-ical readings ith electromechanicalmeters

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S/N ( ENTE0 $R %! * C M!#N"ES

COMPANY PROFILE:

SKN-BENTEX group started operatio s !" #ears $a%& at 'e()i* t)e %apita( state o+ I dia,it) a u+a%turi g o+ E(e%tri%a( ite s. C)opra Brot)ers Mr. Satis) C)opra* Mr. Kapi(C)opra / Mr. Nis)it C)opra )as pro oted t)e group.SKN-BENTEX0 1roup produ%ts are at t)e +ore+ro t o+ i o2atio i i dustria( a dagri%u(tura( +ie(d +or prote%tio a d %o tro( o+ E(e%tri% Motor. It is t)e pio eers a d (eadersi t)e +ie(d ,it) (atest i ter atio a( e gi eeri g produ%ts $ased o t)e ,or(d3s $estte%) o(og# si %e (ast +our de%ades. 4SKN-BENTEX 0 1roup )as a ri%) )istor# o+ su%%ess*,)i%) )as $ee a%)ie2ed t)roug) dedi%atio * tea ,or& a d 2isio ar# t)i &i g a dsi %ere ser2i%e o+ pride i resu(t orie ted per+or a %e. 4SKN-BENTEX0 1roup )as $ee%o ti uous(# restru%turi g to set up state-o+-t)e-art e(e%tri%a( produ%ts a u+a%tured att)eir o, p(a ts u der stri%t 5ua(it# %o tro( sta dard. I t)is t)rust * ost o+ group%o pa ies adopted I ter atio a( 6ua(it# Sta dard a d )a2e $ee %erti+ied +or ISO-7""8Certi+i%atio a d produ%ts are a(so a2ai(a$(e o ISI-Mar&ed. T)e SKN-BENTEX 1roup o+Co pa ies e gaged i ,ide ra ge o+ produ%ts a d )as ai (# t)ree su$groups o+e(e%tri%a( produ%t ra ge su%) as 4 SKN0* 4SKN0 Be te9 Li ger 4BENTEX-Li ger0 ,it) t)eirseparate produ%ts (i e a d 4SKN-BENTEX 0 1roup is a %o((e%tio o+ s a((er %o pa iesspe%ia(ist i a spe%i+i% ra ge o+ produ%ts. Besides t)is 4SKN-BENTEX 0 group e gaged it)e +ie(d o+* LP1 o e App(ia %es* LP1 Regu(ators* Bui(di g Co stru%tio a d E9portA%ti2ities.o e App(ia %es: LP1 1as Sto2e * Coo&i g Ra ge ;OT1 / O2e


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ENER$1 METERS

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"NTR 2%CT" N T ENER$1 METERS3

!n electric meter or energy meter is a device that measures the amount of electricalenergy supplied to or produced by a residence, business or machine.'lectricity is a clean, convenient way to deliver energy. The electricity meter is howelectricity providers measure billable services.The most common type of meter measures kilo att hours . &hen used in electricityretailing, the utilities record the values measured by these meters to generate an invoicefor the electricity. They may also record other variables including the time when theelectricity was used.3ince it is expensive to store large amounts of electricity, it must usually be generated asit is needed. *ore electricity re?uires more generators, and so providers want consumersto avoid causing peaks in consumption. 'lectricity meters have therefore been devisedthat that encourage users to shift their consumption of power away from peak times, suchas mid6afternoon, when many buildings turn on air6conditioning.

or these applications, meters measure demand, the maximum use of power in someinterval. In some areas, the meters charge more money at certain times of day, to reduceuse. !lso, in some areas meters have relays to turn off nonessential e?uipment.0roviders are also concerned about efficient use of their distribution network. 3o, they tryto maximi@e the delivery of billable power. This includes methods to reduce tamperingwith the meters.!lso, the network has to be upgraded with thicker wires, larger transformers, or moregenerators if parts of it become too hot from excessive currents. The currents can becaused by either real power, in which the waves of voltage and current coincide, orapparent power, in which the waves of current and voltage do not overlap, and so cannotdeliver power.

3ince providers can only collect money for real power, they try to maximi@e the amountof real power delivered by their networks. Therefore, distribution networks alwaysincorporate electricity meters that measure apparent power, usually by displaying orrecording power factors or volt6amp6reactive6hours. *any industrial power meters canmeasure volt6amp6reactive hours.

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%N"TS * ME#S%REMENT3

The most common unit of measurement on the electricity meter is the kilo att hour ,which is e?ual to the amount of energy used by a load of one kilowatt over a period of

one hour, or ,=AA,AAA joules. 3ome electricity companies use the 3I megajoule instead.(emand is normally measured in watts, but averaged over a period, most often a ?uarteror half hour.+eactive power is measured in B olt(am-eres reactive B, 7varh8 in kilovar6hours. !BlaggingB or inductive load, such as a motor, will have negative reactive power. !BleadingB, or capacitive load, will have positive reactive power.Colt6amperes measures all power passed through a distribution network, includingreactive and actual. This is e?ual to the product of root6mean6s?uare volts and amperes.

(istortion of the electric current by loads is measured in several ways. 0ower factor is theratio of resistive 7or real power8 to volt6amperes. ! capacitive load has a leading power

factor, and an inductive load has a lagging power factor. ! purely resistive load 7such as afillament lamp, heater or kettle8 exhibits a power factor of :. "urrent harmonics are ameasure of distortion of the wave form. or example, electronic loads such as computer

power supplies draw their current at the voltage peak to fill their internal storageelements. This can lead to a significant voltage drop near the supply voltage peak whichshows as a flattening of the voltage waveform. This flattening causes odd harmonicswhich are not permissible if they exceed specific limits, as they are not only wasteful, butmay interfere with the operation of other e?uipment. 9armonic emissions are mandated

by law in ' and other countries to fall within specified limits.

%ther units of measurement5

In addition to metering based on the amount of energy used, other types of metering areavailable.*eters which measured the amount of charge 7coulombs8 used, known as ampere6hourmeters, were used in the early days of electrification. These were dependent upon thesupply voltage remaining constant for accurate measurement of energy usage, which wasnot a likely circumstance with most supplies.3ome meters measured only the length of time for which current flowed, with nomeasurement of the magnitude of voltage or current being made. These were only suitedfor constant load applications. $either type is likely to be used today.

T1!ES * METERS3

*odern electricity meters operate by continuously measuring the instantaneous voltage7volts8 and current 7amperes8 and finding the product of these to give instantaneouselectrical power 7watts8 which is then integrated against time to give energy used 7joules,kilowatt6hours etc8. The meters fall into two basic categories, Electromechanical andElectronic.

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E'ECTR (MEC)#N"C#' METERS

"NTR 2%CT" N3

The most common type of electricity meter is the Thomson or electromechanicalinduction watt6hour meter, invented by 'lihu Thomson in :>>>.The electromechanical induction meter operates by counting the revolutions of analuminium disc which is made to rotate at a speed proportional to the power. The numberof revolutions is thus proportional to the energy usage. It consumes a small amount of

power, typically around 2 watts.The metallic disc is acted upon by two coils. %ne coil is connected in such a way that it

produces a magnetic flux in proportion to the voltage and the other produces a magneticflux in proportion to the current. The field of the voltage coil is delayed by 4A degreesusing a lag coil. This produces eddy currents in the disc and the effect is such that a forceis exerted on the disc in proportion to the product of the instantaneous current andvoltage. ! permanent magnet exerts an opposing force proportional to the speed ofrotation of the disc. The e?uilibrium between these two opposing forces results in the discrotating at a speed proportional to the power being used. The disc drives a registermechanism which integrates the speed of the disc over time by counting revolutions,much like the odometer in a car, in order to render a measurement of the total energy usedover a period of time.

The type of meter described above is used on a single6phase !" supply. (ifferent phaseconfigurations use additional voltage and current coils.

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C NSTR%CT" N3

The construction varies in details from one manufacturer


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Bra%ing S stemThe permanent magnet positioned near the edge of the of the !luminium disc forms the

braking system. The aluminium disc moves in the field of this magnet and thus provides a braking tor?ue. The position of the permanent magnet is adjustable, and therefore, braking tor?ue can be adjusted by shifting the permanent magnet to different radial

positions.

"egistering S stemThe function of a registering or a counting mechanism is to record continuously a number which is proportional to the revolutions made by the moving system. ;y a suitablesystem, a train of reduction gears the pinion on the rotor shaft drives a series of five or six

pointers. These rotate on round dials which are marked with ten e?ual divisions.

!ER#T" NThe supply voltage is applied across the pressure coil. The pressure coil winding is highlyinductive as it has very large number of turns and the reluctance of its magnetic circuit isvery small owing to presence of air gaps of very small length. Thus the current I throughthe pressure coil is proportional to the supply voltage and lags it by a few degrees lessthan 4A. This is because the winding has a small resistance and there are iron losses in themagnetic circuit."urrent produces a flux. This flux divides itself into two parts. Themajor portion of it flows across the side gaps as reluctance of this path is small. Thereluctance to the path of flux is large and hence its magnitude is small. This flux goesacross aluminium disc and hence is responsible for production of driving tor?ue. lux isin phase with current I and is proportional to it. Therefore flux is proportional to voltageC and lags it by an angle a few degrees less than 4A. 3ince flux is alternating in nature, itinduces an eddy emf ' in the disc which inturn produces eddy currents.The load current Iflows through the current coil and produces a flux. This flux is proportional to the loadcurrent and is in phase with it. This flux produces eddy current Ies in the disc. $ow theeddy current Ies interacts with flux to produce a tor?ue and eddy current interacts withflux to produce another tor?ue. These two tor?ues are in opposite direction and the nettor?ue is the difference of these.

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Some 0m(ortant "ea&ings

ERR RS "N S"N$'E !)#SE ENER$1 METERSThe errors caused by the driving system are5

:. Incorrect magnitude of fluxes : This maybe due to abnormal values of current orvoltage. The shunt magnet flux maybe in error due to changes in resistance of coilor due to abnormal fre?uencies.

2. Incorrect phase angles : There may not be proper relationship between thevarious phasors. This maybe due to improper lag adjustments, abnormalfre?uencies. "hange in resistance with temperature etc.

. Lack of Symmetry in magnetic circuit : In case the magnetic circuit is notsymmetrical, a driving to?ue is produced which makes the meter creep.

The errors caused by the ;raking system are51. Changes in strength of brake magnet 2. Changes in disc resistance3. Self braking effect of series magnet flux. !bnormal friction of mo"ing parts

#27%STMENT "N S"N$'E !)#SE ENER$1 METERS

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or example, if #h D .2, as above, and one revolution took place in :-.- seconds, the power is :>AA watts. This method can be used to determine the power consumption ofhousehold devices by switching them on one by one.

*ost domestic electricity meters must be read manually, whether by a representative of

the power company or by the customer. &here the customer reads the meter, the readingmay be supplied to the power company by telephone, post or over the internet. Theelectricity company will normally re?uire a visit by a company representative at leastannually in order to verify customer6supplied readings and to make a basic safety checkof the meter.

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E'ECTR N"C METERS

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"NTR 2%CT" N

'lectronic meters compared to traditional mechanical solutions in use offer severaladditional advantages to the utility market. The metering utilities that can be replaced aregas, water and electricity. The advantages are5

E ;etter reliabilityE ;etter accuracyE 'ase of calibrationE !nti6tampering protectionE !utomated meter readingE 3ecurity

E !dvanced billing

%f particular importance to the utility company is the tampering of meters. It is estimatedthat millions of dollars are lost due to the tampering of these meters. !mong thetampering are temporary meter disconnect for a period of time before the readings aretaken, the use of permanent magnets to saturate current transformers and insertion ofmechanical devices to slow down the mechanical turning of the disc.

'lectronic energy meters are replacing traditional electromechanical meters inmany residential, commercial and industrial applications because of the versatility andlow6cost afforded by electronic meter designs. 3ingle6 and multi6chip meter designs arehelping meter manufacturers and their customers reali@e these benefits. Thanks to these

continually evolving metering I"s, meter builders can implement many features that wereimpractical with the older mechanical designs.or example, an electronic design can protect against meter tampering and theft ofservice. It also can measure and record energy usage at different times of the day, soutilities can bill customers for energy based on time of usage. !n electronic energy meteralso can enable automatic meter reading 7!*+8, whereby energy metering data istransmitted to the utility over an + , power line or even infrared communications link.urthermore, electronic meters pave the way for FsubmeteringG of smaller operating units7for example, metering each apartment rather than just the building8.Improved accuracy and lower power consumption are other benefits of electronicmetering. &ith a mechanical meter, the error in the basic energy usage measurement is on

the order of :H. ;ut with an electronic implementation, it is possible to reduce that errorto less than A.:H. *oreover, running the mechanical meter with its continuously spinningdial may re?uire hundreds of milliamps. That power consumption can be reduced to acouple milliamps in an electronic energy meter, producing big power savings for theutility.'lectronic meter designs also change the economics of manufacturing energymeters. ! single hardware design may be customi@ed for different customers and marketsthrough changes in software. In addition, calibrating the finished meter at the factory ismuch easier with an electronic meter design.!nother consideration is the demand for

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mechanical6meter replacements that are as inexpensive as possible. In parts of thedeveloping world where many new customers are being connected to the grid, the lowcost of the electronic meter is its main attraction.

"C 2evelo-ment3

3ince the late :44As, semiconductor vendors with mixed6signal and data conversionexpertise have been developing I"s for electronic energy metering applications.In varying degrees, these components have integrated the energy measurement,calculation and communication functions re?uired to build electronic energy metersranging from simple function, mechanical6meter replacements to advanced function allsolid6state designs.

!s in most areas of silicon development, the level of integration for these componentsgrows with time, so that newer I"s offer more functionality and or less cost."onse?uently, the cost of electronic metering is coming down, which, in turn, is affectingthe types of meters that are being built. !s the metering I"s evolve, there is also a trendto higher accuracy, which is reflected in the energy measurement linearity of the new I"s.

The energy metering market is far from monolithic, so metering I"s target differentapplications. %ne way to differentiate these chips is by the number of phases that must bemeasured. 3ome I"s target single6phase applications, while others are crafted formultiphase 7or poly6phase8 applications. &ithin these categories, the chips also aredistinguished according to whether they target residential, commercial or industrialapplications. !nother way to segment the energy metering I"s is according to the desiredlevel of meter functionality.

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C NSTR%CT" N3

!s in the block diagram, the meter has a power supply, a metering engine, ! processingand communication engine 7i.e. a microcontroller8, and other add6on modules such as+T", L"( display, communication ports modules and so on.

The metering engine is given the voltage and current inputs and has a voltagereference, samplers and ?uantisers followed by an !(" section to yield the digitisede?uivalents of all the inputs. These inputs are then processed using a (igital 3ignal0rocessor to calculate the various metering parameters such as powers, energies etc.

The largest source of long6term errors in the meter is drift in the preamp, followed by the precision of the voltage reference. ;oth of these vary with temperature as well,and vary wildly because most meters are outdoors. "haracteri@ing and compensating forthese is a major part of meter design.

The processing and communication section has the responsibility of calculatingthe various derived ?uantities from the digital values generated by the metering engine.This also has the responsibility of communication using various protocols and interfacewith other addon modules connected as slaves to it.

+T" and other add6on modules are attached as slaves to the processing andcommunication section for various input output functions. %n a modern meter most if notall of this will be implemented inside the microprocessor, such as the +eal Time "lock7+T"8, L"( controller, temperature sensor, memory and analog to digital converters.

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8 R/"N$3

#ilowatt6hour meter for determining, from voltage and current signals, the total energy passing through an alternating electrical supply circuit comprises a clock signal generator for generating timing signals at a fre?uency which is a multiple of the alternating supply

fre?uency, the timing signals being synchronised in phase with the incoming supplyfre?uency, pulse sampling means controlled by said clock signal generator and arrangedto sample simultaneously the magnitude of the voltage on and the current in said supplycircuit at a predetermined time instant or instants in each cycle and digital data processingmeans arranged to process the sampled data to determine energy consumption duringsuccessive predetermined periods of time and to integrate the successive determinationsof energy consumption.

3uch an arrangement may be used with a three phase supply in which case thethree phase voltages and phase currents are separately sampled or it may be used with asingle phase supply in which case only a single voltage and current has to be sampled.The digital data processing means, which is typically a microprocessor system, effects the

re?uired computations from the sampled values.If a single phase supply is considered with the circuit carrying a current I at a

voltage C and with a phase lag 7or phase lead8 between the current and voltage of J, thenif the waveforms were sinusoidal, the power consumption is CI cos J. "onveniently, thiscan be measured by pulse sampling during the peak of one of the waveforms. 0referablythe measurement is made at the peak of the voltage waveform, so as to determine theinstantaneous peak value of C and of I cos J. The r.m.s. product can be readilydetermined by processing of this information. It may be preferred to average successivedeterminations of C and of I cos J separately over a number of cycles of the alternatingsupply fre?uency, typically a few hundred cycles, before determining the product andhence the energy consumption during this period.

The output from the clock signal generator may be integrated, e.g. counted in adigital counter to provide clock time. If a data link is provided, the aforementioned clocksignal generator may be utili@ed to provide clock timing for time6controlled operations,e.g. for example, the customerKs data processing means may compute monetary chargesto ensure correct clock time, the integrated output from the clock signal generator may be

periodically updated over the data link. It will be understood that such periodic updatingis re?uired to correct the clock in the event of any interruption of the supply. 3uch a clock may be used, for example, for effecting changes in the data processing related to absolutetime e.g. variation of charging rates in accordance with time.

The traditional method of detecting the current open or by pass tamper was to measurecurrent imbalance. !s some current imbalance is always there in the system, currentimbalance tampers, which can be caused by partial bypassing of current, is difficult todetect.

"ertain intelligent logics have been developed to detect this type of tamper. This methodis generally used for phase wire meters only, as for phase - wire meters the current

bypass logic is suffice.

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#%T M#T"C METER

RE#2"N$

9#MR:

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8hat is #utomatic Meter Reading;

!utomated *eter +eading 7!*+8 refers to the technology used for automatingcollection of water and energy 7electricity or gas8 consumption data for the purposes ofreal6time billing and consumption analysis. !t any given time, the !*+ system gathersreal6time data and transfers the information gathered to the central database throughnetworking technology.This advance mainly saves utility providers the expense of periodic trips to each physicallocation to read a meter. !nother advantage is billing can be based on near real timeconsumption rather than on estimates based on previous or predicted consumption. Thistimely information coupled with analysis, can help both utility providers and customers

better control the use and production of electric energy, gas usage, or water consumption.!*+ technologies include handheld, mobile and network technologies based ontelephony platforms 7wired and wireless8, radio fre?uency 7+ 8, or power linetransmission.

"ssues ith Stand #lone Meter Reading3(

2=

9ighly 0erson dependant.

9uman errors cannot be avoided.

!ccessibility of meters in rural !gricultural @ones.

'nergy !udits performed based on bill collection which is highly inaccurate.

;illing done mainly on estimated monthly average basis

Inability to monitor and control discrete loads

;illing cycle re?uires excessive time.

*eter data used only for billing, cannot help in analysis like demand analysis, energy audit etc.


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)o #utomated Meter Reading 8orks

!*+ operations are simple on the surface but rather complex underneath. irst, themeter must be read by the meter interface. !fter that, this same interface has to translatethe data into digital information to facilitate transmission. There must also be a codeadded to the meter data reading so that the data can be attributed to the correct subscriber.%nce the data is ready, the data has to be picked up by a meter person. 0icking up meterdata, however, involves digital transfer from the meter interface to a device that the meter reader controls. !fter that, data collected is downloaded in the office. (ata can also beautomatically transmitted to the database through automatic data transmission protocols.

Technological advances have expanded the scope of !*+ activities. %ther possible usesfor the !*+ include monitoring for leaks and theft and detecting meter tampering."onsumer profiling 7especially on such points as peak and lean periods of use8, providingempirical data on the effects of energy saving devices and mindsets, and so on can also bedone.

The Elements o< #utomatic Reading

!n !*+ system has a meter interface apparatus. This is generally an integratedcomponent containing power supply, sensors, and control electronics andcommunications programming. !t its heart, the meter interface module aims to translatedata gathered from the movement of mechanical dials into digital data as well as to

properly identify data for the purposes of correct billing.!n !*+ system also has a transmission and communications protocol in place

for transferring or transmitting data from the meter to the central office. !mong thesystems developed for !*+ are handheld devices 7utility company personnel merelyhave to touch or point their stylus to the meter interface for data to be KreadK8 or vehicle6mounted devices 7the meter readers need to pass by the meter for data to be picked upand transmitted8. (ata is temporarily stored in their device until itKs downloaded at theoffice. (ata transmission may also be sent to the office through wires 7data is transmittedthrough 'thernet cables, broadcasting cable, or power lines8.

inally, the central office must have the software and hardware for transmittedmeter data reception, allocation, analysis and automatic billing.

TEC)N ' $"ES3

,. Touch Technology6. Radio *re=uency Net ork 5. !o er 'ine Communication

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)andheld3

In handheld !*+, a meter reader carries a handheld computer with a built6in or attachedreceiver transceiver 7radio fre?uency or touch8 to collect meter readings from an !*+capable meter. This is sometimes referred to as Bwalk6byB meter reading since the meterreader walks by the locations where meters are installed as they go through their meterreading route. 9andheld computers may also be used to manually enter readings withoutthe use of !*+ technology as an alternate but this will not support exhaustive data whichcan be accurately read using the meter reading electronically.

Mo+ile3

*obile or Bdrive6byB meter reading is where a reading device is installed in a vehicle.The meter reader drives the vehicle while the reading device automatically collects themeter readings. %ften for mobile meter reading the reading e?uipment includesnavigational and mapping features provided by )03 and mapping software. &ith mobilemeter reading, the reader does not normally have to read the meters in any particularroute order, but just drives the service area until all meters are read. "omponents oftenconsist of a laptop or proprietary computer, software, + receiver transceiver, andexternal vehicle antennas.

*ixed Net ork

ixed $etwork !*+ is a method where a network is permanently installed to capturemeter readings. This method can consist of a series of antennas, towers, collectors,repeaters, or other permanently installed infrastructure to collect transmissions of meterreadings from !*+ capable meters and get the data to a central computer without a

person in the field to collect it.There are several types of network topologies in use to get the meter data back to

a central computer. ! star network is the most common, where a meter transmits its datato a central collector or repeater. 3ome systems use only collectors which receive andstore data for processing. %thers also use a repeater which forwards a reading from amore remote area back to a main collector without actually storing it. ! repeater may beforwarded by R* signal or sometimes is converted to a wired network such as telephoneor I0 network to get the data back to a collector.

3ome manufacturers are developing mesh networks where meters themselves actas repeaters passing the data to nearby meters until it makes it to a main collector. The3wedish city of )othenburg is having their electric meters connected in this manner,using the Nig;ee protocol.! mesh network may save the infrastructure of manycollection points, but is more data intensive on the meters. %ne issue with mesh networksit that battery operated ones may need more power for the increased fre?uency oftransmitting. It also re?uires that the meter devices be receivers as well as transmitters

potentially making individual transceiver cost higher. 9owever, the additional cost may be outweighed by the savings of multiple collectors and repeater antennas and finding

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places to mount them.

3ome fixed network systems are also capable of being installed as a hybrid !*+ systemwhere mobile and fixed network are intermixed by design. In a hybrid system, part of thesystem is read by fixed network, and parts may read by mobile or other technology, or

both. tilities with low density rural areas may not cost justify the fixed networkinfrastructure for parts of their service area, using it only for higher density @ones orcommercial accounts. 3ome hybrid networks allow reading of a meter by both methodsconcurrently as a source of redundancy. In the event of a failure of the network due anatural disaster, sabotage, power failure, or other network interruption, the mobilereading system is available in their disaster recovery plan as an alternative means of datacollection to the fixed network.

R* technologies commonly used


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primarily used for electric meter reading. 3ome providers have interfaced gas and watermeters to feed into a 0L" type system.

#MR NET8 R/ #RC)"TECT%REConnectivity in #MR #rchitecture3

Two stages of communication in !*+ 3ystem56

:. )3* ;ased "ommunication3ingle stage communication between *eter and central station through )3* *odem

2. 9ybrid "ommunication

$SM ased Communication39as mainly two components ie )3* *odem and !ntennae

$SM Modem

2

E (ual ;and or Triband )3* )0+3 modem 7')3*4AA :>AA*9@8 7')3* 4AA :>AA :4AA *9@ 8

E (esigned for )0+3, data, fax, 3*3 and voiceapplications

E ully compliant with 'T3I )3* 0hase 2P specifications7$ormal *38E "nter


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%T'#1


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%T'#13

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AMR ARCHITECTURE

R* I !STN ? Modem R*?!STN ? Modem

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2 *eter 2 *eter 2*eter *eter *eter

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*eter / *eter / *eter /

*eter n *eter n *eter n

Central O''ice 2ost Com(,ter

Station.

DistributionTransformer 2.



Data Co entratorUnit DCU 2



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two ty&es of M#"s, a single-channel ty&e connected to a single meter only, and a multi-channelty&e, which can $e connected u& to /0 meters' #n &ro1ects where meters are scattered around inan o&en area, single-channel M#"s are usually used for individual meters' 2ut for &ro1ects wheremeters are grou&ed together in a meter room or ca$inet, Multi-channel Meter #nterface "nits(MM#") are more cost effective' There are $asically two stages of communication in the system, namely, that $etween the M#"sand the ! ", and that $etween the ! "s and the H S' The communication channel or mediumused $etween M#" and ! " is the .ower *ine3 and the channel used $etween ! " and H Scan $e the .u$lic Switched Tele&hone +etwork (.ST+), SM network, radio network, or directlywith handheld terminals 4 note$ook . s with standard RS-565 interface or through a modem'

!LCC Communication:The communication device for the .* communication system is a $uilt-in .ower *ine Modem(.*M), which transmits and receives data over the &ower line' 2oth the M#" and the ! " containthe .*M device' The $inary data stream is keyed onto a carrier signal $y means of the 7re8uencyShift 9eying (7S9) techni8ue' The central fre8uency is shifted :;'69H to re&resent / or ; of the$inary data stream' This signal is then cou&led onto the &ower line $y the .*M' At the receivingend, an identical .*M will detect the signal and convert it $ack to a $inary data stream' The .*Mso&erate in a Half !u&le%, two-way, Time !ivision Multi&le% communication mode' Two-way

communication $etween ! " and M#" is essential in esta$lishing a &ro&er communicationchannel, for system synchroni ation and status re&orting' #n AMRS, transmission s&eed is not a great concern $ut relia$ility is im&ortant' The datarate of the .* channel is set at 0;; $&s, to ensure communication over a longer distance andreduced transmission error' very M#" is also e8ui&&ed with re&eater function' #f re8uired, the! " can designate any M#" in the su$-system as a re&eater to enhance communication with a&articular M#"' ith the sensitive signal detection and so&histicated digital filtering techni8ue, this .* communication is highly immune to electrical noise and interference'

0L" 3chematics5


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3ignal, (ata and Information low5

The M#" is an intelligent device, which can collect, &rocess, and record &ower consum&tion data

from the electric meter' #t &icks u& the &ulse out&ut of the meter and converts the measurement of the meter into a digital format suita$le for data &rocessing' Thus it is &ossi$le to monitor theelectrical load in real time' The M#" saves the data collected in non-volatile memory, and all dataand settings are &rotected against &ower failure' #t will automatically resume normal o&erationwhen &ower returns after a &ower failure' After receiving a Multi-rate Tariff command and loadingthe time-of-use ta$le from the ! ", the M#" will &rocess energy consum&tion data according to&re-set time intervals' #t will u&date the &eak values and their time of occurrence at each tariff rate&roviding real time information of electrical consum&tion for the information management system' !ata stored in the M#" are transmitted to the ! " via the &ower line through the $uilt-in.ower *ine Modems (.*M)' ommunication is initiated $y the ! ", which &olls the M#" $ycalling its address' !ata received from different M#"s are stored in the corres&onding *oad !ataRecords in the 7lash memory of the ! "' The ! " su&&orts communication with any u&warde8ui&ment in conformity with RS-565 standard, e'g' a handheld com&uter' #n most cases, the! " communicates with the remote Host entral Station through standard modem via thee%isting tele&hone line or the SM network' The Host entral Station (H S) is the control center of the system, where all the functions ofthe system are controlled and monitored' The H S &asses instructions and information re8uestsonto the !ata oncentrator "nits (! ") $y calling their addresses (or the tele&hone num$ers incase of a &u$lic switched network), and the ! " will res&ond accordingly' The address codes(tele&hone num$er) of the ! "s are stored in the H S' ith sufficient mass storage,theoretically all ! "s can $e covered $y the H S, in actual fact the ma%imum num$er of ! "scan $e connected to a H S is a$out /;;; as it will $e limited $y the re8uired res&onse time andefficiency of data management' #n case of failures in self-diagnostics or any a$normal $ehavior of the M#"s, the ! " can also make re8uests to re&ort $y dialing to the H S' The H S will convertthe data received into a te%t file com&ati$le with the cor&oration


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!R"M#R1 C M! NENTS * #MR3

Meter inter


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between the meter interface units and the central office.E )3* $etwork E 0ower Line

Central


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" 3T%*'+ ;'$' IT3 3

-:

.recise consum&tion information

lear and accurate $illing

Automatic outage information and faster recovery

2etter and faster customer service

7lag &otential high consum&tion $efore customer gets a high $ill'


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C MM N METER

RE#2"N$ "NSTR%MENT

-2


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INTRODUCTION

Analogic's CMRI is a State-of-the-art product for Meter Reading needs. CMRI is a LightWeight, Compact Instrument that is 100% compatible to a desktop DOS PC added withportability and ruggedness. The CMRI is compatible with all types of existing ElectronicTri Vector Energy Meters in the market.Analogic's CMRI is designed to run MS-DOS and the vast majority of DOS Based PCapplications comes with superlative features like LCD with monochrome CGA text andgraphics, high-speed serial ports, 2 MB system RAM, 2MB systemFLASH for programs and 2MB static RAM for Data Storage which is expandable upto16 MB.

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SUMMARY

uring this co$plete training# 2 got +ell -ersed +ith -ariouselectrical de-ices and circuits. 'esides this# 2 did a deepstudy about the -arious $ethods of theft of electricity and

also the techni&ues used to control such theft# the -ariouslatest trends in technology used for energy $eters to get anaccurate energy $easure$ent.

0nce the Energy $eters +ere deeply studied# 2 gained,no+ledge about -arious other products $anufactured bythe co$pany li,e M ' s# Monobloc, 4u$ps# eiling ans andMotor Starters etc.

6ll in all this training has been really bene%cial for $e ingaining -ital practical ,no+ledge about -arious de-ices andcircuits in the %eld of Electrical and Electronics.

aman yugtgt

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