EDITORIAL - Technique Polytechnic Institute · MANIK SAHA, ANUSHREE BASAK & SOUMYA MUKHERJEE Student of Electrical Engineering Department 22–28 7. Smart Grid Technology ARIJIT MONDAL

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EDITORIAL

It is great privilege to bring before you the technical magazine of the

department of Electrical Engineering. Students are gradually getting

interested in self-study and study beyond syllabus. They come up with

interesting ideas and technologies. This year students have also

participated in the publication of the technical magazine. The faculty

members have thrown light on some interesting topics. As management

is a very important aspect of engineering, project management has also

been discussed. Hope it will intrigue in the readers and urge to read the

articles.

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INTRODUCTION

Busy with the framed schedule and academic calendar, we often miss

out some interesting technologies of the ever-growing world of

innovations. Whether it is energy, power, storage, measurement,

instrumentation or management, technologies are ever widening. It is a

responsibility of the engineers to keep track of the new technologies as

well as research on further possibilities. This technical magazine

contains some interesting aspects of engineering and management.

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Editor Mr. Avijit Karmakar, Lecturer, In – Charge

Faculty Members

Miss. Anjana Sengupta, Lecturer

Mr. Rajeev Kumar, Lecturer

Mr. Ayan Ghosh, Lecturer

Mr. Snehashis Das, Lecturer

Mr. Shamik Chattaraj, Lecturer

Mr. Kaustav Mallick, Lecturer

Mr. Pintu Das, Technical Assistant

Mr. Sk. Ansar, Support Staff

Our SincereThanks to

Mr. Tapas Kumar Saha, Chairman, Governing Body, TechniquePolytechnic InstituteMr. Soumendra Nath Basu, Executive Director, Technique PolytechnicInstitute

Mr. Abhijit Chakroborty, Principal, Technique Polytechnic Institute

Mr. Partha Sarathi Bhattacharya, Co-ordinator, Technique PolytechnicInstitute

Publisher

Department of Electrical Engineering

Technique Polytechnic Institute

Panchrokhi, Sugandhya, Hooghly

West Bengal – 712102

©Voltaffair – 2015, Department of Electrical Engineering

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CONTENTSSl. No. Subject Pages

1.Project- Planning, Supervision and EvaluationANJANA SENGUPTALecturer of Electrical Engineering Department

1 – 5

2.Energy-Efficient MotorsAYAN GHOSHLecturer of Electrical Engineering Department

6 – 10

3.Rogowsky Coil & Its ApplicationsKAUSTAV MALLICKLecturer of Electrical Engineering Department

11 – 14

4.New Technologies in Space craftPRIYANKA ROY, SOUNAK GHOSH & ARNAB BANERJEEStudent of Electrical Engineering Department

15 – 18

5.The Prospect of Nuclear EnergyANKITA PAUL, KRISHNA GOPAL MONDAL & KAUSTAV DASStudent of Electrical Engineering Department

19 – 21

6.Prospect of Solar Power in IndiaMANIK SAHA, ANUSHREE BASAK & SOUMYA MUKHERJEEStudent of Electrical Engineering Department

22 – 28

7.Smart Grid TechnologyARIJIT MONDAL & ADITI MANNAStudents of Electrical Engineering Department

29 – 34

8.TO STUDY THE VARIOUS TECHNOLOGIES OF LED IN LIGHTING INDUSTRYAVIJIT KARMAKARIn-Charge of Electrical Engineering Department

35 – 39

VOLTAFFAIR-2016Department Of Electrical Engineering, TPI

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© Voltaffair: Department Of Electrical Engineering-2016 Page 1

Project- Planning, Supervision and Evaluation

ANJANA SENGUPTA

Lecturer of Electrical Engineering Department

Technique Polytechnic Institute, Hooghly, West Bengal, India

Email id: [email protected]

ABSTRACT

Very important programme outcome expected from the diploma or B.Tech engineering students isthat they should be able to plan, supervise and analyze a project. All these qualities contribute inan engineer developing his entrepreneurial skills. The wave of MAKE IN INDIA will need

contribution from the fresh graduates who should have in them the qualities of an entrepreneurembedded. In the process decision taking forms an important part. This paper covers some aspects anengineer should be aware of while participating in a project which may be departmental ormultidisciplinary and participation may be as a group member or as a leader.

A. INTRODUCTION

ver the past decade the use of projects atthe undergraduate level in theUniversity curricula has been seen as

increasingly important for a number of reasons.The project works have always been viewed asan effective means of research training and ofencouraging discovery approach to learningthrough the generation and analysis of primarydata. This type of approach is aimed at thedevelopment of higher level of cognitive skillssuch as analysis, synthesis and evaluation. Apartfrom this a project is considered as an effectivemeans of-

Diversifying assessment; Promoting transferable skills and skills

of employability; Empowering the learner; Motivating students into self-learning; Development of multidisciplinary

studies.

B. WHAT IS PROJECT?

Before going into details we should know whatactually a project is. A project is a long termprogramme which has a particular starting timeand ending time. It involves planning for thebasic course of action and allocation ofresources. The resources may be humanresources, material resources or the requiredknowledge or technology. The course of actioncan be divided into four distinct parts- ideation,planning, execution, evaluation and analysis.The various steps of project work as should befollowed by a student are as follows:

The student selects the project topic; Locates own resource material; Presents an end product; Conducts and independent piece of

work;

The project lasts for a period of time underthe guidance of teacher.

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As a matter of fact the project work isintended to integrate the attitude, skill andknowledge (famously known as ASK)which the student should have acquired overthe entire period of courses of study. Itshould have a measurable and achievableoutcome, a realistic time frame \; an actionplan and persons identified for each activity.The project work consists of various meritcomponents relating students. They are:

Develops decision making skills; Develops idea of designing and

presenting; Enhances innovation skills; Encourages interest in taking

initiatives; Enhances confidence and skills to

solve problems.

C. OBJECTIVES OF THE LEARNINGSTRATEGY

The objective of choosing a project should beclear to the students and the supervisor. Ateaching learning process may precede theproject so that the objectives are clear. Theproject should encourage student centeredlearning and not only be traditional. The projectwork also should invoke research techniques andmethods among students. The unique feature ofproject signifies the shift of control fromsupervisor to supervise which imposes thegreatest challenge to both students andsupervisor.

D. SUPERVISOR OF PROJECT WORK

The supervisor has a very important role to playin the project work. The supervision requires atime bound managed activity that requiresmanagement skills on the part of both supervisorand supervisee. In the process the teacher shouldtake up the role of a facilitator who can easilytransfer the control to the students. Beforetaking up the role of a supervisor the teacher

should evaluate whether they themselves aresuitable for the role. The key points to bechecked are:

Their own motivation in choosing aproject as a learning strategy;

Whether to opt for structured orunstructured projects;

Ways of broadening the prospects ofsupporting the team members.

The following pictorial representationprovides an insight into the various aspects asupervisor should take care of during thevarious stages of the project work. And thevarious stratas of an institution involved inthe process.

The four major features of the supervisory framework requiring planning and sharing are:

Determination and reaching ofagreement regarding educationalobjectives;

Determination and reaching ofagreement on specific objectives toinclude formative deadlines;

Reaching agreement on set targets; Review and ensure understanding of the

assessment criteria.


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E. STUCTURED AND UNSTRUCTUREDPROJECTS

The required framework is planned beforestarting to decide whether the project isStructured or unstructured. Though generating aframework of the project helps in the time, costand quality management structured projects alsohave some disadvantages. They are:

Insufficiently open ended; Too prescriptive; Offering rationalist approach; Lacking constructive approach; Absence of real challenges.

And though the unstructured or semi-structuredprojects don’t provide a preview, the positiveaspects are:

Promotes a deep approach in learning; Allows potential for students to progress

along a hierarchy of understanding; Encourages awareness among students.

In short the management of work schedule of asupervisor can be divided into the following:

Planning for the supervision; Agenda preparation; Collecting Information needed to be

referred. Arrangement for the supervision

meeting; Well-structured meeting.

F. EVALUATION OF PROJECT WORK

The evaluation of performance of a student aftercompletion of the project according to objectivesshall be performed to verify:

Awareness of basic factors involved insuccessful completion of the project;

Skill in utilizing standard codes ofpractice;

Skill in fabrication and in utilizing themachines and tools;

Resourcefulness and initiative incollecting information and making useof available resources;

Ability to analyze and solve problemsindependently;

Quality of work regarding its utility; Confidence on his/her ability to arrive at

the goal; Preparedness to try other alternative in

case of failure at any stage.

Proper evaluation pattern would always providejustice to the worth of project work. In technicalinstitutions generally two types of project worksare followed-

Design and implementation basedprojects

Design based projects.

Thus the evaluation process also varies. Theevaluation process may be in tabulated form.


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The following may be considered a generalizedpattern of evaluation.

G. PROJECT TYPE: DESIGN BASED

STUDENT’S NAME:ROLL NO:TITLE:

Mark the suitable block for each criterion.

Criteria Excellent Satisfactory Unsatisfactory

Background-generalunderstanding ofthe subjectReportorganization andstructureJustifiedconclusions andcritical appraisalKey problemsidentified andsolvedDocumentationWhetherobjectives wereachieved fullyRequirementsand objectiveswell understoodand presentedAppropriate useof designmethodologyOverall qualityof the finaldesignVerification ofthe design(prototyping)Practicality ofthe designCount the ticksin each column

H. PROJECT TYPE: DESIGN ANDIMPLEMENTATION BASED

STUDENT’S NAME:ROLL NO:

TITLE:

Mark the suitable block for each criterion.

Criteria Excellent Satisfactory Unsatisfactory

Background-generalunderstandingof the subjectReportorganizationand structure

Justifiedconclusionsand criticalappraisalKey problemsidentified andsolved

DocumentationWhetherobjectives wereachieved fully

Requirementsand objectiveswellunderstood andpresentedAppropriateuse of designmethodologyOverall qualityof the finaldesignVerification ofthe design(prototyping)Practicality ofthe designCount the ticksin each column


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I. CONCLUSION

A project can be described as a unique learningopportunity where students can demonstrateproject management skills and a time bounddomain. The project work is clearly a studentcentered learning experience where a teachertakes up the role of supervisor. Furthersupervisor’s management and interpersonalskills can also be tested through the process. Butbefore starting a project analysis of thestrengths, weaknesses, opportunities and threats(commonly known as SWOT ANALYSIS)should be done to measure the practicality of aproject.

J. REFERENCE

1. A handbook for teaching and learningin higher education- Heather fry, SteveKetteridge, Stephanie Marshall.

2. Project Management Principles Appliedin Academic Research ProjectsPollyana Notargiacomo Mustaro &Rogério Rossi Mackenzie PresbyterianUniversity, São Paulo, SP, Brazil.


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Energy-Efficient Motors

AYAN GHOSH




ABSTRACT

lectric motor systems account for about 60 percent of industrial electricity consumption and about15 percent of final energy use in industry worldwide. It is estimated that a full implementation ofefficiency improvement options could reduce worldwide electricity demand by about 7 percent.Electric motors drive both core industrial processes, like presses or rolls, and auxiliary systems,

like compressed air generation, ventilation or water pumping. They are utilized throughout all industrialbranches, though the main applications vary. With only some exceptions, electric motors are the mainsource for the provision of mechanical energy in industry. Size classes vary between motors with less thanone kW and large industrial motors with several MW rated power. In recent years, many studiesidentified large energy efficiency potentials in electric motors and motor systems with many savingoptions showing very short payback times and high cost-effectiveness.Still, investments in improving the energy efficiency of electric motor systems are often delayed orrejected in favor of alternative investments. Different barriers and market failures were found to beresponsible for that. Among them are a lack of attention of the plant manager, principal agent dilemmas,higher initial cost for efficient motors and many more. Particularly in developing countries, access tocapital and initial higher costs of energy efficient motors are a very relevant barrier. In many cases,broken motors are rewound and reused even though motor rewinding often reduces its efficiency.

Keywords: Efficiency, Electric motor drive, Payback time, cost-effectiveness etc.

A. INTRODUCTION

he electric motor has a long historyof development since its invention in1887, with most early effort aimed at

improving power and torque and reducingcost. The need for higher efficiency becameapparent during the late 1970s and by theearly 1980s. Energy-efficient motors (EEM)are the ones in which, design improvements areincorporated. Specifically to increase operatingefficiency over motors of standard design(as shown in Figure 1).Design improvementsfocus on reducing intrinsic motor losses.Improvements include the use of lower-losssilicon steel, a longer core (to increase activematerial), and thicker wires (to reduceresistance),

Figure 1: Standard Vs. High EfficiencyMotors Efficiency according to Motor Rating

(kW)

thinner laminations, smaller air gap betweenstator and rotor, copper instead of aluminum barsin the rotor, superior bearings and a smaller fan,etc.

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Energy-efficient motors now available inIndia operate with efficiencies that aretypically 3 to 4 percentage points higher thanstandard motors. These motors are designedto operate without loss in efficiency at loadsbetween 75 % and 100 % of rated capacity.This may result in major benefits in varyingload applications. The power factor is aboutthe same or may be higher than for standardmotors. Furthermore, energy- efficientmotors have lower operating temperaturesand noise levels, greater ability to acceleratehigher-inertia loads, and are less affected bysupply voltage fluctuations.Energy-efficient motors offer other benefits.Because they are constructed with improvedmanufacturing techniques and superiormaterials, energy-efficient motors usuallyhave higher service factors, longer insulationand bearing lives, lower waste heat output,and less vibration, all of which increasereliability. Most motor manufacturers offerlonger warranties for their most efficientmodels.An electric motor can consume electricityto the equivalent of its capital cost withinthe first 500 hours of operation - a merethree weeks of continuous use, or threemonths of single shift working. Everyyear, the running cost of the motor will befrom four to sixteen times its capital cost.Over its working life, an average ofthirteen years, it may consume over 200times its capital cost in energy. Clearly, thelowest overall cost will not be achieved unlessboth capital and running costs are consideredtogether.

B. ENERGY LOSSES

It must be emphasized that the standardelectric motor is already a very efficientdevice with efficiencies above 80% overmost of the working range, rising to over90% at full load. However, because of thehigh energy consumption, and the very largenumber of installed units, even a smallincrease in efficiency can have a major

impact on costs. The efficiency of an electricmotor depends on the choice of materialsused for the core and windings, their physicalarrangement and the care and precision withwhich they are handled and assembled.Losses can be categorized into two groups;those that are relatively independent of load(constant losses), and those that increasewith load (load dependent losses). Thefactors that affect efficiency a r e :

Conductor content (Load dependent)Magnetic steel (Mainly constant)Thermal design (Mainly load dependent)Aerodynamic design (Constant)Manufacture and and

quality control(Constant)

C. CONDUCTOR CONTENT

Resistive losses in the windings increasewith the square of the current (whichincreases with the load) and normally accountfor around 35% of the total losses. Theseresistive losses can be reduced by puttingmore copper into the windings - using athicker gauge wire - and improvingmanufacturing techniques to shorten the endwindings (which do not contribute to outputpower but do contribute to loss). Sincemore copper requires more space, both forthe end windings and in the stator slots, thevolume of material in the magnetic circuitwould be reduced, leading to earliersaturation and increased iron losses.Consequently, it is necessary to increase t h elength o f the magnetic core, and sometimesthe diameter as well. Normally, the increasedlength is accommodated by increasing theoverhang at the non-drive end of the unit.Because copper losses are load-dependent, thebenefit of increasing the copper content is mostapparent at high loading. Since the coefficientof resistance of copper is positive, the lossesincrease as temperature rises.

D. MAGNETIC STEEL

Magnetic steel is the most expensive componentof the motor, so any increase i n the total


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amount u s e d is undesirable on cost grounds.Core losses are those found in the stator-rotormagnetic steel and are due to hysteresis effect andeddy current effect during 50 Hz magnetization ofthe core material. These losses are independent ofload and account for 20 – 25 % of the total losses.Hysteresis loss is due to the non-linearity ofthe flux density/magnetizing force curve andis a property of the steel itself and tominimize it two properties are required - alow energy loss grade of silicon steellaminations and good high field permeability,i.e. the steel must be easy to magnetize andmust not saturate at high flux densities of up to1.8 Tesla. This is the subject of on-goingresearch that is making promising progress.Eddy-current losses are due to induced currentin the stator laminations and are reduced byreducing the thickness of the laminations andby ensuring good insulation betweenadjacent laminations. Thinner laminationsare, naturally much more expensive toproduce and more difficult to handle, so thechosen thickness is always a compromise.Magnetic losses are particularly importantwhen the supply is distorted by harmonicsbecause eddy current losses increase with thesquare of the frequency while hysteresislosses are proportional to frequency. Thebenefit of using improved magnetic steel is areduction in loss across the whole of theworking range, but, because it is not loaddependent, it is particularly apparent at lowloadings.

E. THERMAL DESIGN

New modeling techniques have allowed theproduction of motors with optimizedcooling flow, reduced clearances (increasingthe efficiency of the magnetic circuit) andlower copper losses. Lower losses andgood thermal design result in lower operatingtemperatures and hence a longer service life.

F. AERODYNAMICS

Most electric motors are cooled by drawingair through the windings by an integral fanand exhausting it over the externally ribbedcasing. The airflow is complex and

computer modeling has been used tooptimize the design of the fan and cowlingto produce more efficient cooling with alower noise level. Windage losses can bereduced by careful design of the rotor.

G. MANUFACTURE & QUALITY CONTROL

The introduction of stresses in the magneticsteel during motor assembly can increaseiron loss by up to 50%. By consideringassembly techniques at the design stageand by paying attention to handlingtechniques, this increase in iron lossduring manufacture has been reduced tonegligible proportions. Eccentricity betweenthe stator and rotor generates harmonic fluxeswith consequently higher losses. The overallresult of these improvements is an increasein efficiency of 3% (corresponding to areduction in loss of about 30%) at full loadand a halving of losses at low loads.Figure 2 shows the comparison between theefficiency of 75 kW standard and high-efficiency motors against actual load.Because many motors spend considerabletime running at low loading or idling,designers of high- efficiency units havepaid great attention to reduction of theconstant losses. The result is a halving oflosses at loadings less than 25% load and anefficiency improvement of 3 to 5% at fullload, a reduction in losses of about 28%.This represents an impressive achievement.

Figure 2: Standard Vs. High Efficiency MotorsEfficiency according to Motor Loading (kW)


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H. APPLICATION of HIGH EFFICIENCYMOTORS

The benefits of HE motors will only berealized if good installation techniques areused. Energy is lost in cabling. Voltage balancein three phase machines causes unbalancedcurrents in the stator winding. The effect issuper-proportional i.e. the percentageunbalanced current is much higher than thepercentage unbalanced voltage, causingsignificantly increased temperatures. The effectis equivalent to the introduction of anegative sequence voltage, i.e. one that has arotation opposite to that of the fundamental,leading to higher current, reduced torqueand reduced full-load speed. Preferably, thevoltages should be balanced as closely ascan be read on a voltmeter, and where thisis not possible, the motor should be de-ratedaccording to Figure 3. Operation above 5%unbalance is not recommended.

Figure 3: De-rating factor Vs. PercentageVoltage Unbalance

Voltage balance can be improved bysegregating motor supply circuits, usingoversized conductors to reduce voltage dropand ensuring that single-phase loads are not fedfrom a three phase motor circuit.

I. ECONOMIC JUSTIFICATION FORSELECTING HIGH-EFFICIENCYMOTORS

Justifying a capital purchase is probably onethe most difficult tasks. This is because thereare so many methods of calculation, andeven more opinions about which is right!There is enormous pressure to minimize thecost of projects, and this means that decisionmakers tend to be looking for lowest firstcost. However, this initial cost is only part ofthe story - as mentioned above, a motor mayconsume up to 200 times its capital cost inelectricity, so a proper examination must includerunning costs.Starting from the premise that the need for, andcost justification of, the purchase of a newmotor has been made, how can the selection ofa premium quality motor be justified?As with any project, the capital outlayrequired, in this case the difference in costbetween the high-efficiency motor and astandard unit, must be judged against the futurecash, in this case the savings due to reducedenergy consumption, generated in future years.The criteria by which the results are assessedwill depend on the culture of the organization,and may often involve comparison with otherpotential uses for the capital available.Electrical Energy Efficiency defines some of thepopular methods of calculation, together withseveral case histories, which demonstrate that,under a wide range of circumstances, thepayback periods are typically around two years.This payback period is short enough to beconsidered a good investment by mostorganizations.The economics of the installation of high-efficiency motors are best when new plant isbeing built. However, in certain circumstances,the cost of replacing an existing motor beforethe end of its serviceable life can be justified,but the economic considerations are morecomplex. It may be justified by comparing theadditional cost of early replacement (the lostvalue of the residual life of the existing unit, thehigher cost of immediate, rather than future,capital) with the future savings, or by takingaccount of future energy savings to avoid ordelay the expense of increasing the capacity of


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local supply transformers and circuits.Another good time to consider the selection ofhigh-efficiency motors is when an existing unitis being considered for rewinding. Theefficiency of rewound motors is extremelyimportant. The loss in efficiency on rewindingdepends on the techniques; processes and skillused to perform the rewind, and is usuallybetween 1 and 2%. If the choice is betweenrewinding a standard efficiency motor andpurchasing a new HE motor, the difference inefficiency will be 4 to 5% at full load in favorof the HE motor, which will also have a muchlonger service life. It will be found more costeffective in most cases to prefer the new high-efficiency unit. The rewinding of HE motorshas been studied with the objective of definingrewinding techniques which will limit thereduction in efficiency to 0.5%, so that theadvantage of the HE motor can be preservedafter rewinding.Whenever a motor is to be newly installed orreplaced, it should be standard practice toexamine the cost benefits of selecting a high-efficiency type. The cost of running the plantcan be estimated for both types of motors. Ifthe 'equipment is going to be running for asignificant proportion of each day, then it isvery likely that it is worth selecting a highquality high-efficiency design. There is a needfor a management policy commitment towardspotential cost savings at the design andspecification stages.

J. CONCLUSION

Over half of all electrical energy consumed in acountry is used by electric motors. Improving theefficiency of electric motors and the equipmentthey drive can save energy, reduce operatingcosts, and improve the nation’s productivity.Energy efficiency should be a majorconsideration when we purchase or rewind amotor. The annual energy cost of running a motoris usually many times greater than its initialpurchase price. For example, even at therelatively low energy rate of $0.04/kWh, a typical20-horsepower (hp) continuously running motoruses almost $6,000 worth of electricity annually,about six times its initial purchase price.

K. REFERENCES

[1] Energy efficiency in electric motorsystems: Technical potentials and policyapproaches for developing countries (2011) -Tobias Fleiter, Fraunhofer Institute for Systemsand Innovation Research Karlsruhe. WolfgangEichhammer, Fraunhofer Institute for Systemsand Innovation Research Karlsruhe. JoachimSchleich Fraunhofer Institute for Systems andInnovation Research Karlsruhe.

[2] Energy-Efficient Electric Motor SelectionHandbook (1993) - Gilbert A. McCoy,Todd Litman, John G. Douglass, WashingtonState Energy Office, Olympia, Washington

[3] BUYING AN ENERGY-EFFICIENTELECTRIC MOTOR- a Program of the U.S.Department of Energy.

[4] ELECTRICAL DESIGN – A GOODPRACTICE GUIDE (1997) - David Chapman,AMIEE


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ROGOWOSKY COIL & Its APPLICATIONS

KAUSTAV MALLICK




ABSTRACT:

his writing presents a brief idea about Rogowsky coil-it’s working principle, its advantage designas well as its area of application. Going through this writing basic over view about Rogowskysensing technology can be obtained.

Key words: Rogowsky coil principle, benefits, Power and Power Quality Monitoring, RectifierMonitoring, Relay Protection, switchgear etc.

A. INTRODUCTION

odern days Rogowsky coil isproviding most promisingtechnology to be used in varieties

of ac current monitoring application.Rogowski coils have been in use since 1912.Early applications of the technology werelimited because the low output voltage wasinadequate to drive the measuring equipment ofthe day. As the sensitivity of measurementequipment improved, Rogowski coils began tobe used in a variety of specialized ac currentmonitoring applications. Solid state electronicsand increased use of microprocessor technologyprovides opportunities to apply Rogowski coiltechnology in an ever widening range of

Applications More recently Rogowskitechnology has been incorporated intocommercially available sensor products in avariety of configurations, including the popularflexible type. These products offer severaldistinct advantages over other forms of ac

current measurement, in some cases at lowercost.

B. WHAT IS ROGOWSKY COILPRINCIPLE?

Rogowsky coil is basically named after thescientist Walter Rogowsky. It is being used forlast few decades for measuring alternatingcurrent as well as transient current. It is toroidalcoil without any iron core. Now this coil isplaced around the conductor whose current is tobe measured. Thus the magnetic field producedby the current carrying conductor inducesvoltage in the coil. Now this output voltage isproportional to the rate of change of current inthe conductor. The output voltage is now fed TOAN INTEGRATOR CIRCUIT WHICHPRODUCES an output signal maintainingproportionality with the current.

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Basic Rogowsky coil diagram

C. DESIGN

The wire loop may be configured as single turnsimple helix or any other configuration used toform a sensor. Rogowsky coil sensor may beformed by making a flexible coil wound upon anonferrous core or air core. One characteristic ofthis configuration is the coaxial routing of thecoil end back to the beginning. This allows thecoil end to be separated temporarily to allowinstallation around the primary conductor. If thisco-axial return was not incorporated, the sensorwould essentially become one turn loop aroundthe conductor and the Rogowsky coil would besensitive to any magnetic field which wasperpendicular to the plane of coil.

D. MATHAMETICAL EXPRESSION

In this configuration the sensor provides avoltage output is proportional to the rate ofchange of magnetic field expressed as follows:

V = -K N A df/dt

Where:K = ConstantN = Turns per lengthA = Average area of a turndf/dt = Time rate of change of magnetic flux‘

The rate of change of the magnetic field isdirectly proportional to the rate of change of theprimary current and the voltage output of aRogowski coil can be defined by the followingsimplified equation.

V = -K N A dI/dtWhere,

dI/dt= rate of change of current.

E. MAIN FEATURES OF ROGOWOSKYCOIL

1. Suitable to measure currents from mA tohundreds of kA.

2. High linearity

3. Wide dynamic range

4. Very useful with large size or awkwardshaped conductors or in places

5. with limited access

6. No danger from open-circuitedsecondary

7. Not damaged by large overloads

8. Non-intrusive, no power drawn from themain

F. BENEFITS OF ROGOWOSKY COIL

Low Cost Not influenced by external magnetic

fields Are non-intrusive – draws no power

from the main circuit Have a very wide Sensing bandwidth

extending from 0.1 Hz up to 17 MHz Measures AC signals superimposed on a

large DC Current No danger from open-circuited

secondary


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G. APPLICATION

The advantages offered by Rogowski technologyare accuracy, measurement range, bandwidth,unlimited short circuit current tolerance anddesign flexibility are rapidly generating interestin a number of application. Some mainapplications are

Power and Power QualityMonitoring:

Flexible Rogowski based current probes havegained rapid acceptance in the power monitoringand power quality industry. The advantages of aflexible measurement head and light weight areimportant factors to those involved in fieldstudies of power and power quality. Theadvantages of bandwidth and measurementrange provide the user with confidentmeasurement of transients and harmonics whenused with a range of power quality analyzerspower recorders and data loggers. Theapplications for power quality measurementsrange from monitoring office equipment toutility distribution equipment.

Rectifier Monitoring :

Although Rogowski coils are insensitive to dcthey can be used to measure pulsed dc current.

Relay Protection :

Microprocessor-based relays do not accept the1A or 5A signal directly from a CT secondarybut require low voltage inputs in the range of5V. In a typical application the signal from theCT secondary is transformed to the low voltagelevel by the insertion of scaling transformers.The low voltage output of a Rogowski coil canbe connected directly to the relay voltage inputeliminating the need for scaling transformers.

Switchgear :Rogowski coils could be used for relayprotection in medium voltage switchgear.Recently, some switchgear manufacturers havebegun to use Rogowski coils as an alternative

to traditional CT.s in medium voltageswitchgear.

H. CONNECTION OF ROGOWOSKYCOIL ALONG WITH ANINTEGRATOR CIRCUIT

I. SPECIFICATION OF A ROGOWSKYCOIL SAMPLE:

Some required values which are needed tospecify a Rogowsky coil are

Coil length Coil diameter Fastening Weight Material Protection degree Operating temperature Output level (RMS) Coil resistance Accuracy Frequency range Working voltage Test voltage


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J. CONCLUSION

Rogowsky coil can provide a very usefulcontribution to the art of measuring electriccurrent in very difficult situations. A widerunderstanding of what they are and what theycan do is obviously essential if their fullpotential is to be exploited and hopefully thisarticle has made a contribution in that direction.

K. REFERENCES

1. Using Rogowski coils for transientcurrent measurements by D. A. Wardand J. La T. Exon , engineering scienceand education journal june 1993

2. Using Rogowski Coils Inside ProtectiveRelays by Veselin Skendzic and BobHughes Schweitzer EngineeringLaboratories, Inc. 39th Annual WesternProtective Relay Conference, October2012

3. Practical Aspects of Rogowski CoilApplications to Relaying. Sponsored byPower System Relaying Committee ofthe IEEE Power Engineering Society,September 2010.


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New Technologies in Space craft

Priyanka Roy1 Sounak Ghosh2 Arnab Banerjee3

Student of Electrical Engineering Department


Email id: [email protected] [email protected] [email protected]

ABSTRACT

n early 2011, NASA’s office of the Chief Technologist released a set of technology roadmaps with theaim of fostering the development of concepts and cross-cutting technologies addressing NASA’s needsfor the 2011-2021 decade and beyond. NASA reached out to the National Research Council (NRC) to

review the program objectives and prioritized technologies. Specifically this chapter focuses ontechnology area TA04 “Robotics, Tele-Robotics and autonomous Systems” and discusses in some detailthe technical aspects and challenges associated with three high priority TA04 technologies; “RelativeGuidance Algorithms”, “Extreme Terrain Mobility” and “small body/microgravity mobility. Each ofthese technologies is discussed along g four main dimensions, scope, need, state of the art and challengesand future direction. The result is a unified explanation of key autonomy challenges for next generationspace missions.

Keywords: NASA, Chief Technologist, National Research Council, Tele-Robotics, Relative GuidanceAlgorithms

A. INTRODUCTION

n early 2011, in an effort tostreamline future resource allocationand refine its plans, NASA’s Office ofthe Chief Technologist (OCT)released a set of technology roadmapswith the aim of fostering the

development of concepts and cross-cuttingtechnologies addressing NASA’s needs for the2011-2021 decade and beyond (NRC, 2011;NASA2011). This set was organized into 14technology areas (TA01 through TA14), dividedinto a total of 64 technology subareas. NASAreached out to the National Research Council(NRC) to review the program objectives andprioritize their list of technologies. In January2012, the NRC released its report entitled“Restoring NASA’s Technological Edge andPaving the Way for a New Era in Space,” which

reviewed an initial 320 technologies. The NRCreport revolved around three technologyobjectives:

I. TECHNOLOGY OBJECTIVE A: Extend andsustain human activities beyond low Earth orbit.Invest in technologies to enable humans tosurvive long voyages throughout the solarsystem, get to their chosen destination, work andreturn safely.

II. TECHNOLOGY OBJECTIVE B: Explorethe evolution of the solar system and thepotential for life elsewhere (in situmeasurements). Investigate technologies thatenable humans and robots to perform in situmeasurements on bodies effectively.

III. TECHNOLOGY OBJECTIVE C: Expandunderstanding of Earth and the universe (remotemeasurements). Develop technologies for

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capturing remote measurements from platformsthat orbit or fly-by Earth and other planetarybodies, and from other in-space and ground-based observatories Earth (astrobiology) and onother planets.

B. SPACECRAFT

In recent years, increasing attention has beenpaid to smaller spacecraft enabling low-costmissions through then utilization of COTStechnology, consumer technology and rideshares. In order to drastically reduce missioncosts, the objective is to have one or more smallspacecraft complete the same task as theircompartments. A SYSTEM VIEW OF SPACECRAFT:-

The journal is concerned with spacecraftsystem. The variety of types and shapes of thesesystems is extremely wide. But it is alsoimportant to recognize that the satellite itself isonly an element within a larger system. Theremust be a supporting ground control system thatenables commands to be sent up to the vehicleand status and payload information to bereturned to the ground. There must also belauncher system that sets the vehicle on its wayto its final orbit. Each of the elements of theoverall system must interact with the otherelements, and it is the job of the system designerachieve an overall optimum in which themission objectives and realized efficiently.Chambers science and Technology Dictionaryprovides the following very apt definition of theterm ‘System engineering’ as used in the spacefield:

“A logical process of activities that transforms aset of requirements arising from a specificmission objective into a full description of asystem which fulfills the objective in an optimumway. It ensures that all aspects of a project havebeen considered and integrated into a consistentwhole.”

DYNAMIC OF SPACECRAFT:- This chapter serves as a general

introduction to the subject of thedynamics of bodies and sets aframework for the subjects of celestialmechanics and attitude control(Chapters 4 and 9). For both of these,Newtonian dynamics will provide asufficient means of forecasting and ofunderstanding a spacecraft's behavior.The summary presented here is chosenwith a view to its relevance tospacecraft. The approach adopted is todevelop an understanding of dynamicsin two stages. The first is to expressdynamics of both translation androtation in terms of the appropriateform of momentum-linear or angular.Momentum becomes an importantconcept. In terms of which it isrelatively easy to determine theconsequences of forces or moments.The second stage is to interpret themomenta in terms of the physicalmovement-the velocities, linear andangular. This is straightforward forlinear momentum since momentum andvelocity are in the same direction.More difficult is the relationshipbetween rotational movement andangular momentum.

State-of-the-art:-

Small spacecraft missions are made possiblethrough miniaturization technologies.Miniaturization is the act of creating systems ofever-smaller scales and thereby increasing thefunctional density of the product. Devices have acomparable capability, but are of smaller sizethan their predecessors. Perhaps the Most ofwhich roughly states that the number oftransistors on integrated circuits doubles everytwo years (Moore, 1998): this trend hasremained valid since the invention of the


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integrated circuit in the late 1950’s. AlthoughMoore’s two-year law cannot be applied directlyto small spacecraft, a significant amount ofminiaturization has been achieved for spacecraftsubsystems and components.

RELATIVE GUIDANCE ALGORITHMICCHALLENGES FOR AUTONOMOUSSPACECRAFT:-

Relative guidance algorithms were categorizedby the NRC as the top-ranked technology forrobotics, Tele-robotics, and autonomoussystems; their improvement would mark atremendous milestone for robustifying andaugmenting current capabilities in autonomousguidance and control. This section addresses thetechnical details and challenges for relativeguidance of autonomous spacecraft in fourspace-based application areas:

a. Planetary Entry, Descent, and Landing (EDL)

b. Proximity Operations for primitive bodies

c. Autonomous Rendezvous and Docking(AR&D)

d. Autonomous Inspection and Servicing (AIS)

EXTREME MOBILITY:-

Among the top technical challenges oftechnology area TA-04 is maneuvering in a widerange of NASA relevant environmental,gravitational, and surface and subsurfaceconditions. Two different review boards in theNRC process ranked extreme terrain mobility ahigh-priority technology for the next five yearsto address part of this maneuvering challenge:the study panel ranked it 6th and the steeringcommittee ranked it 8th (National ResearchCouncil, 2012). This section discusses thetechnical aspects and challenges associated withextreme terrain mobility.

MICROGRAVITY MOBILITY:-

The National Research Council recommendedsmall body/microgravity mobility as a highpriority technology for NASA for the next fiveyears. Initially, microgravity mobility wasassigned a low score due to the expensive natureof development and testing of microgravitysystems and its limited applicability outside theaerospace community. The panel later elevatedthe priority of this technology from medium tohigh because the NASA 2010 Authorization Actindicated that small body missions should be anobjective for NASA human spaceflight beyondEarth orbit. If this goal is pursued as a highNASA priority, it would also likely requireprecursor robotic missions to small body. Thissection describes the benefit, technical aspects,and challenges facing the robotics communitytoday in achieving microgravity mobility.

C. CHALLENGES & FUTUREDIRECTIONS:-

To date, planetary rovers have been designed toexplore rocky but relatively flat regions andwere not intended for terrains such as deep


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craters, canyons, fissures, gullies and cryvolcanoes. Such extreme terrains pose a uniqueset of challenges and requirements for a roboticexplorer. Conventional, flat topography roverdesigns must be re-evaluated in the context ofhigh-risk terrain missions. Typical of Martiancraters, Victoria consists of steep slopes,scattered rocks, exposed bedrock, and tall cliffs.A rocker-bogie class rover such as MER or MSLis not designed for such terrain and would notlikely be well-suited to navigate it. Such terrainswould be very difficult to traverse, as platformswould face reduced mobility on such steepslopes due to loose soil that can severelydiminish traction forces, interplanetaryspacecraft, must operate over distances of manymillions of kilometers from Earth.

D. CONCLUSION

This chapter has addressed the engineeringaspects and challenges of technology area TA04“Robotics, Tele-Robotics, and AutonomousSystems,” extending the discussion of the 2011NRC Report on top technology priorities forNASA’s Office of the Chief Technologist to amore detailed &technical scope. Specifically,this chapter has discussed “Relative GuidanceAlgorithms”, “Extreme Terrain Mobility”, and“Microgravity Mobility” in the autonomoussystems area, motivating the importance of eachtechnology, highlighting current state-of-the-artmethods, and outlining major technical hurdlesfacing the aerospace engineering and roboticscommunities.

E. REFERENCES

1)http://www.nasa.gov/directorates/spacetech/small_spacecraft2)https://www.google.co.in/Pavone.ea.Springer.2013


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The Prospect of Nuclear Energy

Ankita Paul1 Krishna Gopal Mondal2 Kaustav Das3

Student of Electrical Engineering Department


Email Id: [email protected] [email protected] [email protected]

ABSTRACT

or many years the idea of the nuclear energy was unknown to the human race. But with theushering light of discovery of these minute atomic particles, there was a rapid reformation in thehuman way of thinking. Presently as there a great shortage of the natural resources in the world

an immediate need of tremendous supply of energy is needed to fulfill the need of the human race. Sohumans have shifted their focus over the renewable sources of energy. Coming to the nuclear energy ithas been seen that the output is expectedly much higher than any other sources. The energy producedper unit weight of the isotopes is much higher than that produced by the coal or any other energysources. People are also thinking of expanding this source of energy over a wide area and not justkeeping it confined within a small space. Thus a report over the prospects of the nuclear energy can beof help in better understanding of its advantages and also the disadvantages too.

Keywords: nuclear energy, atomic particles, renewable sources of energy

A. INTRODUCTION

uclear power is the use of nuclearreactions that release nuclear energy togenerate heat, which most frequently is

then used in steam turbines to produce electricityin a nuclear power station. The term includesnuclear fission, nuclear decay and nuclearfusion. Presently, the nuclear fission of elementsin the actinide series of the periodic tableproduce the vast majority of nuclear energy inthe direct service of humankind, with nucleardecay processes, primarily in the form ofgeothermal energy, and radioisotopethermoelectric generators, in niche uses makingup the rest.

Along with other sustainable energy sources,nuclear fission power is a low carbon powergeneration method of producing electricity,

meaning that it is in the renewable energy familyof low associated greenhouse gas emissions perunit of energy generated. As all electricitysupplying technologies use cement etc., duringconstruction, emissions are yet to be brought tozero. A 2014 analysis of the carbon footprintliterature by the Intergovernmental Panel onClimate Change (IPCC) reported that fissionelectricity embodied total life-cycle emissionintensity value of 12 g CO2 eq/kWh is thelowest out of all commercial Base-load energysources, and second lowest out of allcommercial electricity technologies known, afterwind power which is an Intermittent energysource with embodied greenhouse gasemissions, per unit of energy generated of 11 gCO2eq/kWh. Each result is contrasted with coal& fossil gas at 820 and 490 g CO2 eq/kWh.With this translating into, from the beginning of

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Fission-electric power station commercializationin the 1970s, having prevented the emission ofabout 64 billion tone of carbon dioxideequivalent, greenhouse gases that would haveotherwise resulted from the burning of fossilfuels in thermal power stations.

B. DISCOVERY of the PARTICLES

Many attempts had been made to know as towhat is the ultimate particle of matter. The ideaof the smallest unit of matter was first given byMAHARSHI KANADA in 16th century BCIndia. According to him, matter consisted ofindestructible particles called ‘paramanus’(param means ultimate and anu means particle),which is now generally called atoms.

The Greek philosopher Democritus called the‘paramanu’ an atom, which comes from theGreek word meaning indivisible. But thescientific theory about the structure of matterwas given by John Dalton in 1808 whichconsidered atoms as indivisible particles that arethe fundamental building blocks of matter.

Rutherford’s experiment led to the discovery ofatom. Following him several scientistsdiscovered protons, neutrons and electrons.While Professor J.J. Thomson discoveredelectrons, Goldstein explained the positively

charged particles protons, neutrons were knownfrom the Rutherford’s Atomic models itself.

With the discovery of these fundamentalparticles many initiatives were beingimplemented for studying their properties. Theseproperties of the atomic particles were laterutilized in different fields.

C. WORKING of A NUCLEAR REACTOR

A nuclear reactor produces and controls therelease of energy from splitting the atoms ofuranium. Uranium-fuelled nuclear power is aclean and efficient way of boiling water to makesteam which drives turbine generators. Exceptfor the reactor itself, a nuclear power stationworks like most coal or gas fired fire station.

D. THE REACTOR CORE

Several hundred fuel assemblies containingthousands of small pellets of ceramic uraniumoxide fuel make up the core of a reactor. For areactor with an output of 1000 megawatts(MWe), the core would contain about 75 tons ofenriched uranium.

major energyproduction of the

world

coal

natural gas

hydro

nuclear fission

oil

others


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In the reactor core the U-235 isotope fissions orsplits, producing a lot of heat in a continuousprocess called a chain reaction. The processdepends on the presence of a moderator such as

water or graphite, control rods, shieldingmaterial &is fully controllable.

The moderator slows down the neutronsproduced by fission of the uranium nuclei so thatthey go on to produce more fission.

Some of the U-238 in the reactor core is turnedinto plutonium and about half of this is alsofissioned similarly, providing about one third ofthe reactor's energy output.

The fission products remain in the ceramic fueland undergo radioactive decay, releasing a bitmore heat. They are the main wastes from theprocess.

The reactor core sits inside a steel pressurevessel, so that water around it remains liquideven at the operating temperature of over 320°C.Steam is formed either above the reactor core orin separate pressure vessels, and this drives theturbine to produce electricity. The steam is thencondensed and the water recycled.

E. NUCLEAR POWER IN JAPAN

The people of Japan have extensivelyimprovised the nuclear power, because it ismajor source of electricity in their country.When India is putting a lot of efforts in building

up greater number of thermal and hydroelectricplants, Japan has always topped the list fornuclear plants. Nuclear power has been expectedto play an even bigger role in Japan’s future. Inthe context of the Ministry of Economy, Tradeand Industry Cool Earth 50 energy innovativetechnology plan in 2008, the Japan AtomicEnergy Agency modeled 54% reduction incarbon dioxide emission by 2050.

F. NUCLEAR WEAPONS

As discussed earlier nuclear energy is atremendous source of energy which can be bothuseful and destructive, if not handled properly.A major application of this is in the productionof nuclear weapons.

Atom bombs and the hydrogen bombs aremainly based on the principle of the nuclearfission and fusion respectively. The bombing ofthe Hiroshima and Nagasaki are the livingexamples for it.

G. CONCLUSION

The prospect of nuclear energy has a large areawhere it can be implemented. It is also expectedin the coming years the great need of energycould only be supplied by the nuclear sources.Thus its curve will always have a rising nature.Irrespective of the immense advantages of thenuclear power, care should also be taken aboutits harmful effect for the human race. Nuclearsources are the major store house of the harmfulradiations causing fatal diseases to the livingorganism. Thus with its increase in the positiveaspect there must also be development for itssafety and protection.


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Prospect of Solar Power in India

MANIK SAHA1 ANUSHREE BASAK2 SOUMYA MUKHERJEE3

Students of Electrical Engineering Department


Email Id: [email protected] [email protected] [email protected]

ABSTRACT

ith the ever growing increase in population, demand of energy is also increasing every day. Aswe know the non-renewable sources are limited and not environment friendly. The increase ordecrease in production of these sources can have direct result on the inflation. Since day by day

we are facing serious energy crisis, as the oil production is peaking worldwide which means no morecheap oil. In this situation, we need an alternative source of energy that universally available, abundant,renewable and efficient. Solar energy fits all these criteria and so we have to deal with this alternativesource of energy. Solar energy is not only sustainable, it is renewable and this means that will never berun out of it. It is a natural source of power implemented as to generate electricity. The creation of solarenergy requires a little maintenance. Once the solar panels have been installed and are working atmaximum efficiency. The paper is discussing on the basis of the following topic.

Keywords: Demand of energy, Non-renewable, Solar energy, Sustainable

A. INTRODUCTION

ass uproar against global warmingincreasing greenhouse gas has becomeheadache to the mankind. Light and

lightening to ignite man uses different chemicalcombination that gives off more poisonous gasesthan the use of usual fuel resources in nature likecoal, petrol, bog wood etc. Realizing the impactof dreadful environmental stand man has been inquest of source of such an energy that may causeless harm for pollution. Now he is bent onfollowing up the use of solar energy but he isdreading the cost of initial state that lies ontechnological expanses. If it is worth of echofriendly, man will be relieved from theunwanted danger. To keep up the traditionalcivilization man must have to be up and going in

invention of alternative fuel system thinking all-around of its effect.

B. WAYS TO HARNESS SOLAR ENERGY

Photovoltaic Cells

A photovoltaic cell is a specializedsemiconductor diode that converts visible lightinto direct current. Some of the photovoltaiccells can also convert the infrared or ultravioletradiation in DC electricity. These cells made ofthin wafers of two slightly different types ofsilicon. One, the P-type, which is doped withtiny quantities of Boron and contains positivelycharged "holes," that are missing electrons. Theother type of silicon, called N-type, which is

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doped with small amounts of Phosphorus andcontains extra electrons. When these two thin Pand N materials are put together, it produces ajunction that, when it is comes in contact tolight, it produces a movement of electrons, thusproducing an electric current. The panels ofthese types of cells are widely used to convertsolar energy to electricity. The industrial averagefor the efficiency of solar energy conversion intoelectricity using solar panel is about 15-20%.However, researchers are developing thin filmsolar panel systems which can deliver sameefficiency but at about 20% of the cost. Theseare based on nanotechnologies and useextremely thin layers of solar conversionmaterial which significantly lowered theproduction costs.

Solar thermal collector

A solar thermal collector collects heat byabsorbing sunlight. It is a collector device whichcaptures solar radiation. Solar radiation is energyin the form of electromagnetic radiation from theinfrared to the ultraviolet wavelengths. Thequantity of solar energy striking the Earth'ssurface averages about 1,000 watts per squaremeter under clear skies, depending upon weatherconditions, location and orientation. It isbasically used in the sunnier regions of ourcountry; it can still be used in regions where itsnows. By using solar thermal system one cansave around 70-80% on annual water heatingcosts. These kinds of systems have beenaccepted by many countries for many years.These have been widely used in countries like

Greece, Turkey, Israel, Australia, Japan, Austriaand China.

Concentrated Solar Power

It is a process in which solar energy isconcentrated at a single place which is like a bigtower. There are many water pipes in the tower.Water is circulated in these pipes. Whenconcentrated solar energy falls on these pipes,the water in them gets heated. Heated waterforms steam and the kinetic energy in this steamcan then be used to run turbines that produceelectricity. The process is very similar toconventional energy generation where coal isused to heat water to form steam. Burning ofcoal releases some harmful gasses like carbon-monoxide and other greenhouse gasses, that mayaffect our environment adversely. If solar energyis used for the same process, then no such gassesare released into the atmosphere.

A Dynamic Duo

There have been many significant developmentsin the field of solar energy but the mostsignificant one was from the scientists ofMassachusetts Institute of Technology (MIT).They developed a process for storing solar cellgenerated electricity in a fuel cell for later use,when the sun is not shining. Users could usetheir solar panels during the day to power theirhomes, while also using energy to split waterinto hydrogen and oxygen for storage. At night,when sunlight is not available, hydrogen can becombined with oxygen to generate energy usinga fuel cell. The energy generated during this


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process can be used to generate power when thesolar panels are not active.

C. HOW DOES SOLAR ENERGY WORKS?

Solar Panel— solar panel is designed to absorbthe sun's ray as a source of energy for gettingelectricity. The solar panels are made up ofphotovoltaic (PV) cells, which convert sunlightinto direct current (DC) electricity throughoutthe day.Inverter—this device converts the DCelectricity generated by the solar panels into thealternating current (AC) electricity.Electrical Panel—the AC electricity is sentfrom the inverter to your electrical panel topower your lights and appliances with solarenergy. The electrical panel is often called a"breaker box."Utility Meter—the utility meter measures yourenergy use. It actually goes backward when yoursystem generates more power than youimmediately need. This excess solar energyoffsets the energy you use at night.Utility Grid—your business is still connected tothe grid. You’ll need that power from the utilitycompany at night, but don’t worry. The cost isoffset by any excess solar energy you put intothe grid during the day.

Power Guide Monitoring System—ourexclusive Power Guide monitoring systemcontinuously tracks your energy production andensures that your solar power system is runningsmoothly. It will even alert our repair crews inthe rare event that problems arise.

Significant steps are being undertaken in India toestablish a solid foundation for solar power,

including re-vamping policies and infrastructurein the country.With a population of more than 1.2 billionpeople, a widening supply and demand gap inthe energy sector has led to widespread poweroutages, leaving as many as 75 millionhouseholds, especially in rural areas, withoutpower.

In response to issues caused by theoverburdened grid network, officials areincreasingly looking to alternative energysources like solar power to solve the powershortage.

A recent article in the Economic Timesaccounted plans to establish the country’s largestultra-mega solar power plant in MadhyaPradesh's Rewa district, and similar initiativesare being undertaken across the country.

D. LONG TERM PLANS TO INCREASESOLAR POWER GENERATION

In a country that receives almost 3,000 hours ofsunshine each year; solar power does seem to bethe answer to India’s energy woes. Those 3,000hours translate into 5,000 trillion kWh of energy,and have huge potential to bridge the energysupply and demand gap.Ambitious plans have been undertaken acrossthe country and the Indian Government hasoutlined long-term plans to attain an installedsolar power generation capacity of 20,000 MWby 2020, which would increase to 100,000 MWby 2030 and to 200,000 MW by 2050.


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Regional Segmentation of Solar PowerMarket in India by State

E. HUGE POTENTIAL IN THE INDIANSOLAR POWER INDUSTRY

Surprisingly, given the average of 300 sunnydays that the country experiences, solar powerproduction facilities are not nearly as wellestablished in India compared with otheralternative energies like wind power. This ispartly due to the high capital investmentinvolved in the installation of PV cells or CSPsystems. Recently though, several private andcorporate firms have started showing interest insolar power generation and are adopting greenand emission-free technologies.

General Solar Energy Facts

Solar Energy is healthier for theenvironment than traditional fossilrelated forms of energy.

Solar energy has many positive uses,such as the production of electricitythrough photovoltaic cells, and thedirect heating of water for a variety ofother applications.

Solar energy can also be used to heatswimming pools, power cars, for attic

fans, calculators and other smallappliances. It produces lighting forindoors and outdoors. You can evencook food with solar energy.

Solar Energy is becoming more andmore popular. The worldwide demandfor Solar Energy is currently muchgreater than the amount we have beenable to supply.

Photovoltaic Energy and ItsDevelopment

The two primary technologies used today tocapture solar energy are photovoltaic andthermal. Photovoltaic (PV) cells convert lightenergy into electricity at the atomic level. Thereare some materials that exhibit a property knownas the photoelectric effect. This causes them toabsorb photons of light, and in turn, releaseelectrons. When these free electrons that arereleased are captured, it results in an electriccurrent, or electricity. When these solar cells areused in conjunction with each other, they formsolar panel. A solar panel, otherwise known as aphotovoltaic module or photovoltaic panel, is apackaged assembly of many solar orphotovoltaic cells. The solar panel can then beused as a component of a larger photovoltaicsystem, or solar array. This is then used togenerate and supply electricity for residentialsolar power or for commercial solar panels.

F. SOLAR IS THE FUTURE OFRENEWABLE ENERGY IN INDIA

Energy prices in India are climbing, and supply,while growing, is not keeping pace with steepdemand. Solar power, despite initial challenges,is becoming a multibillion-dollar opportunity.

Coal is becoming more difficult to obtain,sources of domestic gas are shrinking, and thereis more focus than ever on sustainability. Theresult: Stakeholders are scaling back


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expectations that conventional energy sourcescan fulfill India's power needs. Solar energy willbecome a crucial component of India’s energyportfolio in the next decade perhaps more sothan it is in most other countries. We believe asolar market can develop fairly quickly goingfrom nothing to several billion-dollar solar-centric firms within a decade.

Clean and green energy is a basic theory ofmodern life although the governmental focus ismore on grid power, which is a polluting,inefficient and unreliable source of power.AT&C losses account for close to 40% of thetotal power generation, amounting to a total ofRs 75 thousand crores and more every year thatcould wipe out energy poverty across thecountry. Smart grids and infrastructure updatesare the need of the hour. But the government isstill focused on spending Rs 2 lakh crores to bailout bankrupt companies whereas that amountcould have been used to deliver distributedenergy and reduce dependence on companies forlarge part of the country in near future.

The Indian government recognized this potentialand the MNRE (Ministry of New andRenewable Energy) launched an ambitiousprogramme in 2010 called JNNSM (JawaharlalNehru National Solar Mission) to deploy 22,000MW of grid-connected solar power by 2020.The programme has seen limited success withphase I meeting its PV targets and phase 2 onthe way in the form of 750 MW via the ViabilityGap Funding (VGF) programme.

Thermal-concentrated sources of energy areoptimal for urban and semi-urban areas.However, towns need to reduce dependence onthe grid and adopt the German model, whichenables local, as well as distributed power, usingnet-metering.

The MNRE programmes have barely managedto dent the potential of distributed RE, requiringfocused attention and financial muscle to enablethe nation on its path towards renewable energy.But MNRE has not paid out a large part of theresidential subsidies of 30% of capital costs overthe past year due to lack of funds, a seriousdamper, especially for solar on rooftops. Thecurrent VGF programme is scheduled to cost theMNRE Rs 2,500 crores and push solarprocurement costs down to below Rs 5.5 perKWh, enabling it to compete with conventionalenergy.

The essence of solar success lies in empoweringthe distributed 400 million poor who arecurrently consuming fossil fuel not touched bythe power grid and thus reduce India's CAD(current account deficit), environmentalpollution and health concerns. But there lies theirony. The rural/tribal populace pays nearlytwice or thrice the rate of power than thoseliving in cities, but has received minimalattention although the impact is the highest tothose using fossil fuel and government subsidiesin daily life.


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Every unit of power generated has the ability tomultiply economic growth, especially in ruralareas that suffer from energy paucity due tounreliable connections or load shedding. Stategovernments of Tamil Nadu, Kerala and a fewother states have already initiated proactive stepsby increasing the state subsidies, in addition tosubsidies from the central government, and arealso looking at replacing grid-connectedagricultural equipment with solar-enabled ones.

Solar has the potential to reduce the currentenergy peak deficit significantly and improvedelivery due to its distributed nature, provided itcan get the appropriate financial support fromthe Centre, as well as all the states. The centralgovernment continues to think that grid power,with its huge losses, is the solution. But inreality, distributed energy, delivered to everyhome and the excess pumped into the grid,would result into least amount of losses whilereducing energy generation needs.

Over the next few years, solar power will comeinto its own, both from financial viability andavailability perspectives, with exponentialgrowth in distributed solar, coupled withstorage, transforming the entire energy spectrumin India. The future of Indian energy segment ishere and it is the Sun that will continue to powerour economic and energy growth into the nextmillennium. Rate of power than those living incities, but has received minimal attentionalthough the impact is the highest to those usingfossil fuel and government subsidies in dailylife.

G. DISCUSSION

It is a well-known fact that the rapidly growingbusinesses and population are putting a lot ofpressure on India’s power resources.Unfortunately, India is woefully lacking in alltypes of power resources, except one – solar

power. We take a look at what solar powergeneration entails for India and how it willchange the energy scenario in India.

Solar power entails producing energy from thesun instead of oil and electricity. The sun’senergy is available abundantly and freely andcan be used in two ways:

Solar thermal energy: Here the solarenergy is converted into solar powerthrough equipment. Example, solar hotwater heating system, solar dryingsystem, solar cooking system, etc.

Solar photovoltaic energy: In thismethod, the solar energy is convertedinto electrical energy through equipmentusing solar photovoltaic technology. Itcan be used to power anything from asingle bulb to all the street lights in thecity.

Solar power can be an important source ofpower for India. These are the reasons why Indiashould focus more on solar power:

India gets plenty of sunlight due to itsproximity to the equator. It receives anannual average of 4-7KWh per day forevery square meter, meaning the countryreceives a lot more sunlight than what itcan use in a year, making it an abundantsource of power.

India is a poor source for conventionalfuel sources. It is dependent on the Gulfcountries for its oil supplies. With theoil prices skyrocketing and thereluctance of the Indian government tohike the prices of LPG and kerosene,Indian oil companies are suffering majorlosses. Even electric supply in thecountry is unable to meet the


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burgeoning demands of the growingpopulation and businesses.

India does not have resources to pay thehuge bills of the oil producers.

Keeping in mind the growing potential of solarpower generation, several large players haveentered into this business. Solar Power India,Tata and Reliance Industries are some of thebiggies that have major plans for this industry.This will give a big boost to this field as thesecompanies can invest a lot of money in researchto make the technology cheaper. This, in turn,will make solar energy accessible to thecommon man. As more and more people take tosolar power, the costs are expected to reduce.

What are the steps you think the Government ofIndia should take to encourage companies to setup solar power plants in India? What do youthink is the future of this source of energy inIndia?

H. REFERENCES

http://www.eai.in/ref/ae/sol/policies.html

http://www.indiafilings.com/learn/2015-solar-subsidy-in-india/

https://en.wikipedia.org/wiki/Solar_power_in_India

http://www.seci.gov.in/content/govt_initiatives.php


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Smart Grid Technology

ARIJIT MONDAL1 ADITI MANNA2

Students of Electrical Engineering Department


Email Id: [email protected] [email protected]

ABSTRACT

mart Grids components include scalable metering, energy prediction (both production andconsumption) and pricing. Their primary objective is to attract consumers for using green energy,to promote periods of low consumption and introducing a solution to the customers to get rid of the

use of their greedy devices during peak periods. The main aim is to determine the optimal suggestedprices by the energy operator and the optimal demands of consumers. Micro grid development isprimarily the implementation of micro grid was to satisfy the energy demands of remote areas due toinaccessibility of utility power. But with the gradual merging of the rural and remote areas of the worldinto urban communities the burden on utility grid is increasing at an alarming rate. Hence, Hybrid PowerSystems (HPS) are nowadays playing an active in designing micro grid by using locally availablerenewable energy sources (RES).Smart Grid facilitates efficient and reliable end-to-end intelligent two-way delivery system from source to sink through integration of renewable energy sources, smarttransmission and distribution. This paper is based on the active role of the smart grid technology in thedevelopment of mankind.

Keywords: Green energy, Hybrid Power Systems (HPS), renewable energy sources (RES), smart grids,active grid, micro grid, distributed generation.

A. INTRODUCTION

“SMART GRID” generally refers to a class oftechnologies that people are using to bring utilityelectricity delivery systems into the 21st century,using computer-based remote control andautomation. The central nervous system of thistechnology lies in a two way digitalcommunications technology and computerprocessing that has been used in other industriesover decades. Nowadays they are being used in alarge scale on electricity networks, from thepower plants and wind farms all the way to theconsumers of electricity in homes andbusinesses. They are very much beneficial to us– mainly high energy efficiency and reliability.Smart Grid facilitates efficient and reliable end-

to-end intelligent two-way delivery system fromsource to sink through integration of renewableenergy sources, smart transmission anddistribution. In this way Smart Grid technologyshall efficiently bring sustainability in meetingthe growing demand for electricity withreliability and best of the quality.Smart Grid also enables real time monitoringand controlling of power system as well as helpsin reducing AT&C losses, demand response anddemand side management, power qualitymanagement, outage management, smart homeenergy system etc. Smart Grid as a backboneinfrastructure will pave the path for newbusiness models like smart city, electricvehicles, smart communities apart from more

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resilient and efficient energy system and tariffstructures. With the aim of satisfying the futurepower demand and to reduce 2 emissionsdesigners of the next generation of electricpower, distribution grid initiate a large researchand technological action under the "Smart Grid"banner that starts to tackle some of the issues asfollows: Indicative reductions in residential peak

demand energy consumption achievedby providing real-time price andenvironmental signals in alliance withadvanced endogenous technologies.

Amalgamation of the green energyproduction from both second tieroperators and private clients to reducecarbon impressions. Hence this energysource is going to play a major role inthe future Smart Grid. Nowadayselectric vehicles are also beingconsidered as very important futureelements as they can affect theconsumption peaks but they could alsoact as energy buffers to provide missingenergy during these peaks.

Provision of open infrastructure fornewcomers to be easily mingled, in thesame way as mobile telecom market hasbeen deregulated.

Provide a real time measurement andcontrol tools that administer scalableand amelioration actions on the energygrid.

The resulting architecture of a Smart Grid isdefined as a standard power grid that is coupledwith both a telecommunication network and adistributed information management system, andassociated with services (handled within anenergy-dedicated service architecture) to allowthe following: Administering better energy

consumption. Better management of energy

production and its delivery.

Mixing of heterogeneous energysources both renewable and non-renewable in an efficient and dynamicway.

Reduction of the impacts of powerblackouts.

Dynamic evaluation of cost. Increment in efficiency of global

energy.

B. SCOPE OF A SMART GRIDA smart grid uses digital technology to improvereliability, security, and efficiency of the electricsystem from large generation, through thedelivery systems to electricity consumers and agrowing number of distributed-generation andstorage resources. The information networkstransforming our economy in other areas are alsobeing applied to applications for dynamicupgrade of electric system operations,maintenance, and planning. Separately managedresources and services are now being integratedand rejuvenated as we address traditionalproblems in new ways, harmonize the systemtackling new challenges, and innovating newbenefits that have transformational potential.The various fields of electric system that coverthe scope of a smart grid enclose the following: The delivery infrastructure (e.g.,

transmission and distribution lines). The end-user based systems and related

distributed-energy resources (e.g.,building and factory loads, electricvehicles, distributed generation).

Administration of the generation anddelivery infrastructure at the variousstages of system coordination (e.g.,transmission and distribution controlcenters, regional reliability coordinationcenters and national emergencyresponse centers).

The information forms a network amongthem (e.g., public Internet, inter- andintra-enterprise communications).


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Investments and motivation of thedecision makers to promote, practice,and maintain all aspects of thesystem(e.g., stock and bond markets,government incentives, regulated ornon-regulated rate-of-return oninvestment) is controlled by thefinancial and regulatory environment.

C. OVERVIEW OF SMART GRID

In terms of overall vision, the smart grid showsthe following characteristics:

Intelligent – It has capability to sensesystem overloads and preventing orminimizing a potential blackout byrerouting the power. Moreover it’s alsocapable of working autonomously whenconditions require resolution faster thanhumans can respond and cooperativelyin aligning the goals of utilities,consumers and regulators.

Efficient – Without addition ofinfrastructure it can conveniently meetthe increased consumer demands.

Accommodating – It has capability tointegrate any and all better ideas andtechnologies like energy storagetechnologies. Besides it can acceptenergy from virtually any fuel sourceincluding solar and wind as easily andconspicuously as coal and natural gas.

Motivating – It motivates real-timecommunication between the consumerand utility so that consumers can tailortheir energy consumption based onindividual requirements.

Opportunistic – It creates newopportunities and markets by the aid ofits ability of capitalizing plug-and-playinnovation wherever and wheneverfelicitous.

Quality-focused – It is proficient ofdelivering the power quality necessary

(free of sags, spikes, disturbances andinterruptions) to power our increasinglydigital economy and the data centers,computers and electronics necessary tomake it run.

Resilient – Being more decentralizedand reinforced with Smart Grid securityprotocols it can efficiently resist naturaldisasters and attacks.

“Green” – It is providing a genuinepath toward significant environmentalimprovement by loitering the advance ofglobal climate change.

D. CHALLENGES FOR DISTRIBUTIONSYSTEM

Electricity distribution networks create a marketplace for small-scale power producers and forcustomers (consumers). Here, the role ofdistribution networks is of highest priority.There are many challenges for distributionsystem to aggrandize its functionality as the realmarket place, as stated below: Improvement of the capability to serve

the increasing amount of distributedgeneration.

Sanctioning the electricity marketdevelopment at the customer level.

Safe and cost-efficient operation ofdistribution networks in all prospects.

Consistently power generation, distributionnetwork management and loads have beenconsidered as quite independent processes.Along with increasing amount of distributedgeneration there is a gradual change in thetraditional approach. One of the main barriersfor the penetration of active energy resourceslike loads, storages and plug-in hybrid vehiclesat distribution network level is the intricacy ofthe interconnection process. From the point ofview of network management increasing amountof distributed generation is often consideredwith reluctance as it brings the convolution of


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transmission network to distribution networklevel. The main reason for the intricacy is causedby the present methods for management of thedistribution networks as well as the features ofdifferent active resource componentsthemselves, which are not adequately developedto enable easy interconnection. So far from thenetwork point of view loads and customers havebeen considered passive. Thus by making thecustomer connection point more adjustable andinteractive the demand response functionsbecomes more achievable and the use of existingnetwork and energy resources by marketmechanisms can be improved efficiently.

E. CHALLENGES TO SMART GRIDDEPLOYMENTS

Among the most important challenges that thedevelopment of a smart grid is facing are thecost of implementing a smart grid, withestimates for just the electric utility advancedmetering capability ranging up to $27 billion(Kuhn 2008), and the regulations for allowanceof recovery of such investments. For objectivity,the Brattle Group estimated the budget as muchas $1.5 trillion (Chupka et al. 2008) to upgradethe grid within 2030. Another hurdle for stateand federal regulators is the confirmation ofinteroperability of smart-grid standards.Among the major technical barriers thedevelopment of economical storage systems isof great importance. These storage systems canhelp solve other technical issues, such asharmonizing distributed renewable-energysources with the grid, addressing power-qualityproblems that would otherwise exacerbate thesituation, and enhancing asset utilization.Without a smart grid, high penetrations ofvariable renewable resources may become moredifficult and expensive to manage due to thegreater need to tantamount these resources withexpeditious generation and demand.

Another challenge faced by a smart grid is theuncertainty of the path that its development willtake over time with changing technology,changing energy mixes, changing energy policy,and developing climate change policy.Attempting to regulate the development of asmart grid or its related technologies canseverely criticize the benefits of the virtual,adjustable, and conspicuous energy market itstrives to provide. Thus, the challenge ofdevelopment of smart grid becomes a matter ofcontention for provision of flexible regulationthat leverages desired and developingtechnology through goal-directed and business-case-supported policy that promotes a positiveeconomic payoff.

F. ACTIVE GRID

An active grid is a network which not only playthe passive role of supplying the finalconsumers, but also a significant role in whichthe operator controls and/or rules the powerrequired or generated by the loads or thegenerators, the bus voltages and the branchpower flows. It is possible to ascertain thematuration in three different phases:First-phase: A simplified localized control ofgeneration at the connection point;Second-phase: An integral control system for allthe distributed energy resources in the controlledarea, realizing a combined delivering and avoltage profile optimization.(See Figure 1);


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Third-phase: This phase consists of creating astrongly interconnected structure with asubdivision in cells responsible of their ownmanagement (protection, voltage regulation,etc.) that take part in the market, selling orbuying energy to/from adjacent cells or from /tothe transmission system(See Figure 2).

G. MICRO GRID

A micro grid comprises a set of generators, loadsand storage systems connected and able tooperate independently from the electrical gridand that internally recreates the energyproduction and distribution system. In Figure 3an example of a micro-grid projecting a micro-grid separation device to perform the islandingoperation, an energy manager connected toseveral power flow controllers and protectioncoordinators to control and manage the energyflowing in the micro grid branches and manydifferent type sources to inlet energy not onlyfrom the main grid, but also to allow distributedgeneration is given.It can be contemplated similar to the activenetwork cell, as it is provided with a localcontrol system that rules the exchanges ofenergy among the loads, generators and externalnetwork. Moreover it can remain in intentionalislanding configuration, crippling the loads thataccept to be part of a “load curtailment”program.

H. CONCLUSION

This paper is discussing the aspects of smartgrids in general and gives some examples onsmart grid features studied and developed. Thepaper presents some smart grid features atdistribution level dealing with interconnection ofdistributed generation and active distributionmanagement. Different kind of advancedfunctions based on local intelligence and powerelectronic applications as a part of activedistribution networks are in the process ofimplementation. The interactive customergateway will be based on the use of modernpower electronics, advanced digital technologyand two-way communication between date basesand applications of the distribution systemoperator (DSO), transmission system operator(TSO), service providers and electricity energymarket players (e.g. aggregators). Thus theintroduction of the smart grid technologyefficiently fulfilled the primary objective tospread the use of green energy among theconsumers, promotion of periods of lowconsumption thereby introducing a solution tothe customers to get rid of the use of theirgreedy devices during peak periods.

I. REFERENCE

“Active Smart Grid Analytics™:Maximizing Your Smart GridInvestment” by Sharelynn MooreDirector, Product Marketing Itron,


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Stephen Butler Managing Partner –Industry Consulting Teradata.

U.S. Energy InformationAdministration, “Electricity Explained:Use of Electricity,”

W. Steinhurst, “The Electric Industry ata Glance” (Silver Spring, MD: NationalRegulatory Research Institute, 2008).

S. W. Blume, Electric Power SystemBasics: For the NonelectricalProfessional (Hoboken, NJ: Wiley–IEEE Press, 2007).

A. V. Meier, Electric Power Systems: AConceptual Introduction (Hoboken, NJ:Wiley–IEEE Press, 2006).

I. J. Pérez-Arriaga, H. Rudnick, and M.Rivier, “Electric Energy Systems. AnOverview,” in Electric Energy Systems:Analysis and Operation, Eds. A.Gomez-Exposito, A. J. Conejo, and C.Canizares (Boca Raton, FL: CRC Press,2009), 60.

F. Schweppe, M. C. Caramanis, R. D.Tabors, and R. E. Bohn, Spot Pricing ofElectricity (Boston, MA: KluwerAcademic Publishers, 1988).

“SMART GRID IN INDIAN POWERSYSTEM” by Sanjeev Kumar Director(Distribution) Ministry of Power.

“SMART GRID TECHNOLOGY ANDAPPLICATIONS” by JanakaEkanayake - Cardiff University, UK;Kithsiri Liyanage - University ofPeradeniya, Sri Lanka; Jianzhong Wu-Cardiff University, UK; AkihikoYokoyama - University of Tokyo,Japan; Nick Jenkins - CardiffUniversity, UK.

“A game theory approach with dynamicpricing to optimize smart gridoperation” by Makhlouf Hadji(Technological Research Institute - IRTSystemX,8 avenue de la vauve, 91120,Palaiseau, France), Marc Girod-Genet(Institut Mines-Telecom, telecomSudParis, 17 rue charles fourier, 91010,Evry, France), Hossam Affifi.

Pertti Järventausta*, Sami Repo*, AnttiRautiainen* (*Tampere University ofTechnology, P.O.Box 692, 33101Tampere,) Jarmo Partanen**

(**Lappeenranta University ofTechnology, P.O. Box 20, 53851Lappeenranta).

“Communications and Control in SmartGrid” by Dr. Hamed Mohsenian-Rad)(Rad Texas Tech University).

“Smart Grid Vision and Route map” byof gem (Department of Energy andclimate Change).

“Smart Grid System Report” by US.Department Of Energy.


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TO STUDY THE VARIOUS TECHNOLOGIES OF LED IN LIGHTING INDUSTRY

AVIJIT KARMAKAR




ABSTRACT

ight Emitting Diode or LED Technology in lighting can be traced back to 1927 although itdidn’t make an entrance into commercial applications till much later. Having taken a back seat

for many years largely owing to its high production cost LED lighting is rapidly gaining ground in the lighting space in more recent times. LED lamps have a lifespan and electrical efficiencywhich are several times longer than incandescent lamps, and significantly more efficient than mostfluorescent lamps, with some chips able to emit more than 300 lumens per watt. The LED lamp market isprojected to grow by more than twelve-fold over the next decade, from $2 billion in the beginning of 2014to $25 billion in 2023, a compound annual growth rate (CAGR) of 25%. As of 2016, LEDs use only about10% of the energy an incandescent lamp requires. The demand of new technologies of LED like SMD,COB, OLED is also increases with respect to the time.

KEY WORDS – LED, SMD, COB, OLED

A. INTRODUCTION

LED Chips comes now in different formdepending on the use and technology used bythe LED manufacturer. The most common LEDis used for indicator lights (conventional DIP-Dual in-line package structure) which have verylow lumens per watt. The development of SMD-Surface Mounted Device Structure LEDs pavethe way for a better or higher lumens per wattthat reaches 50 to 80Lm/W and having alifespan of 20,000 to 50,000 burning hourshowever the only problem is, it has a highmanufacturing cost. Another development inLED light chips is the COB or Chips on board, anew technology in LED packaging. MultipleLED chips are package as one lighting modulethat also increased the heat dissipation to 70%.

The latest LED development is the S-COB LED(Stereoscopic Chips on Board). S-COB LEDhave a simple structure (LED Chips are directlyembedded on the heat sink) that made lowermanufacturing cost but giving a better quality byhaving a faster heat dissipation of up to 97% anda higher lumens that can reach 90 Lumen tomore than 140 Lumen per watt. S-COB LED hasa burning hours of 40,000 to 100,000 hours.Faster heat dissipation prolong the life ofinternal electrical components, because of lowerheat operation and lower energy consumptionwhile giving a superb lighting, S-COB LEDlights change the way how we see lights. LEDLights have no Toxic materials, longer life spanand lower energy consumption but is brighter 3times than a CFL and more than 10 times that anincandescent light. Because of the many

L


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advantages of LED's and having a lower energyconsumption that can drastically lower downcarbon emission of our planet that in turn helpsolve global warming.

B. SMD LED

SMDs (Surface Mounted Device) are the newgeneration of LED lighting, the majority of ourbulbs contains SMD chips allowing our bulbs tobe much brighter than older generations of LED.The LED is soldered directly onto the PCBtherefore requiring less space and improves thethermal connection. The competent design of anSMD LED has resulted in better heat dispersionwith high lumen output. The SMDs have single-handedly abled the manufacturers to mechanizeLED production along with improved qualitycontrol.

SMDs are easier to maintain in comparison withother LEDs and have a longer life.

SMD LED BASICS

Surface mounted device light emitting diodes(SMD LEDs) are the most common type of LEDlights right now - these consist of a LED chipthat is permanently fused to a printed circuitboard, resulting in solid units that can beconnected in a simple circuits to create variouslighting configurations (including light bulbsand strip LED lights).

Up to 3 diodes can be fused onto a single SMDchip - this gives SMD LEDs the ability to outputa huge range of colors when a chip is built usingblue, red and green diodes (while the old-styleDIP LEDs are mono-colored).

SMD LEDs are available in a range ofdimensions - tuners might be familiar with thetwo most common sizes, SMD 3528 and SMD5050; those are the two most common sizes usedfor 12V LED light strips.

APPLICATIONS

SMD LED modules are widely used, in LEDlamps, for backlighting, home illumination,shop-windows, advertising, automobile interiorlighting, Christmas lights, and numerouslighting applications.

FAILURE OF SMD LED LIGHTSIN SOME PROJECTS ACROSSINDIA

1100 SMD LED Street Lights wereinstalled in Kanpur (U.P), out ofwhich the KMC states that nearly72% are non-functional

Various SMD LED lightinginstallations were made in Bangalore(Karnataka). The authoritiescomplain that nearly 45% are havingproblems, while minimum 10% haveto be replaced annually

Guwahati (Assam) got LED’sequipped in perspective departments,but they are not pretty pleased withtheir performance as due to moistureherald & other climatic conditionssome of the SMD LED’s in thelighting units turned faulty. Thus,making the lighting unit lookawkward & low on performance

The demo project at Kalka (Haryana)was a disaster, as the SMD LED’slighting units blew up due to highjunction temperature caused as thelighting was left on for 1 whole day.

C. COB LED

Chip on Board (COB) is the most recentdevelopment in LED technology using chipswith multiple diodes (typically 9, or more).


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There is no casing with COB technology whichenables a much denser LED array of lightcompared to SMD. A consistent and controlledlight beam is given off, without any visibleindividual light points, thus offering great optics.COB offers a greatly improved lumen per wattratio compared with other LED technologiessuch as DIP and SMD. COB technology givesthe best conditions for optimal cooling, which inturn will increase efficiency and lengthen theoverall life of the lamp.

Chip-on-Board or COB LEDs, as opposed toSMDs are segmented into numerous tiny piecesof semi-conductor crystals and are directlyplaced over a substrate. COBs are popular fortheir heat efficient behavior. They ensureminimum heat production and emithomogeneous light. The behavior is enhancedwith the addition of a ceramic substrate whichinduces a cooling effect in addition to thehomogeneous light production. COBs’assembling is relatively cheap and the LEDshave a longer life span.

LED lighting technology is also growingrapidly; there are now three major types of LEDlights available; DIPs (a.k.a. old-school LEDs),SMDs and COBs. Here’s a brief rundown on thetwo most common types of LED lights currentlyin use today – COB LEDs and SMD LEDs.

COB LED BASICS

Chip on board light emitting diodes, aka COBLEDs, are the newest type of LED lights to hitthe market. Like SMD LEDs, COB LEDsconsist of multiple diodes that are soldereddirectly onto a microchip, however, unlikeSMDs, COBs typically use 9 or more diodes perchip - this produces a light that looks like aglowing panel (rather than a bunch of tiny littlelights as with SMDs).

COB LEDs are extremely ' heat efficient'; theyproduce very little heat, thanks in part to theircooling ceramic substrate. Unlike SMD LEDs,COB LEDs do not have the ability to emitdifferent light colors, however, the lighttemperature (such as warm or cool) can becontrolled.

COB LEDs can produce a higher lumen-per-watt ratio in comparison to both SMD and DIPLEDs. COB LEDs use a single circuit and justtwo contacts, regardless of how many diodes areon each chip.

Because they are relatively cheap tomanufacture, consumers can look forward tolower prices on COB LEDs as production of thislatest generation of LED lights ramps up.

APPLICATIONS:

COB LED light sources LED lighting fixture which use

COBLED light source

D. OLED

An organic light-emitting diode (OLED) is alight-emitting diode (LED) in which, theemissive electroluminescent layer is a film oforganic compound that emits light in response toelectric current. This layer of organicsemiconductor is situated between twoelectrodes; typically, at least one of theseelectrodes is transparent. OLEDs are used tocreate digital displays in devices such astelevision screens, computer monitors, andportable systems such as mobile phones,handheld game consoles and PDAs. A majorarea of research is the development of whiteOLED devices for use in solid-state lightingapplications.


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OLED BASICS

There are two main families of OLED: thosebased on small molecules and those employingpolymers. Adding mobile ions to an OLEDcreates a light-emitting electrochemical cell(LEC) which has a slightly different mode ofoperation. OLED displays can use eitherpassive-matrix (PMOLED) or active-matrix(AMOLED) addressing schemes. Active-matrixOLEDs (AMOLED) require a thin-filmtransistor backplane to switch each individualpixel on or off, but allow for higher resolutionand larger display sizes.

An OLED display works without a backlight;thus, it can display deep black levels and can bethinner and lighter than a liquid crystal display(LCD). In low ambient light conditions (such asa dark room), an OLED screen can achieve ahigher contrast ratio than an LCD, regardless ofwhether the LCD uses cold cathode fluorescentlamps or an LED backlight.

APPLICATIONS

OLED technology is used in commercialapplications such as displays for mobile phonesand portable digital media players, car radiosand digital cameras among others. Such portableapplications favor the high light output ofOLEDs for readability in sunlight and their lowpower drain. Portable displays are also usedintermittently, so the lower lifespan of organicdisplays is less of an issue.

OLEDs have been used in most Motorola andSamsung color cell phones, as well as someHTC, LG and Sony Ericsson models. Nokia hasalso introduced some OLED products includingthe N85 and the N86 8MP, both of which featurean AMOLED display. OLED technology canalso be found in digital media players such as

the Creative ZEN V, the iriver clix, the Zune HDand the Sony Walkman X Series.

Textiles incorporating OLEDs are an innovationin the fashion world and pose for a way tointegrate lighting to bring inert objects to awhole new level of fashion. The hope is tocombine the comfort and low cost properties oftextile with the OLEDs properties ofillumination and low energy consumption.

E. CONCLUSION

The selection of LED is depends upon the uses.If it is required for color-changeable interiorand/or exterior accent lighting, then need to gowith SMD LEDs; if requirement is themaximum lumens per Watt for a mono-coloredlight (such as a fog light, headlight or dome

light) then COB LEDs is the best choice.

Where SMDs demand a low maintenancecost, COBs have a low production cost.However, both being energy efficient, COBsproduce better results with respect to heatemission. Where SMDs alleviate heatdispersion, COBs minimises the heat outputaltogether. Both the types of LED lightshave a long life span and generally speakingboth can prove to be of advantage in differingcircumstances.

However, where both SMDs and COBs fail is interms of shape and design. Till now they havebeen unable to imitate the exterior design of aconventional incandescent bulb. But with theadvancement in LED technology, there now isavailable the LED filament bulb. The LEDfilament bulb successfully structures itselfaround the conventional shape of a regular bulbwhile being energy efficient and having longerlife span, where OLED is used only in displayscreen of different electronics devices.


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F. REFERENCE

1. Shinar, Joseph (Ed.), Organic Light-Emitting Devices: A Survey. NY:Springer-Verlag (2004). ISBN 0-387-95343-4.

2. Kamtekar, K. T.; Monkman, A. P.;Bryce, M. R. (2010). "Recent Advancesin White Organic Light-EmittingMaterials and Devices (WOLEDs)".Advanced Materials. 22 (5): 572–582.doi:10.1002/adma.200902148.PMID 20217752

3. SMD-LED-Module-Dimensions 5050SMD LED Module Dimensions" 2835SMD LED Module

4. Jacques, Carole (28 January 2014) LEDLighting Market to Grow Over 12-Foldto $25 Billion in 2023, Lux Research

5. Bergesen, Joseph D.; Tähkämö, Leena;Gibon, Thomas; Suh, Sangwon (2016)."Potential Long-Term GlobalEnvironmental Implications of EfficientLight-Source Technologies". Journal ofIndustrial Ecology. 20 (2): 263.doi:10.1111/jiec.12342.

Documents

EDITORIAL - Technique Polytechnic Institute · MANIK SAHA, ANUSHREE BASAK & SOUMYA MUKHERJEE Student of Electrical Engineering Department 22–28 7. Smart Grid Technology ARIJIT MONDAL