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8/3/2019 Wireless Transmission 1

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WIRELESS TRANSMISSION

OF ELECTRICITY DEVELOPMENT AND POSSIBILITY

Presented by

G.CHANDRASEKHAR(IV year) S.GOVARDHAN(IV year)

Email:[email protected] [email protected]

DEPARTMENT OF ELECTRICAL& ELECTRONICS ENGINEERING

MANDAVA INSTITUTE OF ENGINEERING&TECHNOLOGY

(Affiliated to J N T U, Kakinada)

JAGGAYYAPETA-521 175


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AbstractIn the present paper the various technologies

available so far forwireless transmission ofelectricity and the need for a Wireless Systemof Energy Transmission is being discussed tofind its possibility in actual practices, theiradvantages, disadvantages and economicalconsideration. This paper is mainlyconcentrated on:i) The most popular concept known as TeslaTheory,ii) The microwave power transmission(MPT) called Solar power satellite and

iii) The highly efficient fiber lasers forwireless power transmission.Many concepts, research papers, patents areavailable on wireless transmission ofelectricity but the commercial technologiesare yet to be materialized. The paper alsodiscusses the possible ways to get useful andpractical results out of all research carriedout so far elsewhere. Microwave ovenmagnetron with electronics to control theoutput power. The output microwave power

ranges from 50 W to 200 W at 2.45GHz. Acoaxial cable connects the output of themicrowave source to a coax-to-waveguideadapter. This adapter is connected to awaveguide ferrite circulator which protectsthe microwave source from reflected power.The circulator is connected to a tuningwaveguide section to match the waveguideimpedance to the antenna input impedance.The slotted waveguide antenna consists of 8waveguide sections with 8 slots on each

section. These 64 slots radiate the poweruniformly through free space to the rectenna.The slotted waveguide antenna is ideal forpower transmission because of its highaperture efficiencyKey words Wireless transmission, Teslatheory, Microwave power transmission, Fiberlasers, Collaborative research.

I. INTRODUCTION

In our present electricity generation systemwe waste more than half of its resources.specially the transmission and distributionlosses are the main concern of the presentpower technology. Much of this power iswasted during transmission from power plantgenerators to the consumer. The resistance ofthe wire used in the electrical griddistribution system causes a loss of 26-30%of the energy generated. This loss impliesthat our present system of electrical

distribution is only 70-74% efficient. Wehave to think of alternate state of - arttechnology to transmit and distribute theelectricity. Now- a- days global scenario hasbeen changed a lot and there are tremendousdevelopment in every field. If we dont keeppace with the development of new powerechnology we have to face a decreasing trendin the development of power sector. Thetransmission of power without wires may beone noble alternative for electricity

transmission.

II. THE TECHNOLOGIES

AVAILABLE

In this remarkable discovery of the "TrueWireless" and the principles upon whichtransmission and reception, even in thepresent day systems, are based, Dr. NikolaTesla shows us that he is indeed the "Fatherof the Wireless." The most wellknown and

famous Wardenclyffe Tower (Tesla Tower)was designed and constructed mainly forwireless transmission of electrical power,rather than telegraphy [1]. The most popularconcept known is Tesla Theory in which itwas firmly believed that Wardenclyffe (Fig.1)would permit wireless transmission andreception across large distances with


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negligible losses [2]. In spite of this he hadmade numerous experiments of high qualityto validate his claim of possibility of wirelesstransmission of electricity (Fig.2). But thiswas an unfortunate incidence that people of

that century was not in a position torecognize his splendid work otherwise todaywe may transmit electricity wirelesslyand will convert our mother earth awonderful adobe full of electricity.

Fig.1. The 187-foot Wardenclyffe Tower

(Tesla Tower) in 1903.This was to be the first broadcasting system

in the world. Tesla wanted to transmitelectricity from this Tower to the whole globe

without wires using the Ionosphere. Thesource of the transmitted electricity was to bethe Niagara Falls power plant[1].Fig.1. The187-foot Wardenclyffe Tower (Tesla Tower)in 1903. Without wires may be one noblealternative for electricity This was to be thefirst broadcasting system in the world.Tesla transmission. wanted to transmitelectricity from this Tower to the whole globewithout wires using the Ionosphere. Thesource of the transmitted electricity was to bethe Niagara Falls power plant[1]. The modernideas are dominated by microwave powertransmission (MPT, Figure 3) called Solarpower satellite to be built in high earth orbitto collect sunlight and convert that energyinto microwaves, then beamed to a very largeantenna on earth, the microwaves would beconverted into conventional electrical power.

Fi

g.2. The basis for Teslas system for the

wireless transmission of electrical power[3].

Fig 2

William C. Brown, the leading authority onwireless power transmission technology, hasloaned this demonstration unit to the TexasSpace Grant Consortium to show how powercan be transferred through free space byicrowaves. A block diagram of thedemonstration components is shown below.The primary components include a


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microwave source, a transmitting antenna,and a receiving rectenna. Fig.3 .Microwavepower transmission [4].


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Fig.3 .Microwave power transmissionThe microwave source consists of a mi%)and high power handling capability.Arectifying antenna called a rectenna receivesthe transmitted power and converts themicrowave power to direct current (DC)power. This demonstration rectenna consistsof 6 rows of dipoles antennas where 8 dipolesbelong to each row. Each row is connected toa rectifying circuit which consists of low passfilters and a rectifier. The rectifier is a Ga AsSchottky barrier diode that is impedancematched to the dipoles by a low pass filter.The 6 rectifyingdiodes are connected to light bulbs forindicating that the power is received. Thelight bulbs also dissipated the receivedpower. This rectenna has a 25% collectionand conversion efficiency, but rectennas havebeen tested with greater than 90% efficiencyat 2.45 GHz[4]. The transmission of powerwithout wires is not a theory or a merepossibility, it is now a reality. The electricalenergy can be economically transmittedwithout wires to any terrestrial distance,many researchers have established innumerous observations, experiments andmeasurements, qualitative and quantitative[5-9]. These have demonstrated that it ispracticable to distribute power from a centralplant in unlimited amounts, with a loss notexceeding a small fraction of one per cent, inthe transmission, even to the greatestdistance, twelve thousand miles - to theopposite end of the globe. This seeminglyimpossible feat can now be readily performedby electrical researchers familiar with the


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design and construction of my "highpotentialmagnifying transmitter," There were threepopular theories present in the literature ofthe late 1800's and early 1900's. They were:1. Transmission through or along the Earth,

2. Propagation as a result of terrestrialresonances, 3. Coupling to the ionosphereusing propagation through electrifiedgases(Fig.4&5).

Fig4: Diagram showing the transmitting &receiving circuit For the transmission &

reception of electric power by wireless

Fig.5. Two optical forms of wireless

antennae formed of search light beamionized

atmospheric streams

It has been proven that electrical energy canbe propagated around the world between thesurface of the Earth and the ionosphere atextreme low frequencies in what is known asthe Schumann Cavity. Knowing that aresonant cavity can be excited and that power

can be delivered to that cavity similar to themethods used in microwave ovens for homeuse, it should be possible to resonate anddeliver power via the Schumann Cavity toany point on Earth. This will result in

practical wireless transmission of electricalpower. The intent of the experiments and thelaboratory Tesla had constructed was to provethat wirelesstransmission of electrical powerwas possible. Although Tesla was notable to commercially market a system totransmit power around the globe, modernscientific theory and mathematicalcalculations support his contention that thewireless propagation of electrical power ispossible and a feasible alternative to the

extensive and costly grid of electricaltransmission lines used today for electricalpower distribution. Power transmissionsystem using directional ultrasound for powertransmission includes a transmittingdevice and a receiving device. Thetransmitting device has a set of ultrasoundtransducers forming an ultrasound transducerarray, wherein the array is a set of spacedindividual transducers placed in the X-Yplane disposed to generate an ultrasoundbeam in the Z direction . Anotherpossibility is to use highly efficient fibrelasers for wireless power transmission wherethe possibilities are similar to microwavesconcept but lasers emit energy at frequenciesmuch higher that microwaves. For severalyears NASA, ENTECH, and UAH have beenworking on various aspects of collection ofthe laser radiation and conversion toelectrical power for laser wireless powertransmission.

III. MERITS, DEMERITS &

ECONOMICS OF WIRELESS

TECHNOLOGIES

3.1. Merits

An electrical distribution system,based onhis method would eliminate the need for an


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inefficient, costly, and capital intensive gridof cables, towers, and substations. Thesystem would reduce the cost of electricalenergy used by the consumer and rid thelandscape of wires, cables, and transmission

towers. There are areas of the world wherethe need for electrical power exists, yet the reis no method for delivering power. Africais in need of power to run pumps to tap intothe vast resources of water under the SaharaDesert. Rural areas, such as those in China,require the electrical power necessary tobring them into the 20th century and to equalstanding with western nations. The wirelesstransmission will solve many of theseproblems The electrical energy can be

economically transmitted without wires toany terrestrial distance, so there will be notransmission and distribution loss. Moreefficient energy distribution systems andsources are needed by both developed andunder developed nations. In regards to thenew systems, the market for wireless powertransmission is enormous. It has the potentialto become a multibillion dollar per yearmarket. The increasing demand for electricalenergy in industrial nations is welldocumented. If we include the demand ofthird world nations, pushed by theirincreasing rate of growth, we could expect aneven Faster rise in the demand for electricalpower in the near future. These systems canonly meet these requirements with 9094%efficient transmission [3, 8].

High Transmission Integrity and Low Loss: -To transmit wireless power to any distancewithout limit. It makes no difference what thedistance is. The efficiency of thetransmission can be as high as 96 or 97 percent, and there are practically no losses.

3.2. Demerits

Biological Impact: - One commoncriticism of the Tesla wireless power systemis regarding its possible biological effects.Calculating the circulating reactive power, it

was found that the frequency is very smalland such a frequency is very biologicallycompatible [3, 8].

3.3.Economic ImpactThe concept looks to be costly initially. The

investment cost of Tesla Tower was $150,000(1905). In terms of economic theory, manycountries will benefit from this service. Onlyprivate, dispersed receiving stations will beneeded. Just like television and radio, a singleresonant energy receiver is required, whichmay eventually be built into appliances, so nopower cord will be necessary! Monthlyelectric utility bills from oldfashioned, fossil-fuelled, lossprone electrified wire-griddelivery services will be optional, much like

cable TV of today. In the 21st century,Direct TV is the rage, which is an exactparallel of Teslas DirectElectricity.

IV. ADDITIONAL REMARKSMany concepts, research papers, patents areavailable on wireless transmission ofelectricity but most research work werecarried out in isolation, so it needs a jointcollaborative efforts to get a very usefulresults on this advanced technology on power

transmission for the benefit of mankindglobally in future. Whatever the future maybring, the universal application of these greatprinciples is fully assured, though it may belong in coming. With the opening of the firstpower plant, incredulity will give way towonderment, and this to ingratitude, as everbefore. The world is still not able to achievethe benefit of the God gifted potential of DrN.Tesla. People neglected him and his goodwork. He deserved much better treatment

from the tycoons of his age, than to spendthe last 40 years of his life in abject poverty.However, he was too much of a gentleman tohold a grudge. Instead, regarding themagnifyingtransmitter, Tesla wrote in his autobiography,I am unwilling to accord to some small-minded and jealous individuals the


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satisfaction of having thwarted my efforts.These men are to me nothing more thanmicrobes of a nasty disease. My project wasretarded by laws of nature. The world wasnot prepared for it. It was too far ahead of

time. But the same laws will prevail in theend and make it a triumphal success. [3, 8-9]. If this has had not been happened, thentoday we will be in a wonder world of plentyof powerusing the technology of wirelesstransmission of electricity.

V. CONCLUSIONThe transmission of power without wires isnot a theory or a mere possibility, it is now areality. The electrical energy can beeconomically transmitted without wires to

any terrestrial distance. Many researchershave established in numerous observations,experiments and measurements, qualitativeand quantitative. Dr.N.Tesla is the pioneer ofthis invention. Wireless transmission ofelectricity have tremendous merits like hightransmission integrity and Low Loss (90 97% efficient) and can be transmitted to anywhere in the globe and eliminate the need foran inefficient, costly, and capital intensivegrid of cables, towers, and substations. The

system would reduce the cost of electricalenergy used by the consumer and get rid ofthe landscape of wires, cables, andtransmission towers. It has negligibledemerits like reactive power which wasfound insignificant and biologicallycompatible. It has a tremendous economicimpact tohuman society. Many countries

willbenefit from this service. Monthlyelectric utility bills from oldfashioned, fossil-fuelled, lossprone electrified wire-griddelivery services will be optional, much likecable TV of today.

ACKNOWLEDGEMENTThe author is thankful to the management ofLoyala institute of technology andmanagement, Guntur for giving permission topublish this paper. The author is gratefullyacknowledged the support and constantencouragement of HOD, Dean, ED, & MD,Nalanda institute of engineering andtechnology, Guntur

REFERENCES[1] Nikola Tesla, The Transmission

of Electrical Energy Without Wires asa Means for Furthering Peace,Electrical World and Engineer. Jan.7, p. 21, 1905.[2] Nikola Tesla,My Inventions, BenJohnston, Ed., Austin, Hart Brothers,p. 91,1982.[3] Thomas F. Valone, TeslasWireless Energy... For the 21stCentury!!! One Step beyond DirectTV!!!Extra Ordinary Technology, 1,

no. 4, Oct / Nov / Dec 2003.[4] James O. McSpadden, WirelessPower Transmission Demonstration,Texas A&M University, June, 1997.[5] Thomas W. Benson , Wirelesstransmission of power now possible,News Letter, pp1118 9, March ,1920.

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