Wireless Electricity

Submitted By:-Sayantany Ghanty

Saumyadip Moitra

Satyajit Marik

SumantaDas

Rishi RoySubmitted To-

BCREC Electrical Dept.(2013) 1

What is ‘Witricity’?History of Wireless power.Basic Principle.Experimental DesignHow does ‘Witricity’ Work?Applications of ‘Witricity’.Advantages & Disadvantages.Electromagnetic HazardsRecommendations

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Electricity without wires

Magnetic loop antennas

Electromagnetic near-field

Magnetic Field around a bar magnet

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History of Wireless Power: In 1893,Nikola Tesla publicly

demonstrates wireless power before a

meeting of the National Electric Light

Association in St. Louis.

In 1894, Nikola Tesla lights

incandescent lamps wirelessly at

the laboratory in New York City by

means of "electro-dynamic induction" or

resonant inductive coupling.

Jagdish Chandra Bose rings a

bell at a distance

using electromagnetic waves and

also ignites gunpowder , thus

contributing & developing to

wireless electrical power transfer

in the year 1894.

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RESONANCE COUPLING:

MIT powered 60 watt light bulb from 2 meters (7 ft) at 40% efficiency

The forgotten invention is reborn in 2007

A group of engineers at MIT came up with the idea to use resonant induction to

transmit power wirelessly.

“Resonance", a phenomenon that causes an object to vibrate when energy of a

certain frequency is applied.

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Basic Principle:

The basic principle involved in ‘Witricity’ concept is,

Two objects having same resonating frequency and in Magnetic

resonance at Strongly coupled regime tend to exchange energy ,

while dissipating relatively little energy to the extraneous off-

resonant objects.

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Experimental Design:Our experimental scheme consists of two Self-resonant

coils. One coil (source coil) is coupled inductively to an

oscillating circuit; the other (device coil) is coupled

inductively to a resistive load. Self-resonant coils rely on the

interplay between distributed inductance and distributed

capacitance to achieve resonance.

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Near-field inductive coupling through magnetic fields

Interact weakly with surrounding objects (biological tissue)

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The microwave source consists of a microwave oven magnetron with electronics to control the output power. The output microwave power ranges from 50 W to 200 W at 2.45 GHz

This rectenna has a 25% collection and conversion efficiency, but rectennas have been tested with greater than 90% efficiency at 2.45 GHz.

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On April 27,2011 leading Japanese car-manufacturer Toyota signed an agreement with WiTricity Corpn. regarding the sharing of wireless technology in their hybrid cars.

Sony showed a wireless electrodynamic-induction powered TV set, 60 W over 50 cm

Haier Group debuted “the world's first” completely wireless LCD television

Intel implemented electrodynamic induction by wirelessly powering a nearby light bulb with 75% efficiency.

Palm (now a division of HP) launched the Palm Pre smart phone with the Palm Touchstone wireless charger.

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Automatic wireless charging of mobile electronics (phones, laptops, game

controllers, etc.) in home, car, office, Wi-Fi hotspots … while devices are in

use and mobile.

Direct wireless power and communication interconnections at points of

use in harsh environments (drilling, mining, underwater, etc.) … where it is

impractical or impossible to run wires.

Automatic wireless charging for existing electric vehicle classes: golf

carts, industrial vehicles.

Automatic wireless charging for future hybrid and all-electric passenger

and commercial vehicles, at home, in parking garages, at fleet depots, and

at remote kiosks.

Direct wireless power interconnections and automatic wireless charging

for implantable medical devices ( pacemaker, defibrilator, etc.).

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These hazards will exist when an electromagnetic field of sufficient

intensity is generated to: (a) induce or otherwise couple currents or

voltages large enough to initiate electroexplosive devices or other

sensitive explosive components of weapon systems, ordnance, or

explosive devices; (b) cause harmful or injurious effects to humans and

wildlife; (c) create sparks having sufficient magnitude to ignite flammable

mixtures of materials that must be handled in the affected area.

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Need of ‘Witricity’:

Now a days there is a Rapid development of autonomous

electronics like Laptops, Cell-phones, House-hold robots and all

those devices typically rely on chemical energy storage(Battery)

As they are becoming daily needs to present generation, Wire

less energy transfer would be useful for many applications as

above and they need midrange energy.

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Advantages of ‘witricity’:No Need of Wires For Power Transfers.

Highly Resonant Strong Coupling Provides High

Efficiency Over Distance

Energy Transfer via Magnetic Near Field Can

Penetrate and Wrap Around Obstacles

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Disadvantages of ‘Witricity’:Mainly require short distances to charge

Does not give enough energy to power larger

vehicles and equipment

Cost and supplying the public

Still under production and improvement

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In theory, there are endless possibilities for the application of Wireless

Electricity ,however it is yet to be tried & tested on a large scale basis

.The experimental results have so far been positively reviewed by

scientists & electrical engineers but its widespread applications are yet

to be fully understood & applied. There need to be further investments

in the field of wireless electrical energy transfer so as to widen &

deepen its applications.

Recommendation:

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