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International journal of recent advances in engineering & technology (IJRAET)
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ISSN (Online): 2347 - 2812, Volume-4, Issue -9, 2016
1
Wireless Power Transmission: Witricity -An Advanced Generation
1Anusha.B.K,
2PreranaKulkarni,
3Trupthi.G,
4Shwetha.D
1,2,3,4Department of EEE, East West Institution of Technology, Bengaluru 560091
Abstract- This paper describes an original idea to eradicate
the dangerous usage of electrical wires which involve lot of
confusion in particularly organizing them. We cannot
imagine the world pertaining to electricity. We can
conceive a future in which power transfer without electric
wires is practicable. We present the idea of transmission of
electricity without wires i.e., Witricity (wireless power
transmission). Power crisis is one of the huge problem of
the present century. We can’t even survive without
electricity. Just imagine our daily usage electronic devices
such as mobile phones, mp3 players, laptops, computers
and other portable electronic devices which are competent
of charging themselves without being plugged in for
charging. This paper consists of the techniques of power
transmission without using wires with an efficiency of
about 95% with non-radiation methods. This paper is
mainly based on:-
1) The popular technology called Tesla Theory
2) Solar power satellite (Microwave power transmission)
Index Terms-Microwave power transmission (MPT), solar
power satellite (SPS), Tesla theory and Wireless electricity.
I. INTRODUCTION
In our present electric power transmission and
distribution system half of the power is wasted. Most of
the electric power is being wasted during transmission
from generating station to the consumers. The ability to
communicate with people on the move has evolved
remarkably and wireless communication services have
been enthusiastically adopted by us throughout the
world. In this manner power distribution looks like
outdated with using big transmission lines and cables.
The present transmission and distribution scheme has
heavy losses and comparatively low efficiency. Hence it
is necessary for us to replace the present transmission
method with the efficient one. The demand for power is
increasing day by day, at the same manner power loss is
also increased. The utmost reason for loss of power is
the resistance of wires used for electrical grid
distribution system. This loss indicates that our system
of distribution of electricity is only 70-75% efficient.
According to the World Resources Institute (WRI) the
highest transmission and distribution losses in the world
is India's electricity grid. Hence it is very necessary for
us to have an alternate technology to transmit and
distribute the power.
II. TESLA THEORY
In this remarkable discovery of the "True Wireless" and
the principles upon which transmission and reception,
even in the present day systems, are based, Dr. Nikola
Tesla shows us that he is indeed the "Father of the
Wireless". The famous Wardenclyffe tower (Tesla
Tower) shown in fig.1was constructed and designed
mainly for wireless transmission of electricity rather
than telegraphy. In 1893, Tesla demonstrated the
illumination of vacuum bulbs without using wires for
transmission of power at the world Columbian
exposition in Chicago. This was the first broadcasting
system in the world. Tesla wanted to transmit electricity
from this tower to the whole globe without wires using
the Ionosphere.
Fig.1the 187-foot Wardenclyffe Tower (Tesla Tower) in
1903.
The most popular concept known is Tesla theory in
which it was firmly believed that Wardenclyffe shown
in fig.1would allow wireless transmission and reception
across large distance with negligible losses. He had also
made numerous experiments of high quality to give
validity to his assert of possibility of wireless
transmission of electricity. But this was an unfortunate
incidence that people of that century was not in a
position to recognize his magnificent work otherwise
today we may transmit electricity wirelessly and will
International journal of recent advances in engineering & technology (IJRAET)
_______________________________________________________________________________________________
_______________________________________________________________________________________________
ISSN (Online): 2347 - 2812, Volume-4, Issue -9, 2016
2
convert our mother earth a wonderful adobe full of
electricity. This was the first step towards a practical
wireless system. Tesla realized that electrical energy
from one source can be sent externally into space and
that can be detected by a receiving instrument in the
surrounding area of the source without the need of any
interconnecting wires. His views and his experimental
work are showing a path to the development for the
world. Fig.2 below is the Tesla's apparatus for
transmission of electricity.
Fig 2. System of transmission of electrical energy
III. MICROWAVE POWER
TRANSMISSION
The most extended documented area of research is being
done with the aim of putting solar power generating
satellites into space and transmitting power to earth
stations. This was first introduced in1968 and all of the
experiments thus far have only been carried out in
terrestrial laboratories.
Fig.3 solar power satellite
William C. Brown, the chief delegated power on
wireless power transmission technology, has loaned this
demonstration unit to the Texas space grant consortium
to show how power can be transferred through free
space by microwaves. A block diagram for this is as
shown in fig.4.
Fig.4 Block diagram of solar power satellite
Space-based solar power has three main components-
1. Microwave source
2. A transmitting antenna
3. Receiving rectanna
The microwave source consists of a microwave oven
magnetron and high power handling capacity. The
output microwave power ranges from 50W to 2.45 GHz.
A co axial cable connects the output of the microwave
source to a coax-to-wave guide adapter. The microwave
source is protected from reflected power by adapter
which is connected to a tuner and bidirectional coupler
to match the waveguide impedance to the antenna input
impedance. The slotted waveguide antenna contains 8
waveguide sections with 8 slots on each section. These
64 slots radiate the power uniformly through free space
to the rectanna. A rectifying antenna called a rectanna
receives the transmitted power and converts the
microwave power to direct current (DC) power. This
rectanna has a 25% collection and conversion efficiency,
but retinas have been tested with greater than 90%
efficiency at 2.45 GHz.
The transfer of power without wires is now possible and
can be rapidly applied with the design and construction
of my "high-potential magnifying transmitter". There
were three important theories regarding this-
1. Transmission through or along the earth
2. Propagation as a result of terrestrial resonances
3. Coupling to the ionosphere using propagation
International journal of recent advances in engineering & technology (IJRAET)
_______________________________________________________________________________________________
_______________________________________________________________________________________________
ISSN (Online): 2347 - 2812, Volume-4, Issue -9, 2016
3
It has been experimented that electrical energy can be
propagated around the world between the surface of the
earth and the ionosphere at extreme low frequencies,
what is known as the Schumann cavity. We know that
resonant cavity can be excited and power can be sent to
that cavity similar to the techniques applied in
microwave ovens for home use, it should be possible to
resonate and deliver power via the Schumann cavity to
any point on earth. Tesla experimented many techniques
to prove wireless power transmission is possible.
Even though he was not able to apply this system in a
market, latest scientific theory and mathematical
calculations support his invention that the transmission
of power without wires is now possible and a practicable
alternative to the comprehensive and costly grid of
electrical transmission lines used today for electrical
power distribution.
Another possibility is to use highly efficient fiber lasers
for wireless power transmission where the possibilities
are similar to microwaves concept but lasers emit energy
at frequencies much higher than microwaves. For
several years NASA, ENTECH and UAH have been
working on various aspects of collection of the laser
radiation.
IV. MERITS, DEMERITS AND ECONOMIC
IMAPCT OF WIRELESS ELECTRICITY
4.1 MERITS
Wireless technology is efficient and easy. The cost of
electricity used is reduced by the system. Need for grid
is eliminated. Maintenance cost is low. More effective
when the transmitting and receiving points are along a
line of sight. This system can reach the places which are
remote. This technology reduces the need of power
cables. Wastage of power is minimized. Reduction of e-
waste by eliminating the need for power cords, does not
interfere with radio waves & negative health
implications. Transfer efficiency in this technology will
be more compared to copper coil. This technology
creates shock free environment, avoid of any chances of
power thefts. Provides solution to the ever increasing
demand for power.
4.2 DEMERITS
This technology is radioactive. When lasers are used
conversion is inefficient and absorption loss is high.
When microwaves are used interference may arise.
Operating frequency can be decreased within a specific
range. If not, it will affect the power transfer efficiency.
Frequency below 1 MHz preferably 200 KHz is
applicable for power transfer in the present system.
4.3 ECONOMIC IMPACT
Wireless electricity is expected to have its biggest
impact in the mobile electronic device and electric car
markets in which three-fourths of power is wasted in
idle mode. You cannot feel the oscillating magnetic field
wireless electricity used to transfer the power. Wireless
electricity can eliminate the complicacy of power cables
and charging stations that clutter millions of offices and
home entertainment rooms. Wireless electricity has
many environmental benefits. Companies make about 40
billion disposable batteries each year and wireless
electricity could do away with that.
V. CONCLUSION
The wireless energy system uses common materials,
such as copper wire and capacitors that cause no danger
to humans. The efficiency of the medium used also
matters a lot, since radio waves have proven to be much
more directional than microwaves, which covers a much
larger distance. So radio waves can be used for wireless
power transmission in the future and research in the
same has proven 95% conservation rate of energy,
which proves that it is a really efficient means of
transfer. The requirement of a wireless mode of transfer
of electricity is necessary because this is nonhazardous,
efficient and safe to all problems faced by us. The
efficiency is restrained to increase since there is no issue
of power loss over wires and coils instead of being lost
in the process of transfer. With the development of
efficiency of the transfer mediums, now we can choose
for long distance power transmission using the power of
wireless modes.
REFERENCES
[1] Nikola Tesla," The Transmission of Electrical
Energy Without Wires as a Means for Furthering
Peace," Electrical World and Engineer. jan.7,p.
21,1905.
[2] Nikola Tesla, My inventions, Ben Johnson, Ed.,
Austin, Hart Brothers, p.91, 1982
[3] Thomas F. Valona, "Tesla's Wireless energy...
For the 21st century!!! One step beyond direct
TV!!!" Extra Ordinary Technology, 1, no.4, oct/
nov/dec 2003.
[4] Thomas Benson, "Wireless transmission of
power now possible", News Letter, pp1118-9,
March, 1920.
[5] Nikola Tesla," The true wireless”, Electrical
Experiments, May, 1919.
[6] James O. McSpadden, "Wireless Power
Transmission Demonstration”, Texas A&M
University, June, 1997.
[7] “Goodbye wires..." MIT News
[8] Nikola Tesla's Wireless Systems.