Wireless Energy Transmission is an exciting topic and a handy one to make a presentation. I hope this would be helpful to someone.

1. Wireless Energy
Transmission
NEOTIA INSTITUTE OF TECHNOLOGY
MANAGEMENT AND SCIENCE
DEPARTMENT OF ELECTRONICS AND COMMUNICATION
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2. Contents
• WHAT IS WIRELESS
POWER
TRANSMISSION(WPT)?
• WHY IS WPT?
• HISTORY OF WPT
• TYPES OF WPT
Techniques to transfer
energy wirelessly
• Applications
• ADVANTAGES AND
DISADVANTAGES
• CONCLUSION
• REFERENCES
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3. What is Wireless Energy Transmission?
 The transmission of energy from one place to another without using
wires
 Energy transfer is using wires
 But, the wireless transmission is made possible by using various
technologies
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4. Why not wires?
 As per studies, most electrical energy transfer is through wires.
 Most of the energy loss is during transmission
• On an average, more than 30%
• In India, it exceeds 40%
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5. Why Wireless Energy Transmission?
 Reliable
 Efficient
 Fast
 Low maintenance cost
 Can be used for short-range or long-range.
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6. Nikola Tesla’s
Demonstration
 In 1891, Nikola Tesla gave a
lecture for the members of the
American Institute of Electrical
Engineers in New York City.
 Using glass discharge tubes for
his experiment.
 The tubes were not connected
to any wires.
 He went on to speculate how one
might increase the scale of this
effect to transmit wireless
power.
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7. Tesla’s Other Experiments
 Experiment with Static electricity
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8. Tesla’s Power-Tower
Tesla’s House
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9. Energy Coupling
 The transfer of energy
Magnetic coupling
Inductive coupling
 Simplest Wireless Energy coupling
is a transformer
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10. Air Ionization Experiment
In 1899 Sir NICOLA TESLA and
HEINRICH HERTZ powered a fluorescent
lamp keeping it 25 miles away from source
without using wire.
A high potential transmitter transmits an
“electromotive impulse” through the
ionized path to the upper atmosphere
where it ionizes the air, and this air
between the transmitter and receiver
would conduct like a neon tube .
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11. Wireless Power System
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12. Techniques for
wireless
Transmission of
Power
 NEAR-FIELD
TECHNIQUES
• INDUCTIVE COUPLING
• RESONANT INDUCTIVE COUPLING
FAR-FIELD
TECHNIQUES
• MICROWAVE POWER
TRANSMISSION(MPT)
• LASER POWER TRANSMISSION(LPT)
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13. Inductive Coupling Method
• Primary and secondary coils are not
connected with wires.
• Energy transfer is due to Mutual
Induction
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14. Inductive Coupling(Contd..)
 Transformer is also an example
 Energy transfer devices are usually through air.
 Wireless Charging Pad(WCP),electric brushes are some examples
 On a WCP, the devices are to be kept, battery will be automatically
charged.
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15. Resonant Inductive Coupling
• Combination of inductive coupling and resonance
• Resonance makes two objects interact very strongly inductance induces
current
• Inductance induces current
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16. Resonant Inductive Coupling(Contd…)
• Coil provides the inductance
• Capacitor is connected parallel to the
coil
• Energy will be shifting back and forth
between magnetic field surrounding
the coil and electric field around the
capacitor
• Radiation loss will be negligible
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17. Circuit Diagram
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18. Microwave Transmission Method
 Transfers high power from one place to another. Two places being in line
of sight usually
 Steps:
 Electrical energy to microwave energy
 Capturing microwaves using rectenna
 Microwave energy to electrical energy
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19. Microwave Transmission Concept
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20. Microwave
Power
Transmission
(Contd….)
• AC CAN NOT BE DIRECTLY
CONVERTED TO MICROWAVE
ENERGY
• AC IS CONVERTED TO DC
FIRST
• DC IS CONVERTED TO
MICROWAVES USING
MAGNETRON
• TRANSMITTED WAVES ARE
RECEIVED AT RECTENNA
WHICH RECTIFIES, GIVES DC
AS THE OUTPUT
• DC IS CONVERTED BACK TO
AC
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21. Rectenna
 It is a rectifying antenna
 Microwaves are received with about 95%
efficiency
 Converts microwave energy into DC
 Consists of mesh of dipole antennas
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22. LASER Transmission Method
 LASER is highly directional, coherent
 Not dispersed for very long
 But, gets attenuated when it propagates through atmosphere
 Simple receiver
 Photovoltaic cell
 Cost-efficient
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23. Laser (Contd…)
In the case of electromagnetic radiation
closer to visible region of spectrum (10s of
microns(um) to 10s of nm), power can be
transmitted by converting electricity into a
laser beam that is then pointed at a solar cell
receiver. This mechanism is generally known
as "power beaming" because the power is
beamed at a receiver that can convert it to
usable electrical energy.
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24. Laser Method Block diagram
Transformer
Receiver
Current
Source
Laser
Optical Fiber
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25. Wireless Electricity-
WiTricity
• BASED ON RIC
• LED BY MIT’S MARIN
SOLJAČIĆ
• ENERGY TRANSFER
WIRELESSLY FOR A
DISTANCE JUST MORE THAN
2M.
• COILS WERE IN HELICAL
SHAPE
• NO CAPACITOR WAS USED
• EFFICIENCY ACHIEVED WAS
AROUND 40%
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26. WiTricity contd…
 WiTricity experimented to power
incandescent bulb kept few meters away.
 WiTricity experimented to power
incandescent bulb kept few
meters away with a obstacle.
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27. WiTricity Now
 No more helical coils
 Companies like Intel are also working on devices that make use of RIC
 Researches for decreasing the field strength
 Researches to increase the range
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28. Applications
 Wireless Parking charger  Wireless Electronic charger
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29. WiTricity Corporation products
 WiTricity Corporation plans to
operate each and every
household electronic gadgets
with wireless energy control
techniques
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30. Air Ionisation
 Toughest technique under near-field energy transfer
techniques
 Air ionizes only when there is a high field
 Needed field is 2.11MV/m
 Natural example: Lightening
 Not feasible for practical implementation
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31. RIC vs Inductive Coupling
 RIC is highly efficient
 RIC has much greater range than inductive coupling
 RIC is directional when compared to inductive coupling
 RIC can be one-to-many. But usually inductive coupling is one-to-one
 Devices using RIC technique are highly portable
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32. Advantages of Near-Field Techniques
 No wires
 No e-waste
 Need for battery is eliminated
 Efficient energy transfer using RIC
 Harmless, if field strengths under safety levels
 Maintenance cost is less
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33. Disadvantage
 Distance constraint
 Field strengths have to be under safety levels
 Initial cost is high
 In RIC, tuning is difficult
 High frequency signals must be the supply
 Air ionization technique is not feasible
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34. Laser vs Microwave Power Transmission
 When LASER is used, the antenna sizes can be much smaller
 Microwaves can face interference (two frequencies can be used for
WPT are 2.45GHz and 5.4GHz)
 LASER has high attenuation loss and also it gets diffracted by
atmospheric particles easily
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35. Advantages of far-field energy transfer
 Efficient
 Easy
 Need for grids, substations etc are eliminated
 Low maintenance cost
 More effective when the transmitting and receiving points are along a line-of-sight
 Can reach the places which are remote
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36. Disadvantages of a far-field energy
transfer
 Radiative
 Needs line-of-sight
 Initial cost is high
 When LASERs are used,
 conversion is inefficient
 Absorption loss is high
 When microwaves are used,
 interference may arise
 FRIED BIRD effect
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37. Conclusion
 Transmission without wires- a reality
 Efficient
 Low maintenance cost. But, high initial cost
 Better than conventional wired transfer
 Energy crisis can be decreased
 Low loss
 In near future, world will be completely wireless
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38. References
 S. Sheik Mohammed, K. Ramasamy, T. Shanmuganantham,” Wireless power transmission –
a next generation power transmission system”, International Journal of Computer
Applications (0975 – 8887) (Volume 1 – No. 13)
 Peter Vaessen,” Wireless Power Transmission”, Leonardo Energy, September 2009
 C.C. Leung, T.P. Chan, K.C. Lit, K.W. Tam and Lee Yi Chow, “Wireless Power Transmission
and Charging Pad”
 David Schneider, “Electrons unplugged”, IEEE Spectrum, May 2010
 Shahrzad Jalali Mazlouman, Alireza Mahanfar, Bozena Kaminska, “Mid-range Wireless
Energy Transfer Using Inductive Resonance for Wireless Sensors”
 Chunbo Zhu, Kai Liu, Chunlai Yu, Rui Ma, Hexiao Cheng, “Simulation and Experimental
Analysis on Wireless Energy Transfer Based on Magnetic Resonances”, IEEE Vehicle
Power and Propulsion Conference (VPPC), September 3-5, 2008
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39. References(contd…)
 André Kurs, Aristeidis Karalis, Robert Moffatt, J. D. Joannopoulos, Peter Fisher
and Marin Soljačić, “Wireless Power Transfer via Strongly Coupled Magnetic
Resonances”, Science, June 2007
 T. R. Robinson, T. K. Yeoman and R. S. Dhillon, “Environmental impact of high
power density microwave beams on different atmospheric layers”,
 White Paper on Solar Power Satellite (SPS) Systems, URSI, September 2006
 Richard M. Dickinson, and Jerry Grey, “Lasers for Wireless Power Transmission”
 S.S. Ahmed, T.W. Yeong and H.B. Ahmad, “Wireless power transmission and its
annexure to the grid system”
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40. Thank You!
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