1. DEPARTMENT OF
ELECTRICAL AND
1 EEE NMIET 20L14ECTRONICS ENGINEERING

2. WIRELESS POWER TRANSFER
2 EEE NMIT 2014

3. overview
What is wireless power transfer
History
Why not wires..?
Why wireless…?
Principle
Methods of WPT
Merits and demerits
Biological Impact
Application
Conclusion
Reference
3 EEE NMIT 2014

4. What is Wireless power transfer
The transmission of energy from one place to
another without using wires.
Solution is WiTricity.
WPT emerges out as the best alternative for
efficient power transmission.
4 EEE NMIT 2014

5. HISTORY
 Nikola Tesla -Pioneer of induction techniques
 His vision for “World Wireless System”
 In 1894 Nikola Tesla used resonant inductive coupling, also
known as "electro-dynamic induction" to wirelessly light up
incandescent lamps .
1897 he patented a device called
high-voltage resonance transformer or"Tesla coil” capable of
producing
very high voltagesat high frequency.
In 1899 - an aerial tower called Wardenclyffe .
which was meant to be a pilot plant for his “World Wireless
System” to broadcast energy around the globe.
The idea of Tesla is taken in to research after 100 years in 2007.
5 EEE NMIT 2014
Nikola Tesla (1856 - 1943)

6. 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%
Risk of electrical hazards
Complicated wiring structure
Maintenance cost is high.
6 EEE NMIT 2014

7. Why wireless…?
Reliable
Efficient
Fast
Low maintenance cost
Can be used for short-range or long-range.
7 EEE NMIT 2014

8. Method Of WPT
There are mainly 5 method to transfer power
Inductive Coupling
Air Ionization
LASER power transmission
Resonant Inductive Coupling
Microwave Power Transmission (MPT)
8 EEE NMIT 2014

9. For the application of
Short range – INDUCTIVE COUPLING, AIRIONIZATION
9 EEE NMIT 2014
LASER POWER TRANSMISSION
Medium range – RESONANT INDUCTION
Long range power transfer – MICROWAVE POWER
TRANSMISSION

10. Inductive coupling
The principle of mutual induction between two coils
can be used for the transfer of electrical power.
The simplest example is
transformer
where there is no physical contact
between the primary and the secondary
coils
10 EEE NMIT 2014

11. Air ionization
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
11 EEE NMIT 2014

12. Laser power transmission
LASER is highly directional, coherent
Simple receiver
Photovoltaic cell
Cost-efficient
Not suitable for very long
gets attenuated when it propagates through
atmosphere
12 EEE NMIT 2014

13. Need of Resonance coupling
 transformers work on the principle of inductive
coupling, short range power transfer & requires
a magnetic core.
 Over greater distances this method is highly
inefficient and wastes the majority of the energy in
resistive losses of the primary coil.
concept of resonant coupling comes where two
coils are tuned to a particular frequency called
resonating frequency & absorb optimal energy.
13 EEE NMIT 2014

14. Resonant inductive coupling
The capacitor and inductor forms the resonator.
Charge oscillates between inductor (as magnetic
field) and capacitor (as electric field.)
This type of oscillation is called resonance if the
reactance's of the
inductor and capacitor are equal.
14 EEE NMIT 2014

15. BLOCK DIAGRAM RIC
15 EEE NMIT 2014

16. RIC continue…..
This wireless power transmission concept based
on strongly-coupled resonator.
Time taken for energy transfer is less than the
time of loss . So high efficiency.
Since the resonant wavelength is much larger
than the resonators, the field not need of line-of-sight.
This method is safe, since magnetic fields interact
weakly with living organisms..
16 EEE NMIT 2014

17. Microwave Power
Transfer(MPT)
In this method Electrical energy is converted to
microwave energy.
AC is converted to DC first then this DC is
converted to microwaves using magnetron.
This wave is Captured using rectenna and convert
Microwave energy to electrical energy.
THIS Methord is used where transfers high power
from one place to another being in line of sight
usually.
17 EEE NMIT 2014

18. MPT(Continued….
)
Rectenna:
Transmitted waves are received at rectenna.
Consists of mesh of dipoles and diodes
Converts microwave to its DC equivalent
DC is converted back to AC
Usually multi-element phased array
Eg. Solar power satellite
18 EEE NMIT 2014
Solar Power
Satellite

19. Merits of WPT
 Eliminates the existing transmission line cables, towers and
sub stations
 More freedom of choice of both receiver and transmitters
Cost of transmission and distribution become less.
Power could be transmitted to the places where the wired
transmission is not possible.
 Loss of transmission is negligible level.
Safer by eliminating the sparking hazard.
19 EEE NMIT 2014

20. More Reliable/Less Costly
- Never run out of battery power in wireless zones
- Power transfers more efficiently than through wires
 More Convenient
- No more changing batteries
- No messy cords to carry.
 Environmentally Friendly
- Reduces the use of disposable batteries
- Reduces energy loss
20 EEE NMIT 2014

21. Demerits
The Capital Cost for practical implementation of WPT
seems to be very high.
Interference of microwave with present communication
systems
Common belief fears about the effect of microwave
radiation among peoples
When LASERs are used,
21 EEE NMIT 2014
conversion is inefficient
Absorption loss is high

22. Biological Impact
 Institute of Electrical and Electronic Engineers
(IEEE) and by the International Commission on Non-
Ionizing Radiation Protection (ICNIRP).
Experimently prooved that
no radio frequency (RF) electromagnetic fields
causes cancer,
but there is a very small increase a person’s body
temperature or may heat body tissues and may
stimulate nerve and muscle tissues.
22 EEE NMIT 2014

23. Is WiTricity Secure ?
Principle is based on Magnetic Waves.
The question is if Magnetic Waves Secure ?
The answer is we all live in a globe that has already
surrounded by magnetic waves.
Yes it is secure !
23 EEE NMIT 2014

24. Applications
Wireless electricity can be used to power or recharge:
1:Electric Cars
24 EEE NMIT 2014

25. 2,Used to charge Electrical and Electronics gadgets
Mobile phones ,laptops, television,
25 EEE NMIT 2014

26. Schematic representation of the functional benefits of wireless
energy transfer based on HR-WPT.
26 EEE NMIT 2014

27. 3, Medical Devices
Pictures showing two examples of HR-WPT charging
applications in medical
devices: Left ventricular assist device (LVAD) (left)
and pacemakers (right).
27 EEE NMIT 2014

28. 4,home electrification
28 EEE NMIT 2014

29. 6, Led lighting
LED (light emitting diode) lights can be directly powered with
wireless electricity ,which eliminate
the need for batteries enabling architectural lighting
designers to create products that seemingly float in mid-air,
with no power cord.
29 EEE NMIT 2014

30. Defense Systems
Photographs showing several military applications for
highly resonant wireless
charging systems: military robots (left) and soldier
electronics (right).
30 EEE NMIT 2014

31. Future of WiTricity
Think that the city will be covered with WiTricity hot
spots like wi-fi.
which eliminate need of charging batteries or carrying
adapters all around !
Transport system become wirelessly powered
which eliminate fuel engines.
 Which will give rise to the Robotic Technology
they will work for us 24 H 365 days without any
failure.
31 EEE NMIT 2014

32. 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 energy wastage
 In near future, world will be completely
wireless
32 EEE NMIT 2014

33. Reference
Highly Resonant Wireless Power Transfer:
Safe, Efficient, and over Distance by Dr. Morris Kesler
W“iWTririceilteys.s Power Transmission”, Vol No.-45, Electronics For
U –August-2013
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”
White Paper on Solar Power Satellite (SPS)
Systems, URSI, September 2006
Richard M. Dickinson, and Jerry Grey, “Lasers for
Wireless Power Transmission”
David Schneider, “Electrons unplugged”, IEEE
Spectrum, May 2010
33 EEE NMIT 2014

34. 34 EEE NMIT 2014

35. Thanks For
Listening…………….!!!
35 EEE NMIT 2014