Based on microwaves. it may be useful for project.

1. PRESENTED BY,
A. MUTHULAKSHMI
K. DHIVYALAKSHMI

4. SLIDE PLAN
 WPT -definition
Reason for WPT
History
Components of WPT
Efficiency
Applications
Advantages and Disadvantages
Conclusion

5. WHAT IS WPT?
Wireless power transmission is a concept of transmitting
power without using wires.
The power transmission is based on microwaves from one
place to another in order to reduce transmission and
distribution losses.

6. REASONS FOR WPT
Wireless transmission is useful in cases where
interconnecting wires are inconvenient, hazardous,
or impossible.
The losses occur during the
transmission and distribution of
electrical power.
The percentage of loss is 26%.

7. HISTORY
• Experiments performed between 1888 and 1907 by Nikola
Tesla
• Started efforts on wireless transmission at 1891 in his
“experimental station” at Colorado
• He lighted a small incandescent lamp by
means of a resonant circuit grounded on one
end
• William C. Brown, the pioneer in wireless
power transmission technology
• The idea of Tesla is taken in to research after
100 years by a team led by Marin Soljacic from MIT.

8. COMPONENTS OF WPT
Microwave Generator
• The microwave transmitting devices are classified as
Microwave Vacuum Tubes, Microwave Power Module
(MPM) and Semiconductor Microwave transmitters.
• Magnetron is widely used for experimentation of WPT.
• The highest efficiency over 90% is achieved at 2.45 GHz
among all the frequencies.

9. Transmitting Antenna
• The slotted wave guide antenna, microstrip patch
antenna, and parabolic dish antenna are the most
popular type of transmitting antenna.
• The slotted waveguide antenna is ideal for power
transmission because of its high aperture efficiency
(> 95%) and high power handling capability.

10. Rectenna
• It was first conceived by W.C. Brown in the early of
1960s.
• The rectenna is a passive element consists of
antenna, rectifying circuit with a low pass filter

11. Functional block diagram of WPT system
TRANSMITTING
ANTENNA
MICROWAVE
ON FREE SPACE
SCHOTTKY BARRIER DIODE RECEIVING
ANTENNA
Microwave
Power
Source
Coax-
Waveguide
Adaptor
Waveguide
Circulator
Tuner &
Directional
Coupler
Coax-
Waveguide
Adaptor
Impedance
Matching &
Filter Circuit

12. EFFICIENCY
The efficiency of wireless power is the ratio
between power that reaches the receiver and the
power supplied to the transmitter.
A rectenna may be used to convert the microwave
energy back into electricity.
Rectenna conversion efficiencies exceeding 95%
have been realized.

13. MERITS
Eliminates the high-tension power transmission line
cables, towers and sub stations
cost of transmission and distribution become less.
High efficiency.
No power failure and power theft.
Safer by eliminating the sparking hazard.

14. DEMERITS
The capital cost for practical implementation of WPT seems
to be very high.
Interference of microwave with present communication
systems.

15. Biological Impacts
Common beliefs fear the effect of microwave
radiation.
 But the radiation level is less than radiation from
microwave oven and higher than cellular phone.
Thus public exposure to WPT fields would also be
below existing safety guidelines.

16. Environmental issues
Interferences to Existent Wireless System
Safety on Ground
Interaction with Atmosphere
Interaction with Space Plasmas

17. APPLICATIONS OF WPT
I. Wireless Power Transmission for Electric
Vehicles

18. II. Wireless Power Transmission for Mobile
Phones

19. CONCLUSION
WPT emerges out as the best alternative for efficient power
transmission despite its few drawbacks such as very high
installation cost.
WPT has very high efficiency as the loss during power
transmission is nearly negligible and it acts as boon for the
people of those areas where wired transmission is not
possible.
The power failure due to short circuit and electric faults
would not possible at all.

20. REFERENCE
[1] http://cleantechindia.wordpress.com/2008/07/16/indiaselectricity-
transmission-and-distribution-losses/
[2] Nikola Tesla, My Inventions, Ben Johnston, Ed., Austin, Hart
Brothers, p. 91,1982.
[3] Nikola Tesla, “The Transmission of Electrical Energy Without
Wires as a Means for Furthering Peace,” Electrical World and
Engineer. Jan. 7, p. 21, 1905.
[4] The Electrician (London), 1904).
[5] W.C. Brown, J.R. Mims and N.I. Heenan, “An Experimental
Microwave-Powered Helicopter”, 965 IEEE International
Convention Record, Vol. 13, Part 5, pp.225-235.
[6] Brown., W. C. (September 1984). "The History of Power
Transmission by Radio Waves". Microwave Theory and Techniques, IEEE Transactions
on (Volume: 32, Issue: 9 On page(s): 1230- 1242 + ISSN: 0018-9480).
http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=1132833.