This document discusses wireless power transmission (WPT) and its history, mechanisms, applications and advantages/disadvantages. It describes how WPT works through electromagnetic induction or microwave transmission without wires. The document outlines Nikola Tesla's early experiments with WPT in the late 1800s and discusses modern implementations like transferring power to electric vehicles or using solar power satellites to beam energy from space. While WPT could address energy losses during transmission and power remote areas, high initial costs remain a challenge to widespread adoption.

1. Wireless power
transmission
Presented by :-
Rubima
UE114049
BE-EEE( 7th sem)

2. Why WPT?
• One of the major issues in power system is the losses occurring during the
transmission and distribution of electrical power.
• The percentage of loss of power during transmission and distribution is
approximated as 26%.
• The main reason for power loss during transmission and distribution is
the resistance of wires used in grid.
• According to the World Resources Institute (WRI), India’s electricity grid
has the highest transmission and distribution losses in the world – a
whopping 27-40%.
• Tesla has proposed methods of transmission of electricity using
electromagnetic induction.

3. What is WPT?
• As the word wireless means “without wire”.
• Wireless energy transfer or wireless power is the transmission of electrical
energy from a power source to an electric load without interconnecting
man made conductors.
• Wireless transmission is useful in cases where interconnecting wires are
inconvenient, hazardous or impossible.

4. 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 Soljačić from MIT

5. How safe is WPT?
• Human beings or other objects placed between the
transmitter and receiver do not hinder the transmission of
power.
• Magnetic field tend to interact very weakly with the
biological tissues of the body, and so are not prone to cause
any damage to any living being

6. Microwave Transmission
• Microwave transmission refers to the technology of
transmitting information by the use of radio waves whose
wavelengths are conveniently measured in small numbers of
centimeters; these are called microwaves.
• Radio spectrum ranges across frequencies of roughly 1.0
gigahertz(GHz) to 30GHz.
• Corresponds to wavelength from 30 centimeters down to
1.0cm.

7. Microwave Power Transfer
• 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

8. MPT cont…
 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

9. Building Blocks for MWPT
• A converter for converting DC to Microwave frequency.
• Antenna for transmission of the generated microwave.
• A rectifying antenna (RECTENNA) for receiving the microwave
beam and converting back into DC.

10. Magnetrons
 A Magnetrons is a high powered vaccum tube that generates
that generates non -consistent microwaves
with built in resonators or by special
oscillators or solid state devices to control the frequency.
 The electromagnetic energy created from a magnetron can
travel at the speed of light

11. Semiconductor Amplifier
 It generate low power microwave with a low voltage
 It is easy to control a phase and amplitude
 Semiconductor device for microwave circuits are
FET,HBT,HEMT.
 Material for semiconductor device
• Si -lower frequency
• GaAs-higher frequency

12. Antennas
 Antennas can be applied for both the MPT & Communication
system.
 Fixed target of the MPT system we use large parabolic
antenna
 Moving target we use phased array antenna.
 SPS is designed with phased array antenna.

14. Rectenna
 Rectifying circuit and antenna
 Receive and rectify a microwave power to DC
 Passive element
 Ideally 100% of the received microwave power is
converted to DC power

16. Solar Power Satellites
• Solar Power Satellites (SPS) have proposed to collect solar
energy in space and beam it down to the Earth.
• Solar energy is captured using photocells
• Each SPS may have 400 million photocells
• Transmitted to earth in the form of microwaves/LASER
• Using rectenna/photovoltaic cell, the energy is converted to
electrical energy
• Efficiency exceeds 95% if microwave is used.

17. Why use SPS ?
There is no air in space, so the satellites would
receive somewhat more intense sunlight, 3 times
stronger than on the surface.
unaffected by weather.
The SPS concept is simpler than most power
systems here on earth.
 it can be collected 24 hours per day .
( since there are no clouds or night in high Earth
orbit).
SPS does not use up valuable surface area on the
Earth

18. How sps works?

19. Four basic steps to convert
sunlight into electricity
• Capture solar energy in space and convert it to electricity
• Transform the electricity to radio frequency energy and
transmit it to Earth
• Receive the radio frequency energy on Earth and convert it
back to electricity
• Provide the electricity to the utility grid

20. Advantages
• 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
• Zero fuel cost

21. Disadvantages
• The Capital Cost for practical implementation of WPT seems
to be very high.
• Interference of microwave with present communication
systems.
• Common belief fears the effect of microwave radiation.
• initial cost is high.
• Geosynchronous satellites would take up large sections of
space

22. Applications
• Near-field energy transfer
– Electric automobile charging
• Static and moving
– Consumer electronics
– Industrial purposes
• Harsh environment
• Far-field energy transfer
– Solar Power Satellites
– Energy to remote areas
– Can broadcast energy globally (in future)

23. 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

24. Thanks…