Transcript seminar on wireless energy transfer

SEMINAR ON
WIRELESS ENERGY TRANSFER
www.fakengineer.com
What is Wireless Energy Transmission?
• Wireless energy transfer or wireless power is the
transmission of electrical energy from a power source to
an electrical load without interconnecting wires.
• Needs-To energize satellites, electronic gadgets
-To reach the unreachable places
-To use power efficiently lost during transmission
TYEPS
• There are 3 major types(depending on ranges)
– Short range; Electromagnetic induction
– Medium range;Coupled Magnetic Resonance
– Long range; Electromagnetic Wave Power Transfer
Electromagnetic induction
• It is of two types –
- Electrodynamic induction method or inductive
coupling.
- Electrostatic induction method or capacitive coupling
• This method is restricted to very short range
approxmately 1/6 of wavelength
Inductive Coupling
• Non-resonant coupling->
• Inductive coupling works on the principles of
Electromagnetism .
• When a current (electricity) passes through a
wire, it generates a magnetic field perpendicular
to the wire. This effect can be magnified through
coiling the wire. When a wire is in proximity to a
magnetic field, it generates a current in that wire
• Here Z depends on resistance,
inductance, and importantly on
the value of k which depends
on distance.
•Hence power transfer
efficiency depends on distance
• Inductive
coupling is used
for wireless
charging of
electronic
devices, RadioFrequency
Identification
(RFID) tags,
induction heater
Coupled Magnetic Resonances
• Resonant induction still uses the same principles as
magnetic induction (magnetic fields to transfer current),
but it uses resonance to increase the range at which the
transfer can efficiently take place.
• In this method efficiency can be increased by making
Z=r and suitably choosing reactive elements.
• Here efficiency can go upto 40%.
• This technique can used inside a room to energize
different Electrical components.
• Magnetic fields interact weakly with biological masses
(humans), and energy is only transmitted
between resonating objects
Example->
Here, the technique wirelessly
powers an LCD TV in a
prototype demonstrated by
Haier Group Co. (Qingdao,
China) at CES 2010.
Microwave Power Transfer
• Microwave Power Transfer (MPT) is a form of wave
power transfer that, obviously, sends energy
through the air in the form of microwaves (other
forms can use lasers and visible light).
• MPT has a range miles longer than its inductive
counterparts, and it’s being investigated as a
way to beam power to space or vice versa
Working principle
• First, microwaves are converted from DC power, and
sent via a large transmitter. On the other end, the are
caught” by an even larger receiver and converted to AC
power.
• Here disk shaped rectifying antenna or “rectenna” is
used whose conversion efficiency is more than 95%.
• These type of transmission can be helpful to energize
satellites, aircrafts and long distance power transfer .
Drawbacks->
• microwaves has the difficulty that for most space
applications the required aperture sizes are very large
due to diffraction limiting antenna directionality.
• These sizes can be somewhat decreased by using shorter
wavelengths, although short wavelengths may have
difficulties with atmospheric absorption and beam
blockage by rain or water droplets.
• human electromagnetic exposure safety also a matter of
concern here.
Laser method
• In the case of electromagnetic
radiation closer to visible region of
spectrum (10s of microns 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 "powerbeaming"
because the power is beamed at a
receiver that can convert it to usable
electrical energy.
• Advantages->
• no radio-frequency interference .
• compact size of photovoltaic cell, control of access.
• It also provide narrow beam cross section for
transmission over long distance.
• Disadvantages->
• photovoltaic cells have only 40%-50% conversion
efficiency.
• this method requires a direct line of sight
communication.
• Atmospheric absorption causes losses.
CONCLUSION• Wireless power solutions today provide hope for
additional freedoms in the future, but many hurdles still
stand in the way. Magnetic induction, resonant
induction, and electromagnetic wave power transmission
all have applications that could revolutionize the way we
live and use electricity.
REFERENCES• 1.C. G. Kim, D. H. Seo, J. S. You, J. H. Park, and B. H. Cho,
“Design of a contactless battery charger for cellular phone,”
IEEE Trans. Ind. Electron., vol. 48, No. 6, pp. 1238-1247,
December 2001.
• 2. G. B. Joung and B. H. Cho, “An energy transmission system
for an artificial heart using leakage inductance compensation
of transcutaneous transformer,” IEEE Trans. Power
Electron., vol. 13, pp. 1013-1022, November 1998.
• 3. T. Sekitani, M. Takamiya, Y. Noguchi, S. Nakano, Y. Kato,
T. Sakurai, and T. Someya, “A large-area wireless powertransmission sheet using printed organic transistors and
plastic MEMS switches,” Nature Mater., vol. 6, pp. 413-417,
June 2007.
• 4. Z. N. Low, R. A. Chinga, R. Tseng, and J. Lin, “Design and
test of a high-power high-efficiency loosely coupled planar
wireless power transfer system,” IEEE Trans. Ind. Electron.,
vol. 56, No. 6, pp. 1801-1812, May 2009.
• 5. Circuit Analysis of Wireless Power Transfer by “Coupled
Magnetic Resonance” F.Z. Shen1, W.Z. Cui2, W. Ma2, J.T.
Huangfu1*, L.X. Ran11 Department of Information and
Electronic Engineering, Zhejiang University, Hangzhou
310027, China 2Xi’an Institute of Space Radio Technology,
Xi’an 710000, China
• 6. Circuit Model Based Analysis of a Wireless Energy
Transfer System via Coupled Magnetic Resonances
Sanghoon Cheon, Yong-Hae Kim, Seung-Youl Kang, Myung
Lae Lee, Jong-Moo Lee, and Taehyoung Zyung
• 7. IEEE Vehicle Power and Propulsion Conference (VPPC),
September 3-5, 2008, Harbin, China 978-1-4244-18497/08/$25.00○C 2008 IEEE Simulation and Experimental
Analysis on Wireless Energy Transfer Based on Magnetic
resonance.