wireless transmission of power

1. Priyadarshini College of Engineering
(Nagpur)
WIRELESS POWER TRANSMISSION
1

2. 



What is wireless power transmission(WPT)?
Why WPT?
History of WPT
Types of WPT
◦ Techniques to transfer energy wirelessly




Advantages and disadvantages
Applications
Conclusion
References
2

3. 

The transmission of power from one place to
another without using wires, cables or chords
But, the wireless power transmission is made
possible by using various technologies like
microwaves, lasers and EM waves
3

4. 

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%
Wireless Power Transmission
4

5. History of WPT: Tesla’s Expt
 In 1899, Sir Nikola Tesla
Proposed a method of Wireless
Power Transmission.
 As it is in Radiative mode, most
of the Power was wasted and has
less efficiency.
 The
efficient midrange power
transfer concept is Witricity. In
this model source and load are in
Magnetic resonance so there is no
power loss.

6. CONCEPT OF ELECTROMAGNETIC WAVE:
When an electric current passes through a wire, there is an
electric field & magnetic field in the dielectric surrounding
the conductor .
The electric field of a circuit over which energy flows has
three main axes which are mutually perpendicular to each
other:
a. The magnetic field, concentric with the conductor.
b. The lines of electric force, radial to the conductor.
c. The power gradient, parallel to the conductor.
6

7. The Rise Of The Fallen in 2007
RESONANCE COUPLING
 A group of theoretical physicists at MIT came up with the idea to use
resonant induction to transmit power wirelessly led by Dr. Marin Soljacic.
“Resonance", a phenomenon that causes an object to vibrate when
energy of a certain frequency is applied.

8. 8

9.  Reliable
 Efficient
 Fast
 Low
maintenance cost
 Can be used for short-range
or long-range.
9

10. Wireless Power Transmission
2/22/2014
10

11. 
The transfer of energy
◦ Magnetic coupling
◦ Inductive coupling

Simplest Wireless Energy coupling is a
transformer
11

12. 12

13. Electricity
Resonant Magnetic
Coupling
Resonance
Energy/Power
Coupling
Magnetism
Electromagnetism
Magnetic
Induction
13

14. Inductive Coupling:
 It uses magnetic fields that is produced due to current's movement
through- wire. Bending the wire into a coil amplifies the magnetic field.
The more loops the coil makes, the bigger the field will be.
 This is the principle how a transformer works.
Using it an electric toothbrush recharged. It takes three basic steps:
1. Current from the wall outlet flows through a coil inside the
charger, creating a magnetic field. In a transformer, this coil is called
the primary winding.
2. When you place your toothbrush in the charger, the magnetic field
induces a current in another coil, or secondary winding, which
connects to the battery.
3. This current recharges the battery.
14

15. Need of Resonant coupling:
Non-resonant coupled inductors(transformers,)work on the
principle of inductive coupling is of short range power transfer &
requires a magnetic core. Over greater distances the NRI Method is
highly inefficient and wastes the majority of the energy in resistive
losses of the primary coil.
Hence concept of resonant coupling comes where two coils are
tuned to a particular frequency called resonating frequency &
absorb optimal energy.
15

16. Wireless Power Transmission
2/22/2014
16

17. Wireless Power Transmission
2/22/2014
17

18. Comparison with other technologies:
In conventional transformers, for inductive transfer
efficiency around 80% at short range
 in witricity tightly coupled conventional transformers
has efficiency around 90-95% .
In addition, where batteries need periodic maintenance
and replacement, resonant energy transfer can be used
instead. So pollution due to Batteries during their
construction and their disposal is largely avoided.
Wireless Power Transmission
2/22/2014
18

19. Will it harm me?
 Will it harm the environment?
 Will it interfere with important
communication?

NO

20. 





No wires
No e-waste
Need for battery is
eliminated
Efficient energy
transfer
Harmless, if field
strengths under
safety levels
Maintenance cost is
less
Wireless Power Transmission
2/22/2014
20

21. 





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
21

22. 22

23. 23

24. Wireless Power Transmission
2/22/2014
24

25. 






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
Wireless Power Transmission
25

26. 




“Wireless 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”
Wikipedia.
EFY posted articles on WPT.
26

27. Wireless Power Transmission
27