Wireless power transmission involves transmitting power from one place to another without wires. It was first proposed by Nikola Tesla in 1897 using induction techniques. There are two main types: near field technologies like inductive coupling which transfers power over short distances using coils, and far field technologies like microwave power transmission which uses microwaves over longer distances but requires line of sight. While wireless power has advantages like ease of use and low maintenance, it also has disadvantages including distance constraints, high initial costs, and safety concerns over field strengths.

1. Wireless Power Transmission
By: Yogitha R Malkireddy

2. Overview of the topics:
1.What is meant by wireless power
transmission?
2.Reason to go for WPT
3.History of WPT
4.Different Kinds of WPT
5.Advantages
6.Disadvantages
7.Conclusion

3. What is wireless power transmission?
- Transmission of power from one place to another
without using conducting devices/wires.
- Generally this is useful where interconnecting wires are
inconvenient, and hazardous to handle.
- This is achieved by many different methods. It’s also
known as “Witricity”.

4. Why Wireless Power Transmission?
• It is reliable,
• Fast,
• Efficient,
• Low maintenance cost,
• Applicable for both short and long ranges
• And also to reduce the energy losses due to
resistance of conducting wires/transmission lines
during transmission.

5. History:
• The idea of WPT was first proposed by Nikola Tesla
in 1897.
• He is considered as the pioneer of induction
techniques.
• Tesla was successful in transferring energy from
one coil to another.
• He was successful in lighting 200 lamps from a
distance of 40km.
• Later his ideas were taken into consideration and
the phenomenon got named as “Witricity”

6. Recent improvements and achievements in WPT:
In 2007- MIT was the first to demonstrate about wireless power using
resonant near field inductive coupling.
In 2008- Intel achieved wireless power transfer using Inductive
coupling.
Many other charging devices are also invented in recent days for
batteries, iPods and mobiles.
Example: A mouse pad that can send power through distance of
some inches.

7. Energy Coupling Techniques:
The transfer of energy can be done using
- Magnetic Coupling
- Inductive Coupling
Inductive Coupling:
The primary and secondary coils are not in contact with each
other. The transfer of energy takes place due to mutual induction.
*In figure we can observe Transformer
coupling which is inductively coupled.

8. Types of Technologies involved in WPT:
Near Field Technologies:
1. Inductive Coupling
2. Resonant Inductive Coupling
3. Air Ionization
Far Field:
1. Microwave Power Transmission(MPT)
2. LASER Power Transmission
2. Resonant Inductive Coupling:
In this method both resonant and
inductance of the coils interact with each
other.
Resonance generally improves the
interaction between both the coils where
as inductance induces the current.

9. 3. Air Ionization technique:
• This is the toughest technique, because Air ionizes only
when there is high field. (Required field is 2.1MV/m).
• Practically cannot be implemented.
• Natural example with high voltages is:
Lightning
Advantages:
• Less use of wires.
• Shock Proof
• Easy to use
• Portable
• Efficient energy transfer
• Maintenance cost is less
• Harmless if field strengths are under safety levels.

10. Disadvantages:
• Distance constraint
• Field strengths should be taken care all the time
• Initial cost is high
• To implement RIC tuning is difficult
• High frequency must be the supply.

11. Far Field Energy Transfer
1. Microwave Power Transfer: Transfers high
power from one place to another which are in
sight.
- This is like a cyclic process where electrical energy
is converted to microwave. Microwave collected
by rectenna and microwaves are converted to
electrical again.
2. Laser Power Transmission:
• Laser is highly directional.
• Gets attenuated when passed through
atmosphere.

12. Advantages of far field:
- Efficient
- Easy
- Need for grids, substations are eliminated
- Low maintenance cost
- Effective when Line of sight is perfect
- Can reach places which are remote
Disadvantages:
- Need line of sight
- Initial cost is very high
- Radiative, and absorption loss is high
- Interference problem with microwave transmission.
• The disadvantage of MPT is, it cannot convert ac
directly to microwave. First it converts to dc then
using magnetron dc is converted to Microwave.

13. Applications:
1.To charge mobile phones, iPods and
batteries in short distances.
2.The most important advantage I have
observed is for medical applications.
Example: For the people who use pace makers
implanted in their body that runs on a battery.

14. Conclusion:
Since Wireless power transmission is implementable
and cost efficient(even initial costs are high) the
transmission is effective in this method.
Energy losses can be reduced.