Wireless charging

1. CONTENTS
 Introduction
 What are EVs ?
 Need for EVs.
 Types of charging system for EVs .
 What is wireless charging ?
 Why not wires?
 History.
 Working.
 Construction of roads.
 Advantages & disadvantages.
 Conclusion.
 References.

2. INTRODUCTION
 The eco-friendly vehicle is the global trend in the automobile industry.
 The electrical vehicle (EV) is the most suitable alternative of petroleum
vehicles.
 The large capacity, weight, expensive price, short life time, and charging time
of battery obstruct the commercialization of EV.
 To solve these problems, wireless charging of electric vehicle is
introduceded.

3. WHAT ARE EVS (ELECTRIC VEHICLES) ?
 An electric vehicle (EV) uses one or more electric motors for propulsion.
 An electric vehicle may be powered through a collector system by electricity from off-
vehicle sources, or may be self-contained with a battery or generator to convert fuel to
electricity.
 EVs include road and rail vehicles, surface and underwater vessels, electric aircraft and
electric spacecraft.

4. NEED FOR EVS
 Global Warming / Climate Change.
 Rising Prices.
 Acid Rain.
 Effect on Human Health.
 Impact on Aquatic Life by Oil Spills.

5. TYPES OF CHARGING SYSTEMS
Conductive Charging
 It utilizes connector between
the Electric power source and
vehicle battery.
 This type of charging is utilized
in Residential areas.
Inductive Charging
 Wireless charging coupled with
magnetic resonance to transfer
power from a transmitting pad to
a receiving pad.
Battery Switching
 Depleted EV battery pack
is switched with a fully
charged battery pack in
the switching station.

6. WHAT IS WIRELESS CHARGING ?
 Wireless charging uses an electromagnetic field to transfer energy between two objects
through electromagnetic induction.
 Energy is sent through an inductive coupling to an electrical device, which can then use that
energy to charge batteries or run the device.

7. i. As per studies, most electrical energy transfer is
through wires.
ii. Most of the energy loss is during transmission
iii. On an average, more than 30%
iv. In India, it exceeds 40%

8. HISTORY OF WIRELESS POWER TRANSMISSION
• In 1901, Nikola Tesla was able to transfer energy
from one coil to another coil wirelessly.
• 187 feet tall tower to broadcast energy
• He managed to light 200 lamps from a distance
of 40km.
• Due to shortage of funds, tower did not operate.
• The idea of Tesla is taken in to research after
100 years by a team led by Marin Soljačić from
MIT. The project is named as ‘WiTricity’.

9. HOW IT WORKS:
 Specifically, the technology works by generating 20kHz frequencies into an electromagnetic
field by a power inverter which are embedded.
 Wireless charging Electric Vehicles are built with an on-board pick up device that allows an
electric vehicle to be powered by an underground power line while driving.
 This allows the vehicle to carry 4/5 less battery capacity or weight, because it only requires a
small battery for minimal operations off the power grid.

10. CONSTRUCTION OF A ROAD FOR OLEV
Electric power strips are buried 30 cm deep under the
road surface and connected to the power grid.

12. ADVANTAGES:
 80 % reduced operating cost than equivalent gas powered vehicles.
 Lower maintenance costs than gas powered vehicles .
 Pollution free.
 Zero recharging time and unlimited range (when operating on an grid road).
 Light weight vehicles.
 A number of EVs can be charged at a time.
 Electrically safe.
 Charging is convenient.

13. DISADVANTAGES:
 Initial installation cost is very high.
 Working area is limited.
 Currently the speed is limited to 40 miles per hour.
 power outage might cause the EVs to run out of charge.
 Heat generation is more than traditional charging.
 Complex design.
 Construction of wireless charging road is required

14. CONCLUSION:
Charging electric vehicles wirelessly- a reality.
Low maintenance cost but high initial cost.
Better then conventional wired system.
Energy crisis can be decreased.
Low power loss
In the future world will be completely wireless.

15. REFERENCES
1. Nicola Tesla, “The transmission of electrical energy without wires”, Electrical World and Engineer, March
1905. http://www.tfcbooks.com/tesla/1904-03-05.htm, (acc. Dec. 08)
2. William C. Brown, “The history of power transmission by radio waves”, Microwave Theory and Techniques,
IEEE Transactions, 32(9):1230-1242, September 1984.
3. A.B. Kurs, A. Karalis, R. Moffatt, J.D. Joannopoulos, P.H. Fisher, and M. Soljacic, “Wireless Power Transfer via
Strongly Coupled Magnetic Resonances”, Science, 317, pp. 83-86, (2007).
4. A. Karalis, J.D. Joannopoulos, and M. Soljacic, “Efficient Wireless Non-radiative Mid- range Energy Transfer”,
Ann. Phys., 323, pp. 34-48, (2008); published online April 2007.
5. J.D. Joannopoulos, A. Karalis, and M. Soljacic, “Wireless Non-Radiative Energy Transfer”, U.S. Patent
Numbers 7,741,734; 8,022,576; 8,084,889; and 8,076,800.
6. A. Karalis, A.B. Kurs, R. Moffatt, J.D. Joannopoulos, P.H. Fisher, and M. Soljacic, “Wireless Energy Transfer”,
U.S. Patent Numbers 7,825,543 and 8,097,093.
7. A. Karalis, R.E. Hamam, J.D. Joannopoulos, and M. Soljacic, “Wireless Energy Transfer Including Interference
Enhancement”, U.S. Patent Number 8,076,801.

16. THANKS!