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Wireless energy transfer or wireless power is the transmission of electrical energy from a power source to an electrical load without a conductive physical connection. In this paper the technologies available for Wireless Power Transmission (WPT) and its future possible advancements is being discussed to assume its feasibility in actual practices. In our present electricity system much of the power generated is wasted during transmission from power plants to the consumers passing through cables, substations, etc. With WPT the need for inefficient and costly, cables, towers, and substations will be eliminated & so will the power losses, finally reducing the cost of energy. This is one such technology that can make the transmission system highly efficient & economical. One mere demerit of WPT is that it develops reactive power at a small frequency that is very biologically compatible and harmful to environment & living beings on over exposure.
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Wireless Transmission of Electricity
By: Abhinav Goel Tarun Sharma
Avinash
Wireless Transmission of Electricity (Witricity) concept originated during turn between 19th and 20th century. Then scientists who contributed to this technology are – Nickola Tesla William C Brown Bill Brown Hidetsugu Yagi
HISTORY
First scientist to come up with the idea of Wireless Power Transmission(WPT).
Able to light lamps over 25 miles away without using wires (Wardenclyffe tower experiment).
Used oscillators to energize primary coil attached to the power source.
Nikola Tesla (1888)
Induction◦ Electrodynamics◦ Electrostatic
Electromagnetic Radiation◦ Laser◦ Microwaves
Evanescent Wave Coupling
Methods Available for Wireless Power Transmission
Principle: Mutual Induction between isolated coils or conductors. -Electrodynamics (Electromagnetic coupling) -Electrostatic (Capacitive Coupling)
Transformer is a basic example. The main drawback to induction is the short
range. Magnetic field spreads in all directions
wasting a large amount of energy.
Induction
Electricity transmitted by converting it into electromagnetic waves.
Antennas of electronic devices will receive waves converting them back to electrical energy.
Mainly, two types of e.m. waves are used- -Lasers -Microwaves A big disadvantage is that e.m. waves can
harm the environment & even living beings
Electromagnetic RADIATION
Microwave & Laser Transmission
• Microwave– Electrical energy converted
to Microwaves and beamed to a large antenna (Rectenna) that converts it to D.C. electricity.
– More developed– High efficiency up to 85%– Beams is far below the
lethal levels of concentration even for a prolonged exposure
– Cause interference with satellite communication system.
• Laser– Electrical energy
converted to beam fired at a receiving target, (Power Beaming) & is converted back to power.
– Range of 10% to 20% efficiency within a few years
– Conform to limits on eye and skin damage.
– Victim of atmospheric absorption.
In 2006 MIT researchers discovered an efficient method to transfer power.
Transfer power using non-radiative. Electromagnetic energy Resonant Tunnelling.
Does not disturbs communication system. Wastage of energy is small. No need of line of sight between transmitter and
receiver as in lasers. Most efficient way to transmit Power wirelessly
introduced up till now. Negative health effects.
Evanescent Wave Coupling
. Curved coil of wire makes an inductor. A capacitance plate which can hold a charge attaches to each end of the coil. As electricity travels through this coil the coil begins to resonate. Electricity traveling along an e.m. wave can tunnel from one coil
to the other as long as the both have the same resonant frequency.
Electromagnetic energy Resonant Tunnelling
For small portable electronic devices electrical energy can be converted to radio signals and can be transferred to the device which receives radio frequency radiation and converts it to DC electricity that could be stored in a battery for use.
Electrical energy can propagate around the world. Power demands differ at different time, high demands during day and low during night . So, the extra power available during the night could be transmitted to the side of the planet where it is day time.
Ideas to WPT
Merits: Eliminates use of
existing high-tension power transmission line cables, towers and sub stations.
Facilitates transmission of energy on a global scale.
Low Energy costs. The power failure due to
short circuit would never exist.
Power theft would be not possible at all.
Merits & Demerits Demerits
• The Capital Cost for practical implementation of WPT seems to be very high.
• Microwaves interferes with the present communication systems.
• Develops reactive power at a small frequency that is very biologically compatible and harmful to environment & living beings on over exposure.
Wireless transmission is now a reality & is in development.
Will make Transmission system more economical, cheap & reduce pollution.
Merits of this technology overshadow its demerits.
Conclusion
Thank You
