Why do we need wirelesselectricity??? The ever increasing power demand The need of electricity in every nook and corner of the world The demand of eco-friendly power Requirement of efficient and reliable power To reduce dependence on wires and batteries
History of Wireless Power: 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. Tesla was able to transfer energy from one coil to another coil He managed to light 200 lamps from a distance of 40km The idea of Tesla is taken in to research after 100 years by a team led by Marin Soljacic from MIT. The project is named as „WiTricity‟.
Tesla’s ingenious design for the wireless transmission of energy
The Witricity Team1 In 2007,6 MIT members headed by Marin Soljacic were able to successfully transmit power to a bulb within a distance of 2m at a freq of 9.9MHz using concepts of non radiative mid range energy transfer Resonance inductive coupling Efficiency at that point was just approximately 43%
Experimental Design: Our experimental scheme consists of two Self-resonantcoils. One coil (source coil) is coupled inductively to anoscillating circuit; the other (device coil) is coupledinductively to a resistive load. Self-resonant coils rely on theinterplay between distributed inductance and distributedcapacitance to achieve resonance.
Power source is connected to ac power. Bulb is connected to capture device. Blue lines represent the magnetic near field induced by the power source.Yellow lines represent the flow of energy from the source to the capture coil. This powers light bulb. The magnetic field can wrap around the obstacle between power source and capture coil.
electricity Electro magnetism magnetism Magnetic basics induction Resonant magnetic coupling8 resonance Energy coupling
•Electricity is a general term thatencompasses a variety ofphenomena resulting from thepresence and flow of electriccharge.•Magnetism is a force that acts at adistance due to a magnetic field.This field is caused by movingelectrically charged particles or isinherent in magnetic objects suchas magnet.
•Electromagnetic induction is theproduction of voltage across aconductor moving through amagnetic field.•Electromagnetism is one of thefour fundamental interactions ofnature, along with stronginteraction, weak interaction andgravitation. It is the force thatcauses the interaction betweenelectrically charged particles; theareas in which this happens arecalled electromagnetic fields•Energy/Power Coupling: Energycoupling occurs when an energysource has a means oftransferring energy to anotherobject
•Resonance :is the tendency of asystem to oscillate with largeramplitude at some frequencies thanat others. These are known as thesystems resonant frequencies (orresonance frequencies). At thesefrequencies, even small periodicdriving forces can produce largeamplitude oscillations•Resonant Magnetic Coupling:Magnetic coupling occurs when twoobjects exchange energy throughtheir varying or oscillating magneticfields. Resonant coupling occurswhen the natural frequencies of thetwo objects are approximately thesame.
Types of wireless energy transfertechniques are:- Short range– Inductive coupling Mid range– Resonance Inductive coupling Long range-Electromagnetic Wave Power Transfer
•Inductive Coupling is a method forshort range wireless energytransfer.•Inductive coupling works on theprinciples of electro magneticinduction.• Its range can vary, but it’s oftenvery short.Wireless electricity makes useof the concept-“Oscillating electric fieldproduces magnetic field andoscillating magnetic fieldproduces electric field”.
Resonant Inductive1 CouplingUses almost the sameconcept as Inductivecoupling just that the coilsoperate at resonantfrequency leading toefficient transfer of energyover a larger distance
LONG RANGE: FAR-FIELD POWER TRANSFER Far-field method achieves longer ranges which is much greater than the diameter of device. These far-field type techniques include Radio & Microwave Power Transmission Techniques & LASER Techniques.
Block diagram for witricity mechanism
WITRICITY ENABLED ROOM
APPLICATIONSCONSUMER ELECTRONICS Automatic wirelesscharging of mobileelectronics in home, car,office,...while devices are inuse and mobile. Direct wireless poweringof stationarydevices…eliminatingexpensive custom wiring,unsightly cables and “wall-wart” power supplies.
Transportation•Automatic wireless charging forexisting electric vehicle classes:golf carts, industrial vehicles.•Automatic wireless charging forfuture hybrid and all-electricpassenger and commercialvehicles, at home, in parkinggarages, at fleet depots, and atremote kiosks.•Direct wireless powerinterconnections to replacecostly vehicle wiring harnessesand slip rings.
Other Applications•Direct wireless powerinterconnections and automaticwireless charging for implantablemedical devices (ventricular assistdevices, pacemaker, defibrilator, etc).•Automatic wireless charging and forhigh tech military systems (batterypowered mobile devices, covertsensors, unmanned mobile robots andaircraft, etc).•Direct wireless powering andautomatic wireless charging of smartcards.•Direct wireless powering andautomatic wireless charging ofconsumer appliances, mobile robots,etc.
WE CAN REDUCE Trillion Of Towers which are Around UsProduction of 40 Billion Disposable Batteries / Yr can be reduced 22
WiTricity’s technology is a non-radiative mode of energy transfer,relying instead on the magneticnear field. Magnetic fields interactvery weakly with biologicalorganisms—people and animals—and are scientifically regarded tobe safe. WiTricity products arebeing designed to comply withapplicable safety standards andregulations.
ADVANTAGES No need of line of sight. No need of power cables and batteries. Does not interfere with radio waves. Wastage of power is less. Negative health implications. Highly efficient than electromagnetic induction. Less costly 24
Wireless power transmission can be possible only in few meters. Efficiency is only about 40%. 25