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witricity WPT


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wireless power transmission

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witricity WPT

  1. 1. WIRELESS POWER TRANSMISSION By Surya muttamsetty Ravi kiran
  2. 2. AT A GLANCE • What is wireless power transmission? • History behind WPT • Concept of electro magnetic induction and resonance • Types of WPT’s • whether it is virtual concept or existing • Advantages and Disadvantages • Applications and Conclusions
  3. 3. WHAT IS MEANT BY WPT? • The transmission of energy from one place to another without using wires which is also known as “WiTricity”. • Generally conventional energy is transferred using copper wires which results in large Copper loss. • But now-a-days this wireless transmission is made possible in using various technologies based on Resonant frequency ,Inductive coupling etc.
  4. 4. WHAT IS THE NEED OF WPT? • As per studies, most electrical energy transfer is through wires. • Most of the energy loss is during transmission as copper losses • On an average, more than 30% • In India, it exceeds 40%  Billions, trillions of $ is spend on wires and in their installation.  Waste management a challenge in 21 century.  40 billion disposal batteries added to e-waste every year.  PVC is non-biodegradable.
  5. 5. HISTORY  In 1891, 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. • In 2005, Dave Gerding coined the term WiTricity which is being used today. • Forgotton invention was reborn in 2007
  6. 6. A BRIEF HISTORY OF NIKOLA TESLA EXPERIMENT!!! • In 1891, Nikola Tesla invented a type of resonant transformer called the Tesla coil, which was used to generate very high voltage, low current, and high frequency alternating electricity. He experimented with a large variety of coils and configurations, one of which is as:
  7. 7. CONT… • In1899,Tesla achieved a major breakthrough in his work at Colorado by transmitting 100 million volts of electric power wirelessly over a distance of 26 miles to light up a bank of 200 light bulbs and run one electric motor.
  8. 8. LIMITATION OF TESLA’S COIL • A Tesla Coil produces high voltage electric arcs. These arcs cause permanent damage to electrical devices on contact • Tesla coils also destroy hearing aids and cardiac pacemakers in their vicinity.
  9. 9. • RESONANCE INDUCTIVE COUPLING  Two objects having same resonating frequency and in Magnetic resonance at Strongly coupled regime tend to exchange energy , while dissipating relatively little energy to the extraneous off-resonant objects.  The equipment used is sometimes called a resonant or resonance transformer.
  10. 10. • Consider two self resonating copper coils of same resonating frequency with a diameter 20 inches each. One copper wire is connected to the power source , while the other copper wire is connected to the device. DETAILED PRINCIPLE
  11. 11. TYPES AND TECHNOLOGIES OF WPT • Near-field techniques  Inductive Coupling  Resonant Inductive Coupling  Air Ionization • Far-field techniques  Microwave Power Transmission (MPT)  LASER power transmission
  12. 12. ELECTRO MAGNETIC INDUCTIVE COUPLING  It is based on the FARADAY’S LAW OF ELECTROMAGNETIC INDUCTION  Make use of coils. The coils are not connected through wire or any other kind of material.  Transfer of energy is due to mutual induction.  Its based on the concept :- that an oscillating electric field produces magnetic field and an oscillating magnetic field produces oscillating electric field
  13. 13. RESONANT INDUCTIVE COUPLING Same inductive coupling(EMI) concept but the coils here operate at their resonating frequency. Inductance induces current. Resonance makes both the coil to operate at same frequency. Fields are non-radiative in nature.
  14. 14. RIC VS INDUCTIVE COUPLING RIC is highly efficient RIC has much greater range than inductive coupling RIC is directional when compared to inductive coupling RIC can be one-to-many. but usually inductive coupling is one-to-one Devices using RIC technique are highly portable
  15. 15. AIR IONIZATION • Toughest technique under near-field energy transfer techniques • Air ionizes only when there is a high field • Needed field is 2.11MV/m • Natural example: Lightening • Not feasible for practical implementation
  16. 16. ADVANTAGES OF NEAR FIELD TECHNOLOGY  For short range transmission  Aims low power transmission  Need for battery is eliminated  Efficient energy transfer using RIC  Harmless, if field strengths under safety levels  Maintenance cost is less
  17. 17. DISADVANTAGES OF NEAR FIELD TECHNOLOGY  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
  18. 18. APPLICATION OF NEAR FIELD TECHNNOLOGY  Electric automobile charging  Consumer electronics  Industrial purposes  Sharing information
  19. 19.  Microwave Power Transmission (MPT)  LASER Power Transmission  Solar power Satellite(SPS) FAR FIELD ENERGY TRANSMISSION  Aims high power transmission  For long range of transmission  Require line of sight  Radiative in nature
  20. 20. MICROWAVE POWER TRANSMISSION (MPT) Transfers high power from one place to another.  Two places being in line of sight usually. Electrical energy converted to microwave energy using magnetron. Capturing microwave using retina. Conversion of microwave energy into electrical energy. Transmission of electrical energy.
  21. 21. LASER POWER TRANSMISSION LASER is highly directional and coherent But, gets attenuated when it propagates through atmosphere Simple receiver • Photovoltaic cell Cost-efficient
  22. 22.  Satellites are placed in geostationary orbit  Solar energy is captured using photocells  Each SPS may have 400 million photocells  Transmitted to earth in the form of microwaves/LASER  Using rectenna/photovoltaic cell, the energy is converted to electrical energy  Efficiency exceeds 95% if microwave is used.
  23. 23. ADVANTAGE OF FAR FIELD TECHNIQUE  Efficient,Easy  Need for grids, substations etc are eliminated  More effective when the transmitting and receiving points are along a line-of- sight
  24. 24. ADVANTAGES & DISADVANTAGES OF FAR FIELD TECHNIQUE Advantages  Efficient, Easy  Need for grids, substations etc are eliminated  More effective when the transmitting and receiving points are along a line-of-sight Disadvantages  Needs line-of-sight  Initial cost is high  When LASERs are used,  conversion is inefficient  Absorption loss is high  When microwaves are used,  interference may arise  Needs positioning and GPS systems.
  25. 25. The Brain behind WiTricity? • Prof. Marin Soljacic from Massachusetts Institute of Technology (MIT), is the one who has proved that magnetic coupled resonance can be utilized in order to transfer energy without wires. • He used Michael Faraday's principle of electromagnetic induction (1831) came up with WiTricity.
  26. 26. • Direct Wireless Power • No device needs wires • Immobile devices • Automatic Wireless Charging • Device with rechargeable batteries • charges itself • Mobile device • Used in and out of range of its WiTricity power source WITRICITY APPLICATIONS
  27. 27. • Consumer Electronics • Industrial • Transportation • Miscellaneous SOME MORE APPLICATIONS…….
  28. 28. • Safe, fairly efficient, good range: • Magnetic fields interact weakly with biological masses (humans), • Efficiency can be increased with time, most of the 60% lost is from heat radiated from the coils. • Theoretically one stationary coil in a room could power multiple devices with receiving coils. • No more messy wires, and with widespread enough use it could even eliminate costly batteries. ADVANTAGES:
  29. 29.  The resonance condition should be satisfied and if any error exists, there is no possibility of power transfer. If there is any possibility of very strong ferromagnetic material presence causes low power transfer due to radiation. LIMITATIONS
  30. 30. • MIT's WiTricity is only 40 to 45% efficient and they have to be twice as efficient to compete with the traditional chemical batteries. • Aim is to get a robotic vacuum or a laptop working, charging devices placed anywhere in the room • The researchers have said that in another five years time, they will come up with a WiTricity system for commercial use. WHAT'S THE FUTURE OF WITRICITY?
  31. 31. MAY BE IN FUTURE
  32. 32. 1. An article published in the Science Magazine as “Wireless Power Transfer via Strongly Coupled Magnetic Resonances” by Andre kurs, Science 317, 83(2007); Dol:10.1126/ science.1143254. 2. H. Haus , “Waves and Fields in Optoelectronics”, Prentice hall Publishers, Englewood 3. 4. “Efficient Non-Radiative Midrange Energy Transfer” by Aristeidies karalis, Marlin Soljacic. 5. Nikola Tesla, My Inventions, Ben Johnston, Ed., Austin, Hart Brothers, p. 91,1982. 6. Thomas F. Valone, “ Tesla’ s Wireless Energy... For the 21st Century!!! One Step Beyond Direct TV!!!” Extra Ordinary Technology, 1, no. 4, Oct / Nov / Dec 2003. 7. James O. McSpadden, “ Wireless Power Transmission Demonstration”, Texas A&M University, June, 1997. 8. Charych Arthur (Setauket, NY), “ System and method for wireless electrical power transmission”, Patent No. 6,798,716, September 28, 2004. 9. Joe T. Howell, et. al , “Advanced receiver / converter experiments for laser wireless power transmission”5th. Wireless transmission conference, pp 1-8, Garanda, Spain,2004. BIBLIOGRAPHY