WiTricity - Electricity through Wireless Transmission


Published on

Published in: Technology, Business
No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide

WiTricity - Electricity through Wireless Transmission

  2. 2. Introduction  In our present electricity generation system we waste more than half of its resources. Especially transmission and distribution losses are main concern of the present power technology.  The transmission and distribution system causes a loss of 26% to 30% of energy generated.  The transmission of power without wires is
  3. 3. History of Wireless Power In 1899, Sir Nikola Tesla Proposed a method of Wireless Power Transmission. Nikola Tesla – The Genius He enlighted 200 lamps at the distance of 40 km, Wirelessly ! The efficient midrange power transfer concept is Witricity. In this model source and load are in Magnetic resonance so there is no power loss.
  4. 4. What is WiTricity ? definition is : * “Transmission of energy through the air”. * A system of two electromagnetic resonators coupled mostly through their magnetic fields. ** Cables are going to replaced by WiTricity. Efficient power transfer
  5. 5. Need of Witricity: * Cell phones, i pods, laptop computers are capable of re-charging themselves without ever being plugged in.
  6. 6. The forgotten invention is reborn in 2007 RESONANCE COUPLING  A group of engineers at MIT came up with the idea to use resonant induction to transmit power wirelessly. “Resonance", a phenomenon that causes an object to vibrate when energy of a certain frequency is applied.
  7. 7. Research at MIT * Prof. Soljacic – Another Genius MIT-IBM Collaboration * He did succeed to redesign Tesla’s experiment in safer way. * They had lit up a 60W bulb with a power source at a distance of 7 feet(over 2m) with no wires
  8. 8. Experiment demonstrated at MIT. A 60W light bulb lit from source at a distance of 2m from load.
  9. 9. Electric bulb lightened even when a barrier was kept in between.
  10. 10. Types and Technologies  Near-field techniques  Inductive Coupling  Resonant Inductive Coupling  Air Ionization  Far-field techniques  Microwave Power Transmission (MPT)  LASER power transmission
  11. 11. Inductive coupling   Primary and secondary coils are not connected with wires. Energy transfer is due to Mutual Induction
  12. 12. Cont…      Energy transfer devices are usually air-cored Transformer is an example Wireless Charging Pad(WCP),electric brushes are some examples Nokia Lumia 720 The charging pad (primary coil) and the device(secondary coil) have to be kept very near to each other
  13. 13. RESONANT INDUCTIVE COUPLING  The capacitor and inductor forms the resonator. Charge oscillates between inductor (as magnetic field) and capacitor (as electric field.)  This type of oscillation is called resonance if the reactance's of the inductor and capacitor are equal.
  14. 14. RESONANT INDUCTIVE COUPLING  Resonant transfer works by making a coil ring with an oscillating current.  This generates an oscillating magnetic field.  Because the coil is highly resonant any energy placed in the coil dies away relatively slowly over very many cycles.  But if a second coil is brought near it, the coil can pick up most of the energy before it is lost, even if it is some distance away.
  16. 16. BLOCK DIAGRAM    Oscillator used is an astable multivibrator using 555timer which switches IRFP250 to produce oscillations in the primary coil. Secondary coil kept at a distance resonates at the same frequency and power transfer takes place. Signal received in the secondary is rectified and regulated.
  17. 17. Resonant Inductive Coupling
  18. 18. RESONANT INDUCTIVE COUPLING    Inductive charging uses an electromagnetic field to transfer energy between two objects. Greater distances can be achieved by using resonant inductive coupling. Resonant inductive coupling or electrodynamic induction is the near field wireless transmission between two coils that are tuned to resonate at the same frequency.
  19. 19. 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. 
  20. 20. Far-field energy transfer    Microwave Power Transfer(MPT) Transfers high power from one place to another. Steps: Electrical energy to microwave energy  Capturing microwaves using rectenna  Microwave energy to electrical energy       AC can not be directly converted to microwave energy AC is converted to DC first DC is converted to microwaves using magnetron Transmitted waves are received at rectenna which rectifies, gives DC as the output DC is converted back to AC
  21. 21. LASER transmission     LASER is highly directional, coherent Not dispersed for very long But, gets attenuated when it propagates through atmosphere Simple receiver  Photovoltaic  Cost-efficient cell
  22. 22. Applications  Direct Wireless Power  No device needs wires  For TVs, toasters or any form of Immobile devices  Automatic Wireless Charging  Device with rechargeable batteries charges itself  For any form of mobile device
  23. 23. Some more Applications… *Industrial  would be free of heavy installation of wires and devoid of any hazardous electric shock incidents. *Transportation  Could charge an electric car or automobile.
  24. 24. Wireless power transmission is safe  Human beings or other objects placed between the transmitter and receiver do not hinder the transmission of power.  magnetic fields tend to interact very weakly with the biological tissues of the body, and so are not prone to cause any damage to any living beings.
  25. 25. Advantages  Efficient and reliable power.  Provides solution to the ever increasing demand for power. A solution to reduce e-waste- a more safe environment. A more cost effective methodology for getting electricity to your houses which includes paying less for use of power.  
  26. 26. Disadvantages. For short and mid range transfer system has to be set at the right frequency or there would be no power transfer.  For long range the installation cost is high. 
  27. 27. CONCLUSION Transmission without wires- a reality  Efficient  Low maintenance cost. But, high initial cost  Better than conventional wired transfer  Energy crisis can be decreased  Low loss  In near future, world will be completely wireless 