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Pdf witricity


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Pdf witricity

  1. 1. Seminar on WiTricity: Future of Electricity Submitted to: Mr. Abhinav Bansal Assistant Professor Department of ECE Submitted by: Hina Saxena ECE-3rd year Roll no.: 1103331064 Department of electronics & Communication
  2. 2. Contents • What do you mean by WiTricity? • Need of WiTricity • History of Wireless power • Experimental design of WiTricity technology • WiTricity basics • Wireless energy transfer techniques • Working principle of WiTricity • Is WiTricity safe? • WiTricity Applications • Benefits and Advantages • Limitations • References
  3. 3. What is WiTricity • WiTricity is nothing but Wireless Electricity. • Transmission of electrical energy from one object to another without the use of wire is called WiTricity. • Because of the wiTricity, some of the devices won’t require batteries to operate. Cables are going to be replaced by WiTricity
  4. 4. Why we need Witricity • We use Wires..
  5. 5. And we use..
  6. 6. Which sometimes ends as..
  7. 7. Why not wires?? • As per studies, most electrical energy transfer is throughwires. • Most of the energyloss is during transmission • On an average, more than30% • In India, it exceeds by 40% Why not batteries?? Estimated that 40 billionbatteries per year add to the e-waste burden. And of courseits not a good sign.
  8. 8. And this is possible due to WIreless elecTRICITY or WiTricity.. Imagine your cell phones, laptops, i-pods and other power hungry devices getting charged on their own, eliminating the need of plugging in.
  9. 9. History of Wireless power  In late 1890’s, Sir Nikola Tesla proposed the method of wireless power transmission.  In 1899, he was able to light 200 lamps over 25 miles away without using wires.  As it was in radiative mode, most of the power was wasted and less efficiency.  In 2005, Dave Gerding coined the term WiTricity which is being used today.
  10. 10. Built the wardenclyffe tower(Tesla tower) which could broadcast power wirelessly using far-field techniques. Called off as it radiated power into surroundings raising issues of power loss Power theft Health concerns
  11. 11. The forgotten invention is reborn in 2007 The idea of wireless electricity has been around since the early days of the Tesla coil. But thanks to a group of MIT scientists, "WiTricity" (as these scientists call it) is now one step closer to practical reality. 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 . They use concepts of non radiative mid range energy transfer, Resonance, inductive coupling. Efficiency at that point was just approximately 43%.
  12. 12. Experimental design Our experimental scheme consists of two Self-resonant coils. One coil (source coil) is coupled inductively to an oscillating circuit; the other (device coil) is coupled inductively to a resistive load. Self-resonant coils rely on the interplay between distributed inductance and distributed capacitance to achieve resonance.
  13. 13. WiTricity Technology 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 power lights up the bulb. The magnetic field can wrap around the obstacle between power source and capture coil.
  14. 14. Basics of witricity
  15. 15. Fundamentals • Electricityis a general term that encompasses a variety of phenomena resulting from the presence and flow of electric charge. • Magnetism is a force that acts at a distance due to a magnetic field. This field is caused by moving electrically charged particles or is inherent in magnetic objects such as magnet.
  16. 16. • Electromagneticinduction is the production of voltage across a conductor moving through a magnetic field. • Electromagnetism is one of the four fundamental interactions of nature, along with strong interaction, weak interaction and gravitation. It is the force that causes the interaction between electrically charged particles; the areas in which this happens are called electromagnetic fields • Energy/Power Coupling: Energy couplingoccurs when an energy source has a means of transferring energy to another object.
  17. 17. • Resonance : It is the tendency of a system to oscillate with larger amplitude at some frequencies than at others. These are known as the system's resonant frequencies (or resonance frequencies). At these frequencies, even small periodic driving forces can produce large amplitude oscillations. • Resonant Magnetic Coupling: Magnetic coupling occurs when two objects exchange energy through their varying or oscillating magnetic fields. Resonant coupling occurs when the natural frequencies of the two objects are approximately the same.
  18. 18. Types of wireless energy transfer techniques Short range– Inductive coupling Mid range– Resonance Inductive coupling Long range- Electromagnetic Wave Power Transfer
  19. 19. How does Inductive Coupling work?? Inductive coupling works on the principles of electromagnetism: “When a current(electricity) passes through a wire, it generates a magneticfieldperpendicular to the wire. Whena wire is in proximity to a magnetic field, it generates a current in that wire.” Magneticfields decay quickly , making inductive coupling effective only at very short ranges. • Wireless ChargingPad(WCP),electric brushes are some examples • On a WCP, the devices are to be kept, batterywill be automaticallycharged.
  20. 20. How does Resonant Induction work?? • Resonant induction still uses the same principles as magnetic induction (magnetic fields to transfer current) , but it uses resonance to increase the range at which the transfer can efficiently take place. • “Resonance", a phenomenon that causes an object to vibrate when energy of a certain frequency is applied. WiTricity is based on Resonant Inductive coupling..
  21. 21. Long range: Far field power transfer • Far-fieldmethodachieves longer ranges which is much greater than the diameter of device. • These far-field type techniques include Radio & Microwave Power Transmission Techniques & LASER Techniques.
  22. 22. How WiTricity works 1) Power from mains to antenna, which is made of copper. 2) Antenna resonates at a frequency of 10MHz, emitting electromagnetic waves. 3) 'Tails' of energy from antenna 'tunnel' up to 2.5m (8.2ft). 4) Electricity picked up by laptop's antenna, which must also be resonating at 10MHz. Energy used to re-charge device. 5)Energy not transferred to laptop re-absorbed by source antenna. People/other objects not affected as not resonating at 10MHz.
  23. 23. Efficiency Chart of WiTricity It is observedthat efficiency decreases with increasein distance between source coil and load coil.
  24. 24. Is WiTricity Technology safe? • WiTricity’s technology is a non- radiative mode of energy transfer, relying instead on the magnetic near field. • Magnetic fields interact very weakly with biological organisms—people and animals—and are scientifically regarded to be safe. • WiTricity products are being designed to comply with applicable safety standards and regulations.
  25. 25. WiTricity Applications Consumer Electronics • Automatic wireless charging of mobile electronics in home, cars, offices. • Mobile phones, Laptops, Game controllers etc. Industrial Applications • Direct wireless power and communication interconnections at points of use in harsh environments. • In Drilling, Mining, Underwater etc. Transportation • Automatic wireless charging for existing electric vehicle classes. • In Golf carts, Cars etc. Other Applications( Medical devices, Military applications and Robots)
  26. 26. Benefits of WiTricity It will make products : More Convenient: • -No manual recharging or changing batteries. • -Eliminate unsightly, unwieldy and costly power cords. More Reliable: • -Never run out of battery power. • -Reduce product failure rates by fixing the ‘weakest link’: flexing wiring and mechanical interconnects. More Environmentally Friendly: • -Reduce use of disposable batteries. • -Use efficient electric ‘grid power’ directly instead of inefficient battery Charging.
  27. 27. Advantages • Safe, fairly efficient, goodrange • Boon for the devices which uses midrange power • No needof line of sight. • No needof power cables and batteries. • Magnetic fields interact weakly with biological masses (humans), and energy is only transmitted between resonating objects.
  28. 28. Limitations • Transmissions possible only in few meters. • Possibility of “energy theft”. • Efficiency decreases withdistance. • The resonance condition should be satisfied and if any error exists, there is no possibility of power transfer.
  29. 29. Future of Witricity If we apply this idea to the whole city, we might not have to use any wired cable. Moreover, in the future, it would save the material cost, and “WE CAN SAVE THE WORLD, YEAH!!!”
  30. 30. References • • S. Sheik Mohammed, K. Ramasamy, T. Shanmuganantham,” Wireless power transmission – a next generation power transmission system”, International Journal of Computer Applications (0975 – 8887) • An article published in the Science Magazine as “Wireless Power Transfer via Strongly coupled magnetic fields ” • •