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Ppt seminar

  1. 1. Wireless Power Transmission Presented by Rakesh K.K. 4NM07EC080 Department of Electronics and Communication Engineering NMAM Institute of Technology, Nitte
  2. 2. Overview• What is wireless power transmission(WPT)?• Why is WPT?• History of WPT• Types of WPT – Techniques to transfer energy wirelessly• Advantages and disadvantages• Applications• Conclusion• References3/7/2013 Wireless Power Transmission 2
  3. 3. What is WPT?• The transmission of energy from one place to another without using wires• Conventional energy transfer is using wires• But, the wireless transmission is made possible by using various technologies3/7/2013 Wireless Power Transmission 3
  4. 4. Why not wires?• As per studies, most electrical energy transfer is through wires.• Most of the energy loss is during transmission • On an average, more than 30% • In India, it exceeds 40%3/7/2013 Wireless Power Transmission 4
  5. 5. Why WPT? • Reliable • Efficient • Fast • Low maintenance cost • Can be used for short-range or long- range.3/7/2013 Wireless Power Transmission 5
  6. 6. History • Nikola Tesla in late 1890s • Pioneer of induction techniques • His vision for “World Wireless System” • The 187 feet tall tower to broadcast energy • All people can have access to free energy • Due to shortage of funds, tower did not operate3/7/2013 Wireless Power Transmission 6
  7. 7. History (contd…)• 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 Soljačid from MIT. The project is named as ‘WiTricity’.3/7/2013 Wireless Power Transmission 7
  8. 8. Energy Coupling• The transfer of energy – Magnetic coupling – Inductive coupling• Simplest Wireless Energy coupling is a transformer3/7/2013 Wireless Power Transmission 8
  9. 9. Types and Technologies of WPT• Near-field techniques Inductive Coupling Resonant Inductive Coupling Air Ionization• Far-field techniques Microwave Power Transmission (MPT) LASER power transmission3/7/2013 Wireless Power Transmission 9
  10. 10. Inductive coupling• Primary and secondary coils are not connected with wires.• Energy transfer is due to Mutual Induction3/7/2013 Wireless Power Transmission 10
  11. 11. Inductive coupling (contd…) • Transformer is also an example • Energy transfer devices are usually air-cored • Wireless Charging Pad(WCP),electric brushes are some examples • On a WCP, the devices are to be kept, battery will be automatically charged.3/7/2013 Wireless Power Transmission 11
  12. 12. Inductive coupling(contd…)• Electric brush also charges using inductive coupling• The charging pad (primary coil) and the device(secondary coil) have to be kept very near to each other• It is preferred because it is comfortable.• Less use of wires• Shock proof3/7/2013 Wireless Power Transmission 12
  13. 13. Resonance Inductive Coupling(RIC) • Combination of inductive coupling and resonance • Resonance makes two objects interact very strongly • Inductance induces current3/7/2013 Wireless Power Transmission 13
  14. 14. How resonance in RIC? • Coil provides the inductance • Capacitor is connected parallel to the coil • Energy will be shifting back and forth between magnetic field surrounding the coil and electric field around the capacitor • Radiation loss will be negligible3/7/2013 Wireless Power Transmission 14
  15. 15. Block diagram of RIC3/7/2013 Wireless Power Transmission 15
  16. 16. An example3/7/2013 Wireless Power Transmission 16
  17. 17. WiTricity • Based on RIC • Led by MIT’s Marin Soljačid • Energy transfer wirelessly for a distance just more than 2m. • Coils were in helical shape • No capacitor was used • Efficiency achieved was around 40%3/7/2013 Wireless Power Transmission 17
  18. 18. WiTricity (contd…)3/7/2013 Wireless Power Transmission 18
  19. 19. WiTricity… Some statistics • Used frequencies are 1MHz and 10MHz • At 1Mhz, field strengths were safe for human • At 10MHz, Field strengths were more than ICNIRP standards3/7/2013 Wireless Power Transmission 19
  20. 20. WiTricity now… • No more helical coils • Companies like Intel are also working on devices that make use of RIC • Researches for decreasing the field strength • Researches to increase the range3/7/2013 Wireless Power Transmission 20
  21. 21. 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 portable3/7/2013 Wireless Power Transmission 21
  22. 22. 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 implementation3/7/2013 Wireless Power Transmission 22
  23. 23. Advantages of near-field techniques • No wires • No e-waste • Need for battery is eliminated • Efficient energy transfer using RIC • Harmless, if field strengths under safety levels • Maintenance cost is less3/7/2013 Wireless Power Transmission 23
  24. 24. Disadvantages• 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• Air ionization technique is not feasible3/7/2013 Wireless Power Transmission 24
  25. 25. Far-field energy transfer• Radiative• Needs line-of-sight• LASER or microwave• Aims at high power transfer• Tesla’s tower was built for this3/7/2013 Wireless Power Transmission 25
  26. 26. Microwave Power Transfer(MPT) • Transfers high power from one place to another. Two places being in line of sight usually • Steps: – Electrical energy to microwave energy – Capturing microwaves using rectenna – Microwave energy to electrical energy3/7/2013 Wireless Power Transmission 26
  27. 27. MP T (contd…)• 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 AC3/7/2013 Wireless Power Transmission 27
  28. 28. LASER transmission • LASER is highly directional, coherent • Not dispersed for very long • But, gets attenuated when it propagates through atmosphere • Simple receiver – Photovoltaic cell • Cost-efficient3/7/2013 Wireless Power Transmission 28
  29. 29. Solar Power Satellites (SPS) • To provide energy to earth’s increasing energy need • To efficiently make use of renewable energy i.e., solar energy • SPS are placed in geostationary orbits3/7/2013 Wireless Power Transmission 29
  30. 30. SPS (contd…)• 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.3/7/2013 Wireless Power Transmission 30
  31. 31. Rectenna• Stands for rectifying antenna• Consists of mesh of dipoles and diodes• Converts microwave to its DC equivalent• Usually multi-element phased array3/7/2013 Wireless Power Transmission 31
  32. 32. Rectenna in US• Rectenna in US receives 5000MW of power from SPS• It is about one and a half mile long3/7/2013 Wireless Power Transmission 32
  33. 33. Other projects• Alaska’21• Grand Bassin• Hawaii3/7/2013 Wireless Power Transmission 33
  34. 34. LASER vs. MPT• When LASER is used, the antenna sizes can be much smaller• Microwaves can face interference (two frequencies can be used for WPT are 2.45GHz and 5.4GHz)• LASER has high attenuation loss and also it gets diffracted by atmospheric particles easily3/7/2013 Wireless Power Transmission 34
  35. 35. Advantages of far-field energy transfer• Efficient• Easy• Need for grids, substations etc are eliminated• Low maintenance cost• More effective when the transmitting and receiving points are along a line-of-sight• Can reach the places which are remote3/7/2013 Wireless Power Transmission 35
  36. 36. Disadvantages of far-field energy trasnfer• Radiative• 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 – FRIED BIRD effect3/7/2013 Wireless Power Transmission 36
  37. 37. Applications• Near-field energy transfer – Electric automobile charging • Static and moving – Consumer electronics – Industrial purposes • Harsh environment• Far-field energy transfer – Solar Power Satellites – Energy to remote areas – Can broadcast energy globally (in future)3/7/2013 Wireless Power Transmission 37
  38. 38. 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 wireless3/7/2013 Wireless Power Transmission 38
  39. 39. References• S. Sheik Mohammed, K. Ramasamy, T. Shanmuganantham,” Wireless power transmission – a next generation power transmission system”, International Journal of Computer Applications (0975 – 8887) (Volume 1 – No. 13)• Peter Vaessen,” Wireless Power Transmission”, Leonardo Energy, September 2009• C.C. Leung, T.P. Chan, K.C. Lit, K.W. Tam and Lee Yi Chow, “Wireless Power Transmission and Charging Pad”• David Schneider, “Electrons unplugged”, IEEE Spectrum, May 2010• Shahrzad Jalali Mazlouman, Alireza Mahanfar, Bozena Kaminska, “Mid- range Wireless Energy Transfer Using Inductive Resonance for Wireless Sensors”• Chunbo Zhu, Kai Liu, Chunlai Yu, Rui Ma, Hexiao Cheng, “Simulation and Experimental Analysis on Wireless Energy Transfer Based on Magnetic Resonances”, IEEE Vehicle Power and Propulsion Conference (VPPC), September 3-5, 20083/7/2013 Wireless Power Transmission 39
  40. 40. References(contd…)• André Kurs, Aristeidis Karalis, Robert Moffatt, J. D. Joannopoulos, Peter Fisher and Marin Soljačid, “Wireless Power Transfer via Strongly Coupled Magnetic Resonances”, Science, June 2007• T. R. Robinson, T. K. Yeoman and R. S. Dhillon, “Environmental impact of high power density microwave beams on different atmospheric layers”,• White Paper on Solar Power Satellite (SPS) Systems, URSI, September 2006• Richard M. Dickinson, and Jerry Grey, “Lasers for Wireless Power Transmission”• S.S. Ahmed, T.W. Yeong and H.B. Ahmad, “Wireless power transmission and its annexure to the grid system”3/7/2013 Wireless Power Transmission 40
  41. 41. THANK YOU!3/7/2013 Wireless Power Transmission 41

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