Wireless power transmission
- 1. Wireless Power TransmissionPresented byRakesh K.K.4NM07EC080Department of Electronics and Communication EngineeringNMAM Institute of Technology, Nitte
- 2. OverviewWhat is wireless power transmission(WPT)?Why is WPT?History of WPTTypes of WPTTechniques to transfer energy wirelesslyAdvantages and disadvantagesApplicationsConclusionReferences 26-Aug-10Wireless Power Transmission2
- 3. What is WPT?The transmission of energy from one place to another without using wiresConventional energy transfer is using wiresBut, the wireless transmission is made possible by using various technologies26-Aug-10Wireless Power Transmission3
- 4. Why not wires? As per studies, most electrical energy transfer is through wires. Most of the energy loss is during transmissionOn an average, more than 30%
- 5. In India, it exceeds 40%26-Aug-10Wireless Power Transmission4
- 6. Why WPT?ReliableEfficientFastLow maintenance costCan be used for short-range or long-range.26-Aug-10Wireless Power Transmission5
- 7. HistoryNikola Tesla in late 1890sPioneer of induction techniquesHis vision for “World Wireless System”The 187 feet tall tower to broadcast energyAll people can have access to free energyDue to shortage of funds, tower did not operate26-Aug-10Wireless Power Transmission6
- 8. History (contd…)Tesla was able to transfer energy from one coil to another coilHe managed to light 200 lamps from a distance of 40kmThe idea of Tesla is taken in to research after 100 years by a team led by Marin Soljačić from MIT. The project is named as ‘WiTricity’. 26-Aug-10Wireless Power Transmission7
- 9. Energy CouplingThe transfer of energyMagnetic couplingInductive couplingSimplest Wireless Energy coupling is a transformer26-Aug-10Wireless Power Transmission8
- 10. Types and Technologies of WPTNear-field techniquesInductive Coupling
- 12. Air IonizationFar-field techniquesMicrowave Power Transmission (MPT)
- 13. LASER power transmission26-Aug-10Wireless Power Transmission9
- 14. Inductive coupling Primary and secondary coils are not connected with wires.Energy transfer is due to Mutual Induction26-Aug-10Wireless Power Transmission10
- 15. Inductive coupling (contd…)Transformer is also an exampleEnergy transfer devices are usually air-coredWireless Charging Pad(WCP),electric brushes are some examplesOn a WCP, the devices are to be kept, battery will be automatically charged.26-Aug-10Wireless Power Transmission11
- 16. Inductive coupling(contd…)Electric brush also charges using inductive couplingThe charging pad (primary coil) and the device(secondary coil) have to be kept very near to each otherIt is preferred because it is comfortable.Less use of wiresShock proof26-Aug-10Wireless Power Transmission12
- 17. Resonance Inductive Coupling(RIC)Combination of inductive coupling and resonanceResonance makes two objects interact very stronglyInductance induces current26-Aug-10Wireless Power Transmission13
- 18. How resonance in RIC?Coil provides the inductanceCapacitor is connected parallel to the coilEnergy will be shifting back and forth between magnetic field surrounding the coil and electric field around the capacitorRadiation loss will be negligible26-Aug-10Wireless Power Transmission14
- 19. Block diagram of RIC26-Aug-10Wireless Power Transmission15
- 20. An example26-Aug-10Wireless Power Transmission16
- 21. WiTricityBased on RICLed by MIT’s Marin SoljačićEnergy transfer wirelessly for a distance just more than 2m. Coils were in helical shapeNo capacitor was usedEfficiency achieved was around 40%26-Aug-10Wireless Power Transmission17
- 22. WiTricity (contd…)26-Aug-10Wireless Power Transmission18
- 23. WiTricity… Some statisticsUsed frequencies are 1MHz and 10MHzAt 1Mhz, field strengths were safe for humanAt 10MHz, Field strengths were more than ICNIRP standards26-Aug-10Wireless Power Transmission19
- 24. WiTricity now…No more helical coilsCompanies like Intel are also working on devices that make use of RICResearches for decreasing the field strengthResearches to increase the range26-Aug-10Wireless Power Transmission20
- 25. RIC vs. inductive couplingRIC is highly efficientRIC has much greater range than inductive couplingRIC is directional when compared to inductive couplingRIC can be one-to-many. But usually inductive coupling is one-to-oneDevices using RIC technique are highly portable26-Aug-10Wireless Power Transmission21
- 26. Air IonizationToughest technique under near-field energy transfer techniquesAir ionizes only when there is a high fieldNeeded field is 2.11MV/mNatural example: LighteningNot feasible for practical implementation26-Aug-10Wireless Power Transmission22
- 27. Advantages of near-field techniquesNo wiresNo e-wasteNeed for battery is eliminatedEfficient energy transfer using RICHarmless, if field strengths under safety levelsMaintenance cost is less26-Aug-10Wireless Power Transmission23
- 28. DisadvantagesDistance constraintField strengths have to be under safety levelsInitial cost is highIn RIC, tuning is difficultHigh frequency signals must be the supplyAir ionization technique is not feasible26-Aug-10Wireless Power Transmission24
- 29. Far-field energy transferRadiativeNeeds line-of-sightLASER or microwaveAims at high power transferTesla’s tower was built for this26-Aug-10Wireless Power Transmission25
- 30. Microwave Power Transfer(MPT)Transfers high power from one place to another. Two places being in line of sight usuallySteps:Electrical energy to microwave energyCapturing microwaves using rectennaMicrowave energy to electrical energy26-Aug-10Wireless Power Transmission26
- 31. MP T (contd…)AC can not be directly converted to microwave energyAC is converted to DC firstDC is converted to microwaves using magnetronTransmitted waves are received at rectenna which rectifies, gives DC as the outputDC is converted back to AC26-Aug-10Wireless Power Transmission27
- 32. LASER transmissionLASER is highly directional, coherentNot dispersed for very longBut, gets attenuated when it propagates through atmosphereSimple receiverPhotovoltaic cellCost-efficient26-Aug-10Wireless Power Transmission28
- 33. Solar Power Satellites (SPS) To provide energy to earth’s increasing energy needTo efficiently make use of renewable energy i.e., solar energySPS are placed in geostationary orbits26-Aug-10Wireless Power Transmission29
- 34. SPS (contd…)Solar energy is captured using photocellsEach SPS may have 400 million photocellsTransmitted to earth in the form of microwaves/LASERUsing rectenna/photovoltaic cell, the energy is converted to electrical energyEfficiency exceeds 95% if microwave is used.26-Aug-10Wireless Power Transmission30
- 35. RectennaStands for rectifying antennaConsists of mesh of dipoles and diodesConverts microwave to its DC equivalentUsually multi-element phased array26-Aug-10Wireless Power Transmission31
- 36. Rectenna in USRectenna in US receives 5000MW of power from SPSIt is about one and a half mile long26-Aug-10Wireless Power Transmission32
- 37. Other projectsAlaska’21Grand BassinHawaii26-Aug-10Wireless Power Transmission33
- 38. LASER vs. MPTWhen LASER is used, the antenna sizes can be much smallerMicrowaves 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 easily26-Aug-10Wireless Power Transmission34
- 39. Advantages of far-field energy transferEfficientEasyNeed for grids, substations etc are eliminatedLow maintenance costMore effective when the transmitting and receiving points are along a line-of-sightCan reach the places which are remote26-Aug-10Wireless Power Transmission35
- 40. Disadvantages of far-field energy trasnferRadiativeNeeds line-of-sightInitial cost is highWhen LASERs are used, conversion is inefficientAbsorption loss is highWhen microwaves are used, interference may ariseFRIED BIRD effect26-Aug-10Wireless Power Transmission36
- 41. ApplicationsNear-field energy transferElectric automobile chargingStatic and movingConsumer electronicsIndustrial purposesHarsh environmentFar-field energy transferSolar Power SatellitesEnergy to remote areasCan broadcast energy globally (in future)26-Aug-10Wireless Power Transmission37
- 42. ConclusionTransmission without wires- a realityEfficientLow maintenance cost. But, high initial costBetter than conventional wired transferEnergy crisis can be decreasedLow loss In near future, world will be completely wireless26-Aug-10Wireless Power Transmission38
- 43. ReferencesS. 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 ShahrzadJalaliMazlouman, AlirezaMahanfar, BozenaKaminska, “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, 2008 26-Aug-10Wireless Power Transmission39
- 44. References(contd…)André Kurs, AristeidisKaralis, Robert Moffatt, J. D. Joannopoulos, Peter Fisher and Marin Soljačić, “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” 26-Aug-10Wireless Power Transmission40
- 45. THANK YOU!26-Aug-10Wireless Power Transmission41