Analysis on efficiency of wireless power transfer using HTS coil
- 1. ANALYSIS ON EFFICIENCY OF WIRELESS POWER TRANSFER USING HTS COIL
- 2. Overview History of WPT Resonance inductive coupling Theortical approach Experimental Setup Different cases Major losses Advantages and disadvantages Future research Conclusion References
- 3. Wireless electricity way back in the 1800s…….. In the year 1891,Nikola Tesla proposed the method of wireless transmission of electric power One of the greatest breakthroughs of science at that time
- 4. Built the wardenclyffe tower which could broadcast power wirelessly,is called off as it radiated power into surroundings raising issues of •Power theft •Health concerns The Wardenclyffe Tower A dream crashes……
- 5. Resonance Inductive Coupling(RIC) 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.
- 7. HIGH TEMP SUPER CONDUCTOR The electrical resistivity of a metallic conductor decreases gradually as temperature is lowered and at the same time its conductivity becomes infinity.
- 8. • BSCCO needs to be hole-doped by an excess of oxygen atoms in order to superconductor. • By changing the oxygen content Tc can thus be altered at will. • Even though BSCCO has a higher upper critical field than YBCO due to some variations in chemical composition, YBCO are preferred to BSCCO though they are much more difficult to fabricate. • Experimental setup
- 9. Theoretical approach Couple mode theory The wireless power transfer can be presented as a set of first order linear differential equations Assumptions • Internal loss of coils is comparatively small. • Frequency range of operation is narrow enough to assume inductance and internal capacitance of the coils be constant.
- 10. Circuit model
- 11. Assumption • Transmitting and receiving coil should have same resistance and inductance. • The coupling capacitors,should be such that both capacitors must have the same rating at resonant condition.
- 13. • Superconductors preferred :BSCCO (Bismuth Strontium Calcium Copper Oxide).YBCO (Yttrium Barium Copper Oxide) • Shape : corresponds to a ribbon which can be wound easily can also be used. • Treated with liquid nitrogen to enhance the thermal stability. • Kapton tape is used as insulation between HTS tapes when winding the coils. • Then AC power is supplied.
- 14. • The capacitor used can be also made of superconducting material . • External capacitance provided to lower the operating frequency and to attain high efficiency and large distance transmission. • Booster resonator coil can be positioned between the primary and secondary coil for large transfer distance. • Frequency range selection for eliminating radiative loss.
- 15. Different case for frequency 1.4KHz to 4.3KHz • HTS coil (as transmitting coil) to HTS coil (as receiving coil) at 77 K • copper coil to copper coil at 77 K • copper coil to copper coil at RT • copper coil at RT to HTS coil at 77 K • copper coil at 77 K to HTS coil at 77 K • HTS coil at 77 K to copper coil at RT • HTS coil to copper coil at 77K
- 16. • The resistances of the coils were measured by RLC testing consist of 2 parts: • ac losses in HTS coils device. The resistances of HTS coils • AC losses in the HTS coils contain 3 parts. The Transport Loss The Hysteresis Loss Caused by Magnetic Field The Eddy-Current Loss Main losses..
- 17. To reduce the losses… • Use superconducting material • Lower the operating frequency
- 18. Inference Deviation in the graph because the transport current becomes higher near the resonant frequency, and ac losses of HTS coils cannot be neglected under such condition.
- 19. At transfer distance of 6.5 cm 1) 92.78% 2) 53.47% 3) 27.07%,
- 20. At transfer distance of 11cm 1)68.73% 2) 62.28% 3) 34.05% 4) 24.58%
- 21. • The maximum power transfer efficiency at 11 cm of a WPT system with HTS coil as transmitting coil is 2.5 times higher than that of a WPT system with HTS coil as receiving coil. Hence, HTS coils are more suitable for being as a transmitting coil than as a receiving one.
- 22. Advantage Disadvantage • Transfer Efficiency Will Be More Compared To Copper Coil • HTS coil can be used as transmitting coil for higher efficiencies • Booster resonator coil can be placed between the transmitter and receiver coil for long distance transmission. • Capacitance is added inorder to reduce radiative losses and to maintain the coil in resonance. • Operating frequency can be decreased within a specific range.If not,it will affect the power transfer efficiency. • Frequency below 1MHz preferably 200KHz is applicable for power transfer in the present system.
- 23. Conclusion • Simulation results concludes that HTS coil can give high efficiency and can be transmit power to larger distance by placing a booster resonator. • Transfer efficency will be high if the HTS coil is used as transmitting coil.
- 24. Future research Wireless power transmission can be done by • employing different coil shapes. • adding intermediate coils. • Using low temperature capacitors or HTS capacitors. • Situations where we have to sign in to a power zone to charge the devices.
- 25. Reference • GuoMin Zhang, Hui Yu, Liwei Jing, Jincheng Li, Qi Liu, and XianghuaFeng ‘Wireless Power Transfer Using High Temperature Superconducting Pancake Coils’IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, VOL. 24, NO. 3, JUNE 2014 • Senthil Nathan.M1, Pandiarajan.K / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com Vol. 3, Issue 1, January -February 2013, pp.1125-1130 1125 |P a g e A Review Of Wireless Power Transmission
- 26. • T. Nakamura *, K. Higashikawa, I. Muta, A. Fujio, K. Okude, T. Hoshino ‘Improvement of dissipative property in HTS coil i`mpregnated with solid nitrogen’ Department of Electrical Engineering, Graduate School of Engineering, Kyoto University, Yoshida-Honmachi, Sakyo, Kyoto 606-8501, Japan :www.sciencedirect.com • Alexey Bodrov and Seung-Ki SulIEEEFellow,Republic of Korea “Analysis of Wireless Power Transfer by Coupled Mode Theory (CMT) and Practical Considerations to Increase Power Transfer Efficiency” • RAYMOND J.SEDWICK UNIVERSITY ARK ,MD (US)”Methods and system for long range wireless power transfer” United States Patent Applicationpublication.Pub:US 2012/001079 A1:Pub date:Jan 12,2012