依靠强磁谐振的无线能量传输原稿.docVIP

Wireless Power Transfer via Strongly Coupled Magnetic Resonances Originally published in Science Express on 7 June 2007，Science 6 July 2007:Vol. 317. no. 5834, pp. 83 - 86 DOI: 10.1126/science.1143254Prev | Table of Contents | Next André Kurs,1* Aristeidis Karalis,2 Robert Moffatt,1 J. D. Joannopoulos,1 Peter Fisher,3 Marin Soljai1 Using self-resonant coils in a strongly coupled regime, we experimentally demonstrated efficient nonradiative power transfer over distances up to 8 times the radius of the coils. We were able to transfer 60 watts with 40% efficiency over distances in excess of 2 meters. We present a quantitative model describing the power transfer, which matches the experimental results to within 5%. We discuss the practical applicability of this system and suggest directions for further study. 1 Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. 2 Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. 3 Department of Physics and Laboratory for Nuclear Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. * To whom correspondence should be addressed. E-mail: akurs@ In the early 20th century, before the electricalwire grid, Nikola Tesla (1) devoted much effort toward schemes to transport power wirelessly. However, typical embodiments (e.g., Tesla coils) involved undesirably large electric fields. The past decade has witnessed a surge in the use of autonomous electronic devices (laptops, cell phones, robots, PDAs, etc.). As a consequence, interest in wireless power has reemerged (2–4). Radiative transfer (5), although perfectly suitable for transferring information, poses a number of difficulties for power transfer applications: The efficiency of power transfer is very low if the radiation is omnidirectional, and unidirectional radiation requires an uninterrupted line of sight and sophisticated tracking mechanisms.