The Journal of Korean Institute of Electromagnetic Engineering and Science (한국전자파학회논문지)

The Korean Institute of Electromagnetic Engineering and Science (한국전자파학회)
권호 표지
DOI QR코드

DOI QR Code

Realization of Optimum Loads for Maximum WPT Efficiencies Using Multi-Turn Receiving Coil

수신 코일 권선 수 변화에 의한 무선전력전송 최적 부하 구현

  • Hwang, Sungyoun (Department of Electronics & Radio Engineering, Kyung Hee University) ;
  • Lee, Bomson (Department of Electronics & Radio Engineering, Kyung Hee University)
  • 황성연 (경희대학교 전자.전파공학과) ;
  • 이범선 (경희대학교 전자.전파공학과)
  • Received : 2016.01.07
  • Accepted : 2016.03.04
  • Published : 2016.04.30
Download PDF
⟨ Previous Next ⟩

Abstract

In this paper, we propose the method of controling the turns of a receiving coil for the matching directly to the receiver input impedance(typically $50{\Omega}$) with a maximum wireless power transfer(WPT) efficiency. Based on the presented the expression of the optimum load depending on a system figure of merit, number of the turns of a receiving coil, and proximity effect between conducting lines, the theoretical efficiencies have been compared with the measured ones with a good agreement. The results of this work may be used to realize a allowable maximum efficiency with a simple and low-profile 2-coil WPT system not requiring a separate feeding loop.

본 논문에서는 최대 무선전력전송 효율 구현에 필요한 최적 부하저항을 수신기 입력 임피던스(통상 $50{\Omega}$)에 바로 정합하기 위하여 수신 코일의 권선 수를 제어하는 방법을 제안한다. 수신 코일 권선 수와 도선 사이의 근접 효과가 고려된 최적 부하저항의 수식에 따라 수신 코일을 설계, 제작 및 측정하였다. 이론과 EM 시뮬레이션, 측정을 통하여 최적 부하 저항과 효율을 비교한 결과 비교적 잘 일치함을 확인할 수 있었다. 본 논문의 결과를 활용하면 별도의 급전 루프 없는 단순하고 부피가 작은 2-coil 시스템으로도 허용된 최대 전력을 구현할 수 있다.

Keywords

References

  1. T. Eom, C. Oh, and S. Park, "Wireless power transfer technologies trends", Journal of Energy of Engineering, vol. 24, no. 2, pp. 174-178, Jun. 2015. https://doi.org/10.5855/ENERGY.2015.24.2.174
  2. G. Lee, B. H. Waters, C. Shi, W. Park, and J. R. Smith, "Design considerations for asymmetric magnetically coupled resonators used in wireless power transfer applications", IEEE Topical Conf. Wireless Sensors and Sensor Networks, Austin, TX, pp. 124-126, Jan. 2013.
  3. T. P. Duong, J. Lee, "Experimental results of high-efficiency resonant coupling wireless power transfer using a variable coupling method", IEEE Microw. and Wireless Components Lett., vol. 21, no. 8, pp. 442-444, Aug. 2011. https://doi.org/10.1109/LMWC.2011.2160163
  4. B. Park, J. Lee, "Adaptive impedance matching of wireless power transmission using multi-loop feed with single operating frequency", IEEE Trans. Antennas and Prop., vol. 62, no. 5, May 2014.
  5. Y. Jung, B. Lee, "Design tunable optimal load circuit for maximum wireless power transfer efficiency", Microw. Optimal Technology Lett., vol. 56, no. 11, pp. 2619-2622, Nov. 2014. https://doi.org/10.1002/mop.28661
  6. B. H. Waters, A. P. Sample, and J. R. Smith, "Adaptive impedance matching for magnetically coupled resonators", PIERS Proc., pp. 694-701, Aug. 2012.
  7. Y. Lim, H. Tang, S. Lim, and J. Park, "An adaptive impedance- matching network based on a novel capacitor matrix for wireless power transfer", IEEE Trans. Power Electronics, vol. 29, no. 8, pp. 4403-4413, Aug. 2014. https://doi.org/10.1109/TPEL.2013.2292596
  8. G. Kim, B. Lee, "Analysis of magnetically coupled wireless power transfer between two resonators based on power conservation", IEEE Wireless Power Transfer Conf.(WPTC), Jeju, pp. 231-234, May 2014.
  9. J. Kim, Y. Park, "Approximate closed-form formula for calculating ohmic resistance in coils of parallel round wires with unequal pitches", IEEE Trans. Ind. Electron., vol. 62, no. 6, pp. 3482-3489, Jun. 2015. https://doi.org/10.1109/TIE.2014.2370943
  10. G. S. Smith, "Radiation efficiency of electrically small multiturn loop antennas", IEEE Trans. Antennas Propag., vol. 20, no. 5, pp. 656-657, Sep. 1972. https://doi.org/10.1109/TAP.1972.1140293
  11. J. T. Conway, "Inductance calculations for noncoaxial coils using bessel functions", IEEE Trans. Magn., vol. 43, no. 3, pp. 1023-1034, Mar. 2007. https://doi.org/10.1109/TMAG.2006.888565