DOI QR코드

DOI QR Code

Alternative Expressions for Mutual Inductance and Coupling Coefficient Applied in Wireless Power Transfer

Kim, Gunyoung;Lee, Bomson

  • Received : 2015.11.10
  • Accepted : 2016.03.10
  • Published : 2016.04.30

Abstract

Alternative analytic expressions for the mutual inductance ($L_m$) and coupling coefficient (k) between circular loops are presented using more familiar and convenient expressions that represent the property of reciprocity clearly. In particular, the coupling coefficients are expressed in terms of structural dimensions normalized to a geometric mean of radii of two loops. Based on the presented expressions, various aspects of the mutual inductances and coupling coefficients, including the regions of positive, zero, and negative value, are examined with respect to their impacts on the efficiency of wireless power transmission.

Keywords

Coupling Coefficient;Magnetic Flux;Mutual Inductance;Transfer Efficiency;Wireless Power Transfer

References

  1. J. T. Conway, "Inductance calculations for noncoaxial coils using Bessel functions," IEEE Transactions on Magnetics, vol. 43, no. 3, pp. 1023-1034, 2007. https://doi.org/10.1109/TMAG.2006.888565
  2. S. I. Babic and C. Akyel, "Calculating mutual inductance between circular coils with inclined axes in air," IEEE Transactions on Magnetics, vol. 44, no. 7, pp. 1743-1750, 2008. https://doi.org/10.1109/TMAG.2008.920251
  3. C. Kim and B. Lee, "Analysis of magnetic coupled wireless power transmissions considering radiation loss," Journal of the Korea Electromagnetic Engineering Society, vol. 11, no. 3, pp. 156-160, 2011. https://doi.org/10.5515/JKIEES.2011.11.3.156
  4. A. Kurs, A. Karalis, R. Moffatt, J. D. Joannopoulos, P. Fisher, and M. Soljacic, "Wireless power transfer via strongly coupled magnetic resonance," Science, vol. 317, no. 5834, pp. 83-86, 2007. https://doi.org/10.1126/science.1143254
  5. S. Raju, R. Wu, M. Chan, and C. P. Yue, "Modeling of mutual coupling between planar inductors in wireless power applications," IEEE Transactions on Power Electronics, vol. 29, no. 1, pp. 481-490, 2014. https://doi.org/10.1109/TPEL.2013.2253334
  6. H. D. Lang, A. Ludwig, and C. D. Sarris, "Convex optimization of wireless power transfer systems with multiple transmitters," IEEE Transactions on Antennas and Propagation, vol. 62, no. 9, pp. 4623-4636, 2014. https://doi.org/10.1109/TAP.2014.2330584
  7. R. Zhang, R. G. Maunder, and L. Hanzo, "Wireless information and power transfer: from scientific hypothesis to engineering practice," IEEE Communications Magazine, vol. 53, no. 8, pp. 99-105, 2015. https://doi.org/10.1109/MCOM.2015.7180515
  8. Y. Zhang, T. Lu, Z. Zhao, F. He, K. Chen, and L. Yuan, "Employing load coils for multiple loads of resonant wireless power transfer," IEEE Transactions on Power Electronics, vol. 30, no. 11, pp. 6174-6181, 2015. https://doi.org/10.1109/TPEL.2015.2396943
  9. F. W. Grover, Inductance Calculations. New York: Dover, 1964.
  10. C. R. Paul, Inductance: Loop and Partial. Hoboken, NJ: Wiley, 2010.

Cited by

  1. An Effective Experimental Optimization Method for Wireless Power Transfer System Design Using Frequency Domain Measurement vol.17, pp.4, 2017, https://doi.org/10.26866/jees.2017.17.4.208
  2. Control of Power Distribution for Multiple Receivers in SIMO Wireless Power Transfer System vol.18, pp.4, 2018, https://doi.org/10.26866/jees.2018.18.4.221
  3. Investigation of Single-Input Multiple-Output Wireless Power Transfer Systems Based on Optimization of Receiver Loads for Maximum Efficiencies vol.18, pp.3, 2018, https://doi.org/10.26866/jees.2018.18.3.145

Acknowledgement

Supported by : National Research Foundation of Korea (NRF)