Browse > Article
http://dx.doi.org/10.5370/KIEE.2015.64.11.1651

Loss and Efficiency Dependence of a 6.78 MHz, 100 W, 30 cm Distance Wireless Power Transfer System on Cable Types  

Lee, Seung-Hwan (Metropolitan Transportation Research Center, Korea Railroad Research Institute)
Lee, Byung-Song (Metropolitan Transportation Research Center, Korea Railroad Research Institute)
Jung, Shin-Myung (Metropolitan Transportation Research Center, Korea Railroad Research Institute)
Park, Chan-Bae (Dept. of Railroad Operation System Engineering, Korea National University of Transportation)
Publication Information
The Transactions of The Korean Institute of Electrical Engineers / v.64, no.11, 2015 , pp. 1651-1657 More about this Journal
Abstract
In MHz operating wireless power transfer systems, skin- and proximity-effect losses in the transmitter and the receiver coils dominate the coil-to-coil efficiency of the system. A Litz-wire was regarded as a common solution for minimizing such Ohmic losses in high frequencies. In this paper, equivalent series resistances of 12 different cables including Litz-wire and copper tubing have been calculated and measured for a 6.78 MHz, 100W, 30 cm wireless power transfer system. It has been shown that the copper tubing has lower resistances compared to the Litz-wire in that frequency and a wireless power transfer system with the copper tubing was able to achieve much higher efficiency than a system using the Litz-wire. Calculations of the resistances and efficiencies were accomplished with analytical equations and those calculations were evaluated by experimental results.
Keywords
Wireless power transfer; inductive power transfer; copper loss; Litz-wire; copper tube; efficiency;
Citations & Related Records
연도 인용수 순위
  • Reference
1 A. Kurs, A. Karalis, R. Moffatt, J. D. Joannopoulos, P. Fisher, and M. Soljacic, "Wireless power transfer via strongly coupled magnetic resonances.," Science, vol. 317, no. 5834, pp. 83-6, Jul. 2007.   DOI
2 E. Waffenschmidt and T. Staring, "Limitation of inductive power transfer for consumer applications," in Power Electronics and Applications, 2009. EPE '09. 13th European Conference on, 2009, pp. 1-10.
3 J. Acero, R. Alonso, J. M. Burdio, L. A. Barragan, and D. Puyal, "Frequency-dependent resistance in Litz-wire planar windings for domestic induction heating appliances," Power Electron. IEEE Trans. On, vol. 21, no. 4, pp. 856-866, 2006.   DOI
4 New England Wire Technologies, "Litz design." [Online]. Available: http://www.litzwire.com/litz_design.htm. [Accessed: 22-Jul-2015].
5 G. S. Smith, "Proximity Effect in Systems of Parallel Conductors," J. Appl. Phys., vol. 43, no. 5, pp. 2196-2203, 1972.   DOI
6 S.-H. Lee, "Design methodologies for low flux density, high efficiency, kW level wireless power transfer systems with large air gaps," PhD Dissertation, University of Wisconsin-Madison, 2013.