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Exhaustive algorithms applied to the design of inductive power transfer couplers

  • Rodolfo Castanho Fernandes (a1) and Azauri Albano De Oliveira (a1)


The design of magnetic couplers for inductive power transfer has probably become the major challenge for those who wish to enter this promising research field. The number of variables that determine physical dimensions of a coupler is typically too high to allow analytical (exact) solutions in practical time when realistic magnetic materials are to be included. Thus, this paper suggests and describes a series of algorithms based on the finite element method (FEM) able to convert basic inputs (target inductances, primary current, frequency, and mechanical restrictions) into a geometric solution that satisfies user-defined targets for uncompensated power, open-circuit voltage, and short-circuit current. Advantages of these algorithms when compared with other existing design methods are: simplicity in terms of structure at the same time that require minimum user intervention to complete a full design; do not rely in expensive finite element solvers; user does not require previous background in FEM formulation. Experimental results show that the proposed design method based on two-dimensional FEM has errors of <8% when compared with three-dimensional FEM and can perform iterations in seconds. It is expected that the proposed routines encourage and provide design insights for practitioners, enthusiasts, and non-specialized engineers.


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Corresponding author: R. C. Fernandes Email:


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[1] Mirbozorgi, S.A.; Bahrami, H.; Sawan, M.; Gosselin, B.: A smart multicoil inductively coupled array for wireless power transmission. IEEE Trans. Ind. Electron., 61 (2014), 60616070.
[2] Choi, S.Y.; Huh, J.; Lee, W.Y.; Rim, C.T.: Asymmetric coil sets for wireless stationary EV chargers with large lateral tolerance by dominant field analysis. IEEE Trans. Power Electron., 29 (2014), 64066420.
[3] Wu, H.H.; Gilchrist, A.; Sealy, K.; Bronson, D.: A 90 percent efficient 5 kW inductive charger for EVs, in Proc. IEEE Energy Conversion Congress and Exposition, 2012, 275282.
[4] Christ, A. et al. : Evaluation of wireless resonant power transfer systems with human electromagnetic exposure limits. IEEE Trans. Electromagn. Compat., 55 (2013), 265274.
[5] Jonah, O.; Merwaday, A.; Georgakopoulos, S.V.; Tentzeris, M.M.: Spiral resonators for optimally efficient strongly coupled magnetic resonant systems. Wireless Power Transfer, 1 (2014), 2126.
[6] Nagendra, G.R.; Covic, G.A.; Boys, J.T.: Determining the physical size of inductive couplers for IPT EV systems. IEEE J. Emerging Sel. Topics Power Electron., 2 (2014), 571583.
[7] Fisher, T.M.; Farley, K.B.; Gao, Y.; Bai, H.; Tse, Z.T.H.: Electric vehicle wireless charging technology: a state-of-the-art review of magnetic coupling systems. Wireless Power Transfer, 1 (2014), 8796.
[8] Arteaga, I.K.; Iturralde, M.M.; Ibanez, F.M.; Elosegui, I.: Analytical sizing methodology for inductive power transfer systems, in Proc. IEEE Workshop on Control and Modeling for Power Electronics, 2014, 1–7.
[9] Inoue, K.; Nagashima, T.; Wei, X.; Sekiya, H.: Design of high-efficiency inductive-coupled wireless power transfer system with class-DE transmitter and class-E rectifier, in Proc. IEEE IECON, 2013, 611–616.
[10] Sekiya, H.; Ezawa, T.; Tanji, Y.: Design procedure for Class E switching circuits allowing implicit circuits equations. IEEE Trans. Circuits Syst. I, 55 (2008), 36883696.
[11] Meeker, D.: FEMM – Finite element method magnetics (Version 4.2) “Software”. Available at, 2012.
[12] Arthur, J.W.: An elementary view of Maxwell's displacement current. IEEE Antennas Propag. Mag., 51 (2009), 5868.
[13] International Commission on Non-Ionizing Radiation Protection, ICNIRP: Guidelines for limiting exposure to time-varying electric and magnetic fields (1 Hz to 100 kHz). Health Phys., 99 (2010), 818836.
[14] Beh, H.Z.; Covic, G.A.; Boys, J.T.: Investigation of magnetic couplers in bicycle kickstands for wireless charging of electric bicycles. IEEE J. Emerging Sel. Topics Power Electron., 3 (99) (2014), 87100.
[15] Elliot, G.A.J.; Raabe, S.; Covic, G.A.; Boys, J.T.: Multiphase pickups for large lateral tolerance contactless power-transfer systems. IEEE Trans. Ind. Electron., 57 (2010), 15901598.
[16] Covic, G.A.; Boys, J.T.: Modern trends in inductive power transfer for transportation applications. IEEE J. Emerging Sel. Top. Power Electron., 1 (2013), 2841.
[17] Wan, C.S.; Stielau, O.H.; Covic, G.A.: Design considerations for a contactless electric vehicle battery charger. IEEE Trans. Ind. Electron., 52 (2005), 13081314.
[18] Budhia, M.; Covic, G.A.; Boys, J.T.: Design optimization of circular magnetic structures for lumped inductive power transfer systems. IEEE Trans. Power Electron., 26 (2011), 30963108.
[19] Ng, W.M.; Zhang, C.; Lyn, D.; Hui, S.Y.R.: Two- and three-dimensional omnidirectional wireless power transfer. IEEE Trans. Power Electron., 29 (2014), 44704474.
[20] Zhong, W.X.; Lee, C.K.; Hui, S.Y.R.: Wireless power domino-resonator systems with noncoaxial axes and circular structures. IEEE Trans. Power Electron., 27 (2012), 47504762.
[21] Pinuela, M.; Yates, D.C.; Lucyszyn, S.; Mitcheson, P.D.: Maximizing DC-to-Load efficiency for inductive power transfer. IEEE Trans. Power Electron., 28 (2012), 24372447.



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