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Design for continuous-current-mode operation of inductive-power-transfer converters with load-independent output

Design for continuous-current-mode operation of inductive-power-transfer converters with load-independent output

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The control design of inductive power transfer (IPT) converters can be greatly simplified by exploring the property of load-independent output. However, IPT converters can easily enter a discontinuous current mode (DCM) operation due to the non-linearity of the output diode rectification circuit at some loading conditions. The switching between operations of continuous current mode (CCM) and DCM within a switching cycle is highly non-linear, making the converter behaviour difficult to predict and analyse. The well-known first harmonic approximation (FHA) analysis method and the load-independent output property are no longer applicable when the converter enters DCM operation. This paper presents a simple and yet effective harmonic analysis method to reveal the main reason for the converter to enter DCM operation. Subsequently, the load boundary between CCM and DCM operations is derived in detail as a design criterion. A solution by increasing the input impedances at some higher order harmonic frequencies is also suggested to extend the load range against DCM operation. Finally, IPT prototypes using two higher order compensation circuits, having load-independent voltage output and capacitor filter, are demonstrated to verify the theoretical analysis.


    1. 1)
      • 1. Covic, G.A., Boys, J.T.: ‘Inductive power transfer’, Proc. IEEE, 2013, 101, (6), pp. 12761289.
    2. 2)
      • 12. Zhang, W., Wong, S.C., Tse, C.K., et al: ‘Load-independent duality of current and voltage outputs of a series or parallel compensated inductive power transfer converter with optimized efficiency’, IEEE J. Emerging Sel. Top. Power Electron., 2015, 3, (1), pp. 137146.
    3. 3)
      • 8. Liu, X., Hui, S.Y.R.: ‘Equivalent circuit modeling of a multilayer planar winding array structure for use in universal contactless battery charging platform’, IEEE Trans. Power Electron., 2007, 22, (1), pp. 2129.
    4. 4)
      • 7. Lee, S., Chao, B., Rim, C.T.: ‘Dynamics characterization of the inductive power transfer system for online electric vehicles by Laplace phasor transform’, IEEE Trans. Power Electron., 2013, 28, (12), pp. 59025909.
    5. 5)
      • 2. Hui, S.Y.: ‘Planar wireless charging technology for portable electronic products and Qi’, Proc. IEEE, 2013, 101, (6), pp. 12901301.
    6. 6)
      • 15. Li, S., Li, W., Deng, J., et al: ‘A double-sided LCC compensation network and its tuning method for wireless power transfer’, IEEE Trans. Veh. Technol., 2015, 64, (6), pp. 22612273.
    7. 7)
      • 18. Huang, Z., Wong, S.C., Tse, C.K.: ‘Control design for optimizing efficiency in inductive power transfer systems’, IEEE Trans. Power Electron., 2018, 33, (5), pp. 45234534.
    8. 8)
      • 20. Keeling, N.A., Covic, G.A., Boys, J.T.: ‘A unity-power-factor IPT pickup for high-power applications’, IEEE Trans. Ind. Electron., 2010, 57, (2), pp. 744751.
    9. 9)
      • 14. Madawala, U.K., Thrimawithana, D.J.: ‘A bidirectional inductive power interface for electric vehicles in V2G systems’, IEEE Trans. Ind. Electron., 2011, 58, (10), pp. 47894796.
    10. 10)
      • 13. Qu, X., Han, H., Wong, S.C., et al: ‘Hybrid IPT topologies with constant-current or constant-voltage output for battery charing applications’, IEEE Trans. Power Electron., 2015, 30, (11), pp. 61296337.
    11. 11)
      • 5. Miller, J.M., Jones, P.T., Li, J.M., et al: ‘ORNL experience and challenges facing dynamic wireless power charging of EV's’, IEEE Trans. Power Electron. Mag., 2015, 15, (2), pp. 4053.
    12. 12)
      • 16. Qu, X., Jing, Y., Wong, S.C., et al: ‘Higher order compensation for inductive-power-transfer converters with constant voltage or constant-current output combating transformer parameter constraints’, IEEE Trans. Power Electron., 2017, 32, (1), pp. 394405.
    13. 13)
      • 17. Song, K., Li, Z., Jiang, J., et al: ‘Constant current/voltage charging opeartion for series-series and series-parallel compensated wireless power transfer systems employing primary-side controller’, IEEE Trans. Power Electron., 2018, 33, (9), pp. 80658080.
    14. 14)
      • 10. ‘Tesla car can be summoned and park itself’, 2016. Available at
    15. 15)
      • 11. ‘Wireless charging system’, 2017. Available at
    16. 16)
      • 19. Safaee, A., Woronowicz, K.: ‘Time-domain analysis of voltage-driven series-series compensated inductive power transfer topology’, IEEE Trans. Power Electron., 2017, 32, (7), pp. 49815003.
    17. 17)
      • 9. Achterberg, J., Lomonova, E.A., Boeij, J.: ‘Coil array structures compared for contactless battery charging platform’, IEEE Trans. Magn., 2008, 44, (5), pp. 617622.
    18. 18)
      • 6. Covic, G.A., Boys, J.T.: ‘Modern trends in inductive power transfer for transportation applications’, IEEE J. Emerging Sel. Top. Power Electron., 2013, 1, (1), pp. 2841.
    19. 19)
      • 4. Li, S., Mi, C.C.: ‘Wireless power transfer for electric vehicle applications’, IEEE J. Emerging Sel. Top. Power Electron., 2015, 3, (1), pp. 417.
    20. 20)
      • 3. Ahn, D., Hong, S.: ‘Wireless power transmission with self-regulated output voltage for biomedical implant’, IEEE Trans. Ind. Electron., 2014, 61, (5), pp. 22252235.
    21. 21)
      • 21. Zhang, X., Kan, T., You, C., et al: ‘Modeling and analysis of AC output power factor for wireless chargers in electric vehicles’, IEEE Trans. Power Electron., 2017, 32, (2), pp. 14811492.

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