Vol. 83

Front:[PDF file] Back:[PDF file]
Latest Volume
All Volumes
All Issues

Multi-Objective Optimization of Wireless Power Transfer Systems with Magnetically Coupled Resonators and Nonlinear Loads

By Johan Winges, Thomas Rylander, Carl Petersson, Christian Ekman, Lars-Ake Johansson, and Tomas McKelvey
Progress In Electromagnetics Research B, Vol. 83, 25-42, 2019


We present an optimization procedure for wireless power transfer (WPT) applications and test it numerically for a WPT system design with four resonant circuits that are magnetically coupled by coaxial coils in air, where the magnetic field problem is represented by a fully populated inductance matrix that includes all magnetic interactions that occur between the coils. The magnetically coupled resonators are fed by a square wave voltage generator and loaded by a rectifier followed by a smoothing filter and a battery. We compute Pareto fronts associated with a multi-objective optimization problem that contrasts: 1) the system efficiency; and 2) the power delivered to the battery. The optimization problem is constrained in terms of: 1) the physical construction of the system and its components; 2) the root-mean-square values of the currents and voltages in the circuit; and 3) bounds on the overtones of the currents in the coils in order assure that the WPT system mainly generates magnetic fields at the operating frequency. We present optimized results for transfer distances from 0.8 to 1.6 times the largest coil radius with a maximum power transfer from 4 kW to 9 kW at 85 kHz, which is achieved at an efficiency larger than 90%.


Johan Winges, Thomas Rylander, Carl Petersson, Christian Ekman, Lars-Ake Johansson, and Tomas McKelvey, "Multi-Objective Optimization of Wireless Power Transfer Systems with Magnetically Coupled Resonators and Nonlinear Loads," Progress In Electromagnetics Research B, Vol. 83, 25-42, 2019.


    1. Jawad, A. M., R. Nordin, S. K. Gharghan, H. M. Jawad, and M. Ismail, "Opportunities and challenges for near-field wireless power transfer: A review," Energies, Vol. 10, No. 7, 2017.

    2. Kazmierkowski, M. P. and A. J. Moradewicz, "Unplugged but connected: Review of contactless energy transfer systems," IEEE Ind. Electron. Mag., Vol. 6, 47-55, Dec. 2012.

    3. Kim, S., H.-H. Park, J. Kim, J. Kim, and S. Ahn, "Design and analysis of a resonant reactive shield for a wireless power electric vehicle," IEEE Trans. Microw. Theory Tech., Vol. 62, 1057-1066, Apr. 2014.

    4. Musavi, F. and W. Eberle, "Overview of wireless power transfer technologies for electric vehicle battery charging," IET Power Electronics, Vol. 7, 60-66, Jan. 2014.

    5. Kurs, A., A. Karalis, R. Mofatt, J. D. Joannopoulos, P. Fisher, and M. Soljacic, "Wireless power transfer via strongly coupled magnetic resonances," Science, Vol. 317, 83-86, Jul. 2007.

    6. Kesler, M., "Highly resonant wireless power transfer: Safe, efficient, and over distance," Tech. Rep., WiTricity Corporation, Watertown, MA, USA, 2013.

    7. Sallan, J., J. L. V. A. Llombart, and J. F. Sanz, "Optimal design of ICPT systems applied to electric vehicle battery charge," IEEE Trans. Ind. Electron., Vol. 56, 2140-2149, Jun. 2009.

    8. Bosshard, R., J. W. Kolar, J. Muhlethaler, I. Stevanovic, B. Wunsch, and F. Canales, "Modeling and η-α-Pareto optimization of inductive power transfer coils for electric vehicles," IEEE J. Emerg. Sel. Topics Power Electron., Vol. 3, No. 1, 50-64, 2015.

    9. Kiani, M. and M. Ghovanloo, "The circuit theory behind coupled-mode magnetic resonance-based wireless power transmission," IEEE Trans. Circuits Syst. I, Vol. 59, 2065-2074, Sep. 2012.

    10. Bou, E., E. Alarcon, and J. Gutierrez, "A comparison of analytical models for resonant inductive coupling wireless power transfer," PIERS Proceedings, 689-693, Aug. 2012.

    11. Hui, S. Y. R., W. Zhong, and C. K. Lee, "A critical review of recent progress in mid-range wireless power transfer," IEEE Trans. Power Electron., Vol. 29, No. 9, 4500-4511, 2014.

    12. Zhong, W., C. K. Lee, and S. Y. R. Hui, "General analysis on the use of Tesla’s resonators in domino forms for wireless power transfer," IEEE Trans. Ind. Electron., Vol. 60, 261-270, Jan. 2013.

    13. Alberto, J., U. Reggiani, L. Sandrolini, and H. Albuquerque, "Fast calculation and analysis of the equivalent impedance of a wireless power transfer system using an array of magnetically coupled resonators," Progress In Electromagnetics Research B, Vol. 80, 101-112, 2018.

    14. Chu, J., W. Gu, W. Niu, and A. Shen, "Frequency splitting patterns in wireless power relay transfer," IET Circuits, Devices & Systems, Vol. 8, No. 6, 561-567, 2014.

    15. Bosshard, R. and J. W. Kolar, "Multi-objective optimization of 50 kW/85 kHz IPT system for public transport," IEEE J. Emerg. Sel. Top. Power Electron., Vol. 4, 1370-1382, Dec. 2016.

    16. Haupt, R. L., "An introduction to genetic algorithms for electromagnetics," IEEE AP Magazine, Vol. 37, No. 2, 7-15, 1995.

    17. Rahmat-Samii, Y., E. Michielssen, and eds., Electromagnetic Optimization by Genetic Algorithms, 1st Ed., John Wiley & Sons, Inc., New York, NY, USA, 1999.

    18. Cheon, S., Y.-H. Kim, S.-Y. Kang, M. L. Lee, J.-M. Lee, and T. Zyung, "Circuit-model-based analysis of a wireless energy-transfer system via coupled magnetic resonances," IEEE Trans. Ind. Electron., Vol. 58, 2906-2914, Jul. 2011.

    19. Sample, A. P., D. A. Meyer, and J. R. Smith, "Analysis, experimental results, and range adaptation of magnetically coupled resonators for wireless power transfer," IEEE Trans. Ind. Electron., Vol. 58, No. 2, 544-554, 2011.

    20. SAE Standard, J2954, wireless power transfer for light-duty plug-in/electric vehicles and alignment methodology, 2016.

    21. Jackson, J. D., Classical Electrodynamics, 3rd Ed., Willey, New York, 1999.

    22. Winges, J., T. Rylander, C. Petersson, C. Ekman, L.-A. Johansson, and T. McKelvey, "System identification and tuning of wireless power transfer systems with multiple magnetically coupled resonators," Trans. Environ. Electr. Eng., Vol. 2, No. 2, 86-92, 2018.

    23. Hamnerius, Y., T. Nilsson, T. Rylander, J. Winges, C. Ekman, C. Petersson, and T. Fransson, "Design of safe wireless power transfer systems for electric vehicles," Proc. 2nd URSI AT- RASC, Grand Canaria, Spain, May 2018.

    24. Bosshard, R. and J. W. Kolar, "All-SiC 9.5 kW/dm 3 on-board power electronics for 50 kW/85 kHz automotive IPT system," IEEE J. Emerg. Sel. Top. Power Electron., Vol. 5, 419-431, Mar. 2017.

    25. Tamaki, H., H. Kita, and S. Kobayashi, "Multi-objective optimization by genetic algorithms: A review," Proc. IEEE Int. Conf. Evolutionary Computation, 517-522, May 1996.

    26. Press, W. H., S. A. Teukolsky, W. T. Vetterling, and B. P. Flannery, "Numerical Recipes in C: The Art of Scientific Computing," Cambridge University Press, 1992.

    27. Abramowitz, M. and I. A. Stegun, Handbook of Mathematical Functions: With Formulas, Graphs, and Mathematical Tables, National Bureau of Standards, 1965.

    28. Brocard, G., The LTSpice IV Simulator: Manual, Methods and Applications, Swiridoff Verlag, Kunzelsau, Germany, 2013.

    29. Steigerwald, R., "A comparison of half-bridge resonant converter topologies," IEEE Trans. Power Electron., Vol. 3, 174-182, Apr. 1988.