volume | PIER Journals

Abstract

Magnetic resonant wireless power transfer (WPT) is an emerging technology that may create new applications for wireless power charging. However, the output voltage and efficiency fluctuations resulting from lateral misalignments are main obstructing factors for promoting this technology. In this paper, a structure of tower-type coils is proposed. The mathematical model of the proposed structure is built based on equivalent circuit method. The expressions of the output voltage and efficiency are then derived by solving the system equivalent equations. In addition, a method of optimizing the mutual inductance between the transmission coil and intermediate coil and the strong-coupling parameters between the intermediate coil and receiving coil is proposed. The mutual inductance between the transmission coil and intermediate coil can be kept nearly constant with lateral misalignments, and the optimum strong-coupling parameter between the intermediate coil and the receiving coil can be obtained by the proposed method. Therefore, the output voltage and efficiency can be kept nearly constant with different lateral misalignments. The WPT system based on tower-type coils via magnetic resonance coupling is designed. Simulated and experimental results validating the proposed method are given.

1. Musavi, F. and W. Eberle, "Overview of wireless power transfer technologies for electric vehicle battery charging," IET Power Electronics, Vol. 7, 60-66, 2014.
doi:10.1049/iet-pel.2013.0047 Google Scholar

2. Mi, C. C., G. Buja, S. Y. Choi, and C. T. Rim, "Modern advances in wireless power transfer systems for roadway powered electric vehicles," IEEE Transactions on Industrial Electronics, Vol. 63, 6533-6545, 2016.
doi:10.1109/TIE.2016.2574993 Google Scholar

3. Li, J., Y. Lu, F. Liu, B. Mu, Z. Dong, S. Pan, and C. Zheng, "Optimization method of magnetic coupling resonant wireless power transfer system with single relay coil," Progress In Electromagnetics Research M, Vol. 80, 57-70, 2019.
doi:10.2528/PIERM18110107 Google Scholar

4. Liu, B. J., H. T. Xu, and X. W. Zhou, "Resource allocation in wireless-powered mobile edge computing systems for internet of things applications," Electronics, Vol. 8, No. 2, 2, Feb. 2019.
doi:10.1016/j.tej.2019.03.002 Google Scholar

5. Choi, S. Y., B. W. Gu, S. Y. Jeong, and C. T. Rim, "Advances in wireless power transfer systems for roadway-powered electric vehicles," IEEE Journal of Emerging and Selected Topics in Power Electronics, Vol. 3, 18-36, 2015.
doi:10.1109/JESTPE.2014.2343674 Google Scholar

6. Li, Z., C. Zhu, J. Jiang, K. Song, and G.Wei, "A 3-kWwireless power transfer system for sightseeing car supercapacitor charge," IEEE Transactions on Power Electronics, Vol. 32, 3301-3316, 2017.
doi:10.1109/TPEL.2016.2584701 Google Scholar

7. Wang, T. F., X. Liu, N. Jin, H. J. Tang, X. J. Yang, and M. Ali, "Wireless power transfer for battery powering system," Electronics, Vol. 7, No. 9, 178, Sep. 2018.
doi:10.3390/electronics7090178 Google Scholar

8. Zhang, Y., K. Chen, F. He, Z. Zhao, T. Lu, and L. Yuan, "Closed-form oriented modeling and analysis of wireless power transfer system with constant-voltage source and load," IEEE Transactions on Power Electronics, Vol. 31, 3472-3481, 2016.
doi:10.1109/TPEL.2015.2465847 Google Scholar

9. Huang, S., Z. Li, Y. Li, X. Yuan, and S. Cheng, "A comparative study between novel and conventional four-resonator coil structures in wireless power transfer," IEEE Transactions on Magnetics, Vol. 50, 1-4, 2014. Google Scholar

10. Fotopoulou, K. and B. W. Flynn, "Wireless power transfer in loosely coupled links: Coil misalignment model," IEEE Transactions on Magnetics, Vol. 47, 416-430, 2011.
doi:10.1109/TMAG.2010.2093534 Google Scholar

11. Wang, J., J. Li, S. L. Ho, W. N. Fu, Y. Li, H. Yu, and M. Sun, "Lateral and angular misalignments analysis of a new PCB circular spiral resonant wireless charger," IEEE Transactions on Magnetics, Vol. 48, 4522-4525, 2012.
doi:10.1109/TMAG.2012.2196980 Google Scholar

12. Huang, S. D., Z. Q. Li, and Y. Li, "Transfer efficiency analysis of magnetic resonance wireless power transfer with intermediate resonant coil," Journal of Applied Physics, Vol. 115, May 7, 2014. Google Scholar

13. Zhang, Y., 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, 6174-6181, 2015.
doi:10.1109/TPEL.2015.2396943 Google Scholar

14. Zhang, Y., T. Lu, Z. Zhao, K. Chen, F. He, and L. Yuan, "Wireless power transfer to multiple loads over various distances using relay resonators," IEEE Microwave and Wireless Components Letters, Vol. 25, 337-339, 2015.
doi:10.1109/LMWC.2015.2409776 Google Scholar

15. Li, H., J. Li, K. Wang, W. Chen, and X. Yang, "A maximum efficiency point tracking control scheme for wireless power transfer systems using magnetic resonant coupling," IEEE Transactions on Power Electronics, Vol. 30, 3998-4008, 2015.
doi:10.1109/TPEL.2014.2349534 Google Scholar

16. Huh, J., S. W. Lee, W. Y. Lee, G. H. Cho, and C. T. Rim, "Narrow-width inductive power transfer system for online electrical vehicles," IEEE Transactions on Power Electronics, Vol. 26, 3666-3679, 2011.
doi:10.1109/TPEL.2011.2160972 Google Scholar

17. Choi, S. Y., S. Y. Jeong, B. W. Gu, G. C. Lim, and C. T. Rim, "Ultraslim S-type power supply rails for roadway-powered electric vehicles," IEEE Transactions on Power Electronics, Vol. 30, 6456-6468, 2015.
doi:10.1109/TPEL.2015.2444894 Google Scholar

18. Waffenschmidt, E., "Homogeneous magnetic coupling for free positioning in an inductive wireless power system," IEEE Journal of Emerging and Selected Topics in Power Electronics, Vol. 3, 226-233, 2015.
doi:10.1109/JESTPE.2014.2328867 Google Scholar

19. Zhang, Z. and K. T. Chau, "Homogeneous wireless power transfer for move-and-charge," IEEE Transactions on Power Electronics, Vol. 30, 6213-6220, 2015.
doi:10.1109/TPEL.2015.2414453 Google Scholar

20. Su, Y. C., H. Jin, W. Y. Lee, and C. T. Rim, "Asymmetric coil sets for wireless stationary EV chargers with large lateral tolerance by dominant field analysis," IEEE Transactions on Power Electronics, Vol. 29, 6406-6420, 2014. Google Scholar

21. Ram Rakhyani, A. K., S. Mirabbasi, and M. Chiao, "Design and optimization of resonancebased efficient wireless power delivery systems for biomedical implants," IEEE Transactions on Biomedical Circuits and Systems, Vol. 5, 48-63, 2011.
doi:10.1109/TBCAS.2010.2072782 Google Scholar

22. Soma, M., D. C. Galbraith, and R. L. White, "Radio-frequency coils in implantable devices: misalignment analysis and design procedure," IEEE Transactions on Biomedical Engineering, Vol. 34, 276-282, 1987.
doi:10.1109/TBME.1987.326088 Google Scholar

23. Zierhofer, C. M. and E. S. Hochmair, "Geometric approach for coupling enhancement of magnetically coupled coils," IEEE Transactions on Biomedical Engineering, Vol. 43, 708-714, 1996.
doi:10.1109/10.503178 Google Scholar

24. Ke, Q., W. Luo, G. Yan, and K. Yang, "Analytical model and optimized design of power transmitting coil for inductively coupled endoscope robot," IEEE Transactions on Biomedical Engineering, Vol. 63, 694-706, 2016.
doi:10.1109/TBME.2015.2469137 Google Scholar

Dr. Zhongqi Li

Dr. Min Zhang

Dr. Shoudao Huang

Dr. Jiliang Yi