volume | PIER Journals

Abstract

Nowadays, misalignment tolerant wireless power transfer systems providing simultaneous power supply to several devices are the subject of intensive research in the field of wireless charging of electronic devices. A critical parameter in such systems is the uniformity of magnetic field generated by a transmitting coil. In this paper, we examine the characteristics of the magnetic field distribution of arbitrary shape planar transmitting coils and propose a genetic algorithm for optimizing their design with the objective of increasing the field uniformity. This study stands out from existing literature by introducing an optimization approach that not only encompasses traditional circular and square coils but also extends to convex polygonal coils. The results of the algorithm are validated experimentally on coils of three various geometries including circular, square, and hexagonal coils. The coefficient of variation of the magnetic field, which serves as a quantitative measure of its uniformity, is found to be 3.6% for circular coil, 5.2% for square one, and 5.1% for hexagonal one in a region of interest encompassing half of the total area of transmitting coil.

1. Song, Mingzhao, Prasad Jayathurathnage, Esmaeel Zanganeh, Mariia Krasikova, Pavel Smirnov, Pavel Belov, Polina Kapitanova, Constantin Simovski, Sergei Tretyakov, and Alex Krasnok, "Wireless power transfer based on novel physical concepts," Nature Electronics, Vol. 4, No. 10, 707-716, Oct. 2021.

2. Yu, Xipei, Junjie Feng, Liyan Zhu, and Qiang Li, "Design and optimization of a planar omnidirectional wireless power transfer system for consumer electronics," IEEE Open Journal of Power Electronics, Vol. 5, 311-322, 2024.
doi:The server didn't respond in time.

3. Essa, Amine, Eqab Almajali, Soliman Mahmoud, Rony E. Amaya, Saqer S. Alja’Afreh, and Muhammad Ikram, "Wireless power transfer for implantable medical devices: Impact of implantable antennas on energy harvesting," IEEE Open Journal of Antennas and Propagation, Vol. 5, No. 3, 739-758, 2024.

4. Moloudian, Gholamhosein, Mohammadamin Hosseinifard, Sanjeev Kumar, Roy B. V. B. Simorangkir, John L. Buckley, Chaoyun Song, Gualtiero Fantoni, and Brendan O’Flynn, "RF energy harvesting techniques for battery-less wireless sensing, Industry 4.0, and Internet of Things: A review," IEEE Sensors Journal, Vol. 24, No. 5, 5732-5745, Mar. 2024.

5. Ahmed, Marwa M., Mohamed A. Enany, Ahmed A. Shaier, Haneen M. Bawayan, and Shimaa A. Hussien, "An extensive overview of inductive charging technologies for stationary and in-motion electric vehicles," IEEE Access, 69875-69894, 2024.

6. Ramakrishnan, Venkatesan, Narayanamoorthi Rajamanickam, Hossam Kotb, Ali Elrashidi, et al. "A comprehensive review on efficiency enhancement of wireless charging system for the electric vehicles applications," IEEE Access, Vol. 12, 46967-46994, 2024.

7. De Almeida, Jorge Virgilio, Xiaoqiang Gu, and Ke Wu, "SWIPT base stations for battery-free, wirelessly powered IoT networks: A review on architectures, circuits and technologies," IEEE Microwave Magazine, Vol. 25, No. 6, 22-40, Jun. 2024.

8. Zhong, W. X., Xun Liu, and S. Y. Ron Hui, "A novel single-layer winding array and receiver coil structure for contactless battery charging systems with free-positioning and localized charging features," IEEE Transactions on Industrial Electronics, Vol. 58, No. 9, 4136-4144, 2011.

9. Zhang, Cun, Wei Wang, Chenjin Xu, and Jingyu Yang, "Research on uniform magnetic field compensation structure of array circular coils for wireless power transfer," IEEE Transactions on Magnetics, Vol. 57, No. 6, 1-5, 2021.

10. Jow, Uei-Ming and Maysam Ghovanloo, "Geometrical design of a scalable overlapping planar spiral coil array to generate a homogeneous magnetic field," IEEE Transactions on Magnetics, Vol. 49, No. 6, 2933-2945, Jun. 2013.

11. Liu, Xun and S. Y. Hui, "Optimal design of a hybrid winding structure for planar contactless battery charging platform," IEEE Transactions on Power Electronics, Vol. 23, No. 1, 455-463, 2008.

12. Cai, Changsong, Junhua Wang, Hui Nie, Pengcheng Zhang, Zhongzheng Lin, and Ying-Guo Zhou, "Effective-configuration WPT systems for drones charging area extension featuring quasi-uniform magnetic coupling," IEEE Transactions on Transportation Electrification, Vol. 6, No. 3, 920-934, 2020.

13. Kudo, Ryotaro, Koutaro Hachiya, Toshiki Kanamoto, and Atsushi Kurokawa, "A bernoulli spiral coil transmitter for charging various small electronic devices," IEICE Electronics Express, Vol. 19, No. 23, 20220419-20220419, Dec. 2022.

14. Casanova, Joaquin J., Zhen Ning Low, Jenshan Lin, and Ryan Tseng, "Transmitting coil achieving uniform magnetic field distribution for planar wireless power transfer system," 2009 IEEE Radio and Wireless Symposium, 530-533, San Diego, CA, USA, Jan. 2009.

15. Kudo, Ryotaro, Koutaro Hachiya, Toshiki Kanamoto, and Atsushi Kurokawa, "A parabolic spiral coil transmitter with uniform magnetic field for smart devices," IEICE Electronics Express, Vol. 20, No. 1, 20220492-20220492, Jan. 2023.

16. Wang, Shengming, Zhaoyang Hu, CanCan Rong, Conghui Lu, Junfeng Chen, and Minghai Liu, "Planar multiple-antiparallel square transmitter for position-insensitive wireless power transfer," IEEE Antennas and Wireless Propagation Letters, Vol. 17, No. 2, 188-192, Feb. 2018.

17. Li, Jie, Ruiyang Qin, Jingjing Sun, and Daniel Costinett, "Systematic design of a 100-W 6.78-MHz wireless charging station covering multiple devices and a large charging area," IEEE Transactions on Power Electronics, Vol. 37, No. 4, 4877-4889, Apr. 2022.

18. Shen, Laiwei, Wanchun Tang, Huiling Xiang, and Wei Zhuang, "Uniform magnetic field by changing the current distribution on the planar coil for displacement-insensitive wireless power transfer/near field communication," Microwave and Optical Technology Letters, Vol. 57, No. 2, 424-427, Feb. 2015.

19. Zhang, Yun, Lifang Wang, Yanjie Guo, and Yuwang Zhang, "Optimisation of planar rectangular coil achieving uniform magnetic field distribution for EV wireless charging based on genetic algorithm," IET Power Electronics, Vol. 12, No. 10, 2706-2712, Aug. 2019.

20. Xu, Qi, Quankun Hu, Hao Wang, Zhi-Hong Mao, and Mingui Sun, "Optimal design of planar spiral coil for uniform magnetic field to wirelessly power position-free targets," IEEE Transactions on Magnetics, Vol. 57, No. 2, 1-9, Feb. 2021.

21. Rong, Cancan, Xiangrui He, Yitong Wu, Yongtao Qi, Ruohan Wang, Yunong Sun, and Minghai Liu, "Optimization design of resonance coils with high misalignment tolerance for drone wireless charging based on genetic algorithm," IEEE Transactions on Industry Applications, Vol. 58, No. 1, 1242-1253, Jan.-Feb. 2022.

22. Bilandžija, Domagoj, Davor Vinko, and Luka Filipović, "Genetic algorithm based optimization of circular planar coil geometry with homogeneous magnetic field distribution," 2023 46th MIPRO ICT and Electronics Convention (MIPRO), 218-222, Opatija, Croatia, May 2023.

23. Hui, Shu-Yuen Ron, Yun Yang, and Cheng Zhang, "Wireless power transfer: A paradigm shift for the next generation," IEEE Journal of Emerging and Selected Topics in Power Electronics, Vol. 11, No. 3, 2412-2427, Jun. 2023.

24. Simpson, James C., John E. Lane, Christopher D. Immer, and Robert C. Youngquist, ``Simple analytic expressions for the magnetic field of a circular current loop'', NASA, Tech. Rep., Feb. 2001.

25. Kramer, Oliver, Genetic Algorithm Essentials, Studies in Computational Intelligence. Springer Cham, 2017.
doi:10.1007/978-3-319-52156-5

26. De Rainville, François-Michel, Félix-Antoine Fortin, Marc-André Gardner, Marc Parizeau, and Christian Gagné, "DEAP: A python framework for evolutionary algorithms," Proceedings of the 14th Annual Conference Companion on Genetic and Evolutionary Computation, 85-92, Philadelphia Pennsylvania, USA, Jul. 2012.

27. Fortin, Félix-Antoine, François-Michel De Rainville, Marc-André Gardner, Marc Parizeau, and Christian Gagné, "DEAP: Evolutionary algorithms made easy," The Journal of Machine Learning Research, Vol. 13, No. 1, 2171-2175, Jul. 2012.

28. Lee, Wang-Sang, Han Lim Lee, Kyoung-Sub Oh, and Jong-Won Yu, "Uniform magnetic field distribution of a spatially structured resonant coil for wireless power transfer," Applied Physics Letters, Vol. 100, No. 21, 214105, May 2012.

29. Bilandžija, Domagoj, Davor Vinko, and Marinko Barukčić, "Genetic-algorithm-based optimization of a 3D transmitting coil design with a homogeneous magnetic field distribution in a WPT system," Energies, Vol. 15, No. 4, 1381, Feb. 2022.

30. Li, Jie, Jingjing Sun, Ruiyang Qin, and Daniel Costinett, "Transmitter coil design for multi-load wireless power transfer systems," 2020 IEEE Energy Conversion Congress and Exposition (ECCE), 1032-1038, Detroit, MI, USA, Oct. 2020.

31. Zhang, Cun, Wei Wang, Chenjin Xu, and Jingyu Yang, "Research on uniform magnetic field compensation structure of array circular coils for wireless power transfer," IEEE Transactions on Magnetics, Vol. 57, No. 6, 1-5, Jun. 2021.

32. Miroshnikov, A., N. Zotov, P. Smirnov, and P. Kapitanova, "Spiral coil magnetic field optimizer," [Online]. Available: https://github.com/MiroshnikovAleksandr/Spiral-coil-magnetic-field-optimizer, 2024.

Mr. Pavel Smirnov

Dr. Aleksandr Miroshnikov

Professor Polina V. Kapitanova