Constrained Efficiency Optimization for the Wireless Charging System with LC-Series Compensating Topology
Valery Zavyalov1, Irina Semykina1,2, Evgeny Dubkov1, Amet-Khan Velilyaev1, Amr Refky3
1. Institute of Nuclear Energy and Industry Sevastopol State University Sevastopol 299053 Russia; 2. Mining Industry Digital Transformation Laborotory T. F. Gorbachev Kuzbass State Technical University Kemerovo 650000 Russia; 3. Faculty of Engineering Al-Azhar University Cairo 4391064 Egypt
Abstract：The intensive development of electric vehicles contributes to advancing battery charging systems. One of the promising areas is wireless charging systems based on inductive power transfer. However, parameter optimization of the resonant circuit’s inductances and capacitances can affect the wireless charging system’s efficiency. This paper aims to optimize the constraint efficiency of wireless charging systems with LC-series compensating topology at a given resonant frequency and a given distance between transmitting and receiving coils. The constraints reflect dimensional restrictions on coils, ensuring transferred power is within an input voltage limit and limiting excess voltages on components. A mathematical model is used that assumes load as active resistance, no loss besides the ohm one, and the idealized inverter, rectifier, and power supply. The optimization criteria include four components: (1) the efficiency function ξ1 to be maximized; (2) the constraint function ξ2 determining the amount of transferred power to be lower limited; (3) and (4) the constraint functions ξ3 and ξ4 determining the excess voltage on the primary and secondary capacitors that to be upper limited. The dependencies are established using a frequency domain to describe each component of the optimization criteria on the resonant circuit parameters of the wireless charging systems. Due to complexity, some resonant circuit parameters are treated as constants in the given circumstance and discarded. Next, the dependencies between the rest of the parameters are obtained using Chebyshev polynomial approximation through the least-squares method, reducing the parameters to the coil inductance L. Moreover, the dependencies ξ1(L)~ξ4(L) are compared with their boundary conditions. Thus, the resonant circuit parameters that fulfill optimization criteria are theoretically obtained. The presented constrained efficiency optimization is validated using the specially-made wireless charging system for the electric truck ET-20132. Addressing various sources of loss, including those caused by the skin effect, transistors in the high-frequency inverter, diodes in the high-voltage bridge rectifier, and control schemes, is considered. Comparison of experiments and theoretical analysis shows good convergence at the resonant frequency 91.3 kHz, with acceptable deviations beyond the frequency range (approximately below 88 kHz and beyond 96 kHz). The wireless charging system normally operates within the frequency range of 91.3 kHz to 92.5 kHz, where the experimental load current closely aligns with the model, indicating that all the required power is transferred. Minimal average deviations between experiments and theoretical analysis are voltages on the primary and secondary side capacitors. The experimental results generally exceed model predictions. The efficiency can reach 91%.
[1] Lee H, Clark A. Charging the future: challenges and opportunities for electric vehicle adoption[J]. SSRN Electronic Journal, 2018, RWP18-026: 1-77. [2] Sanguesa J A, Torres-Sanz V, Garrido P, et al.A review on electric vehicles: technologies and challenges[J]. Smart Cities, 2021, 4(1): 372-404. [3] 李阳, 石少博, 刘雪莉, 等. 磁场耦合式无线电能传输耦合机构综述[J]. 电工技术学报, 2021, 36(增刊2): 389-403. Li Yang, Shi Shaobo, Liu Xueli, et al.Overview of magnetic coupling mechanism for wireless power transfer[J]. Transactions of China Electrotechnical Society, 2021, 36(S2): 389-403. [4] Foote A, Onar O C.A review of high-power wireless power transfer[C]//2017 IEEE Transportation Elec- trification Conference and Expo (ITEC), Chicago, IL, USA, 2017: 234-240. [5] Omer C Onar, Larry Seiber, Cliff White, et al.Wireless charging of electric vehicles[M]. Oak Ridge: Oak Ridge National Laboratory, 2016. [6] Zhang Bo, Carlson R B, Smart J G, et al.Challenges of future high power wireless power transfer for light-duty electric vehicles: technology and risk management[J]. eTransportation, 2019, 2: 100012. [7] Kurs A, Karalis A, Moffatt R, et al.Wireless power transfer via strongly coupled magnetic resonances[J]. Science, 2007, 317(5834): 83-86. [8] Diekhans T, De Doncker R W. A dual-side controlled inductive power transfer system optimized for large coupling factor variations and partial load[J]. IEEE Transactions on Power Electronics, 2015, 30(11): 6320-6328. [9] Zhang Jianzhong, Zhao Jin, Zhang Yaqian, et al.A wireless power transfer system with dual switch- controlled capacitors for efficiency optimization[J]. IEEE Transactions on Power Electronics, 2020, 35(6): 6091-6101. [10] Bandyopadhyay S, Venugopal P, Dong Jianning, et al.Comparison of magnetic couplers for IPT-based EV charging using multi-objective optimization[J]. IEEE Transactions on Vehicular Technology, 2019, 68(6): 5416-5429. [11] Otomo Y, Igarashi H.A 3-D topology optimization of magnetic cores for wireless power transfer device[J]. IEEE Transactions on Magnetics, 2019, 55(6): 1-5. [12] Hariri A, Elsayed A, Mohammed O A.An integrated characterization model and multiobjective optimi- zation for the design of an EV charger’s circular wireless power transfer pads[J]. IEEE Transactions on Magnetics, 2017, 53(6): 1-4. [13] Gao Pengfei, Tian Zijian, Pan Tao, et al.Trans- mission efficiency analysis and optimization of magnetically coupled resonant wireless power transfer system with misalignments[J]. AIP Advances, 2018, 8(8): 1-10. [14] Huang Wei, Ku H.Analysis and optimization of wireless power transfer efficiency considering the tilt angle of a coil[J]. Journal of Electromagnetic Engin- eering and Science, 2018, 18(1): 13-19. [15] Kim Y H, Kang S Y, Lee M L, et al.Optimization of wireless power transmission through resonant coupling[C]//2009 Compatibility and Power Elec- tronics, Badajoz, 2009: 426-431. [16] Orekan T, Zhang Peng, Shih C.Analysis, design, and maximum power-efficiency tracking for undersea wireless power transfer[J]. IEEE Journal of Emerging and Selected Topics in Power Electronics, 2018, 6(2): 843-854. [17] Ishida H, Furukawa H, Kyoden T.Development of design methodology for 60Hz wireless power trans- mission system[J]. IEEJ Journal of Industry Appli- cations, 2016, 5(6): 429-438. [18] Yan Yixin, Shi Wan, Zhang Xiaobing.Design of UAV wireless power transmission system based on coupling coil structure optimization[J]. EURASIP Journal on Wireless Communications and Networking, 2020, 2020(1): 1-13. [19] Yildiriz E, Kemer S B, Bayraktar M.IPT design with optimal use of spiral rectangular coils for wireless charging of e-tricycle scooters[J]. Engineering Science and Technology, an International Journal, 2022, 33: 101082. [20] 张献, 杨庆新, 崔玉龙, 等. 大功率无线电能传输系统能量发射线圈设计、优化与验证[J]. 电工技术学报, 2013, 28(10): 12-18. Zhang Xian, Yang Qingxin, Cui Yulong, et al.Design optimization and verification on the power trans- mitting coil in the high-power wireless power trans- mission system[J]. Transactions of China Electro- technical Society, 2013, 28(10): 12-18. [21] Borong Hu, Li Ran.High efficiency with multi load wireless power transmission[C]//International Russian- Sino Student Competition, Perm, Russia, 2015: 148-159. [22] Truong B D, Andersen E, Casados C, et al.Mag- netoelectric wireless power transfer for biomedical implants: effects of non-uniform magnetic field, alignment and orientation[J]. Sensors and Actuators A: Physical, 2020, 316: 112269. [23] Zheng Zhongjiu, Wang Ning, Ahmed S.Maximum efficiency tracking control of underwater wireless power transfer system using artificial neural networks[J]. Proceedings of the Institution of Mechanical Engineers, Part I: Journal of Systems and Control Engineering, 2021, 235(10): 1819-1829. [24] Zavylov V M, Semykina I, Abeidulin S A, et al.Criteria for choosing of resonant circuit parameters of wireless power transfer charging system[J]. Iranian Journal of Electrical and Electronic Engineering, 2022, 18: 2236. [25] Chaurasia D, Ahirwar S.An optimal parameter estimation technique for wireless electricity trans- mission[J]. Advances in Electronic and Electric Engineering, 2013, 3(1): 1-9. [26] 程鹏天, 王健强, 杜秀. 电动汽车感应耦合充电系统一种新型拓扑的研究[J]. 电工技术学报, 2013, 28(增刊2): 86-91. Cheng Pengtian, Wang Jianqiang, Du Xiu.Investi- gation of a novel topology for inductively coupled charging system in electric vehicles[J]. Transactions of China Electrotechnical Society, 2013, 28(S2): 86-91. [27] Zhang Wei, Mi C C.Compensation topologies of high-power wireless power transfer systems[J]. IEEE Transactions on Vehicular Technology, 2016, 65(6): 4768-4778. [28] Jayalath S, Khan A.Design, challenges, and trends of inductive power transfer couplers for electric vehicles: a review[J]. IEEE Journal of Emerging and Selected Topics in Power Electronics, 2021, 9(5): 6196-6218. [29] Shevchenko V, Husev O, Strzelecki R, et al.Com- pensation topologies in IPT systems: standards, requirements, classification, analysis, comparison and application[J]. IEEE Access, 2019, 7: 120559-120580. [30] Panchal C, Stegen S, Lu Junwei.Review of static and dynamic wireless electric vehicle charging system[J]. Engineering Science and Technology, an International Journal, 2018, 21(5): 922-937. [31] SAE J2954 Wireless power transfer for light-duty plug-in/electric vehicles and alignment methodo- logy[S]. [32] Kalantarov P L, Zeitlin L A.Calculation of indu- ctances[M] Leningrad: Energoatomizdat. Leningrad branch, 1986.
2024, Vol. 39 
