Implementation Method of Wide Range Zero Voltage Switching in Magnetic Coupling Wireless Power Transfer System
Jia Yahui1, Wang Zhihui1, Xiao Jing2, Zuo Zhiping1, Zhao Lei1
1. School of Automation Chongqing University Chongqing 400044 China; 2. Southern Power Grid Corporation Wireless Power Transmission Joint Laboratory Guangxi Power Grid Co. Ltd Nanning 530023 China
Abstract：Air gap variations between coils are inevitable in magnetic coupling wireless power transfer (MC-WPT) systems. At the same time, due to the presence of magnetic and metallic materials, air gap variations can change mutual inductance and self-inductance, which is particularly evident in small air gap applications. Mutual inductance variations lead to output power fluctuation, and self-inductance variations lead to detuning and system input impedance change. Thus, achieving zero voltage switching (ZVS) in an inverter is challenging. Thus, power and efficiency are reduced. Taking the wireless charging system of an automatic guided vehicle (AGV) as an example, this paper proposes a wide coupling range ZVS implementation method for the MC-WPT system, considering coil parameters and load variations. Firstly, a time-domain analysis model of the LCC-S compensation system is established. The influence of coil parameters (mutual inductance and self-inductance) and load variations on the ZVS operation is studied. As the air gap gradually decreases, the self-inductance of the primary coil and the mutual inductance changes are not conducive to the ZVS operation, and the self-inductance changes of the secondary coil are conducive. By keeping the self-inductance in the primary coil unchanged and combining with the ZVS critical condition, the relationship between the mutual inductance and change in self-inductance of the secondary coil within the full load range is fitted, which is the ZVS operation boundary trajectory of the WPT system. Secondly, phase shift modulation (PSM) achieves constant current/voltage (CC/CV) output to charge the AGV battery. At the same time, based on the ZVS operation boundary trajectory, the self-inductance of the primary coil remains constant through coil structure and compensation parameter optimization, and the self-inductance of the secondary coil changes into a favorable variable inductive input impedance, effectively expanding the ZVS operating range of PSM. Moreover, the reactive current of the system is minimized within the full coupling range, which is beneficial for improving efficiency. Compared to the traditional ZVS range expansion method, the proposed method utilizes the parameter variation characteristics of the coil itself without additional control variables to avoid the adverse effects from self-inductance changes, which is more straightforward and more effective. Finally, a 250 W experimental platform is built to verify the correctness and effectiveness of the theoretical analysis. The experimental results show that within the air gap range of 10 mm to 60 mm, under a maximum self-inductance variation range of 32.88 μH to 23.84 μH and a maximum mutual inductance variation range of 19.13 μH to 6.05 μH, wide coupling range ZVS operation and CC/CV output are achieved with the minimum reactive current, and the peak efficiency is 92.5%.
贾亚辉, 王智慧, 肖静, 左志平, 赵雷. 磁耦合无线电能传输系统宽范围零电压开关实现方法[J]. 电工技术学报, 2024, 39(22): 6952-6964.
Jia Yahui, Wang Zhihui, Xiao Jing, Zuo Zhiping, Zhao Lei. Implementation Method of Wide Range Zero Voltage Switching in Magnetic Coupling Wireless Power Transfer System. Transactions of China Electrotechnical Society, 2024, 39(22): 6952-6964.
[1] 陈志鑫, 张献, 沙琳, 等. 基于频率调节的电动汽车无线充电互操作性提升方法研究[J]. 电工技术学报, 2023, 38(5): 1237-1247. Chen Zhixin, Zhang Xian, Sha Lin, et al.Research on improving interoperability of electric vehicle wireless power transfer based on frequency adjustment[J]. Transactions of China Electrotechnical Society, 2023, 38(5): 1237-1247. [2] 冯鸿运, 林飞, 杨中平, 等. 应用于自动导引小车无线充电系统的导航与供电一体化线圈研究[J/OL]. 电工技术学报, 2023: https://doi.org/10.19595/j.cnki.1000-6753.tces.230831. Feng Hongyun, Lin Fei, Yang Zhongping, et al. A research on a navigation and power supply integrated coil for automatic guided vehicle wireless power transfer system[J/OL]. Transactions of China Elec- trotechnical Society, 2023: https://doi.org/10.19595/j.cnki.1000-6753.tces.230831. [3] 刘哲, 苏玉刚, 邓仁为, 等. 基于双边LC补偿的单电容耦合无线电能传输系统[J]. 电工技术学报, 2022, 37(17): 4306-4314. Liu Zhe, Su Yugang, Deng Renwei, et al.Research on single capacitive coupled wireless power transfer system with double-side LC compensation[J]. Transa- ctions of China Electrotechnical Society, 2022, 37(17): 4306-4314. [4] 胡秀芳, 王跃, 吕双庆, 等. 基于谐波状态空间的无线电能传输系统建模和稳定性分析[J]. 电力系统自动化, 2022, 46(11): 121-130. Hu Xiufang, Wang Yue, Lü Shuangqing, et al.Modeling and stability analysis of wireless power transfer system based on harmonic state space[J]. Automation of Electric Power Systems, 2022, 46(11): 121-130. [5] 孙淑彬, 张波, 李建国, 等. 多负载磁耦合无线电能传输系统的拓扑发展和分析[J]. 电工技术学报, 2022, 37(8): 1885-1903. Sun Shubin, Zhang Bo, Li Jianguo, et al.Analysis and development on topologies of multi-load magnetic- coupling wireless power transfer system[J]. Transa- ctions of China Electrotechnical Society, 2022, 37(8): 1885-1903. [6] 崔淑梅, 宋贝贝, 王志远. 电动汽车动态无线供电磁耦合机构研究综述[J]. 电工技术学报, 2022, 37(3): 537-554. Cui Shumei, Song Beibei, Wang Zhiyuan.Overview of magnetic coupler for electric vehicles dynamic wireless charging[J]. Transactions of China Electro- technical Society, 2022, 37(3): 537-554. [7] Lu Fei, Zhang Hua, Zhu Chong, et al.A tightly coupled inductive power transfer system for low- voltage and high-current charging of automatic guided vehicles[J]. IEEE Transactions on Industrial Electronics, 2019, 66(9): 6867-6875. [8] 薛明, 杨庆新, 章鹏程, 等. 机器人随机位置下动态无线供电阵列式发射模组优化设计[J]. 电工技术学报, 2022, 37(24): 6319-6331. Xue Ming, Yang Qingxin, Zhang Pengcheng, et al.Optimal design of dynamic wireless power trans- mitting array module in random position of robot[J]. Transactions of China Electrotechnical Society, 2022, 37(24): 6319-6331. [9] 焦超群, 杨旭, 杨俊峰, 等. 基于多目标优化理论的耦合无关恒压输出型LCC/S补偿感应电能传输系统[J]. 电工技术学报, 2023, 38(24): 6565-6580. Jiao Chaoqun, Yang Xu, Yang Junfeng, et al.Coupling-independent constant-voltage output LCC/S compensation inductive power transfer system based on multi-objective optimization theory[J]. Transa- ctions of China Electrotechnical Society, 2023, 38(24): 6565-6580. [10] 李争, 唐明磊, 解波, 等. 无线电能传输零电压开关角跟踪和动态电容补偿矩阵复合控制策略[J/OL]. 电工技术学报, 2023: https://doi.org/10.19595/j.cnki.1000-6753.tces.230453. Li Zheng, Tang Minglei, Xie Bo, et al. Composite control strategy of zero voltage switch angle tracking and dynamic capacitance compensation matrix for wireless power transfer[J/OL]. Transactions of China Electrotechnical Society, 2023: https://doi.org/10.19595/j.cnki.1000-6753.tces.230453. [11] Li Yong, Liu Shunpan, Zhu Xiao, et al.Extension of ZVS region of series-series WPT systems by an auxiliary variable inductor for improving effici- ency[J]. IEEE Transactions on Power Electronics, 2021, 36(7): 7513-7525. [12] Wang Xiaoqiang, Xu Jianping, Leng Minrui, et al.A hybrid control strategy of LCC-S compensated WPT system for wide output voltage and ZVS range with minimized reactive current[J]. IEEE Transactions on Industrial Electronics, 2021, 68(9): 7908-7920. [13] Choi J S, Jeong S Y, Choi B G, et al.Air-gap- insensitive IPT pad with ferromagnetic and conductive plates[J]. IEEE Transactions on Power Electronics, 2020, 35(8): 7863-7872. [14] Prasad K K, Agarwal V.Design recommendations considering charging pads' self-inductance variation with LCC-S and LCC-LCC compensation based IPT chargers in low clearance EVs[J]. IEEE Transactions on Transportation Electrification, 2023, 99: 1. [15] Kim D H, Ahn D.Self-tuning LCC inverter using PWM-controlled switched capacitor for inductive wireless power transfer[J]. IEEE Transactions on Industrial Electronics, 2019, 66(5): 3983-3992. [16] Li Weihan, Wei Guo, Cui Chao, et al.A double-side self-tuning LCC/S system using a variable switched capacitor based on parameter recognition[J]. IEEE Transactions on Industrial Electronics, 2021, 68(4): 3069-3078. [17] Li Weihan, Zhang Qianfan, Cui Chao, et al.A self- tuning S/S compensation WPT system without parameter recognition[J]. IEEE Transactions on Industrial Electronics, 2022, 69(7): 6741-6750. [18] Tan Ping'an, Song Bin, Lei Wang, et al.Decoupling control of double-side frequency tuning for LCC/S WPT system[J]. IEEE Transactions on Industrial Electronics, 2023, 70(11): 11163-11173. [19] 陆远方, 黎祎阳, 杨斌, 等. 考虑线圈参数变化的SS型动态无线电能传输系统参数优化设计方法[J]. 电工技术学报, 2022, 37(18): 4537-4547. Lu Yuanfang, Li Yiyang, Yang Bin, et al.Parameter design method for SS compensated dynamic wireless power transfer system considering coils' parameters variations[J]. Transactions of China Electrotechnical Society, 2022, 37(18): 4537-4547. [20] Yang Bin, Lu Yuanfang, Peng Yuner, et al.Analysis and design of a T/S compensated IPT system for AGV maintaining stable output current versus air gap and load variations[J]. IEEE Transactions on Power Electronics, 2022, 37(5): 6217-6228. [21] Lu Yuanfang, Yang Bin, He Shuangjiang, et al.Design of compensation topology for IPT system considering coils' parameters and load variations for CC or CV output[J]. IEEE Transactions on Trans- portation Electrification, 2023, DOI: 10.1109/TTE. 2023.3272919. [22] Jia Yahui, Wang Zhihui, Tang Chunsen, et al.An efficiency improvement method for the small air gap wireless power transfer system with variable parameters[J]. IEEE Transactions on Power Elec- tronics, 2023, 38(11): 13443-13453. [23] 潘帅帅, 麦瑞坤, 徐叶飞, 等. 自动导引车感应充电系统目标三维空间漏磁屏蔽[J]. 电工技术学报, 2022, 37(5): 1078-1087. Pan Shuaishuai, Mai Ruikun, Xu Yefei, et al.Three- dimensional target space magnetic leakage shielding for automated guided vehicle inductive charging system[J]. Transactions of China Electrotechnical Society, 2022, 37(5): 1078-1087. [24] Hu Hongsheng, Cai Tao, Duan Shanxu, et al.An optimal variable frequency phase shift control strategy for ZVS operation within wide power range in IPT systems[J]. IEEE Transactions on Power Electronics, 2020, 35(5): 5517-5530.
2024, Vol. 39 
