Abstract:The wireless sensor is an effective method to monitor the status of the substation busbar. The traditional power supply source of sensors is the battery. However, the battery has limited life and needs to be replaced frequently, which challenges the long-term stable operation of the sensor. The non-invasive magnetic field energy harvester system has the advantages of a simple structure, stable power supply, and convenient installation, which can effectively solve the power supply problem of the sensor. Since the core structure of the non-invasive magnetic field energy harvester system is non-closed, the power density of the system is low. In addition, the application of the non-invasive magnetic field energy harvester is seriously restricted. For the non-invasive magnetic field energy harvester system, the influence of core and coil parameters on its power density is very significant. Especially in the application scenario where the space is limited, the system power density cannot be improved by increasing the volume of the magnetic core. Hence, optimizing the magnetic core and coil parameters is particularly critical in this scenario. Unfortunately, the existing system optimization methods for analyzing magnetic core and coil parameters are relatively independent. Only mutual inductance is taken as the optimization index when optimizing the magnetic core, so the influence of coil parameter changes on the power density is ignored, which cannot accurately guide the design of the system prototype. Considering the influence of magnetic core size on coil parameters and taking power density instead of mutual inductance as an optimization index, this paper proposed a power density improvement method to optimize magnetic core and coil parameters. Firstly, the equivalent circuit of the system was analyzed, and the power density expression was established. Then, the optimization direction was clarified to improve the induced voltage, reduce the coil resistance, and reduce the magnetic core volume. Secondly, the H-shaped structure magnetic core was proposed to effectively gather the magnetic flux and reduce the coil resistance. Then, the induced voltage, the coil resistance, and the magnetic core volume were represented by magnetic core and coil parameters, and the influencing factors of the power density were determined. Thirdly, the influences of coil turns, coil diameter, lamination thickness, and magnetic column side length on the system power density were analyzed based on the finite element simulation. A power density improvement method was proposed by optimizing the magnetic core and coil parameters, i.e., designing the optimal values of coil turns, coil diameter, laminate thickness, and magnetic column side length to obtain higher power density. Finally, the energy harvester with different core and coil parameters was fabricated, and their output performance was tested. The experimental test results show that for the energy harvester with a limited core size of 30 mm× 30 mm×40 mm, under the condition of 100 A busbar current, the load voltage of the energy harvester is 3.64 V after optimization, which meets the power supply demand of most sensors. Moreover, the power density can reach 4.18 mW/cm3, 35 times the power density before optimization, verifying the effectiveness of the proposed power density improvement method.
李勇, 罗海军, 杨环宇, 闫一骅. 基于磁心与线圈参数优化的非侵入式磁场取能系统功率密度提升方法[J]. 电工技术学报, 2024, 39(2): 313-324.
Li Yong, Luo Haijun, Yang Huanyu, Yan Yihua. Power Density Improvement Method of Non-Invasive Magnetic Field Energy Harvester System Based on Optimization of Magnetic Core and Coil Parameters. Transactions of China Electrotechnical Society, 2024, 39(2): 313-324.
[1] 姚睿丰, 王妍, 高景晖, 等. 压电材料与器件在电气工程领域的应用[J]. 电工技术学报, 2021, 36(7): 1324-1337. Yao Ruifeng, Wang Yan, Gao Jinghui, et al.Applications of piezoelectric materials and devices in electric engineering[J]. Transactions of China Elec-trotechnical Society, 2021, 36(7): 1324-1337. [2] 刘友波, 王晴, 曾琦, 等. 能源互联网背景下5G网络能耗管控关键技术及展望[J]. 电力系统自动化, 2021, 45(12): 174-183. Liu Youbo, Wang Qing, Zeng Qi, et al.Key technologies and prospects of energy consumption management for 5G network in background of energy internet[J]. Automation of Electric Power Systems, 2021, 45(12): 174-183. [3] 雷怡琴, 孙兆龙, 叶志浩, 等. 电力系统负荷非侵入式监测方法研究[J]. 电工技术学报, 2021, 36(11): 2288-2297. Lei Yiqin, Sun Zhaolong, Ye Zhihao, et al.Research on non-invasive load monitoring method in power system[J]. Transactions of China Electrotechnical Society, 2021, 36(11): 2288-2297. [4] 高树国, 汲胜昌, 孟令明, 等. 基于在线监测系统与声振特征预测模型的高压并联电抗器运行状态评估方法[J]. 电工技术学报, 2022, 37(9): 2179-2189. Gao Shuguo, Ji Shengchang, Meng Lingming, et al.Operation state evaluation method of high-voltage shunt reactor based on on-line monitoring system and vibro-acoustic characteristic prediction model[J]. Transactions of China Electrotechnical Society, 2022, 37(9): 2179-2189. [5] 李阳, 李垚, 王瑞, 等. 无线传感器网络单线电能传输系统的电磁安全性分析[J]. 电工技术学报, 2022, 37(4): 808-815. Li Yang, Li Yao, Wang Rui, et al.Electromagnetic safety analysis on single wire power transfer system based on wireless sensor networks[J]. Transactions of China Electrotechnical Society, 2022, 37(4): 808-815. [6] 刘慧芳, 曹崇东, 赵强, 等. 悬臂式铁镓合金振动能量收集的存储方法[J]. 电工技术学报, 2020, 35(14): 3137-3146. Liu Huifang, Cao Chongdong, Zhao Qiang, et al.The method of vibration energy collection and storage of cantilever gallium-iron alloy[J]. Transactions of China Electrotechnical Society, 2020, 35(14): 3137-3146. [7] 赵争鸣, 王旭东. 电磁能量收集技术现状及发展趋势[J]. 电工技术学报, 2015, 30(13): 1-11. Zhao Zhengming, Wang Xudong.The state-of-the-art and the future trends of electromagnetic energy harvesting[J]. Transactions of China Electrotechnical Society, 2015, 30(13): 1-11. [8] 施翔, 王雅斌, 姚磊, 等. 风光互补一体供电系统在输电线路中的研究与应用[J]. 电气应用, 2015, 34(增刊2): 746-748. Shi Xiang, Wang Yabin, Yao Lei, et al.Research and application of wind-solar integrated power supply system in transmission lines[J]. Electrotechnical Application, 2015, 34(S2): 746-748. [9] 隋宇, 宁平凡, 牛萍娟, 等. 面向架空输电线路的挂载无人机电力巡检技术研究综述[J]. 电网技术, 2021, 45(9): 3636-3648. Sui Yu, Ning Pingfan, Niu Pingjuan, et al.Review on mounted UAV for transmission line inspection[J]. Power System Technology, 2021, 45(9): 3636-3648. [10] 骆一萍, 曾翔君, 雷永平, 等. 基于放电法的高压电场感应取能技术[J]. 电力系统自动化, 2015, 39(8): 113-119. Luo Yiping, Zeng Xiangjun, Lei Yongping, et al.High voltage electric field induction energy acquisition technology based on discharge method[J]. Automation of Electric Power Systems, 2015, 39(8): 113-119. [11] 熊兰, 何友忠, 宋道军, 等. 输变电线路在线监测设备供电电源的设计[J]. 高电压技术, 2010, 36(9): 2252-2257. Xiong Lan, He Youzhong, Song Daojun, et al.Design on power supply for the transmission line on-line monitoring equipment[J]. High Voltage Engineering, 2010, 36(9): 2252-2257. [12] 刘铮, 樊绍胜, 胡劼睿. 基于阻抗匹配的输电线路在线取能方法研究[J]. 中国电机工程学报, 2019, 39(23): 6867-6876, 7100. Liu Zheng, Fan Shaosheng, Hu Jierui.Research on on-line energy acquisition method for transmission lines based on impedance matching[J]. Proceedings of the CSEE, 2019, 39(23): 6867-6876, 7100. [13] 王黎明, 李海东, 陈昌龙, 等. 新型高压输电线路低下限死区大功率在线取能装置[J]. 高电压技术, 2014, 40(2): 344-352. Wang Liming, Li Haidong, Chen Changlong, et al.A novel online energy extracting device with low lower limit deadband on transmission line[J]. High Voltage Engineering, 2014, 40(2): 344-352. [14] 兰天, 蓝元良, 刘伟麟, 等. 面向换流阀状态监测用传感器节点电磁取能仿真分析与设计[J]. 电网技术, 2022, 46(4): 1503-1510. Lan Tian, Lan Yuanliang, Liu Weilin, et al.Design and analysis of electromagnetic induction based energy harvester for smart sensor node employed in HVDC converter[J]. Power System Technology, 2022, 46(4): 1503-1510. [15] Roscoe N M, Judd M D.Harvesting energy from magnetic fields to power condition monitoring sensors[J]. IEEE Sensors Journal, 2013, 13(6): 2263-2270. [16] Yuan Sheng, Huang Yi, Zhou Jiafeng, et al.Magnetic field energy harvesting under overhead power lines[J]. IEEE Transactions on Power Electronics, 2015, 30(11): 6191-6202. [17] Yuan Sheng, Huang Yi, Zhou Jiafeng, et al.A high-efficiency helical core for magnetic field energy harvesting[J]. IEEE Transactions on Power Elec-tronics, 2017, 32(7): 5365-5376. [18] Moghe R, Yang Yi, Lambert F, et al.A scoping study of electric and magnetic field energy harvesting for wireless sensor networks in power system appli-cations[C]//2009 IEEE Energy Conversion Congress and Exposition, San Jose, CA, USA, 2009: 3550-3557. [19] Moghe R, Yang Yi, Lambert F, et al.Design of a low cost self powered “stick-on” current and temperature wireless sensor for utility assets[C]//2010 IEEE Energy Conversion Congress and Exposition, Atlanta, GA, USA, 2010: 4453-4460. [20] 柳百毅, 陈为, 李榜, 等. 基于感应取能的微功率能量收集器[J]. 中国电机工程学报, 2020, 40(5): 1474-1485. Liu Baiyi, Chen Wei, Li Bang, et al.Micro-power energy harvester based on electromagnetic indu-ction[J]. Proceedings of the CSEE, 2020, 40(5): 1474-1485. [21] Pellitteri F, Boscaino V, Di Tommaso A O, et al. Experimental test on a contactless power transfer system[C]//2014 Ninth International Conference on Ecological Vehicles and Renewable Energies (EVER), Monte-Carlo, Monaco, 2014: 1-6. [22] Kaverine E, Palud S, Colombel F, et al.Investigation on an effective magnetic permeability of the rod-shaped ferrites[J]. Progress in Electromagnetics Research Letters, 2017, 65: 43-48. [23] DIN 43671-1975. Copper bus bars; design for continuous currentIN 43671-1975. Copper bus bars; design for continuous current[S]. 1975.