Fully Integrated Magnetic Structure and Optimized Design of Dual Buck-Boost-CLLC Three-Port Converter
Cheng He1, Li Pengsheng1, Xu Kai1, Huang Weiwei2, Yu Dongsheng1
1. School of Electrical Engineering China University of Mining and Technology Xuzhou 221116 China; 2. School of Mathematics China University of Mining and Technology Xuzhou 221116 China
Abstract：Due to its shared structure, the dual Buck/Boost-CLLC three-port converter has a simple structure and few power devices. The integrated interleaved parallel Buck/Boost unit significantly reduces input current ripple, while the integration of CLLC units endows the converter with excellent buck-boost conversion capability and soft-switching capability. However, the large number and volume of magnetic components in the shared structure are the main factors limiting the size of the power converter. Increasing the switching frequency or using magnetic integration can increase the power density of the power converter. However, in some studies, some schemes integrate two energy storage inductors and the resonant inductor in the converter to enhance coupled inductor current sharing and converter power density. Nonetheless, these schemes can only integrate full inverse coupling at a fixed duty cycle and cannot control the inverse coupling coefficient. Integration schemes with controllable coupling coefficients have been proposed, but two magnetic components remain after integration. This paper proposes a fully integrated magnetic structure based on a dual Buck/Boost-CLLC three-port converter. By unevenly distributing the windings and establishing low reluctance paths, all magnetic components are integrated into a single magnetic element under variable duty cycle and coupling coefficient conditions. The proposed fully integrated magnetic component achieves inverse coupled inductor current sharing and ripple reduction, thereby enhancing system stability. Additionally, by integrating all magnetic components into a single magnetic element, the increased magnetic flux cancellation within the core further reduces core losses. Fig.A1 shows the proposed fully integrated magnetic structure, which consists of a cover magnetic core and a base magnetic core. Firstly, based on the partially integrated structures and the proposed fully integrated structure, magnetic circuit models were established for both partially integrated and fully integrated magnetic components. The magnetic flux distribution and cancellation with different integration methods were compared. It is shown that the proposed fully integrated structure exhibits more magnetic flux cancellation and has lower losses. Next, the performance-influencing parameters were analyzed, and a loss model was developed. Low losses for the fully integrated magnetic component were achieved through finite element parameterization scanning. Finally, a 500W prototype platform was built, and comparative experiments of non-integrated, partially integrated, and fully integrated magnets were conducted. Steady-state and dynamic experiments verified the feasibility of the integrated magnetic design. Efficiency and temperature comparison experiments validated the effectiveness of the integrated magnetic design. The results show that the proposed fully integrated magnetic component maintains the same volume and footprint and exhibits more magnetic flux cancellation and uniform temperature distribution. The fully integrated magnetic component achieves an efficiency of 94.6% under full load, demonstrating higher power density and efficiency compared to non-integrated and partially integrated structures.
[1] 刘畅, 卓建坤, 赵东明, 等. 利用储能系统实现可再生能源微电网灵活安全运行的研究综述[J]. 中国电机工程学报, 2020, 40(1): 1-18. Liu Chang, Zhuo Jiankun, Zhao Dongming, et al.A review on the utilization of energy storage system for the flexible and safe operation of renewable energy microgrids[J]. Proceedings of the CSEE, 2020, 40(1): 1-18. [2] 李建林, 田立亭, 来小康. 能源互联网背景下的电力储能技术展望[J]. 电力系统自动化, 2015, 39(23): 15-25. Li Jianlin, Tian Liting, Lai Xiaokang.Outlook of electrical energy storage technologies under energy Internet background[J]. Automation of Electric Power Systems, 2015, 39(23): 15-25. [3] 蒋玮, 余斌, 郁家麟, 等. 蜂巢状有源配电网中多端口能量枢纽控制策略[J]. 电力工程技术, 2023, 42(5): 70-79. Jiang Wei, Yu Bin, Yu Jialin, et al.Control strategy of multi-port energy hub in honeycomb active dis- tribution network[J]. Electric Power Engineering Technology, 2023, 42(5): 70-79. [4] 张英敏, 张婉欣, 李保宏, 等. 基于光储联合系统的电网分段恢复策略[J]. 电力工程技术, 2024, 43(4): 26-35. Zhang Yingmin, Zhang Wanxin, Li Baohong, et al.Segmentation restoration strategy of power grid based on combined optical storage system[J]. Electric Power Engineering Technology, 2024, 43(4): 26-35. [5] 高圣伟, 祝庆同. 一种独立光储发电系统用宽输入范围非隔离三端口变换器[J]. 电工技术学报, 2023, 38(4): 970-982. Gao Shengwei, Zhu Qingtong.A wide input range non-isolated three-port converter for stand-alone PV storage power generation system[J]. Transactions of China Electrotechnical Society, 2023, 38(4): 970-982. [6] 奚磊, 崔巍. 适用于直流微网系统的新型双向三端口变换器及其控制策略[J]. 电气自动化, 2024, 46(3): 73-75, 79. Xi Lei, Cui Wei.Novel bidirectional three-port converter for DC microgrid system and its control strategy[J]. Electrical Automation, 2024, 46(3): 73-75, 79. [7] 李俊杰, 吴红飞, 花文敏, 等. CLLC双向谐振变换器电感-变压器矩阵式一体化集成与优化设计[J]. 中国电机工程学报, 2022, 42(10): 3720-3729. Li Junjie, Wu Hongfei, Hua Wenmin, et al.Integrated inductor-transformer matrix and optimization design of CLLC bidirectional resonant converter[J]. Pro- ceedings of the CSEE, 2022, 42(10): 3720-3729. [8] 花文敏. 基于PCB绕组和矩阵磁集成的双向CLLC谐振变换器[D]. 南京: 南京航空航天大学, 2021. Hua Wenmin.Bidirectional CLLC resonant converter based on PCB winding and matrix magnetic inte- gration[D]. Nanjing: Nanjing University of Aeronautics and Astronautics, 2021. [9] 杨玉岗, 李洪珠, 王建林, 等. 可削减直流偏磁集成磁件在DC/DC变换器中的应用[J]. 中国电机工程学报, 2005, 25(11): 50-54. Yang Yugang, Li Hongzhu, Wang Jianlin, et al.Research on the application of an integrated mag- netics whose DC-bias can be reduced in DC/DC converter[J]. Proceedings of the CSEE, 2005, 25(11): 50-54. [10] 蒋丹, 刘福鑫, 毛韵雨, 等. 采用耦合电感的Buck/ Boost集成型三端口直流变换器[J]. 电力系统自动化, 2014, 38(3): 7-13. Jiang Dan, Liu Fuxin, Mao Yunyu, et al.A Buck/ Boost integrated three-port DC-DC converter with coupled inductors[J]. Automation of Electric Power Systems, 2014, 38(3): 7-13. [11] 杨玉岗, 李涛, 冯本成. 交错并联磁集成双向DC/DC变换器的设计准则[J]. 中国电机工程学报, 2012, 32(30): 37-45. Yang Yugang, Li Tao, Feng Bencheng.Design criterion for interleaving and magnetically integrated bidirectional DC/DC converters[J]. Proceedings of the CSEE, 2012, 32(30): 37-45. [12] 高圣伟, 李永宵, 田金锐, 等. 双频DC-DC变换器的磁集成技术[J]. 电工技术学报, 2024, 39(13): 4025-4036. Gao Shengwei, Li Yongxiao, Tian Jinrui, et al.Magnetic integration technology of dual-frequency DC-DC converter[J]. Transactions of China Electro- technical Society, 2024, 39(13): 4025-4036. [13] 申彦峰. 用于独立光伏发电系统的LLC集成型三端口直流变换器研究[D]. 秦皇岛: 燕山大学, 2015. Shen Yanfeng.Research on LLC integrated three-port DC converter for independent photovoltaic power generation system[D]. Qinhuangdao: Yanshan University, 2015. [14] 李鹏程, 张纯江, 阚志忠, 等. 软开关高增益Buck- Boost集成CLLC型直流双向变换器[J]. 中国电机工程学报, 2018, 38(11): 3295-3305. Li Pengcheng, Zhang Chunjiang, Kan Zhizhong, et al.An integrated Buck-Boost CLLC bidirectional DC converter with high gain and soft switching[J]. Proceedings of the CSEE, 2018, 38(11): 3295-3305. [15] 李洪珠, 罗帅. 磁集成双Buck/Boost-LLC三端口DC-DC变换器[J]. 电机与控制学报, 2022, 26(5): 125-134. Li Hongzhu, Luo Shuai.Magnetically integrated dual Buck/Boost-LLC three-port DC-DC converter[J]. Electric Machines and Control, 2022, 26(5): 125-134. [16] D’Antonio M, Chakraborty S, Khaligh A. Planar transformer with asymmetric integrated leakage inductance using horizontal air gap[J]. IEEE Transa- ctions on Power Electronics, 2021, 36(12): 14014-14028. [17] 汪航, 安少亮, 常天豪, 等. 基于CLLC谐振变换器的磁集成变压器优化设计[J]. 电力电子技术, 2023, 57(2): 95-97. Wang Hang, An Shaoliang, Chang Tianhao, et al.Optimization design of magnetically integrated trans- former based on CLLC resonant converter[J]. Power Electronics, 2023, 57(2): 95-97. [18] Wu Qunfang, Jiang Menghan, Sun Zhifeng, et al.An internal magnetic core termination integration method for LLC four-elemental matrix transformer[J]. IEEE Transactions on Power Electronics, 2023, 38(11): 13573-13579. [19] Liu Yue, Wu Hongfei, Ge Zixian, et al.Magnetic integration for multiple resonant converters[J]. IEEE Transactions on Industrial Electronics, 2023, 70(8): 7604-7614. [20] Alaql F, Batarseh I.A Boost and LLC resonant-based three-port DC-DC converter[C]//2021 IEEE Energy Conversion Congress and Exposition (ECCE), Vancouver, BC, Canada, 2021: 2118-2122. [21] Wong P L, Wu Q, Xu Peng, et al.Investigating coupling inductors in the interleaving QSW VRM[C]//APEC 2000. Fifteenth Annual IEEE Applied Power Electronics Conference and Exposition (Cat. No. 00CH37058), New Orleans, LA, USA, 2000: 973-978. [22] Gao Yihan, Zhou Lu, Ding Qiang, et al.Power decoupling three-port converter with integrated trans- former[C]//2022 IEEE International Power Elec- tronics and Application Conference and Exposition (PEAC), Guangzhou, China, 2022: 817-821. [23] Wang Zhiqing, Luo Quanming, Wei Yuqi, et al.Topology analysis and review of three-port DC-DC converters[J]. IEEE Transactions on Power Electro- nics, 2020, 35(11): 11783-11800. [24] 王芷晴. PWM+变电感控制LLC三端口DC/DC变换器研究[D]. 重庆: 重庆大学, 2020. Wang Zhiqing.Study on LLC three-port DC/DC converter with PWM+variable inductor control[D]. Chongqing: Chongqing University, 2020. [25] 程鹤, 徐恺, 李朋圣, 等. 三相CLLC谐振变换器磁集成平面变压器设计与优化[J]. 电工技术学报, 2024, 39(12): 3774-3786. Cheng He, Xu Kai, Li Pengsheng, et al.Design and optimization of three-phase CLLC resonant converter with magnetic integrated planar transformer[J]. Transactions of China Electrotechnical Society, 2024, 39(12): 3774-3786. [26] 周国华, 邱森林, 张小兵. 宽增益高效率级联式四开关Buck-Boost LLC变换器[J]. 电工技术学报, 2024, 39(4): 1103-1115. Zhou Guohua, Qiu Senlin, Zhang Xiaobing.Wide gain and high efficiency cascaded four-switch Buck- Boost LLC converter[J]. Transactions of China Elec- trotechnical Society, 2024, 39(4): 1103-1115. [27] 李加明, 任小永, 周治成, 等. 基于谐振网络优化的双向LLC-DCX多模块并联系统均流优化研究[J]. 电工技术学报, 2023, 38(10): 2720-2730, 2756. Li Jiaming, Ren Xiaoyong, Zhou Zhicheng, et al.Research on current sharing optimization of bidi- rectional LLC-DCX multi-module parallel system based on resonant network optimization[J]. Transa- ctions of China Electrotechnical Society, 2023, 38(10): 2720-2730, 2756. [28] 赵剑, 张哲, 李召端, 等. 三端口CLLC固态变压器的设计与优化[J]. 电工技术学报, 2024, 39(23): 7542-7553. Zhao Jian, Zhang Zhe, Li Zhaoduan, et al.Design and optimization of three-port CLLC solid-state trans- former[J]. Transactions of China Electrotechnical Society, 2024, 39(23):7542-7553. [29] 张新闻, 刘文泽, 杨树德, 等. MOSFET输出电容对CLLLC谐振变换器模型的优化[J]. 电工技术学报, 2024, 39(22): 7228-7238. Zhang Xinwen, Liu Wenze, Yang Shude, et al.Optimization of CLLLC resonant converter modeling by MOSFET output capacitance[J]. Transactions of China Electrotechnical Society, 2024, 39(22): 7228-7238. [30] 赵永秀, 刘泽伟, 王崇杰, 等. 变模态倍压型LLC谐振变换器多目标参数优化[J]. 电工技术学报, 2024, 39(22): 7139-7153. Zhao Yongxiu, Liu Zewei, Wang Chongjie, et al.Multi objective parameter optimization of variable mode voltage doubling LLC resonant converter[J]. Transactions of China Electrotechnical Society, 2024, 39(22): 7139-7153.
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