|
|
|
| Parameter Optimal Design of Full-Bridge CLL Resonant Converter Considering Backflow Power Factor |
| Huang Hewei1, Cao Taiqiang1, Pan Guangxu2, Cao Weizhong3, Zheng Min1, Yang Xiaoming1 |
1. School of Electrical and Electronic Information Xihua University Chengdu 610039 China;
2. Civil Aviation Chengdu Electronic Technology Co. Ltd Chengdu 611430 China;
3. Chengdu SIWI High-Tech Industry Company Limited Chengdu 610097 China |
|
|
|
Abstract Resonant converters are widely used in distributed power systems, notebook computers, communication equipment, and new energy electric vehicles due to their excellent performance. However, the parameters of resonant elements are the main factors affecting the gain, loss, volume of the converter, and overall performance. Therefore, optimizing these parameters can lead to improvements in converter performance.
Among many resonant topologies, the LLC resonant converter has received significant attention and is widely used in practical applications. This paper studies a new resonant topology converter with a T-type CLL structure resonant tank. Its operating characteristics are very similar to the traditional LLC, which can be realized in the ZVS of the primary-side MOSFETs and the ZCS of the secondary-side diodes. The advantage of the resonant converter is its high conversion efficiency. Nonetheless, the converter cannot avoid generating backflow power during the operation, and the increase in backflow power can lead to a sharp increase in the conduction loss and current stress of the converter switch, ultimately reducing conversion efficiency. Therefore, this paper analyzes and optimizes the backflow power generated by the CLL resonant converter.
Firstly, the operating modes of the full-bridge CLL converter are analyzed based on the backflow power definition. It is pointed out that backflow power is generated in both positive and negative operating modes. In addition, a time-domain expression for backflow power is derived, though its complexity makes direct calculation and characterization challenging. Secondly, two insights emerge from the modal analysis of backflow power: (1) Backflow power is essentially reactive power circulating in the circuit and is not directly equivalent to power loss. (2) Power loss due to the substantial backflow power in the circuit is dissipated mainly within the equivalent resistance of the active and passive components in the reactive path. As a result, direct calculation is unnecessary, and it suffices to characterize backflow power using a relevant variable. Thirdly, by analyzing the AC equivalent model of the CLL converter and combining it with the modes that generate backflow power, it is derived that backflow power can be indirectly characterized by the phase shift angle of the resonant tank’s input voltage and current. Accordingly, a simple characterization method for the backflow power of CLL resonant converters is proposed. Backflow power is reduced by optimizing resonance parameters within the constraints of voltage gain and ZVS, thereby enhancing conversion efficiency. Finally, the design method is verified by simulation and experiment using two sets of resonant parameters. The results show that conversion efficiency is improved by about 1.8% at the resonant frequency point under full-load conditions.
|
|
Received: 25 March 2023
|
|
|
|
|
|
[1] 赵烈, 裴云庆, 刘鑫浩, 等. 基于基波分析法的车载充电机CLLC谐振变换器参数设计方法[J]. 中国电机工程学报, 2020, 40(15): 4965-4976, 23.
Zhao Lie, Pei Yunqing, Liu Xinhao, et al.Design methodology of CLLC resonant converters for electric vehicle battery chargers[J]. Proceedings of the CSEE, 2020, 40(15): 4965-4976, 23.
[2] 丁超, 李勇, 姜利, 等. 电动汽车直流充电系统LLC谐振变换器软开关电压边界分析[J]. 电工技术学报, 2022, 37(1): 3-11.
Ding Chao, Li Yong, Jiang Li, et al.Analysis of soft switching voltage boundary of LLC resonant converter for EV DC charging system[J]. Transa- ctions of China Electrotechnical Society, 2022, 37(1): 3-11.
[3] 王皓, 朱金大, 侯凯, 等. 基于混合控制式交错并联LLC谐振变换器的充电模块研制[J]. 电力系统自动化, 2017, 41(7): 108-113.
Wang Hao, Zhu Jinda, Hou Kai, et al.Development of charging module based on interleaving paralleled LLC resonant converter with hybrid control[J]. Automation of Electric Power Systems, 2017, 41(7): 108-113.
[4] Zhao Bin, Zhang Xin.An efficiency-oriented two- stage optimal design methodology of high-frequency LCLC resonant converters for space travelling-wave tube amplifier applications[J]. IEEE Transactions on Industrial Electronics, 2020, 67(2): 1068-1080.
[5] Huang Daocheng, Fu Dianbo, Lee F C, et al.High-frequency high-efficiency-resonant converters with synchronous rectifiers[J]. IEEE Transactions on Industrial Electronics, 2010, 58(8): 3461-3470.
[6] Asa E, Colak K, Czarkowski D.Analysis of a CLL resonant converter with semi-bridgeless active rectifier and hybrid control[J]. IEEE Transactions on Industrial Electronics, 2015, 62(11): 6877-6886.
[7] Liu Yue, Wu Hongfei, Zou Jun, et al.CLL resonant converter with secondary side resonant inductor and integrated magnetics[J]. IEEE Transactions on Power Electronics, 2021, 36(10): 11316-11325.
[8] 吴建雪, 许建平, 陈章勇. CLL谐振变换器谐振电路参数优化设计[J]. 电力自动化设备, 2015, 35(1): 79-84, 152.
Wu Jianxue, Xu Jianping, Chen Zhangyong.Optimal design of resonant circuit parameters for CLL resonant converter[J]. Electric Power Automation Equipment, 2015, 35(1): 79-84, 152.
[9] Zhao Biao, Yu Qingguang, Sun Weixin.Extended- phase-shift control of isolated bidirectional DC-DC converter for power distribution in microgrid[J]. IEEE Transactions on Power Electronics, 2012, 27(11): 4667-4680.
[10] 范恩泽, 李耀华, 葛琼璇, 等. 基于优化移相的双有源串联谐振变换器前馈控制策略[J]. 电工技术学报, 2022, 37(20): 5324-5333.
Fan Enze, Li Yaohua, Ge Qiongxuan, et al.Feed- forward control strategy of dual active bridge series resonant converter based on optimized phase shift[J]. Transactions of China Electrotechnical Society, 2022, 37(20): 5324-5333.
[11] 周路遥, 姜久春. LCL谐振型双有源全桥双向DC-DC变换器分析与控制[J]. 电力系统自动化, 2016, 40(19): 82-86, 93.
Zhou Luyao, Jiang Jiuchun.Analysis and control of dual active bridge DC-DC converter based on LCL resonant network[J]. Automation of Electric Power Systems, 2016, 40(19): 82-86, 93.
[12] 王武, 雷文浩, 蔡逢煌, 等. 结合电流应力优化的双有源全桥DC-DC变换器自抗扰控制[J]. 电工技术学报, 2022, 37(12): 3073-3086.
Wang wu, Lei Wenhao, Cai Fenghuang, et al. Active disturbance rejection control of dual-active-bridge DC-DC converter with current stress optimization[J]. Transactions of China Electrotechnical Society, 2022, 37(12): 3073-3086.
[13] Shi Haochen, Wen Huiqing, Chen Jie, et al.Minimum-backflow-power scheme of DAB-based solid-state transformer with extended-phase-shift control[J]. IEEE Transactions on Industry Appli- cations, 2018, 54(4): 3483-3496.
[14] 杨超, 许海平, 张祖之, 等. PWM与移相结合控制下的混合三电平隔离型双向DC-DC最小回流功率控制研究[J]. 电工技术学报, 2019, 34(15): 3186-3197.
Yang Chao, Xu Haiping, Zhang Zuzhi, et al.Minimum backflow power control of the hybrid three level isolated bi-directional DC-DC converters based on PWM-phase-shifting control[J]. Transactions of China Electrotechnical Society, 2019, 34(15): 3186-3197.
[15] Shi Zhe, Tang Yu, Guo Yingjun, et al.Optimal design method of LLC half-bridge resonant converter considering backflow power analysis[J]. IEEE Transactions on Industrial Electronics, 2022, 69(4): 3599-3608.
[16] Kan Jiarong, Xie Shaojun, Tang Yu, et al.Voltage-fed dual active bridge bidirectional DC/DC converter with an immittance network[J]. IEEE Transactions on Power Electronics, 2014, 29(7): 3582-3590.
[17] 黄何伟, 曹太强, 李蔚, 等. 基于等效谐振腔的半桥CLL谐振变换器回流功率优化方法[J/OL]. 电源学报, 2023: 1-15. [2023-04-28] http://kns.cnki.net/kcms/ detail/12.1420.tm.20230427.1103.004.html.
Huang Hewei, Cao Taiqiang, Li Wei, et al. Optimi- zation method of backflow power of half-bridge CLL resonant converter based on equivalent resonant tanks[J/OL]. Journal of Power Supply, 2023: 1-15. [2023-04-28] http://kns.cnki.net/kcms/detail/12.1420.tm.20230427. 1103.004.html.
[18] 丁超, 李勇, 姜利, 等. 电动汽车直流充电系统LLC谐振变换器软开关电压边界分析[J]. 电工技术学报, 2022, 37(1): 3-11.
Ding Chao, Li Yong, Jiang Li, et al.Analysis of soft switching voltage boundary of LLC resonant converter for EV DC charging system[J]. Transa- ctions of China Electrotechnical Society, 2022, 37(1): 3-11. |
|
|
|
2023, Vol. 38 
