基于移相和调频的单级双向AC-DC变换器临界电流调制策略

doi:10.19595/j.cnki.1000-6753.tces.221020

Abstract
Figure/Table
References
Related Citation (15)

Download: PDF (10272 KB) HTML (1 KB)
Export: BibTeX | EndNote (RIS)

Abstract In optical storage, DC microgrids, and V2G (vehicle-to-grid) systems, isolated bidirectional AC/DC converters are important power conversion components whose performance specifications directly affect the performance and rollout of microgrid and V2G systems. The single-stage topology combines an AC-DC converter with power factor correction and an isolated DC-DC converter offering fewer switching devices, resulting in higher efficiency and lower cost. The single-stage topology based on the dual active bridge (DAB) is widely used due to its modularity and symmetrical structure. However, the traditional dual active bridge single-stage AC-DC converter usually adopts phase shift modulation, which has the difficulty of full range soft switching and high switching losses. Therefore, this paper proposes a modulation strategy based on boundary current mode (BCM), combining single-phase-shift and variable frequency to achieve ZVS, effectively reducing turn-on losses and improving converter efficiency.
Firstly, based on the conventional boundary current mode, the reset current is set to a negative value to achieve ZVS with a slight increase in conduction losses. Secondly, according to the inclusion of the reset current, it is difficult to rely on the phase shift duty ratio as a controlled quantity alone to achieve power factor correction on the AC side. Thus, the frequency control quantity is introduced based on the single phase shift control. Thirdly, the mathematical expressions for switching frequency and phase shift duty ratio in this modulation strategy are derived from the set value of the reset current I_B and the power factor correction conditions. The implementation of the modulation and the corresponding control block diagram are also given. Finally, the effect of the reset current on the converter performance is analyzed in terms of the switching frequency range, the RMS value of the inductor current, and the switch-off current to determine the value of the reset current I_B, and the soft switching range for a given reset current is analyzed. The modulation strategy combines single-phase shift and frequency modulation to realize soft switching and effectively improve the conversion efficiency.
In order to verify the feasibility of the modulation strategy, a DC 48 V AC 220 V 500 W experimental prototype was built. The converter with this modulation strategy can operate steadily in rectifier and inverter conditions. The system enables smooth switching between rectifier-inverter operations by changing the phase relationship when the AC voltage crosses zero. The soft switching of the AC and DC side at different phases of the line frequency is observed. It is verified that the modulation strategy can achieve ZVS in the full range. The efficiency of the converter under different load conditions was measured, and the highest efficiency reached 94 %. The THD of the AC side current in grid-connected mode was measured, and the THD above half load was below 5 %, suitable for the field of small and medium power bi-directional converters.

Key words： Phase shift control variable frequency AC-DC converter power factor correction (PFC) zero voltage switching (ZVS)

Received: 02 June 2022

PACS:

TM46

	Service

	E-mail this article
	Add to my bookshelf
	Add to citation manager
	E-mail Alert
	RSS
	Articles by authors
	Wang Zhangyi
	Lu Daorong
	Li Xiang
	Lang Tianchen
	Hu Haibing

Cite this article:

Wang Zhangyi,Lu Daorong,Li Xiang等. Boundary Current Modulation Strategy of Single-Stage Bidirectional AC-DC Converter Based on Phase-Shift and Variable-Frequency Control[J]. Transactions of China Electrotechnical Society, 2023, 38(14): 3888-3897.

URL:

https://dgjsxb.ces-transaction.com/EN/10.19595/j.cnki.1000-6753.tces.221020 OR https://dgjsxb.ces-transaction.com/EN/Y2023/V38/I14/3888

[1] Gu Yunjie, Li Yitong, Yoo H J, et al.Transfverter: imbuing transformer-like properties in an interlink converter for robust control of a hybrid AC-DC microgrid[J]. IEEE Transactions on Power Elec- tronics, 2019, 34(11): 11332-11341.
[2] 周玮, 蓝嘉豪, 麦瑞坤, 等. 无线充电电动汽车V2G模式下光储直流微电网能量管理策略[J]. 电工技术学报, 2022, 37(1): 82-91.
Zhou Wei, Lan Jiahao, Mai Ruikun, et al.Research on power management strategy of DC microgrid with photovoltaic, energy storage and EV-wireless power transfer in V2G mode[J]. Transactions of China Electrotechnical Society, 2022, 37(1): 82-91.
[3] 曾梦隆, 韦钢, 朱兰, 等. 交直流配电网中电动汽车充换储一体站规划[J]. 电力系统自动化, 2021, 45(18): 52-60.
Zeng Menglong, Wei Gang, Zhu Lan, et al.Planning of electric vehicle charging-swapping-storage integrated station in AC/DC distribution network[J]. Automation of Electric Power Systems, 2021, 45(18): 52-60.
[4] Xia Yanghong, Peng Yonggang, Yang Pengcheng, et al.Distributed coordination control for multiple bidirectional power converters in a hybrid AC/DC microgrid[J]. IEEE Transactions on Power Electro- nics, 2017, 32(6): 4949-4959.
[5] 刘晓飞, 张千帆, 崔淑梅. 电动汽车V2G技术综述[J]. 电工技术学报, 2012, 27(2): 121-127.
Liu Xiaofei, Zhang Qianfan, Cui Shumei.Review of electric vehicle V2G technology[J]. Transactions of China Electrotechnical Society, 2012, 27(2): 121-127.
[6] Goel S, Sharma R.Performance evaluation of stand alone, grid connected and hybrid renewable energy systems for rural application: a comparative review[J]. Renewable and Sustainable Energy Reviews, 2017, 78: 1378-1389.
[7] 张志, 孟利伟, 唐校, 等. 有源钳位单级隔离型AC-DC功率因数变换器[J]. 电工技术学报, 2021, 36(12): 2616-2626.
Zhang Zhi, Meng Liwei, Tang Xiao, et al.A single stage isolated AC-DC power factor corrected con- verter with active clamping[J]. Transactions of China Electrotechnical Society, 2021, 36(12): 2616-2626.
[8] 杨东江, 段彬, 丁文龙, 等. 一种带辅助双向开关单元的宽输入电压范围LLC谐振变换器[J]. 电工技术学报, 2020, 35(4): 775-785.
Yang Dongjiang, Duan Bin, Ding Wenlong, et al.An improved LLC resonant converter with auxiliary bi-directional switch for wide-input-voltage range applications[J]. Transactions of China Electrotech- nical Society, 2020, 35(4): 775-785.
[9] Liu Zhengyang, Li Bin, Lee F C, et al.High-efficiency high-density critical mode rectifier/inverter for WBG- device-based on-board charger[J]. IEEE Transactions on Industrial Electronics, 2017, 64(11): 9114-9123.
[10] 李红梅, 张恒果, 崔超. 车载充电PWM软开关DC-DC变换器研究综述[J]. 电工技术学报, 2017, 32(24): 59-70.
Li Hongmei, Zhang Hengguo, Cui Chao.Review of PWM soft-switching DC-DC converter for on-board chargers[J]. Transactions of China Electrotechnical Society, 2017, 32(24): 59-70.
[11] Wu Hongfei, Tang Xinxi, Zhao Jian, et al.An isolated bidirectional microinverter based on voltage-in-phase PWM-controlled resonant converter[J]. IEEE Transa- ctions on Power Electronics, 2021, 36(1): 562-570.
[12] Everts J.Closed-form solution for efficient ZVS modulation of DAB converters[J]. IEEE Transactions on Power Electronics, 2017, 32(10): 7561-7576.
[13] Li Xiang, Guo Liuniu, Lang Tianchen, et al.Steady- state characterization of LLC-based single-stage AC/DC converter based on numerical analysis[J]. IEEE Transactions on Power Electronics, 2021, 36(9): 9970-9983.
[14] 涂春鸣, 管亮, 肖凡, 等. 双有源桥DC-DC变换器的模态分析方法[J]. 中国电机工程学报, 2019, 39(18): 5468-5479, 5595.
Tu Chunming, Guan Liang, Xiao Fan, et al.Modal analysis method of dual active bridge DC-DC con- verter[J]. Proceedings of the CSEE, 2019, 39(18): 5468-5479, 5595.
[15] Zhao Biao, Song Qiang, Liu Wenhua, et al.Overview of dual-active-bridge isolated bidirectional DC-DC converter for high-frequency-link power-conversion system[J]. IEEE Transactions on Power Electronics, 2014, 29(8): 4091-4106.
[16] Dao N D, Lee D C.Modulation of bidirectional AC/DC converters based on half-bridge direct-matrix structure[J]. IEEE Transactions on Power Electronics, 2020, 35(12): 12657-12662.
[17] Weise N D, Castelino G, Basu K, et al.A single-stage dual-active-bridge-based soft switched AC-DC con- verter with open-loop power factor correction and other advanced features[J]. IEEE Transactions on Power Electronics, 2014, 29(8): 4007-4016.
[18] 涂春鸣, 管亮, 肖凡, 等. 基于扩展移相控制下双有源桥移相角优化选取与分析[J]. 电工技术学报, 2020, 35(4): 850-861.
Tu Chunming, Guan Liang, Xiao Fan, et al.Parameter optimization selection and analysis of dual active bridge based on extended phase shift control[J]. Transactions of China Electrotechnical Society, 2020, 35(4): 850-861.
[19] 张勋, 王广柱, 王婷. 双向全桥DC-DC变换器基于电感电流应力的双重移相优化控制[J]. 电工技术学报, 2016, 31(22): 100-106.
Zhang Xun, Wang Guangzhu, Wang Ting.Optimized control based on current-stress of bi-directional full- bridge DC-DC converters with dual-phase-shifting control[J]. Transactions of China Electrotechnical Society, 2016, 31(22): 100-106.
[20] Zhang Qian, Hu Haibing, Zhang Dehua, et al.A controlled-type ZVS technique without auxiliary components for the low power DC/AC inverter[J]. IEEE Transactions on Power Electronics, 2013, 28(7): 3287-3296.
[21] Jauch F, Biela J.Combined phase shift and frequency modulation of a dual active bridge AC-DC converter with PFC[J]. IEEE Transactions on Power Electronics, 2016, 31(12): 8387-8397.