A Topology Morphing Multi-Element Resonant Soft-Switching DC-DC Converter
Wang Yifeng1, Yang Liang1, Chen Bo1, Han Fuqiang1, Zhou Biao2
1. Key Laboratory of Smart Grid of Ministry of Education Tianjin University Tianjin 300072 China; 2. State Grid Tianjin Dongli District Power Supply Company Tianjin 300300 China
Abstract：In this paper, a topology morphing multi-element resonant soft-switching DC-DC converter is discussed. By adopting the dual-transformer architecture, the resonant tank unit employs two auxiliary switches to enable or disable the auxiliary transformer, so that the equivalent circuit of the resonant tank can be flexibly converted between the two different multi-element topologies. At the same time, the inverter cell includes the full-bridge and half-bridge working modes. Consequently, the proposed converter has four different working modes. The multi-mode characteristic can meet different operating requirements. Therefore, by designing appropriate parameters, the topology morphing multi-element resonant converter (MRC) can achieve wide-range adjustment of DC voltage gain within a narrow operating frequency range while maintaining high efficiency. In order to verify the feasibility of the novel converter and the reliability of the theoretical analysis, the experimental results have been presented: when the input DC voltage varies from 25V to 300V, the converter can provide an adjustable voltage gain from 0 to a maximum of 8 times, and thereby the output voltage is stabilized at 200V; the relatively high efficiencies within wide voltage gain range are also guaranteed by the converter, and the highest efficiency reaches as high as 98.1%.
[1] 孙孝峰, 申彦峰, 李午英, 等. 交错并联双向Buck/ Boost集成LLC谐振型三端口直流变换器[J]. 电工技术学报, 2016, 31(14): 165-175.Sun Xiaofeng, Shen Yanfeng, Li Wuying, et al. Interleaved bidirectional Buck/Boost and LLC integrated three-port DC-DC converter[J]. Transa- ctions of China Electrotechnical Society, 2016, 31(14): 165-175. [2] 陈启超, 王建赜, 纪延超. 双向LLC谐振型直流变压器的软启动及功率换向控制[J]. 电工技术学报, 2014, 29(8): 180-186.Chen Qichao, Wang Jianze, Ji Yanchao. Control scheme of bidirectional LLC resonant DC-DC transformer for soft start and power conversion[J]. Transactions of China Electrotechnical Society, 2014, 29(8): 180-186. [3] 石健将, 章江铭, 龙江涛, 等. 高频变压器一次侧串联LLC+输出端并联Buck级联直流变换器[J]. 电工技术学报, 2015, 30(24): 93-102.Shi Jianjiang, Zhang Jiangming, Long Jiangtao, et al. A cascaded DC converter with primary series transformer LLC and output interleaved Buck[J]. Transactions of China Electrotechnical Society, 2015, 30(24): 93-102. [4] 陈申, 吕征宇, 姚玮. LLC谐振型软开关直流变压器的研究与实现[J]. 电工技术学报, 2012, 27(10): 163-169.Chen Shen, Lü Zhengyu, Yao Wei. Research and verification on LLC resonant soft switching DC-DC transformer[J]. Transactions of China Electro- technical Society, 2012, 27(10): 163-169. [5] 杨良, 王议锋, 孟准. 一种基于储能回路的小型并网风力发电系统[J]. 电工技术学报, 2016, 31(增刊2): 120-130.Yang Liang, Wang Yifeng, Meng Zhun. A small- scale grid-connected wind generation system based on a storage branch[J]. Transactions of China Electrotechnical Society, 2016, 31(S2): 120-130. [6] 胡海兵, 王万宝, 孙文进, 等. LLC谐振变换器效率优化设计[J]. 中国电机工程学报, 2013, 33(18): 48-56.Hu Haibing, Wang Wanbao, Sun Wenjin, et al. Optimal efficiency design of LLC resonant converters[J]. Proceedings of the CSEE, 2013, 33(18): 48-56. [7] Yu R, Ho G K Y, Pong B M H, et al. Computer-aided design and optimization of high efficiency LLC series resonant converter[J]. IEEE Transactions on Power Electronics, 2012, 27(7): 3243-3256. [8] 袁义生, 罗峰, 胡盼安. 一种桥型副边LLC谐振直流-直流变换器[J]. 中国电机工程学报, 2014, 34(36): 6415-6425.Yuan Yisheng, Luo Feng, Hu Pan’an. One bridge- type secondary-side LLC resonant DC-DC converter[J]. Proceedings of the CSEE, 2014, 34(36): 6415-6425. [9] Jovanovi´c M M, Irving B T.On-the-fly topology- morphing control—efficiency optimization method for LLC resonant converters operating in wide input- and/or output-voltage range[J]. IEEE Transactions on Power Electronics, 2016, 31(3): 2596-2608. [10] Liang Zhigang, Guo Rong, Li Jun, et al.A high- efficiency PV module-integrated DC/DC converter for PV energy harvest in FREEDM systems[J]. IEEE Transactions on Power Electronics, 2011, 26(3): 897-909. [11] Hu Haibing, Fang Xiang, Chen Frank, et al.A modified high-efficiency LLC converter with two transformers for wide input-voltage range appli- cations[J]. IEEE Transactions on Power Electronics, 2013, 28(4): 1946-1960. [12] 王议锋, 徐殿国, 王懿杰, 等. CLCL谐振软开关DC- AC变换器[J]. 电工技术学报, 2013, 28(4): 95-103.Wang Yifeng, Xu Dianguo, Wang Yijie, et al. Zero- voltage and zero-current resonant CLCL DC-AC converter[J]. Transactions of China Electrotechnical Society, 2013, 28(4): 95-103. [13] Wang Yijie, Guan Yuefei, Xu Dianguo, et al.A CLCL resonant DC/DC converter for two-stage LED driver system[J]. IEEE Transactions on Industrial Electronics, 2016, 63(5): 2883-2891. [14] Fu Dianbo, Lee F C, Liu Ya, et al.Novel multi- element resonant converters for front-end DC/DC converters[C]//IEEE Power Electronics Specialists Conference, Rhodes, Greece, 2008: 250-256. [15] Hu Zhiyuan, Qiu Yajie, Wang Laili, et al.An interleaved LLC resonant converter operating at constant switching frequency[J]. IEEE Transactions on Power Electronics, 2014, 29(6): 2931-2943. [16] 杨良, 王议锋, 孟准. 小型并网风力发电系统控制策略[J]. 电工技术学报, 2017, 32(10): 252-263.Yang Liang, Wang Yifeng, Meng Zhun. Control strategy of a small-scale grid-connected wind generation system[J]. Transactions of China Electro- technical Society, 2017, 32(10): 252-263.
2018, Vol. 33 
