A Synthesis Method for Non-Isolated DC-DC Converters with Bipolar Outputs
Zhou Mingzhu1,2, Liu Chao1,2, Zhuang Yizhan1,2, Mao Xingkui1,2, Zhang Yiming1,2
1. College of Electrical Engineering and Automation Fuzhou University Fuzhou 350108 China; 2. Fujian Key Laboratory of New Energy Generation and Power Conversion Fuzhou 350108 China
Abstract：In the application of new energy, energy storage, and emerging power loads, the power supply architecture using the DC bus has more advantages than the AC bus, which is the development direction of the future power supply system. Bipolar DC microgrid systems are often used to connect various renewable energy sources and emerging loads due to their higher reliability, flexibility, and efficiency. This paper proposes a synthesis method for non-isolated bipolar output DC-DC converters. A series of bipolar output DC-DC converter topologies are deduced. In order to further improve the performance of bipolar output converter, a novel high-voltage-gain DC-DC converter with a three-winding coupled-inductor is proposed by introducing coupled- inductor and switched-capacitor step-up technology to Boost bipolar output DC-DC converter. Based on the characteristics of the bipolar output converter, the topology synthesis principle of the proposed bipolar output DC-DC converter is given. The input ends of a positive output DC-DC converter and a negative output DC-DC converter are connected in parallel, and the output ends are in series. This paper gives a series of bipolar output DC-DC converters by classifying and combining traditional DC-DC converters. However, the boost capacity of these converters is limited, and the positive and negative output voltages are only regulated by the duty cycle of the switch. Thus, a bipolar high-voltage-gain DC-DC converter with a three-winding coupled-inductor is proposed. The bipolar output voltages can be adjusted flexibly by the turns ratio of the coupled inductor and the duty ratio. This paper gives the construction principle, operating mode, voltage gain, and stress derivation of the high-voltage-gain bipolar output converter. Compared with the converters in the literature, the proposed converter has apparent advantages in voltage gain and device voltage stress. An experimental prototype with a rated power of 200 W is designed. Experimental results show that the input current ripple is small, and the actual voltage gain of the converter is 380/32=11.875, slightly lower than the calculated (3+n1+n2)/(1-D)=12, which is caused by parasitic resistance and control signal delay. The efficiency of the proposed converter is 95.5% at full load and 96.7% at half load. The following conclusions can be drawn. (1) High voltage gain can be achieved with low input current ripple and small switching device voltage spikes. (2) Symmetrical bipolar output voltage can be achieved, reducing the need for high voltage gain of power supply and load. (3) The converter power is distributed on two DC bus bars, which makes the system more efficient. (4) Part of the diode realizes zero voltage switching turn-off, reduces the diode reverse recovery loss, and improves the efficiency of the proposed bipolar output converter.
[1] 张玮麟, 梁继业. 一种新型高效电动汽车双向DC-DC变换器[J]. 电机与控制应用, 2020, 47(11): 109-116. Zhang Weilin, Liang Jiye.A novel efficient bi-directional DC-DC converter for electric vehicle[J]. Electric Machines & Control Application, 2020, 47(11): 109-116. [2] 罗朋, 潘锦超, 洪濬哲, 等. 用于直流微电网的高升压变换器设计及效率优化[J]. 电工技术学报, 2023, 38(20): 5530-5546. Luo Peng, Pan Jinchao, Hong Junzhe, et al.Design and efficiency optimization of a high step-up converter for DC microgird[J]. Transactions of China Electrotechnical Society, 2023, 38(20): 5530-5546. [3] 赵先浩, 谢红福, 刘飞, 等. 基于多端口电能路由器的楼宇直流微电网研究与应用[J]. 电气技术, 2022, 23(8): 75-83. Zhao Xianhao, Xie Hongfu, Liu Fei, et al.Research and application of building DC microgrid based on multi port power router[J]. Electrical Engineering, 2022, 23(8): 75-83. [4] 李霞林, 张雪松, 郭力, 等. 双极性直流微电网中多电压平衡器协调控制[J]. 电工技术学报, 2018, 33(4): 721-729. Li Xialin, Zhang Xuesong, Guo Li, et al.Coordinated control of multiple voltage balancers in a bipolar DC microgrid[J]. Transactions of China Electrotechnical Society, 2018, 33(4): 721-729. [5] 汪飞, 雷志方, 徐新蔚. 面向直流微电网的电压平衡器拓扑结构研究[J]. 中国电机工程学报, 2016, 36(6): 1604-1612, 1773. Wang Fei, Lei Zhifang, Xu Xinyu.Research on topologies of voltage balancers applied in DC micro-grid[J]. Proceedings of the CSEE, 2016, 36(6): 1604-1612, 1773. [6] 雷浩东, 郝瑞祥, 游小杰, 等. 基于开关电容和三绕组耦合电感的高电压增益DC-DC变换器[J]. 电工技术学报, 2020, 35(17): 3666-3677. Lei Haodong, Hao Ruixiang, You Xiaojie, et al.High voltage gain DC-DC converter with switched-capacitor and three-winding coupled inductor[J]. Transactions of China Electrotechnical Society, 2020, 35(17): 3666-3677. [7] 桑汐坤, 王懿杰, 徐殿国. 基于输入并联输出串联的高效高升压比DC-DC变换器[J]. 电工技术学报, 2023, 38(20): 5488-5502. Sang Xikun, Wang Yijie, Xu Dianguo.High-efficiency high voltage gain DC-DC converter based on input parallel and output series connection[J]. Transactions of China Electrotechnical Society, 2023, 38(20): 5488-5502. [8] 孙毓璞, 徐玉珍, 金涛. 一种改进二次型高增益Boost-Sepic变换器[J]. 电源学报, 2022, 20(6): 111-116. Sun Yupu, Xu Yuzhen, Jin Tao.Improved quadratic high voltage gain Boost-Sepic converter[J]. Journal of Power Supply, 2022, 20(6): 111-116. [9] 管乐诗, 温兆亮, 许晓志, 等. 适用于宽增益范围的可重构单级DC-DC变换器及其磁元件设计[J]. 电工技术学报, 2023, 38(6): 1571-1583. Guan Yueshi, Wen Zhaoliang, Xu Xiaozhi, et al.A modular reconfigurable single-stage DC-DC converter suitable for wide gain range and its magnetic design[J]. Transactions of China Electrotechnical Society, 2023, 38(6): 1571-1583. [10] 曾怡达, 姚琴, 贾钦贵, 等. 新型二次型高增益DC/DC变换器及特性研究[J]. 电力电子技术, 2023, 57(11): 115-117. Zeng Yida, Yao Qin, Jia Qingui, et al.A new quadratic high-gain DC/DC converter and its characteristics[J]. Power Electronics, 2023, 57(11): 115-117. [11] 丁杰, 高双, 赵世伟, 等. 基于耦合电感的对称式交错并联低输入电流纹波高增益DC-DC变换器[J]. 电工技术学报, 2021, 36(7): 1507-1515. Ding Jie, Gao Shuang, Zhao Shiwei, et al.Symmetrical interleaved low input current ripple high step-up DC-DC converter based on coupled indu-ctor[J]. Transactions of China Electrotechnical Society, 2021, 36(7): 1507-1515. [12] 丁新平, 曹益畅, 赵振伟, 等. 输入电流低纹波的超高增益非隔离DC-DC变换器[J]. 中国电机工程学报, 2023, 43(6): 2359-2370. Ding Xinping, Cao Yichang, Zhao Zhenwei, et al.Non-isolated ultra-high voltage gain DC-DC con-verter with low input current ripple[J]. Proceedings of the CSEE, 2023, 43(6): 2359-2370. [13] 邾玢鑫, 蓝海, 支树播, 等. 一种零输入电流纹波高增益DC/DC变换器[J]. 中国电机工程学报, 2023, 43(19): 7640-7648. Zhu Fenxin, Lan Hai, Zhi Shubo, et al.A zero input current ripple high gain DC/DC converter[J]. Proceedings of the CSEE, 2023, 43(19): 7640-7648. [14] Karthikeyan M, Elavarasu R, Ramesh P, et al.A hybridization of Cuk and Boost converter using single switch with higher voltage gain compatibility[J]. Energies, 2020, 13(9): 2312. [15] Kang H, Cha H.A new nonisolated high-voltage-gain Boost converter with inherent output voltage balancing[J]. IEEE Transactions on Industrial Elec-tronics, 2018, 65(3): 2189-2198. [16] Zhang Yun, Zhou Lei, Sumner M, et al.Single-switch, wide voltage-gain range, Boost DC-DC converter for fuel cell vehicles[J]. IEEE Transactions on Vehicular Technology, 2018, 67(1): 134-145. [17] Nathan K, Ghosh S, Siwakoti Y, et al.A new DC-DC converter for photovoltaic systems: coupled-inductors combined Cuk-Sepic converter[J]. IEEE Transactions on Energy Conversion, 2019, 34(1): 191-201. [18] Litrán S P, Durán E, Semião J, et al.Single-switch bipolar output DC-DC converter for photovoltaic application[J]. Electronics, 2020, 9(7): 1171. [19] Ferrera M B, Litrán S P, Durán Aranda E, et al.A converter for bipolar DC link based on Sepic-Cuk combination[J]. IEEE Transactions on Power Elec-tronics, 2015, 30(12): 6483-6487. [20] Premkumar M, Subramaniam U, Haes Alhelou H, et al.Design and development of non-isolated modified Sepic DC-DC converter topology for high-step-up applications: investigation and hardware imple-mentation[J]. Energies, 2020, 13(15): 3960. [21] Arshadi S A, Adib E, Farzanehfard H, et al.New high step-up DC-DC converter for photovoltaic grid-connected applications[C]//The 6th Power Electronics, Drive Systems & Technologies Conference (PEDSTC2015), Tehran, Iran, 2015: 189-194. [22] Pires V F, Cordeiro A, Foito D, et al.A DC-DC converter with capability to support the voltage balance of DC bipolar microgrids[C]//2022 11th International Conference on Renewable Energy Research and Application (ICRERA), Istanbul, Turkey, 2022: 50-55.
2025, Vol. 40 
