Coordinated Control of Multiple Voltage Balancers in a Bipolar DC Microgrid
Li Xialin1, Zhang Xuesong2, Guo Li1, Wang Chengshan1, Zhang Shaohui1, Yang Ping3
1. Key Laboratory of Smart Grid of Ministry of Education Tianjin University Tianjin 300072 China; 2. Electric Power Science Research Institute State Grid Zhejiang Electric Power Corporation Hangzhou 310014 China; 3. Guangdong Key Laboratory of Clean Energy Technology South China University of Technology Guangzhou 511458 China;
Abstract：For neutral-point voltage balancing control in a bipolar DC microgrid, a coordinated control strategy for parallel operation of multiple voltage balancers was proposed, which was composed of droop method and disturbance observer based current feed-forward. With the observer and only the local measurements, the output current of the voltage balancer could be quickly tracked without any additional current sensors. Through the estimated value, DC voltage droop control and current feed-forward had been well designed. It can realize unbalanced current sharing and plug-play feature without communication, and improve the dynamics and stability of neutral-point voltage balancing control respectively. A prototype bipolar DC microgrid, including a DC simulated voltage source, two voltage balancers, resistive DC loads and a DC-DC converter based constant power load, has verified the performance of the presented control.
李霞林, 张雪松, 郭力, 王成山, 张绍辉, 杨苹. 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, Wang Chengshan, Zhang Shaohui, Yang Ping. Coordinated Control of Multiple Voltage Balancers in a Bipolar DC Microgrid. Transactions of China Electrotechnical Society, 2018, 33(4): 721-729.
[1] 王成山, 武镇, 李鹏. 微电网关键技术研究[J]. 电工技术学报, 2014, 29(2): 1-12. Wang Chengshan, Wu Zhen, Li Peng.Research on key technologies of microgrid[J]. Transactions of China Electrotechnical Society, 2014, 29(2): 1-12. [2] 薛花, 李海霞, 王育飞. 基于非线性微分平滑方法的分布式光储直流供电系统电压稳定控制方法[J]. 电力系统保护与控制, 2016, 44(18): 46-53. Xue Hua, Li Haixia, Wang Yufei.DC bus stabilization control of distributed photovoltaic- energy storage DC generation system based on nonlinear differential flatness method[J]. Power System Protection and Control, 2016, 44(18): 46-53. [3] 李武华, 徐驰, 禹红斌, 等. 直流微网系统中混合储能分频协调控制策略[J]. 电工技术学报, 2016, 31(14): 84-92. Li Wuhua, Xu Chi, Yu Hongbin, et al.Frequency dividing coordinated control strategy for hybrid energy storage system of DC micro-grid[J]. Transa- ctions of China Electrotechnical Society, 2016, 31(14): 84-92. [4] 丁明, 田龙刚, 潘浩, 等. 交直流混合微电网运行控制策略研究[J]. 电力系统保护与控制, 2015, 43(9): 1-8. Ding Ming, Tian Longgang, Pan Hao, et al.Research on control strategy of hybrid AC/DC microgrid[J]. Power System Protection and Control, 2015, 43(9): 1-8. [5] 熊远生, 俞立, 徐建明. 光伏发电系统多模式接入直流微电网及控制方法[J]. 电力系统保护与控制, 2014, 42(12): 37-43. Xiong Yuansheng, Yu Li, Xu Jianming.Multimode of photovoltaic generation system connected to DC micogrid and control methods[J]. Power System Protection and Control, 2014, 42(12): 37-43. [6] 陆晓楠, 孙凯, Guerrero J, 等. 适用于交直流混合微电网的直流分层控制系统[J]. 电工技术学报, 2013, 8(4): 35-42. Lu Xiaonan, Sun Kai, Guerrero J, et al.DC hierarchical control system for microgrid appli- cations[J]. Transactions of China Electrotechnical Society, 2013, 8(4): 35-42. [7] 曾正, 邵伟华, 冉立, 等. 基于直流电气弹簧的直流配电网电压波动抑制[J]. 电工技术学报, 2016, 31(17): 23-31. Zeng Zheng, Shao Weihua, Ran Li.DC electrical spring for voltage fluctuation suppressing of DC distribution network[J]. Transactions of China Electrotechnical Society, 2016, 31(17): 23-31. [8] Gu Yunjie, Li Wuhua, He Xiangning.Analysis and control of bipolar LVDC grid with DC symmetrical component method[J]. IEEE Transactions on Power Systems, 2016, 31(1): 685-694. [9] Sebastian R, Bin W, Samir K, et al.Electric vehicle charging station using a neutral point clamped converter with bipolar DC bus[J]. IEEE Transactions on Industrial Electronics, 2015, 62(4): 1999-2009. [10] 金红元, 邹云屏, 林磊, 等. 三电平PWM整流器双环控制技术及中点电压平衡控制技术的研究[J]. 中国电机工程学报, 2006, 26(20): 64-68. Jing Hongyuan, Zou Yunping, Lin Lei, et al.Research on the technology of the neutral-point voltage balance and dual-loop control scheme for three-level PWM rectifier[J]. Proceedings of the CSEE, 2006, 26(20): 64-68. [11] 江晨, 曾国宏, 吴学智, 等. 双极性直流微网的分层控制策略[J]. 电网技术, 2015, 39(8): 2217-2222. Jiang Chen, Zeng Guohong, Wu Xuezhi, et al.Hierarchical control strategy of bipolar-type DC microgrid[J]. Power System Technology, 2015, 39(8): 2217-2222. [12] Kakigano H, Miura Y, Ise T.Low-voltage bipolar- type DC microgrid for super high quality distri- bution[J]. IEEE Transactions on Power Electronics, 2010, 25(12): 3066-3075. [13] Zhang Xianjin, Gong Chunying.Dual-Buck half- bridge voltage balancer[J]. IEEE Transactions on Power Electronics, 2013, 60(8): 3157-3164. [14] 张先进, 龚春英. 三电平半桥电压平衡器[J]. 电工技术学报, 2012, 27(8): 114-119. Zhang Xianjin, Gong Chunying.Three-level half bridge voltage balancers[J]. Transactions of China Electrotechnical Society, 2012, 27(8): 114-119. [15] Zhang Xianjin, Gong Chunying.Three-level DC converter for balancing DC 800V voltage[J]. IEEE Transactions on Power Electronics, 2015, 30(7): 3499-3507. [16] 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. Wang Fei, Lei Zhifang, Xu Xinwei.Research on topologies of voltage balancers applied in DC micro- grid[J]. Proceedings of the CSEE, 2016, 36(6): 1604-1612. [17] 支娜, 张辉, 肖曦. 提高直流微电网动态特性的改进下垂控制策略研究[J]. 电工技术学报, 2016, 31(3): 32-39. Zhi Na, Zhang Hui, Xiao Xi.Research on the improved droop control strategy for improving the dynamic characteristic of DC microgrid[J]. Transa- ctions of China Electrotechnical Society, 2016, 31(3): 32-39. [18] Wang Chengshan, Li Xialin, Guo Li, et al.A nonlinear disturbance observer based DC bus voltage control for a hybrid AC/DC microgrid[J]. IEEE Transactions on Power Electronics, 2014, 29(11): 6162-6177. [19] 李霞林, 郭力, 冯怿彬, 等. 基于非线性干扰观测器的直流微电网母线电压控制[J]. 中国电机工程学报, 2016, 36(2): 350-359. Li Xialin, Guo Li, Feng Yibin.A nonlinear disturbance observer based DC bus voltage control for a DC microgrid[J]. Proceedings of the CSEE, 2016, 36(2): 350-359.
2018, Vol. 33 
