A New Method to Obtain the Droop Control Coefficient in a Meshed DC System Based on Automatically Decentralized Control
Cao Xin1, Han Minxiao1, Zhou Guangyang1, Zhang Lidong2
1. School Electrical and Electronic Engineering North China Electric Power University Beijing 102206 China; 2. ABB Corporate Research Vasteras 72178 Sweden
Abstract：Recent researches focus on droop control coefficient calculation in the radial DC system, and fewer researches investigate its calculation in complex DC systems. This paper proposed a new method for droop control coefficient calculation in a meshed DC system based on automatically decentralized control. Firstly, the information of the converter was collected and interchanged by the system control layer of the automatically decentralized control. After that, all the converters obtained the same global information by the optimal power flow model to calculate the reference values of DC voltage and active power. Then, the virtual node was defined and its voltage was equal to the average of the reference DC voltage. The nodes where the voltage is equal to the virtual voltage were selected, and the system was simplified into radial topology. Subsequently, the reference resistances between nodes and the virtual node under the optimal condition could be obtained, the real resistances between nodes and the virtual node under current condition also could be calculated. Herein, the droop control coefficients are equal to the inverse of difference between the virtual and real resistances. Finally, a 6-terminal MMC-MTDC model was established in PSCAD/EMTDC, and the simulations verified the proposed method.
曹昕, 韩民晓, 周光阳, 张利东. 基于自律分散控制的网孔型直流电网下垂系数计算方法[J]. 电工技术学报, 2020, 35(24): 5164-5174.
Cao Xin, Han Minxiao, Zhou Guangyang, Zhang Lidong. A New Method to Obtain the Droop Control Coefficient in a Meshed DC System Based on Automatically Decentralized Control. Transactions of China Electrotechnical Society, 2020, 35(24): 5164-5174.
[1] 叶婧, 林涛, 张磊, 等. 考虑动态频率约束的含高渗透率光伏电源的孤立电网机组组合[J]. 电工技术学报, 2017, 32(13): 194-202. Ye Jing, Lin Tao, Zhang Lei, et al.Isolated grid unit commitment with dynamic frequency constraint considering photovoltaic power plants participating in frequency regulation[J]. Transactions of China Electrotechnical Society, 2017, 32(13): 194-202. [2] 陆晶晶, 贺之渊, 赵成勇, 等. 直流输电网规划关键技术与展望[J]. 电力系统自动化, 2019, 43(2): 182-191. Lu Jingjing, He Zhiyuan, Zhao Chengyong, et al.Key technologies and prospects for DC power grid planning[J]. Automation of Electric Power Systems, 2019, 43(2): 182-191. [3] 杨海涛, 吉平, 苗淼, 等. 未来中国特高压电网结构形态与电源组成相互关系分析[J]. 电力系统自动化, 2018, 42(6): 9-17. Yang Haitao, Ji Ping, Miao Miao, et al.Analysis on interrelationship between future UHV power grid structural form and power source composition in China[J]. Automation of Electric Power Systems, 2018, 42(6): 9-17. [4] 周天沛, 孙伟. 高渗透率下变速风力机组虚拟惯性控制的研究[J]. 中国电机工程学报, 2017, 37(2): 486-496. Zhou Tianpei, Sun Wei.Study on virtual inertia control for DFIG-based wind farms with high penetration[J]. Proceedings of the CSEE, 2017, 37(2): 486-495. [5] 施琳, 罗毅, 施念, 等. 高渗透率风电-储能孤立电网控制策略[J]. 中国电机工程学报, 2013, 33(16): 78-85, 15. Shi Lin, Luo Yi, Shi Nian, et al.A control strategy of isolated grid with high penetration of wind and energy storage systems[J]. Proceedings of the CSEE, 2013, 33(16): 78-85, 15. [6] 邵冰冰, 赵书强, 高本锋, 等. 连接弱交流电网的VSC-HVDC失稳机理及判据研究[J]. 电工技术学报, 2019, 34(18): 3884-3896. Shao Bingbing, Zhao Shuqiang, Gao Benfeng, et al.Instability mechanism and criterion analysis of VSC-HVDC connected to the weak AC power grid[J]. Transactions of China Electrotechnical Society, 2019, 34(18): 3884-3896. [7] 王一凡, 赵成勇, 郭春义. 双馈风电场孤岛经模块化多电平换流器直流输电并网系统小信号稳定性分析与振荡抑制方法[J]. 电工技术学报, 2019, 34(10): 2116-2129. Wang Yifan, Zhao Chengyong, Guo Chunyi.Small signal stability and oscillation suppression method for islanded double fed induction generator-based wind farm integrated by modular multilevel converter based HVDC system[J]. Transactions of China Electrotechnical Society, 2019, 34(10): 2116-2129. [8] 王渝红, 阳莉汶, 江伟, 等. 直流电网联网设备与控制策略研究综述[J]. 电网技术, 2018, 42(1): 12-24. Wang Yuhong, Yang Liwen, Jiang Wei, et al.Review on equipment and control strategies of DC power grid[J]. Power System Technology, 2018, 42(1): 12-24. [9] 汤广福. 基于电压源换流器的高压直流输电技术[M]. 北京: 中国电力出版社, 2010. [10] 韩民晓, 熊凌飞, 丁辉. 利用电压倾斜控制的VSC-MTDC稳定性分析[J]. 电网技术, 2015, 39(7): 1808-1813. Han Minxiao, Xiong Lingfei, Ding Hui.Stability analysis of VSC-MTDC with voltage droop control[J]. Power System Technology, 2015, 39(7): 1808-1813. [11] 熊凌飞, 韩民晓. 基于组合方式的多端柔性直流输电系统控制策略[J]. 电网技术, 2015, 39(6): 1586-1592. Xiong Lingfei, Han Minxiao.A novel combined control strategy for VSC-MTDC[J]. Power System Technology, 2015, 39(6): 1586-1592. [12] 朱珊珊, 汪飞, 郭慧, 等. 直流微电网下垂控制技术研究综述[J]. 中国电机工程学报, 2018, 38(1): 72-84, 344. Zhu Shanshan, Wang Fei, Guo Hui, et al.Overview of droop control in DC microgrid[J]. Proceedings of the CSEE, 2018, 38(1): 72-84, 344. [13] 孙黎霞, 陈宇, 宋洪刚, 等. 适用于VSC-MTDC的改进直流电压下垂控制策略[J]. 电网技术, 2016, 40(4): 1037-1043. Sun Lixia, Chen Yu, Song Honggang, et al.Improved voltage droop control strategy for VSC-MTDC[J]. Power System Technology, 2016, 40(4): 1037-1043. [14] 罗永捷, 李耀华, 王平, 等. 多端柔性直流输电系统直流电压自适应下垂控制策略研究[J]. 中国电机工程学报, 2016, 36(10): 2588-2599. Luo Yongjie, Li Yaohua, Wang Ping, et al.DC voltage adaptive droop control of multi-terminal HVDC systems[J]. Proceedings of the CSEE, 2016, 36(10): 2588-2599. [15] 刘瑜超, 武健, 刘怀远, 等. 基于自适应下垂调节的VSC-MTDC功率协调控制[J]. 中国电机工程学报, 2016, 36(1): 40-48. Liu Yuchao, Wu Jian, Liu Huaiyuan, et al.Effective power sharing based on adaptive droop control method in VSC multi-terminal DC grids[J]. Pro- ceedings of the CSEE, 2016, 36(1): 40-48. [16] 吴杰, 王志新. 多端柔性直流输电系统的改进下垂控制策略[J]. 电工技术学报, 2017, 32(20): 241-250. Wu Jie, Wang Zhixin.Improved droop control strategy for multi-terminal voltage source converter- HVDC[J]. Transactions of China Electrotechnical Society, 2017, 32(20): 241-250. [17] 阎发友, 汤广福, 贺之渊, 等. 基于MMC的多端柔性直流输电系统改进下垂控制策略[J]. 中国电机工程学报, 2014, 34(3): 397-404. Yan Fayou, Tang Guangfu, He Zhiyuan, et al.An improved droop control strategy for MMC-based VSC-MTDC systems[J]. Proceedings of the CSEE, 2014, 34(3): 397-404. [18] Cao Yijia, Wang Weiyu, Li Yong, et al.A virtual synchronous generator control strategy for VSC- MTDC systems[J]. IEEE Transactions on Energy Conversion, 2017, 33(2): 750-761. [19] 王炜宇, 李勇, 曹一家, 等. 基于虚拟调速器的多端直流虚拟同步机控制策略[J]. 中国电机工程学报, 2018, 38(12): 3461-3470, 5. Wang Weiyu, Li Yong, Cao Yijia, et al.The virtual synchronous generator technology based on virtual governor for multi-terminal direct current system[J]. Proceedings of the CSEE, 2018, 38(12): 3461-3470, 5. [20] 韩民晓, 翟冬玲, 唐晓骏. 连接低惯量系统的柔性直流输电模型预测控制[J]. 电工技术学报, 2017, 32(22): 198-206. Han Minxiao, Zhai Dongling, Tang Xiaojun.Model predictive control of voltage source converter-HVDC connected to low inertia system[J]. Transactions of China Electrotechnical Society, 2017, 32(22): 198-206. [21] 王皓界, 韩民晓, Josep M Guerrero, 等. 基于自律分散系统的直流微电网稳定控制器优化设计[J]. 中国电机工程学报, 2016, 36(2): 360-367. Wang Hanjie, Han Minxiao, Josep M Guerrero, et al.Optimization design of DC micro-grid stability controller based on the autonomous decentralized system[J]. Proceedings of the CSEE, 2016, 36(2): 360-367. [22] 韩民晓, 许冬, 万磊. 基于一致性算法的混合多端直流自律分散控制[J]. 电力系统自动化, 2016, 40(12): 130-136. Han Minxiao, Xu Dong, Wan Lei.Consensus algorithm based decentralized autonomous control of hybrid multi-terminal direct current system[J]. Automation of Electric Power Systems, 2016, 40(12): 130-136. [23] 许冬. 混合多端直流输电运行特性研究[D]. 北京: 华北电力大学, 2017. [24] 曾琦, 李兴源, 张立奎. 考虑运行损耗和功率裕度的VSC-MTDC系统改进优化下垂控制策略[J]. 高电压技术, 2016, 42(10): 98-106. Zeng Qi, Li Xingyuan, Zhang Likui.Improved optimization droop control strategy taking into account the network loss and available headroom for VSC-MTDC system[J]. High Voltage Engineering, 2016, 42(10): 98-106. [25] 邱迪. 交流/混合直流联合系统最优潮流分析[D]. 哈尔滨: 哈尔滨工业大学, 2017. [26] 鲁挺, 赵争鸣, 张颖超, 等. 采样延迟和误差对三电平PWM整流直接功率控制性能的影响及其抑制方法[J]. 电工技术学报, 2010, 25(3): 66-72. Lu Ting, Zhao Zhengming, Zhang Yingchao, et al.Effect of sampling delay and error on direct power control performance of three-level PWM rectifier and its restraining method[J]. Transactions of China Electrotechnical Society, 2010, 25(3): 66-72. [27] Daelemans G, Srivastava K, Reza M, et al.Mini- mization of steady-state losses in meshed networks using VSC HVDC[C]//Power & Energy Society General Meeting, Calgary, AB, Canada, 2009: 1-5. [28] Beerten J, Cole S, Belmans R.A sequential AC/DC power flow algorithm for networks containing multi-terminal VSC HVDC systems[J]. Power & Energy Society General Meeting, 2010, 89(1): 1-7. [29] Boyd S, Vandenberghe L.Convex optimization[M]. Cambridge: Cambridge University Press, 2004.
2020, Vol. 35 
