A Circulating Current Interline DC Power Flow Controller for DC Grid
Li Guoqing, Bian Jing, Wang He, Wang Zhenhao
Key Laboratory of Modern Power System Simulation and Control & Renewable Energy Technology Ministry of Education Northeast Electric Power University Jilin 132000 China
Abstract：Aiming at the problem of insufficient free degree of power flow control in DC grid, this paper proposes a novel interline DC power flow controller (I-PFC). I-PFC can realize the power balance through the AC circulating current without AC transformer as AC internal pathway. Compared with the existing interline DC power flow controller, it further reduces the current fluctuation caused by charging and discharging of a single capacitor, and has the advantages of avoiding additional resonance, reducing harmonics and expanding easily. Firstly, the topology of I-PFC was proposed, and the method of power flow control was analyzed. Then the relationship between line current and series voltage was obtained, and the principle of power balance using internal AC circulating current was introduced. Secondly, according to the power and energy of I-PFC, the capacitor voltage of sub-module was analyzed in detail. It mainly consisted of DC, fundamental frequency and two frequency doubling components. The control strategy including DC power flow control and power balance control was designed. Finally, a three-terminal ring VSC-HVDC including I-PFC was built in PSCAD/EMTDC. The feasibility and effectiveness of the proposed I-PFC were verified by input operation, reverse regulation and dynamic response.
李国庆, 边竞, 王鹤, 王振浩. 适用于直流电网的环流式线间直流潮流控制器[J]. 电工技术学报, 2020, 35(5): 1118-1127.
Li Guoqing, Bian Jing, Wang He, Wang Zhenhao. A Circulating Current Interline DC Power Flow Controller for DC Grid. Transactions of China Electrotechnical Society, 2020, 35(5): 1118-1127.
[1] 陈宝平, 林涛, 陈汝斯, 等. 直驱风电场经VSC-HVDC并网系统的多频段振荡特性分析[J]. 电工技术学报, 2018, 33(增刊1): 176-184. Chen Baoping, Lin Tao, Chen Rusi, et al.Characteristics of multi-band oscillation for direct drive wind farm interfaced with VSC-HVDC system[J]. Transactions of China Electrotechnical Society, 2018, 33(S1): 176-184. [2] 李建国, 刘文华, 王久和, 等. 基于LCC和双钳位MMC混联高压直流输电的实验[J]. 电工技术学报, 2018, 33(16): 3677-3685. Li Jianguo, Liu Wenhua, Wang Jiuhe, et al.Experiment of hybrid high voltage direct current transmission based on LCC and clamp double sub module MMC[J]. Transactions of China Electrotechnical Society, 2018, 33(16): 3677-3685. [3] Matthias K, Roger W, Goran A, et al.Multiterminal HVDC networks—what is the preferred topology[J]. IEEE Transactions on Power Delivery, 2014, 29(1): 406-413. [4] 陈鹏远, 黎灿兵, 周斌, 等. 异步互联电网柔性直流输电紧急功率支援与动态区域控制偏差协调控制策略[J]. 电工技术学报, 2019, 34(14): 3025-3034. Chen Pengyuan, Li Canbing, Zhou Bin, et al.VSC-HVDC emergency power support and dynamic area control error coordinated control strategy for improving the stability of asynchronous interconnected power grids[J]. Transactions of China Electrotechnical Society, 2019, 34(14): 3025-3034. [5] 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. [6] 徐进, 金逸, 胡从川, 等. 适用于海上风电并网的多端柔性直流系统自适应下垂控制研究[J]. 电力系统保护与控制, 2018, 46(4): 78-85. Xu Jin, Jin Yi, Hu Congchuan, et al.DC voltage adaptive droop control of multi-terminal VSC-HVDC system for offshore wind farms integration[J]. Power System Protection and Control, 2018, 46(4): 78-85. [7] 武文, 吴学智, 荆龙, 等. 适用于多端直流输电系统的模块化多端口直流潮流控制器[J]. 电工技术学报, 2019, 34(3): 539-551. Wu Wen, Wu Xuezhi, Jing Long, et al.A modular multi-port DC power flow controller for multi- terminal DC transmission system[J]. Transactions of China Electrotechnical Society, 2019, 34(3): 539-551. [8] Senthooran B, Carlos E, Liang Jun.Experimental validation of dual H-bridge current flow controllers for meshed HVDC grids[J]. IEEE Transactions on Power Delivery, 2018, 33(1): 381-392. [9] 王鹤, 边竞, 李国庆, 等. 适用于柔性直流电网的多端口直流潮流控制器[J]. 电力系统自动化, 2017, 41(22): 102-108. Wang He, Bian Jing, Li Guoqing, et al.Multiport DC power flow controller suitable for flexible DC grid[J]. Automation of Electric Power Systems, 2017, 41(22): 102-108. [10] Ataollah M, Joan S, Eduardo P, et al.Fault mode operation strategies for dual H-bridge current flow controller in meshed HVDC grid[J]. Electric Power Systems Research, 2018, 160: 163-172. [11] 刘斯棋, 朱淼, 钟旭, 等. 具备双自由度控制能力的三线间直流潮流控制器[J]. 电力系统自动化, 2019, 43(18): 75-83. Liu Siqi, Zhu Miao, Zhong Xu, et al.Triple interline DC power flow controller with dual-freedom control ability[J]. Automation of Electric Power Systems, 2019, 43(18): 75-83. [12] Joan S, Eduardo P, Oriol G, et al.Series Interline DC/DC current flow controller for meshed HVDC grids[J]. IEEE Transactions on Power Delivery, 2018, 33(2): 881-891. [13] Mu Qing, Liang Jun, Li Yalou, et al.Power flow control devices in DC grids[C]//IEEE Power and Energy Society General Meeting, San Diego, USA, 2012: 1-7. [14] Jovcic D, Hajian M, Zhang H, et al.Power flow control in DC transmission grids using mechanical and semiconductor based DC/DC devices[C]//IET International Conference on AC and DC Power Transmission(ACDC), Birmingham, United Kingdom, 2012: 1-6. [15] Rouzbehi K, Candela J I, Luna A, et al.Flexible control of power flow in multiterminal DC grids using DC-DC converter[J]. IEEE Journal of Emerging and Selected Topics in Power Electronics, 2016, 4(3): 1135-1144. [16] Etienne V, Boon-teck O. Multiterminal HVDC with thyristor power-flow controller[J]. IEEE Transactions on Power Systems, 2012, 27(3): 1205-1212. [17] Gong Chiheng, Yao Sunjun, Wang Yan, et al.The study and application of power flow controller for DC grids[C]//International Conference on Renewable Power Generation (RPG 2015), Beijing, China, 2015: 1-5. [18] 陶以彬, 姚良忠, 李官军, 等. 适用于直流电网的新型直流潮流控制器[J]. 电网技术, 2016, 40(11): 3427-3432. Tao Yibin, Yao Liangzhong, Li Guanjun, et al.A novel DC power flow controller suitable for DC grid[J]. Power System Technology, 2016, 40(11): 3427-3432. [19] Chen Wu, Zhu Xu, Yao Liangzhong, et al.A novel interline DC power flow controller (IDCPFC) for meshed HVDC grids[J]. IEEE Transactions on Power Delivery, 2016, 31(4): 1719-1727. [20] 姚良忠, 崔红芬, 李官军, 等. 柔性直流电网串联直流潮流控制器及其控制策略研究[J]. 中国电机工程学报, 2016, 36(4): 945-952. Yao Liangzhong, Cui Hongfen, Li Guanjun, et al.Studies of series DC power flow controller and its control strategy in the VSC based DC grid[J]. Proceedings of the CSEE, 2016, 36(4): 945-952. [21] 王鹤, 朱琳, 单凤军, 等. 计及多端口直流潮流控制器的直流电网潮流计算[J]. 电力自动化设备, 2018, 38(8): 8-12, 23. Wang He, Zhu Lin, Shan Fengjun, et al.Power flow calculation of DC power grid with multi-port DC power flow controller[J]. Electric Power Automation Equipment, 2018, 38(8): 8-12, 23. [22] 李国庆, 边竞, 王鹤, 等. 一种基于MMC的新型直流潮流控制器[J]. 电网技术, 2017, 41(7): 2107-2114. Li Guoqing, Bian Jing, Wang He, et al.A new type DC flow controller based on MMC[J]. Power System Technology, 2017, 41(7): 2107-2114. [23] 罗永捷, 李耀华, 李子欣, 等. 适用于高压大容量MMC-HVDC系统的改进低开关频率均压控制策略[J]. 中国电机工程学报, 2017, 37(5): 8-17, 24. Luo Yongjie, Li Yaohua, Li Zixin, et al.An improved reduced switching frequency voltage balancing control strategy for bulk power MMC-HVDC systems[J]. Proceedings of the CSEE, 2017, 37(5): 8-17, 24. [24] Tu Qingrui, Xu Zheng.Impact of sampling frequency on harmonic distortion for modular multilevel converter[J]. IEEE Transactions on Power Delivery, 2011, 26(1): 298-306. [25] 李程昊, 谢竹君, 林卫星, 等. 中高频模块化多电平换流器阀损耗的精确计算方法与分析平台[J]. 中国电机工程学报, 2015, 35(17): 4361-4370. Li Chenghao, Xie Zhujun, Lin Weixing, et al.Accurate valve loss calculation method and analyzing platform for medium and high-frequency MMC[J]. Proceedings of the CSEE, 2015, 35(17): 4361-4370. [26] 辛业春, 王朝斌, 李国庆, 等. 模块化多电平换流器子模块电容电压平衡改进控制方法[J]. 电网技术, 2014, 38(5): 1291-1296. Xin Yechun, Wang Chaobin, Li Guoqing, et al.An improved balance control for sub-module capacitor voltage of modular multilevel converter[J]. Power System Technology, 2014, 38(5): 1291-1296. [27] 徐政, 肖晃庆, 张哲任. 模块化多电平换流器主回路参数设计[J]. 高电压技术, 2015, 41(8): 2514-2527. Xu Zheng, Xiao Huangqing, Zhang Zheren.Design of main circuit parameters of modular multilevel converters[J]. High Voltage Engineering, 2015, 41(8): 2514-2527.
2020, Vol. 35 
