Abstract：In this paper, a novel supplementary frequency-voltage damping control (SFVDC) is proposed to suppress the small-signal instability of line commutated converter-modular multilevel converter (LCC-MMC) hybrid HVDC system under extremely weak receiving AC grid. The proposed control approach generates supplementary DC voltage damping component based on the angular frequency deviation from the phase-locked loop (PLL) of MMC station, and the component is then introduced into the outer loop constant DC voltage controller. The proposed control is used to suppress the small-signal instability of the LCC-MMC hybrid HVDC system connected to extremely weak receiving AC grid, so as to improve the small-signal stability of the system. The results show that the proposed SFVDC method can effectively suppress the small-signal instability under extremely weak receiving AC grid and reduce the requirements of the receiving AC grid strength for stable operation. In addition, the good dynamic responses of the system were also obtained under large power disturbance and single-phase to ground fault at receiving AC bus.
[1] 赵畹君. 高压直流输电工程技术[M]. 2版. 北京: 中国电力出版社, 2011. [2] Son H I, Kim H M.An algorithm for effective mitigation of commutation failure in high voltage direct current systems[J]. IEEE Transactions on Power Delivery, 2016, 31(4): 1437-1446. [3] Nami A, Liang J, Dijkhuizen F, et al.Modular multilevel converters for HVDC applications: review on converter cells and functionalities[J]. IEEE Transactions on Power Electronics, 2015, 30(1): 18-36. [4] Dekka A, Wu B, Fuentes R L, et al.Evolution of topologies, modeling, control schemes, and applications of modular multilevel converters[J]. IEEE Journal of Emerging & Selected Topics in Power Electronics, 2017, 5(4): 1631-1656. [5] 肖湘宁, 李伟, 罗超, 等. 特高压直流孤岛运行特性与稳定控制研究综述[J]. 电工技术学报, 2017, 32(10): 1-11. Xiao Xiangning, Li Wei, Luo Chao, et al.Survey on operational characteristics and stability control of ultra-HVDC transmission system in islanded mode[J]. Transactions of China Electrotechnical Society, 2017, 32(10): 1-11. [6] 徐殿国, 刘瑜超, 武健. 多端直流输电系统控制研究综述[J]. 电工技术学报, 2015, 30(17): 1-12. Xu Dianguo, Liu Yuchao, Wu Jian.Review on control strategies of multi-terminal direct current transmission system[J]. Transactions of China Electrotechnical Society, 2015, 30(17): 1-12. [7] 姚骏, 谭义, 裴金鑫, 等. 模块化多电平变流器高压直流输电系统直流故障改进控制策略[J]. 电工技术学报, 2018, 33(14): 3306-3318. Yao Jun, Tan Yi, Pei Jinxin, et al.Improved control strategy for DC fault in modular multi-level converter HVDC system[J]. Transactions of China Electrotechnical Society, 2018, 33(14): 3306-3318. [8] 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. [9] 饶宏, 洪潮, 周保荣, 等. 乌东德特高压多端直流工程受端采用柔性直流对多直流集中馈入问题的改善作用研究[J]. 南方电网技术, 2017, 11(3): 1-5. Rao Hong, Hong Chao, Zhou Baorong, et al.Study on improvement of VSC-HVDC at inverter side of Wudongde multi-terminal UHVDC for the problem of centralized multi-infeed HVDC[J]. Southern Power System Technology, 2017, 11(3): 1-5. [10] 陈凌云, 程改红, 邵冲, 等. LCC-MMC型三端混合直流输电系统控制策略研究[J]. 高压电器, 2018, 54(7): 146-152. Chen Lingyun, Cheng Gaihong, Shao Chong, et al.Research on control strategy for a 3-terminal LCC-MMC HVDC transmission system[J]. High Voltage Apparatus, 2018, 54(7): 146-152. [11] 卢雨涵. LCC-MMC型混合直流输电系统的建模与控制策略研究[D]. 武汉: 湖北工业大学, 2018. [12] 时伯年, 洪潮, 张野, 等. LCC-MMC三端混合直流输电系统整流站交流故障穿越协调控制策略[J]. 南方电网技术, 2017, 11(7): 11-18. Shi Bonian, Hong Chao, Zhang Ye, et al.Rectifier side AC fault ride-through coordination control strategy for three-terminal LCC-MMC hybrid HVDC system[J]. Southern Power System Technology, 2017, 11(7): 11-18. [13] 蔡宜君, 文明浩, 陈玉, 等. LCC-MMC混合直流输电系统整流侧故障穿越控制策略[J]. 电力系统保护与控制, 2018, 46(14): 1-8. Cai Yijun, Wen Minghao, Chenyu, et al. Control strategy of LCC-MMC hybrid HVDC system under rectifier side fault[J]. Power System Protection and Control, 2018, 46(14): 1-8. [14] 时伯年, 洪潮, 孙刚, 等. 交流不对称故障下的LCC-MMC混合直流系统输送功率提升策略研究[J]. 电力系统保护与控制, 2017, 45(20): 73-78. Shi Bonian, Hong Chao, Sun Gang, et al.Research on power transmission enhancement strategy of LCC-MMC hybrid HVDC system under AC symmetric fault[J]. Power System Protection and Control, 2017, 45(20): 73-78. [15] 杨洋, 王瑶, 李浩涛, 等. 子模块混合型LCC-MMC混合直流输电系统的启动控制策略[J]. 电力系统保护与控制, 2018, 46(8): 58-64. Yang Yang, Wang Yao, Li Haotao, et al.Start-up control strategies for the cell-hybrid LCC-MMC hybrid HVDC system[J]. Power System Protection and Control, 2018, 46(8): 58-64. [16] 郭春义, 殷子寒, 王烨, 等. LCC-MMC型混合直流输电系统小干扰动态模型[J]. 中国电机工程学报, 2018, 38(16): 4705-4714, 4975. Guo Chunyi, Yin Zihan, Wang Ye, et al.Small-signal dynamic model of LCC-MMC hybrid HVDC system[J]. Proceedings of the CSEE, 2018, 38(16): 4705-4714, 4975. [17] Egea-Alvarez A, Fekriasl S, Hassan F, et al.Advanced vector control for voltage source converters connected to weak grids[J]. IEEE Transactions on Power Systems, 2015, 30(6): 3072-3081. [18] Arani M F M, Mohamed A R I. Analysis and performance enhancement of vector-controlled VSC in HVDC links connected to very weak grids[J]. IEEE Transactions on Power Systems, 2017, 32(1): 684-693. [19] Zhang L, Harnefors L, Nee H P.Power-synchronization control of grid-connected voltage-source converters[J]. IEEE Transactions on Power Systems, 2010, 25(2): 809-820. [20] 苑宾, 李探, 许建中, 等. 联接弱交流电网MMC系统小信号稳定性分析[J]. 中国电机工程学报, 2017, 37(18): 5339-5349, 5533. Yuan Bin, Li Tan, Xu Jianzhong, et al.Small-signal stability analysis of modular multilevel converter connected to a weak AC system[J]. Proceedings of the CSEE, 2017, 37(18): 5339-5349, 5533. [21] 喻悦箫, 刘天琪, 王顺亮, 等. 基于平均值模型的双端MMC-HVDC系统小信号建模[J]. 中国电机工程学报, 2018, 38(10): 2999-3006, 3150. Yu Yuexiao, Liu Tianqi, Wang Shunliang, et al.Small signal modeling of two-terminal MMC-HVDC based on AVM model[J]. Proceedings of the CSEE, 2018, 38(10): 2999-3006, 3150. [22] 李探, 赵成勇, Gole A M.MMC-HVDC内部谐波模态识别及其稳定性分析[J]. 中国电机工程学报, 2017, 37(8): 2185-2196. Li Tan, Zhao Chengyong, Gole A M.Identification and stability analysis of the internal harmonic modes of the MMC-HVDC system[J]. Proceedings of the CSEE, 2017, 37(8): 2185-2196. [23] 马燕峰, 刘海航, 俞人楠, 等. 考虑锁相环的双馈风力发电机组无源控制[J]. 电工技术学报, 2017, 32(24): 224-232. Ma Yanfeng, Liu Haihang, Yu Rennan, et al.Passivity-based control for doubly-fed induction generator considering the phase-locked loop[J]. Transactions of China Electrotechnical Society, 2017, 32(24): 224-232. [24] 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.
2020, Vol. 35 
