Power Sliding Mode Compensation Strategy of VSC-HVDC under Unbalanced Grid Voltage
Liu Ziwen, Miao Shihong, Fan Zhihua, Wei Dehua, Tu Qingyu
State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic Engineering Huazhong University of Science and Technology Wuhan 430074 China
Abstract：Under the influence of unbalanced grid voltage, the double line-frequency ripple will appear in the output power of voltage source converter based high voltage direct current transmission (VSC-HVDC). In this paper, the mathematical model of VSC under unbalanced grid voltage is first analyzed, and the double line-frequency ripple of the VSC converter power is consequently ascribed to current factor and voltage factor. Then the double line-frequency power control equation is established, and a power sliding mode variable structure compensation control of VSC-HVDC is proposed to suppress the ripple power caused by current factor and voltage factor. In this case, the double line-frequency power fluctuation and the distorted output current can be suppressed at the same time, hence the system dynamic performance in variable operating conditions can be ensured. The compensation control is introduced into the original vector control and can separately control the double line-frequency component effectively under unbalanced grid voltage, which will not affect system normal operating. The proposed strategy is verified by the simulations of a two-terminal VSC-HVDC in PSCAD/EMTDC.
刘子文, 苗世洪, 范志华, 魏德华, 涂青宇. 不平衡电网电压下柔性直流输电系统功率滑模补偿策略[J]. 电工技术学报, 2018, 33(14): 3296-3305.
Liu Ziwen, Miao Shihong, Fan Zhihua, Wei Dehua, Tu Qingyu. Power Sliding Mode Compensation Strategy of VSC-HVDC under Unbalanced Grid Voltage. Transactions of China Electrotechnical Society, 2018, 33(14): 3296-3305.
[1] 徐政, 薛英林, 张哲任. 大容量架空线柔性直流输电关键技术及前景展望[J]. 中国电机工程学报, 2014, 34(29): 5051-5062. Xu Zheng, Xue Yinglin, Zhang Zheren.VSC-HVDC technology suitable for bulk power overhead line transmission[J]. Proceedings of the CSEE, 2014, 34(29): 5051-5062. [2] 钱甜甜, 苗世洪, 刘子文, 等. 基于PCHD模型的VSC-HVDC的无源控制及滑模辅助改进控制[J]. 电工技术学报, 2016, 31(3): 138-144. Qian Tiantian, Miao Shihong, Liu Ziwen, et al.Passive control and auxiliary sliding mode control strategy for VSC-HVDC system based on PCHD model[J]. Transactions of China Electrotechnical Society, 2016, 31(3): 138-144. [3] Zhang L, Harnefors L, Nee H P.Modeling and control of VSC-HVDC links connected to island systems[J]. IEEE Transactions on Power Systems, 2011, 26(2): 783-793. [4] 黄晟, 王辉, 廖武, 等. 基于VSC-HVDC串并联拓扑结构风电场协调控制策略研究[J]. 电工技术学报, 2015, 30(23): 155-162. Huang Sheng, Wang Hui, Liao Wu.et al.The coordinated control strategy based on VSC-HVDC series-parallel topology in wind farm[J]. Transactions of China Electrotechnical Society, 2015, 30(23): 155-162. [5] 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. [6] 魏晓云, 孙辉, 魏晓光, 等. 改善电能质量的电压源换流器高压直流输电不平衡控制策略[J]. 中国电机工程学报, 2011, 31(9): 8-14. Wei Xiaoyun, Sun Hui, Wei Xiaoguang, et al.Control strategy about power quality improvement for VSC-HVDC under unbalanced AC grid con- ditions[J]. Proceedings of the CSEE, 2011, 31(9): 8-14. [7] 梁营玉, 杨奇逊, 刘建政, 等. 电网电压不平衡时MMC-HVDC的无差拍直接功率控制[J]. 电工技术学报, 2015, 30(15): 15-25. Liang Yingyu, Yang Qixun, Liu Jianzheng, et al.Deadbeat direct power control for MMC-HVDC under unbalanced grid voltages[J]. Transactions of China Electrotechnical Society, 2015, 30(15): 15-25. [8] Liang Y, Liu J, Zhang T, et al.Arm current control strategy for MMC-HVDC under unbalanced con- ditions[J]. IEEE Transactions on Power Delivery, 2017, 32(1): 125-134. [9] García-Cerrada A, Pinzón-Ardila O, Feliú V, et al.Application of a repetitive controller for a three- phase active power filter[J]. IEEE Transactions on Power Electronics, 2007, 22(1): 237-246. [10] Graovac D, Katić V A, Rufer A.Power quality problems compensation with universal power quality conditioning system[J]. IEEE Transactions on Power Delivery, 2007, 22(2): 968-976. [11] Yin Bo, Oruganti R, Panda S K, et al.An output-power-control strategy for a three-phase PWM rectifier under unbalanced supply conditions[J]. IEEE Transactions on Industrial Electronics, 2008, 55(5): 2140-2151. [12] Suh Y, Tijeras V, Lipo T A.A nonlinear control of the instantaneous power in dq synchronous frame for PWM AC/DC converter under generalized unbalanced operating conditions[C]//IEEE Industry Application Society Annual Meeting, Pittsburgh, PA, 2002: 1189-1196. [13] 魏晓云, 卢颖. 电网不平衡时电压源换流器高压直流输电统一控制策略[J]. 中国电机工程学报, 2012, 32(34): 50-57. Wei Xiaoyun, Lu Ying.A unified control strategy for VSC-HVDC under unbalanced grid conditions[J]. Proceedings of the CSEE, 2012, 32(34): 50-57. [14] 王萌, 夏长亮, 宋战锋, 等. 不平衡电网电压条件下PWM整流器功率谐振补偿控制策略[J]. 中国电机工程学报, 2012, 32(21): 46-53. Wang Meng, Xia Changliang, Song Zhanfeng, et al.A power resonance compensation control strategy for PWM rectifiers under unbalanced grid voltage conditions[J]. Proceedings of the CSEE, 2012, 32(21): 46-53. [15] Zhang Y, Qu C, Gao J.Performance improvement of direct power control of PWM rectifier under unbalanced network[J]. IEEE Transactions on Power Electronics, 2017, 32(3): 2319-2328. [16] 郭旭刚, 高增伟, 尹靖元, 等. 不平衡电网电压下的PWM整流器功率预测[J]. 电网技术, 2013, 37(8): 2362-2367. Guo Xugang, Gao Zengwei, Yin Jingyuan, et al.Predictive direct power control for PWM rectifier under unbalanced grid voltage conditions[J]. Power System Technology, 2013, 37(8): 2362-2367. [17] Martinez M I, Tapia G, Susperregui A, et al.Sliding-mode control for DFIG rotor- and grid-side converters under unbalanced and harmonically distorted grid voltage[J]. IEEE Transactions on Energy Conversion, 2012, 27(2): 328-339. [18] Martinez M I, Susperregui A, Tapia G, et al.Sliding- mode control of a wind turbine-driven double-fed induction generator under non-ideal grid voltages[J]. IET Renewable Power Generation, 2013, 7(7): 370-379. [19] Shang L, Sun D, Hu J.Sliding-mode-based direct power control of grid-connected voltage-sourced inverters under unbalanced network conditions[J]. IET Power Electronics, 2011, 4(5): 570-579. [20] Hu J, Shang L, He Y, et al.Direct active and reactive power regulation of grid-connected DC/AC con- verters using sliding mode control approach[J]. IEEE Transactions on Power Electronics, 2011, 26(1): 210-222. [21] 张迪, 魏艳君, 杨宗丰, 等. 不平衡电网电压下基于滑模变结构控制的双馈风电系统转子侧变流器控制策略[J]. 电工技术学报, 2015, 31(10): 121-131. Zhang Di, Wei Yanjun, Yang Zongfeng, et al.Sliding-mode control for rotor-side converters of DFIG-based wind-power generation system under unbalanced grid voltage conditions[J]. Transactions of China Electrotechnical Society, 2015, 31(10): 121-131. [22] 朱晓荣, 刘世鹏, 张海宁, 等. 不平衡电网电压下光伏并网逆变器滑模直接电压/功率控制策略[J]. 电力系统保护与控制, 2016, 44(23): 133-140. Zhu Xiaorong, Liu Shipeng, Zhang Haining, et al.Sliding mode control based direct voltage/power control strategy for PV grid connected inverter under unbalanced grid voltage[J]. Power System Protection and Control, 2016, 44(23): 133-140. [23] 同向前. 电压源换流器在电力系统中的应用[M]. 北京: 机械工业出版社, 2012. [24] 汪海波, 周波, 方斯琛. 永磁同步电机调速系统的滑模控制[J]. 电工技术学报, 2009, 42(9): 71-77. Wang Haibo, Zhou Bo, Fang Sichen.A PMSM sliding mode control system based on exponential reaching law[J]. Transactions of China Electro- technical Society, 2009, 42(9): 71-77. [25] Mizuochi M, Tsuji T, Ohnishi K.Improvement of disturbance suppression based on disturbance observer[C]//International Workshop on Advanced Motion Control, Istanbul, Turkey, 2006: 229-234.
2018, Vol. 33 
