Abstract：In modular Multilevel Converter(MMC),analysis was made based on the power flow and energy fluctuation,in order to discuss the mathematical expression of the module capacitor voltage in the upper and lower arm.The relationships between the capacitor voltage’s fluctuation and the circular current and transferred power have been analyzed.Moreover,a capacitor voltage suppression algorithm is developed by controlling the secondary component of the circular current,which is obtained from the instantaneous value of the output current and the reference signal of the phase leg.A circular current close-loop controller is designed based on the proportional resonance to suppress the capacitor voltage fluctuation.The controller design is simple because it has no second-order negative-sequence coordination transformation and phase decoupling control.The simulation results show that this method can effectively suppress the ripple of the capacitor voltage and enhance the quality of the output voltage without increasing the capacitance.
黄守道, 彭也伦, 廖武. 模块化多电平型变流器电容电压波动及其抑制策略研究[J]. 电工技术学报, 2015, 30(7): 62-71.
Huang Shoudao, Peng Yelun, Liao Wu. Study of Capacitor Voltage Fluctuation and Its Suppression for Modular Multilevel Converter. Transactions of China Electrotechnical Society, 2015, 30(7): 62-71.
[1] 杨晓峰,林智钦,郑琼林,等.模块组合多电平变换器的研究综述[J].中国电机工程学报,2013,33(6):1-14. Yang Xiaofeng,Lin Zhiqin,Zheng Qionglin,et al.A Review of modular multilevel converters[J].Proceedings of the CSEE,2013,33(6):1-14. [2] Debnath S,Qin Jiangchao,Bahrani B,et al.Operation,control,and applications of the modular multilevel converter:a review[J].IEEE Transactions on Power Electronics,2014,30(1):37-35. [3] 刘建涛,王治华,王珂,等.不同结构电压源换流器损耗对比分析[J].电力系统保护与控制,2013,41(6):105-110. Liu Jiantao,Wang Zhihua,Wang Ke,et al.Comparative analysis of losses of voltage source converters with different structures[J].Power System Protection and Control,2013,41(6):105-110. [4] 雷鸣,李耀华,葛琼璇,等.MMC变流器模块电压波动对输出电压的影响[J].电机与控制学,2014,18(3):25-33. Lei Ming,Li Yaohua,Ge Qiongxuan,et al.Effects of the module voltage fluctuation on the output voltage of modular multilevel converter[J].Electric Machines and Control,2014,18(3):25-33. [5] 徐政,等(著).柔性直流输电系统[M].北京:机械工业出版社,2012. [6] 周月宾,江道灼,郭捷,等.模块化多电平换流器子模块电容电压波动与内部环流分析[J].中国电机工程学报,2012,32(24):8-14. Zhou Yuebin,Jiang Daozhuo,Guo Jie,et al.Analysis of sub-module capacitor voltage ripples and circulating currents in modular multilevel converters[J].Proceedings of the Chinese Society for Electrical Engineering,2012,32(24):8-14. [7] Guan Mingyuan,Xu Zheng,Li Huijie.Analysis of DC voltage ripples in modular multilevel converters[C].International Conference on Power System Technology,Hangzhou,2010:1-6. [8] 杨晓峰,王晓鹏,范文宝,等.模块组合多电平变换器的环流模型[J].电工技术学报,2011,26(5):21-27. Yang Xiaofeng,Wang Xiaopeng,Fan Wenbao,et al.Circulating current model of modular multilevel converters[J].Transaction of China Electrotechnical Society,2011,26(5):21-27. [9] 杨晓峰,郑琼林.基于MMC环流模型的通用环流抑制策略[J].中国电机工程学报,2012,32(18):59-65. Yang Xiaofeng,Zheng Qionglin.A novel universal circulating current suppressing strategy based on the MMC circulating current model[J].Proceedings of the Chinese Society for Electrical Engineering,2012,32(18):59-65. [10]高建,苏建徽,高航,等.模块化多电平换流器电容电压与环流的控制策略[J].电力系统保护与控制,2014,42(3):56-62. Gao Jian,Su Jianhui,Gao Hang,et al.Capacitor voltage and circulation current control strategy in modular multilevel converter[J].Power System Protection and Control,2014,42(3):56-62. [11]张建坡,赵成勇.模块化多电平换流器环流及抑制策略研究[J].电工技术学报,2013,28(10):328-336. Zhang Jianpo,Zhao Chengyong.Research on circulation current and suppressing strategy of modular multilevel converter[J].Transactions of China Electrotechnical Society,2013,28(10):328-336. [12]班明飞,申科,王建赜,等.基于准比例谐振控制的MMC新型环流抑制器[J].电力系统自动化,2014,38(11):85-89. Ban Mingfei,Shen Ke,Wang Jianze,et al.A novel circulating current suppressor for modular multilevel converters based on quasi-proportional resonant control[J].Automation of Electric Power Systems,2014,38(11):85-89. [13]Picas R,Pou J,Ceballos S,et al.Minimization of the capacitor voltage fluctuations of a modular multilevel converter by circulating current control[C].IECON 2012-38th Annual Conference on IEEE Industrial Electronics Society,Montreal,QC,2012:4985-4991. [14]Picas R,Pou J,Ceballos S,et al.Optimal injection of harmonics in circulating currents of modular multilevel converters for capacitor voltage ripple minimization[C].IEEE ECCE Asia Downunder,Melbourne,VIC,2013:318-324. [15]Debnath S,Saeedifard M.A new hybrid modular multilevel converter for grid connection of large wind turbines[J].IEEE Transactions on Sustainable Energy,2013,4(4):1051-1064. [16]高航,苏建徽,汪晶晶,等.模块化多电平型换流器电容电压二倍频波动抑制策略研究[J].电力系统保护与控制,2014,42(6):116-122. Gao Hang,Su Jianhui,Wang Jingjing,et al.Study on control strategy for suppressing double fundamental frequency fluctuation of capacitor voltage of modular multilevel converter[J].Power System Protection and Control,2014,42(6):116-122. [17]Pou J,Ceballos S,Konstantinou G,et al.Circulating current injection methods based on instantaneous information for the modular multilevel converter[J].IEEE Transactions on Industrial Electronics,2014,62(2):777-788. [18]赵昕,赵成勇,李广凯.采用载波移相技术的模块化多电平换流器电容电压平衡控制[J].中国电机工程学,2011,31(21):48-55. Zhao Xin,Zhao Chengyong,Li Guangkai,et al.Submodule capacitance voltage balancing of modular multilevel converter based on carrier phase shifted SPWM technique[J].Proceedings of the CSEE,2011,31(21):48-55. [19]杨秋霞,梁雄国,郭小强,等.准谐振控制器在有源电力滤波器中的应用[J].电工技术报,2009,24(7):171-176. Yang Qiuxia,Liang Xiongguo,Guo Xiaoqiang,et al.Application of quasi resonant controller for active power filter[J].Transactions of China Electrotechnical Society,2009,24(7):171-176.
2015, Vol. 30 
