Abstract：The capacitive voltage low-frequency ripple problem of modular multilevel converter (MMC) limits its application in low-frequency applications such as direct-drive permanent magnet wind power generation. To solve this problem, this paper proposed a topology and its control method of medium-voltage wind power generation system based on improved MMC. Compared with the traditional ripple suppression method based on "high-frequency common-mode voltage+high-frequency current injection", this method does not bring about common-mode voltage problems. Firstly, the overall structure of the system was described, the role and design principles of the high-frequency energy channel in the system were introduced, and then the working mechanism of suppressing the low-frequency ripple of the MMC capacitor voltage through the high-frequency current was analyzed in depth. Then the detailed control method of the system was introduced. Finally, a 5MW/10kV medium-voltage wind power generation system was established on the Matlab/Simulink platform for simulation research, and a 2kW experimental prototype was set up for experimental verification. The results prove the correctness and effectiveness of the proposed solution.
关维德, 黄守道, 黄小庆. 一种基于改进模块化多电平换流器的中压风电系统及其控制方法[J]. 电工技术学报, 2018, 33(16): 3782-3791.
Guan Weide, Huang Shoudao, Huang Xiaoqing. A Medium-Voltage Wind Power Generation System Based on Improved Modular Multilevel Converter and Its Control Scheme. Transactions of China Electrotechnical Society, 2018, 33(16): 3782-3791.
[1] 黄科元, 刘静佳, 黄守道, 等. 换流器开路故障下永磁直驱风电系统运行分析[J]. 电力系统自动化, 2014, 38(14): 23-29. Huang Keyuan, Liu Jingjia, Huang Shoudao, et al.Operational analysis of D-PMSG based wind power generation system under open-circuit converter faults[J]. Automation of Electric Power Systems, 2014, 38(14): 23-29. [2] 曹海洋, 沈建辉, 姜子健, 等. 基于双混合钳位式换流器的永磁直驱风力发电系统控制策略[J]. 电工技术学报, 2016, 31(11): 32-40. Cao Haiyang, Shen Jianhui, Jiang Zijian, et al.Control strategy of permanent magnet direct-driven wind generation system based on hybrid clamp dual PWM rectifier[J]. Transactions of China Electro- technical Society, 2016, 31(11): 32-40. [3] Leijon M, Dahlgren M, Walfridsson L, et al.A recent development in the electrical insulation systems of generators and transformers[J]. IEEE Electrical Insulation Magazine, 2001, 17(3): 10-15. [4] Metwally I A, Radwan R M, Abou-Elyazied A M. Powerformers: a breakthrough of high-voltage power generators[J]. IEEE Potentials, 2008, 27(3): 37-44. [5] 张婷婷. 新型高压直驱永磁风力发电机的设计研究[D]. 乌鲁木齐: 新疆大学, 2015. [6] Yaramasu V, Wu Bin.Predictive control of a three-level boost converter and an NPC inverter for high-power pmsg-based medium voltage wind energy conversion systems[J]. IEEE Transactions on Power Electronics, 2014, 29(10): 5308-5322. [7] Calle-Prado A, Alepuz S, Bordonau J, et al.Predictive control of a back-to-back NPC converter- based wind power system[J]. IEEE Transactions on Industrial Electronics, 2016, 63(7): 4615-4627. [8] Yaramasu V, Wu Bin, Rivera M, et al.A new power conversion system for megawatt PMSG wind turbines using four-level converters and a simple control scheme based on two-step model predictive strategy- part Ⅰ: modeling and theoretical analysis[J]. IEEE Journal of Emerging and Selected Topics in Power Electronics, 2014, 2(1): 3-13. [9] 张哲任, 徐政, 许烽, 等. 模块化多电平换流器型高压直流输电系统停运控制策略研究[J]. 中国电机工程学报, 2015, 35(11): 2670-2680. Zhang Zheren, Xu Zheng, Xu Feng, et al.Shut-down control scheme for modular multilevel converter based HVDC[J]. Proceedings of the CSEE, 2015, 35(11): 2670-2680. [10] 贺小明, 范岩, 鲍尖措. MMC-STATCOM在变电站应用中的研究[J]. 电气技术, 2015, 16(5): 44-48. He Xiaoming, Fan Yan, Bao Jiancuo.Research on MMC-STATCOM in substation application[J]. Electrical Engineering, 2015, 16(5): 44-48. [11] 蔡永梁, 任成林, 周竞宇, 等. 基于MMC的柔性直流输电电容电压波动抑制方法[J]. 电力系统保护与控制, 2017, 45(5): 45-50. Cai Yongliang, Ren Chenglin, Zhou Jingyu, et al.Control strategy for suppressing capacitor voltage ripple of MMC-HVDC[J]. Power System Protection and Control, 2017, 45(5): 45-50. [12] 武健, 刘瑜超, 徐殿国. 基于模块多电平变换器的并联有源滤波器控制策略研究[J]. 电工技术学报, 2013, 28(12): 52-59. Wu Jian, Liu Yuchao, Xu Dianguo.Control strategy of shunt active power filter based on modular multilevel converter[J]. Transactions of China Electrotechnical Society, 2013, 28(12): 52-59. [13] 秦海鸿, 赵海伟, 马策宇, 等. 基于模块化多电平变换器的静止同步补偿器桥臂不对称及其控制策略[J]. 电工技术学报, 2016, 31(14): 183-192. Qin Haihong, Zhao Haiwei, Ma Ceyu, et al.Asymmetric bridge arm of static synchronous compensator based on modular multilevel converter and its control strategy[J]. Transactions of China Electrotechnical Society, 2016, 31(14): 183-192. [14] Wang M, Hu Y, Zhao W, et al.Application of modular multilevel converter in medium voltage high power permanent magnet synchronous generator wind energy conversion systems[J]. IET Renewable Power Generation, 2016, 10(6): 824-833. [15] Debnath S, Qin J, Saeedifard M.Control and stability analysis of modular multilevel converter under low-frequency operation[J]. IEEE Transactions on Industrial Electronics, 2015, 62(9): 5329-5339. [16] 殷实, 谭国俊, 方磊, 等. 模块化多电平换流器调速系统变频控制[J]. 电工技术学报, 2016, 31(20): 139-150. Yin Shi, Tan Guojun, Fang Lei, et al.Variable- frequency control strategy of modular multilevel converter[J]. Transactions of China Electrotechnical Society, 2016, 31(20): 139-150. [17] 徐殿国, 李彬彬, 周少泽. 模块化多电平高压变频技术研究综述[J]. 电工技术学报, 2017, 32(20): 104-116. Xu Dianguo, Li Binbin, Zhou Shaoze.Overview of the modular multilevel converter based high voltage motor drive[J]. Transactions of China Electro- technical Society, 2017, 32(20): 104-116. [18] Li B, Zhou S, Xu D, et al.An improved circulating current injection method for modular multilevel converters in variable-speed drives[J]. IEEE Transa- ctions on Industrial Electronics, 2016, 63(11): 7215-7225. [19] He L, Zhang K, Xiong J, et al.Low-frequency ripple suppression for medium-voltage drives using modular multilevel converter with full-bridge submodules[J]. IEEE Journal of Emerging and Selected Topics in Power Electronics, 2016,4(2): 657-667. [20] Jung J J, Lee H J, Sul S K.Control strategy for improved dynamic performance of variable-speed drives with modular multilevel converter[J]. IEEE Journal of Emerging and Selected Topics in Power Electronics, 2015, 3(2): 371-380. [21] Du S, Wu B, Zargari N R, et al.A flying-capacitor modular multilevel converter for medium-voltage motor drive[J]. IEEE Transactions on Power Electronics, 2017, 32(3): 2081-2089. [22] Gao H, Wu B, Xu D, et al.Common-mode- voltage-reduced model-predictive control scheme for current-source-converter-fed induction motor drives[J]. IEEE Transactions on Power Electronics, 2017, 32(6): 4891-4904. [23] 袁义生, 朱本玉. 一种基于耦合电感的模块化多电平换流器控制[J]. 电工技术学报, 2015, 30(6): 216-224. Yuan Yisheng, Zhu Benyu.Control strategy of a modular multilevel converter based on coupled inductor[J]. Transactions of China Electrotechnical Society, 2015, 30(6): 216-224. [24] 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 Trillion Q.A novel universal circulating current suppressing strategy based on the MMC circulating current model[J]. Proceedings of the CSEE, 2012, 32(18): 59-65. [25] 黄守道, 彭也伦, 廖武. 模块化多电平型换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[J]. Transactions of China Electrotechnical Society, 2015, 30(7): 62-71. [26] 宋平岗, 林家通, 李云丰, 等. 采用MMC-RPC治理牵引供电系统负序和谐波的PIR控制策略[J]. 电工技术学报, 2017, 32(12): 108-116. Song Pinggang, Lin Jiatong, Li Yunfeng, et al.PIR control strategy on compensation of negative sequence and harmonic for railway power supply system using MMC-RPC[J]. Transactions of China Electrotechnical Society, 2017, 32(12): 108-116.
2018, Vol. 33 
