Abstract：LCL-filter in grid-connected inverter has a better attenuation on switching ripples. But as a three order system, its resonance is difficult to be suppressed using traditional control strategy. This paper, based on an improved discrete state space model and improved discrete state space observer, proposes a method using optimized pole placement theory to achieve the best damping effect of the whole system, which improves the dynamic response of the system without additional sensors. Furthermore, the influence of closed-loop poles on the placement of observer’s poles, as well as the range within which the observation feedback is stable and the impact of system parameters are discussed. A 10kW grid-connected inverter with LCL-filter prototype is set up to verify the effectiveness and robustness of the proposed control strategy and observer configuration.
李宾, 姚文熙, 杭丽君, 吕征宇. 基于状态观测器的LCL滤波器型并网逆变器状态反馈最优化设计[J]. 电工技术学报, 2014, 29(6): 80-90.
Li Bin , Yao Wenxi ,Hang Lijun , Lü Zhengyu. Optimized Design of State Variable Feedback of Grid-Connected Inverter with LCL-Filter Based on State Observer. Transactions of China Electrotechnical Society, 2014, 29(6): 80-90.
[1] 张强, 张崇巍, 张兴, 等. 风力发电用大功率并网逆变器研究[J]. 中国电机工程学报, 2007, 27(16): 54-59. Zhang Qiang, Zhang Chongwei, Zhang Xing, et al. Study on grid-connected inverter used in high-power wind generation system[J]. Proceedings of the CSEE, 2007, 27(16): 54-59. [2] 戴欣平, 马广, 杨晓红. 太阳能发电变频器驱动系统的最大功率追踪控制法[J]. 中国电机工程学报, 2005, 25(8): 95-99. Dai Xinping, Ma Guang, Yang Xiaohong. A control method for maximum power tracing of photovoltaic generation system[J]. Proceedings of the CSEE, 2005, 25(8): 95-99. [3] 姚志垒, 王赞, 肖岚, 等. 一种新的逆变器并网控制策略的研究[J]. 中国电机工程学报, 2006, 26(18): 61-64. Yao Zhilei, Wang Zan, Xiao Lan, et al. Research on a novel grid-connected control strategy of inverter[J]. Proceedings of the CSEE, 2006, 26(18): 61-64. [4] Liserre M, Blaabjerg F, Hansen S. Design and control of an LCL-filter-based three-phase active rectifier[J]. IEEE Transactions on Industry Applications, 2005, 41(5): 1281-1291. [5] 王斯然, 吕征宇. LCL型并网逆变器中重复控制方法研究[J]. 中国电机工程学报, 2010, 30(27): 69-75. Wang Siran, Lü Zhengyu. Research on repetitive control method applied to grid-connected inverter with LCL filter[J]. Proceedings of the CSEE, 2010, 30(27): 69-75. [6] 徐志英, 许爱国, 谢少军. 采用LCL滤波器的并网逆变器双闭环入网电流控制技术[J]. 中国电机工程学报, 2009, 29(27): 36-41. Xu Zhiying, Xu Aiguo, Xie Shaojun. Dual-loop grid current control technique for grid-connected inverter using a LCL filter [J]. Proceedings of the CSEE, 2009, 29(27): 36-41. [7] Routimo M, Tuusa H. LCL type supply filter for active power filter-comparison of an active and a passive method for resonance damping[C]. IEEE Power Electronics Specialists Conference, 2007: 2939-2945. [8] Liserre M, Dell'Aquila A, Blaabjerg F. Stability improvements of an LCL-filter based three-phase active rectifier[C]. IEEE 33rd Annual Power Electronics Specialists Conference, 2002: 1195-1201. [9] Malinowski M, Bernet S. A simple voltage sensorless active damping scheme for three-phase PWM converters with an LCL filter[J]. IEEE Transactions on Industrial Electronics, 2008, 55(4): 1876-1880. [10] Siran Wang, Xia Zhou, Jifeng Chen, et al. Investiga- tion of fully digital controlled Li-ion battery power recovery system[C]. IEEE Applied Power Electronics Conference and Exposition, Twenty-Fifth Annual, 2010: 2091-2095. [11] Poh Chiang Loh, Holmes D G. Analysis of multiloop control strategies for LC/CL/LCL-filtered voltage- source and current-source inverters[J]. IEEE Transac- tions on Industry Applications, 2005, 41(2): 644-654. [12] Erika Twining, Holmes D G. Grid current regulation of a three-phase voltage source inverter with an LCL input filter[J]. IEEE Transactions on Power Electronics, 2003, 18(3): 888-895. [13] Wessels C, Dannehl J, Fuchs F W. Active damping of LCL-filter resonance based on virtual resistor for PWM rectifiers stability analysis with different filter parameters[C]. IEEE Power Electronics Specialists Conference, 2008: 3532-3538. [14] Shen Guoqiao, Xu Dehong, Cao Luping, et al. An improved control strategy for grid-connected voltage source inverters with an LCL filter[J]. IEEE Transac- tions on Power Electronics, 2008, 23(4): 1899-1906. [15] Shen Guoqiao, Zhu Xuancai, Zhang Jun, et al. A new feedback method for PR current control of LCL- filter-based grid-connected inverter[J]. IEEE Transac- tions on Industrial Electronics, 2010, 57(6): 2033-2041. [16] Eric Wu, Lehn P W. Digital current control of a voltage source converter with active damping of LCL resonance[J]. IEEE Transactions on Power Electronics, 2006, 21(5): 1364-1373. [17] Dannehl J, Fuchs F W, Th X F, et al. PI state space current control of grid-connected pwm converters with LCL filters[J]. IEEE Transactions on Power Electronics, 2010, 25(9): 2320-2330. [18] Ogata Katsuhiko[美]. 离散时间控制系统. 陈杰等译[M]. 北京: 机械工业出版社, 2005. [19] Xue Mingyu, Zhang Yu, Liu Fangrui, et al. Optimized pole and zero placement with state observer for LCL-type grid-connected inverter[C]. IEEE Energy Conversion Congress and Exposition, 2011: 377-382. [20] Choi C H. Step response improvement by pole placement with observer[C]. 40th Southeastern Symposium on System Theory, 2008: 7-12. [21] 侯朝勇, 胡学浩, 惠东. 基于离散状态空间模型的LCL滤波并网变换器控制策略[J]. 中国电机工程学报, 2011, 31(36): 8-15. Hou Chaoyong, Hu Xuehao, Hui Dong. Control strategy of grid-connected converter with LCL filter based on discrete state-space model[J]. Proceedings of the CSEE, 2011, 31(36): 8-15. [22] Gabe I J, Montagner V F, Pinheiro H. Design and implementation of a robust current controller for VSI connected to the grid through an LCL filter[J]. IEEE Transactions on Power Electronics, 2009, 24(6): 1444-1452.
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