Abstract The existence of high-frequency components in common-mode (CM) current would reduce the stability of non-isolated PV grid-connected system. In low power operation, it has great impacts on the output power quality. The single CM inner loop method in suppressing the high-frequency components was not ideal. Based on the CM equivalent circuit model and the causes of the CM current, a novel double CM inner loops method was proposed to restrain the high-frequency components in CM current. This method not only meets the grid connection demand of CM current, but also overcomes the high frequency resonant problem. Furthermore, the high-frequency components in CM current are substantially reduced. The simulating and experimental results have verified the proposed method.
Zhao Ruiguang,Liu Dongliang,Cui Lili等. Research of Common-Mode Current Suppression in Non-Isolated PV Grid-Connected System with Double Common-Mode Inner Loops[J]. Transactions of China Electrotechnical Society, 2016, 31(22): 186-193.
[1] 肖华锋, 谢少军, 陈文明. 非隔离型光伏并网逆变器漏电流分析模型研究[J]. 中国电机工程学报, 2010, 30(18): 9-14. Xiao Huafeng, Xie Shaojun, Chen Wenming. Study on leakage current model for tansformerless photo- voltaic grid-connected inverter[J]. Proceedings of the CSEE, 2010, 30(18): 9-14. [2] Kerekes T, Teodorescu R, Liserre M. Common mode voltage in case of transformerless PV inverters con- nected to the grid[C]//IEEE International Symposium on Industrial Electronics, Cambridge, 2008: 2390- 2395. [3] 郭小强, 贺冉, 张纯江. 高压大容量五电平逆变器共模电压抑制研究[J]. 电工技术学报, 2016, 31(3): 1-7. Guo Xiaoqiang, He Ran, Zhang Chunjiang. Common- mode voltage reduction of high voltage high power five-level inverters[J]. Transactions of China Electro- technical Society, 2016, 31(3): 1-7. [4] 张兴, 孙龙林, 许颇, 等. 单相非隔离型光伏并网系统中共模电流抑制的研究[J]. 太阳能学报, 2009, 30(9): 1202-1208. Zhang Xing, Sun Longlin, Xu Po, et al. Research on common-mode current reduction of non-isolated single-phase grid-connected photovoltaic system[J]. Energiae Solaris Sinica, 2009, 30(9): 1202-1208. [5] Ji Baojian, Wang Jianhua, Zhao Jianfeng. High- efficiency single-phase transformerless PV H6 inver- ter with hybrid modulation method[J]. IEEE Transa- ctions on Industrial Electronics, 2013, 60(5): 2104- 2115. [6] 袁义生, 张伟平, 朱本玉, 等. 新型非隔离光伏并网逆变器拓扑及其共模电流分析[J]. 电网技术, 2014, 38(12): 3286-3292. Yuan Yisheng, Zhang Weiping, Zhu Benyu, et al. Topology and common mode current analysis of new type transformerless grid-connection inverter for photovoltaic generation system[J]. Power System Technology, 2014, 38(12): 3286-3292. [7] 马琳, 孙凯, Teodorescu R, 等. 高效率中点钳位型光伏逆变器拓扑比较[J]. 电工技术学报, 2011, 26(2): 108-114. Ma Lin, Sun Kai, Teodorescu R, et al. Comparison of the topologies of high efficiency neutral point clamping photovoltaic inverters[J]. Transactions of China Electrotechnical Society, 2011, 26(2): 108- 114. [8] VDE V 0126-1-1-2013: automatic disconnection device between a generator and the public low voltage grid-vornorm[S]. 2005. [9] Kumar D, Pattanaik A, Singh S K. Comparative assessment of leakage current in a photovoltaic grid connected single phase transformerless inverter system[C]//Recent Advances and Innovations in Engineering, Jaipur, 2014: 1-7. [10] Souza Figueredo R, Mingorancia de Carvalho K C, Nasri Ama N R, et al. Leakage current minimization techniques for single-phase transformerless grid- connected PV inverters-an overview[C]//Power Elec- tronics Conference, Gramado, 2013: 517-524. [11] Dong Dong, Fang Luo, Boroyevich D, et al. Leakage current reduction in a single-phase bidirectional AC-DC full-bridge inverter[J]. IEEE Transactions on Power Electronics, 2012, 27(10): 4281-4291. [12] 柳少良, 游小杰, 李艳, 等. 非隔离型单相光伏并网逆变器共模漏电流抑制方法研究[J]. 太阳能学报, 2014, 35(12): 2431-2437. Liu Shaoliang, You Xiaojie, Li Yan, et al. Solution of restraining leakage current for single-phase non- isolated PV grid-connection inverters[J]. Acta Energiae Solaris Sinica, 2014, 35(12): 2431-2437. [13] 沈实叠. 3kW单相光伏并网逆变器的研制[D]. 杭州: 浙江大学, 2014. [14] 崔文峰. 具有共模漏电流抑制能力的单相无变压器型光伏逆变技术研究[D]. 杭州: 浙江大学, 2014. [15] 孟建辉, 石新春, 付超, 等. 新型高效率两级式单相光伏并网逆变系统的研究与应用[J]. 电力系统的保护与控制, 2013, 41(20): 87-92. Meng Jianhui, Shi Xinchun, Fu Chao, et al. Research and application of novel high efficiency two-stage single-phase photovoltaic grid connected inverter system[J]. Power System Protection and Control, 2013, 41(20): 87-92. [16] 王丰, 孙鹏举, Fred C L, 等. 基于分布式最大功率跟踪的光伏系统输出特性分析[J]. 电工技术学报, 2015, 30(24): 127-134. Wang Feng, Kong Pengju, Fred C L, et al. Output characteristic analysis of distributed maximum power point tracking PV system[J]. Transactions of China Electrotechnical Society, 2015, 30(24): 127-134. [17] 嵇保健, 王建华, 赵剑锋. 一种高效率H6结构不隔离单相光伏并网逆变器[J]. 中国电机工程学报, 2012, 32(18): 9-15. Ji Baojian, Wang Jianhua, Zhao Jianfeng. A high efficiency non-isolated single-phase photovoltaic grid connected inverter with H6-type configuration[J]. Proceedings of the CSEE, 2012, 32(18): 9-15. [18] 杨晓光, 姜龙斌, 冯俊博, 等. 一种新型高效无变压器型单相光伏逆变器[J]. 电工技术学报, 2015, 30(8): 97-103. Yang Xiaoguang, Jiang Longbin, Feng Junbo, et al. Reduction of low frequency input current ripple in a non-isolated single phase photovoltaic grid-connecteds inverter[J]. Transactions of China Electrotechnical Society, 2015, 30(8): 97-103. [19] 张凯, 周运斌, 张勇高, 等. 基于驱动脉冲自校准的全桥电路共模抑制技术[J]. 中国电机工程学报, 2007, 27(13): 58-63. Zhang Kai, Zhou Yunbin, Zhang Yonggao, et al. Reduction of common mode EMI in a full-bridge converter through automatic-tuning of gating signals[J]. Proceedings of the CSEE, 2007, 27(13): 58-63. [20] 嵇保健, 王建华, 赵剑锋. 不隔离单相光伏并网逆变器系统输入电流低频纹波抑制[J]. 电工技术学报, 2013, 28(6): 139-157. Ji Baojian, Wang Jianhua, Zhao Jianfeng. Reduction of low frequency input current ripple in a non- isolated single phase photovoltaic grid-connecteds inverter[J]. Transactions of China Electrotechnical Society, 2013, 28(6): 139-157. [21] Ridley R B. Secondary LC filter analysis and design techniques for current-mode controlled converters[J]. IEEE Transactions on Power Electronics, 1988, 3(4): 499-507.
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