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Abstract The suppression of common mode current is a key technical issue in transformerless photovoltaic (PV) system. Firstly, the common mode model of the conventional transformerless grid-connected cascaded H-bridge PV system is established. The mathematical expression of the common mode current is derived. The major factors that affect the common mode current are discussed. The reason that the conventional cascaded H-bridge inverter fails to reduce the common mode current is explained. Secondly, a new cascaded H5 topology and its modulation strategy are proposed to solve the common mode current issue. Finally, a prototype with digital control is built. The experiment tests of cascaded H4 and H5 topologies are carried out. The experimental results verify the effectiveness of the proposed solution.
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Received: 07 December 2016
Published: 31 January 2018
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| Fund:河北省杰出青年基金（E2016203133）,河北省高校百名优秀创新人才支持计划（ SLRC2017059 ） 和河北省引进留学人员项目（CL201622）资助 |
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[1] 马琳, 孙凯, Remus Teodorescu, 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, Remus Teodorescu, 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.
[2] 郭小强, 魏宝泽, 贾晓瑜, 等. FB10三相非隔离光伏并网逆变器共模电流抑制研究[J]. 电工技术学报, 2015, 30(8): 135-142.
Guo Xiaoqiang, Wei Baoze, Jia Xiaoyu, et al. Common mode current suppression for FB10 three- phase non-isolated PV grid-connected inverter[J]. Transactions of China Electrotechnical Society, 2015, 30(8): 135-142.
[3] 郭小强, 贺冉, 菅佳敏, 等. 非隔离型三相四桥臂光伏逆变器漏电流抑制研究[J]. 电工技术学报, 2016, 31(19): 66-73.
Guo Xiaoqiang, He Ran, Jian Jiamin, et al. Leakage current reduction for three-phase four-leg photo- voltaic inverter[J]. Transactions of China Electro- technical Society, 2016, 31(19): 66-73.
[4] Hernández J C, Vidal P G, Medina A. Characteri- zation of the insulation and leakage currents of PV generators: relevance for human safety[J]. Renewable Energy, 2010, 35(3): 593-601.
[5] 肖华锋, 杨晨, 谢少军. 基于改进型全桥电路的非隔离光伏并网逆变器[J]. 中国电机工程学报, 2011, 31(3): 40-46.
Xiao Huafeng, Yang Chen, Xie Shaojun. A trans- formerless PV grid-connected inverter based on improved full bridge topology[J]. Proceedings of the CSEE, 2011, 31(3): 40-46.
[6] 张犁, 孙凯, 冯兰兰, 等. 一种低漏电流六开关非隔离全桥光伏并网逆变器[J]. 中国电机工程学报, 2012, 32(15): 1-7.
Zhang Li, Sun Kai, Feng Lanlan, et al. H6 non-isolated full bridge grid-connected PV inverters with low leakage currents[J]. Proceedings of the CSEE, 2012, 32(15): 1-7.
[7] 嵇保健, 洪峰, 赵剑锋. 一种不隔离三电平双Buck光伏并网逆变器[J]. 中国电机工程学报, 2012, 32(12): 7-13.
Ji Baojian, Hong Feng, Zhao Jianfeng. A non-isolated three-level dual Buck photovoltaic grid-connected inverter[J]. Proceedings of the CSEE, 2012, 32(12): 7-13.
[8] Guo Xiaoqiang, Wang H, Lu Z, et al. New inverter topology for ground current suppression in trans- formerless photovoltaic system application[J]. Journal of Modern Power Systems and Clean Energy, 2014, 2(2): 191-194.
[9] Gu Y J, Li W H, Zhao Y, et al. Transformerless inverter with virtual DC bus concept for cost- effective grid connected PV power systems[J]. IEEE Transactions on Power Electronics, 2013, 28(2): 793- 805.
[10] 郭小强, 魏宝泽, 杨秋霞, 等. 六开关光伏并网逆变器共模漏电流抑制方法[J]. 电力系统自动化, 2014, 38(14): 101-105.
Guo Xiaoqiang, Wei Baoze, Yang Qiuxia, et al. Leakage current suppression method with a novel six-switch photovoltaic grid-connected inverter[J]. Automation of Electric Power Systems, 2014, 38(14): 101-105.
[11] San Guocheng, Qi Hanhong, Guo Xiaoqiang. A novel single-phase transformerless inverter for grid- connected photovoltaic systems[J]. Przeglad Elektro- techniczny, 2012, 88(12): 251-254.
[12] 肖华锋, 刘隰蒲, 兰科. 一种零电压转换H6结构非隔离光伏并网逆变器[J]. 中国电机工程学报, 2014, 34(3): 363-370.
Xiao Huafeng, Liu Xipu, Lan Ke. A zero voltage transition H6 type transformerless PV grid connected inverter[J]. Proceedings of the CSEE, 2014, 34(3): 363-370.
[13] 洪峰, 刘周成, 万运强, 等. 无漏电流高效可靠三电平双Buck并网逆变器[J]. 中国电机工程学报, 2014, 34(9): 1327-1336.
Hong Feng, Liu Zhoucheng, Wan Yunqiang, et al. High-efficiency high-reliability dual Buck three-level grid-connected inverters without leakage currents[J]. Proceedings of the CSEE, 2014, 34(9): 1327-1336.
[14] Villanueva E, Correa P, Rodriguez J, et al. Control of a single phase cascaded H-bridge multilevel inverter for grid connected photovoltaic systems[J]. IEEE Transactions on Industrial Electronics, 2009, 56(11): 4399-4406.
[15] Cecati C, Ciancetta F, Siano P. A multilevel inverter for photovoltaic systems with fuzzy logic control[J]. IEEE Transactions on Industrial Electronics, 2010, 57(12): 4115-4125.
[16] 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.
[17] 郭小强, 朱铁影, 魏宝泽, 等. 飞跨电容多电平光伏逆变器共模电流抑制技术[J]. 中国电机工程学报, 2016, 36(18): 4962-4969.
Guo Xiaoqiang, Zhu Tieying, Wei Baoze, et al. Common mode current suppression technique for flying capacitor multilevel PV inverter[J]. Pro- ceedings of the CSEE, 2016, 36(18): 4962-4969.
[18] 叶满园, 周琪琦, 蔡鸿, 等. 基于捕食策略遗传算法的3电平中点箝位型逆变器特定谐波消除脉宽调制技术[J]. 高电压技术, 2014, 40(11): 3569-3576.
Ye Manyuan, Zhou Qiqi, Cai Hong, et al. SHEPWM technique applied to tri-level neutral pointed clamped inverter based on predation strategies genetic algo- rithm[J]. High Voltage Engineering, 2014, 40(11): 3569-3576.
[19] Malinowski M, Gopakumar K, Rodriguez J, et al. A survey on cascaded multilevel inverters[J]. IEEE Transactions on Industrial Electronics, 2010, 57(7): 2197-2206.
[20] Kerekes T, Teodorescu R, Liserre M, et al. Evaluation of three-phase transformerless photo- voltaic inverter topologies[J]. IEEE Transactions on Power Electronics, 2009, 24(9): 2202-2211.
[21] De S, Banerjee D, Kumar K S, et al. Multilevel inverters for low-power application[J]. IET Power Electronics, 2011, 4(4): 384-392. |
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2018, Vol. 33 
