Abstract：Compared to three-phase three-leg inverter, the control of three-phase four-leg (3P4L) inverter could be decoupled to be able to work with unbalanced load. In recent years, parallel inverter has been widely used in power electronic converter system. If current is out of control in parallel inverters connected with the same input and output buses, circulating current will exist in four legs of parallel 3P4L inverters, which may damage converter seriously. Based on dual closed loop control strategy, output impedance modeling is created in this paper by using small signal modeling method. Thereby, output impedance analysis about the relationships between control loop parameters, main circuit and output impedance is accomplished. Accordingly, a design method is proposed to minimize circulating current. Finally, simulation and experimental results verify the analysis method.
陈轶涵, 沈茜, 任磊, 龚春英. 基于虚拟输出阻抗分析的并联三相四桥臂逆变器环流抑制[J]. 电工技术学报, 2016, 31(8): 51-62.
Chen Yihan, Shen Qian, Ren Lei, Gong Chunying. Output Impedance Analysis for Circulating Current Minimization of Paralleled Three Phase Four Leg Inverter. Transactions of China Electrotechnical Society, 2016, 31(8): 51-62.
[1] Vechiu I, Curea O, Camblong H. Transient operation of a four-leg inverter for autonomous applications with unbalanced load[J]. IEEE Transactions on Power Electronics, 2010, 25(2): 399-407. [2] Kim J H, Sul S K. A carrier-based PWM method for three-phase four-leg voltage source converters[J]. IEEE Transactions on Power Electronics, 2004, 19(1): 66-75. [3] 官二勇, 宋平岗, 叶满园. 基于3次谐波注入法的三相四桥臂逆变电源[J]. 电工技术学报, 2005, 20(12): 43-52. Guan Eryong, Song Pinggang, Ye Manyuan. Three- phase inverter with four bridge-legs based on three harmonic injection method[J]. Transactions of China Electrotechnical Society, 2005, 20(12): 43-52. [4] Xu Zhuang, Li Rui, Zhu Hui, et al. Control of parallel multiple converters for direct-drive permanent- magnet wind power generation systems[J]. IEEE Transactions on Power Electronics, 2012, 27(3): 1259-1270. [5] Pouya H R Z, Mokhtari H. Control of parallel three-phase inverters using optimal control and SVPWM technique[C]//IEEE International Symposium on Industrial Electronics, Seoul, 2009: 1823-1828. [6] Tuladhar A, Jin H, Unger T, et al. Parallel operation of single phase inverters with no control interconne- ctions[C]// IEEE Applied Power Electronics Confer- ence and Exposition, 1997, 1: 94-100. [7] Chiang S J, Chang J M. Parrallel control of the UPS inverters with frequency dependent droop scheme[C]// Power Electronics Specialists Conference, 2001, 2: 957-961. [8] 闫耀民, 范瑜, 汪至中. 一种改进的电压电流混合控制的并联逆变器[J]. 铁道学报, 2003, 25(3): 55-58. Yan Yaomin, Fan Yu, Wang Zhizhong. Advanced voltage and current hybrid controlled parallel inver- ters[J]. Journal of the China Railway Society, 2003, 25(3): 55-58. [9] 肖岚, 胡文斌, 蒋渭忠. 基于主从控制的逆变器并联系统研究[J]. 东南大学学报(自然科学版), 2002, 32(1): 133-137. Xiao Lan, Hu Wenbin, Jiang Weizhong. Research on master-slave controlled inverter parallel system[J]. Journal of Southeast University (Natural Science Edition), 2002, 32(1): 133-137. [10] 程荣仓, 刘正之. 大容量单相逆变装置并联技术的分析[J]. 中国电机工程学报, 2004, 24(7): 112-116. Cheng Rongcang, Liu Zhengzhi. Analysis of parallel single-phase inverters of large capacity[J]. Pro- ceedings of the CSEE, 2004, 24(7): 112-116. [11] 方天治, 阮新波, 肖岚, 等. 一种改进的分布式逆变器并联控制策略[J]. 中国电机工程学报, 2008, 28(33): 30-36. Fang Tianzhi, Ruan Xinbo, Xiao Lan, et al. An improved distributed control strategy of parallel inverters[J]. Proceedings of the CSEE, 2008, 28(33): 30-36. [12] Yao Wei, Chen Min, Matas J, et al. Design and analysis of the droop control method for parallel inverters considering the impact of the complex impedance on the power sharing[J]. IEEE Transa- ctions on Industrial Electronics, 2011, 58(2): 576- 588. [13] 张庆梅, 彭楚武, 陈燕东, 等. 一种微电网多逆变器并联运行控制策略[J]. 中国电机工程学报, 2012, 32(25): 126-132. Zhang Qinghai, Peng Chuwu, Chen Yandong, et al. A control strategy for parallel operation of multi- inverters in microgrid[J]. Proceedings of the CSEE, 2012, 32(25): 126-132. [14] 孙驰, 鲁军勇, 马伟明. 一种新的三相四桥臂逆变器控制方法[J]. 电工技术学报, 2007, 22(2): 57-63, 73. Sun Chi, Lu Junyong, Ma Weiming. A novel control method for three-phase four-leg inverter[J]. Transa- ctions of China Electrotechnical society, 2007, 22(2): 57-63, 73. [15] 邓卫华, 张波, 丘东元, 等. 三相电压型PWM整流器状态反馈精确线性化解耦控制研究[J]. 中国电机工程学报, 2005, 25(7): 97-103. Deng Weihua, Zhang Bo, Qiu Dongyuan, et al. The research of decoupled state variable feed back linearization control method of three-phase voltage- source PWM rectifier[J]. Proceedings of the CSEE, 2005, 25(7): 97-103. [16] He Lei, Fei Lanling, Jian Xiong, et al. Research on paralleled three-phase four-leg voltage source inver- ters based on dual-loop control in αβo coordinate[C]// 8th International Conference on Power Electronics and ECCE Asia, 2011: 2912-2919. [17] Chen Wu, Ruan Xinbo, Yan Hong, et al. DC/DC conversion systems consisting of multiple converter modules: stability, control, and experimental veri- fications[J]. IEEE Transactions on Power Electronics, 2009, 24(6): 1463-1474. [18] Li Peng, Lehman B. Accurate loop gain prediction for DC-DC converter due to the impact of source/input filter[J]. IEEE Transactions on Power Electronics, 2005, 20(4): 754-761.
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