Dead-Time Effect and Background Grid-Voltage Harmonic Suppression Methods for Inverters with Virtual Impedance Control
Chen Jie1, Zhang Xinying1, Yan Zhenyu1, Wei Zheng2, Chen Xin1
1. Jiangsu Key Laboratory of New Energy Generation and Power Conversion Nanjing University of Aeronautics & Astronautics Nanjing 211106 China; 2. NARI Group Corporation/State Grid Electric Power Research Institute Nanjing 211106 China
Abstract:Grid-connected inverters, as the interface between distributed energy and large power grids, have high requirements in terms of control structure and power quality. Inverters with indirect- current-control has fast power response and can realize the smooth transfer between grid-connected and stand-alone modes. In this paper, the grid-connected current distortion caused by the dead-time effect of the semiconductor devices and the grid-voltage background harmonics are analyzed. Furthermore, specific solutions by adding virtual parallel and series impedance are given to improve the power quality. Simulation and experiments verify the effectiveness of the proposed method.
[1] 王成山, 李鹏. 分布式发电、微网与智能配电网的发展与挑战[J]. 电力系统自动化, 2010, 34(2): 10-15. Wang Chengshan, Li Peng.Development and challenges of distributed generation, the micro-grid and smart distribution system[J]. Automation of Electric Power Systems, 2010, 34(2): 10-15. [2] 文娟, 谭阳红, 何怡刚, 等. 含分布式电源的复杂配电网多阶段故障恢复方法[J]. 电工技术学报, 2018, 33(14): 3332-3341. Wen Juan, Tan Yanghong, He Yigang, et al.A multi-stage service restoration method for complex distribution networks with distributed generators[J]. Transactions of China Electrotechnical Society, 2018, 33(14): 3332-3341. [3] Faisal A M, Heikki N K.System modelling and online optimal management of microgrid using multi- objective optimization[C]//IEEE International Conference on Clean Electrical Power, Capri, Italy, 2007: 148-153. [4] 石荣亮, 王成山, 张兴, 等. 光储柴独立微电网中的虚拟同步发电机控制策略[J]. 电工技术学报, 2017, 32(23): 127-139. Shi Rongliang, Wang Chengshan, Zhang Xing, et al.A control strategy for islanded photovoltaic-battery- diesel microgrid based on virtual synchronous generator[J]. Transactions of China Electrotechnical Society, 2017, 32(23): 127-139. [5] Rocabert J, Luna A, Blaabjerg F, et al.Control of power converters in AC microgrids[J]. IEEE Transa- ctions on Power Electronics, 2012, 27(11): 4734-4749. [6] 杜燕, 苏建徽, 张榴晨, 等. 改进负荷分配的孤岛微网下垂控制方法[J]. 电力系统自动化, 2015, 39(15): 24-29. Du Yan, Su Jianhui, Zhang Liuchen, et al.A droop control method for improving load distribution in an island microgrid[J]. Automation of Electric Power Systems, 2015, 39(15): 24-29. [7] Kim H, Yu T, Choi S.Indirect current control algorithm for utility interactive inverters in distri- buted generation systems[J]. IEEE Transactions on Power Electronics, 2008, 23(3): 1342-1347. [8] Park S, Kwon M, Choi S.A new anti-islanding method for indirect current control of grid connected inverter[C]//IEEE 3rd International Future Energy Electronics Conference and ECCE Asia, Kaohsiung, 2017: 1230-1234. [9] 赵国鹏, 韩民晓, 刘进军, 等. 基于间接电流控制方法下系统稳定性的静止无功发生器参数设计[J]. 电工技术学报, 2012, 27(9): 17-24. Zhao Guopeng, Han Minxiao, Liu Jinjun, et al.Design of parameters in static synchronous com- pensator with indirect current control based on the system stability[J]. Transactions of China Electro- technical Society, 2012, 27(9): 17-24. [10] 过亮, 许爱国, 谢少军, 等. 间接电流控制独立/并网双模式逆变器研究[J]. 电力电子技术, 2008, 42(4): 36-38. Guo Liang, Xu Aiguo, Xie Shaojun, et al.Research on indirect current control algorithm for grid- connected inverter[J]. Power Electronics, 2008, 42(4): 36-38. [11] 丁顺, 邢岩, 王钧, 等. IGBT串联动态均压特性分析与控制[J]. 电工技术学报, 2018, 33(14): 3194-3201. Ding Shun, Xing Yan, Wang Jun, et al.Control for dynamic voltage-sharing among series-connected IGBTs[J]. Transactions of China Electrotechnical Society, 2018, 33(14): 3194-3201. [12] Liu Yan, Ben Hongqi, Li Chunpeng, et al.Research of the dead-time compensation based on the three- phase grid-connected inverter[C]//IEEE 7th International Power Electronics and Motion Control Conference, Harbin, 2012: 510-514. [13] 沈永波, 年珩. 不平衡及谐波电网下基于静止坐标系的并网逆变器直接功率控制[J]. 电工技术学报, 2016, 31(4): 120-128. Shen Yongbo, Nian Heng.Stationary frame direct power control of grid-connected inverter under unbalanced and harmonic grid voltage[J]. Transa- ctions of China Electrotechnical Society, 2016, 31(4): 120-128. [14] 张笠君, 汪飞, 许德志. 并网逆变器谐波电流抑制研究中的准无穷大输出阻抗概念与应用[J]. 电源 学报, 2016, 14(5): 105-111. 15 Zhang Lijun, Wang Fei, Xu Dezhi.Quasi-infinite output impedance concept and implementation for harmonic current suppression of grid-connected inverters[J]. Journal of Power Supply, 2016, 14(5): 105-111. [15] Chen Xinran, Ruan Xinbo, Yang Dongsheng, et al.Injected grid current quality improvement for a voltage-controlled grid-connected inverter[J]. IEEE Transactions on Power Electronics, 2018, 33(2): 1247-1258. [16] 杨东升, 阮新波, 吴恒. 提高LCL型并网逆变器对弱电网适应能力的虚拟阻抗方法[J]. 中国电机工程学报, 2014, 34(15): 2327-2335. Yang Dongsheng, Ruan Xinbo, Wu Heng.A virtual impedance method to improve the performance of LCL-type grid-connected inverters under weak grid conditions[J]. Proceedings of the CSEE, 2014, 34(15): 2327-2335. [17] 闫俊丽, 彭春华, 陈臣. 基于动态虚拟阻抗的低压微电网下垂控制策略[J]. 电力系统保护与控制, 2015, 43(21): 9-14. Yan Junli, Peng Chunhua, Chen Chen.Droop control strategy based on dynamic virtual impedance in low-voltage microgrid[J]. Power System Protection and Control, 2015, 43(21): 9-14. [18] 闫朝阳, 白鹤, 张喆, 等. 不平衡工况下基于虚拟阻抗法的并联三相四桥臂逆变器的桥臂控制[J]. 电工技术学报, 2017, 32(23): 207-219. Yan Zhaoyang, Bai He, Zhang Zhe, et al.Leg control of parallel three-phase four-leg inverter based on virtual impedance method under unbalanced con- ditions[J]. Transactions of China Electrotechnical Society, 2017, 32(23): 207-219.